Abstract
The present invention regards a fluid actuator arrangement comprising a first and second cylinder of a cylinder arrangement, a piston rod arrangement, a first and second piston device associated with the piston rod arrangement, wherein respective first and second piston device divides respective first and second cylinder into a first and second chamber provided for connection to a valve device of a fluid supply device. The first piston device comprises a piston rod engagement and disengagement device, which is adapted to engage or disengage the first piston device to/from the piston rod arrangement. The invention can be put into use for aircraft, such as commercial aircraft designed for long distance flights, for construction industry, jacking systems for oil well drilling and service platforms, agricultural equipment industry, marine industry, crane manufacture industry, and others.
Claims
1. A fluid actuator arrangement comprising: a first and second cylinder of a cylinder arrangement; a piston rod arrangement; a first and second piston device associated with the piston rod arrangement; respective first and second piston device divides respective first and second cylinder into a first and second chamber provided for connection to a valve device of a fluid supply device; the first piston device comprises a piston rod engagement and disengagement device, which is adapted to engage or disengage the first piston device to/from the piston rod arrangement; the piston rod engagement and disengagement device comprises a cavity forming a flexible piston inner wall portion adapted for releasable engagement with the piston rod arrangement; a channel system is provided for fluid communication between the respective first and second chamber and the cavity.
2. The arrangement according to claim 1, wherein the first and second cylinder being arranged in tandem and the first and second piston device being associated with a common piston rod of the piston rod arrangement.
3. The arrangement according to claim 1, wherein the second piston device comprises a piston rod engagement and disengagement device adapted to engage or disengage the second piston device to/from the piston rod arrangement.
4. The arrangement according to claim 1, wherein a third cylinder comprising a third piston device is arranged in tandem with the first and second cylinder.
5. The arrangement according to claim 1, wherein the channel system comprises a non-return valve or a shuttle valve.
6. The arrangement according to claim 1, wherein the piston rod engagement and disengagement device comprises a membrane device adapted for releasable engagement with the piston rod arrangement.
7. The arrangement according to claim 1, wherein the piston rod engagement and disengagement device comprises a pressure strengthening device, which is provided for strengthening the engagement of the first piston device to the piston rod arrangement.
8. The arrangement according to claim 1, wherein the arrangement comprises a hydraulic actuator arrangement.
9. The arrangement according to claim 1, wherein the arrangement comprises a pneumatic actuator arrangement.
10. The arrangement according to claim 1, wherein a first cross-sectional force area of the first piston device differs in measure from a second cross-sectional force area of the second piston device.
11. The arrangement according to claim 1, wherein the arrangement comprises a first actuator provided with a first force area, a second actuator provided with a force area corresponding with the first force area, a third actuator provided with a third force area, a fourth actuator provided with a fourth force area, the third force area is twice as large as the first force area, the fourth force area is twice as large as the third force area.
12. The arrangement according to claim 1, wherein the arrangement comprises a plurality of cylinders and piston devices adapted to be connectable to the piston rod arrangement.
13. The arrangement according to claim 1, wherein the arrangement comprises an electro-hydraulic cylinder apparatus.
14. An aircraft comprising an arrangement according claim 1.
15. An arrangement according to claim 1, wherein the arrangement is adapted to any of the following industrial segments; construction industry, jacking systems for oil well drilling and service platforms, agricultural equipment industry, marine industry, crane manufacture industry.
16. A method for controlling a fluid actuator arrangement comprising: a first and second cylinder of a cylinder arrangement; a piston rod; a first and second piston device associated with the piston rod); the respective first and second piston device divides respective first and second cylinder into a first and second cylinder chamber provided for connection to a valve device of a fluid supply device; a first and second piston rod engagement and disengagement device of the respective first and second piston device; a first and second cavity of the respective piston rod engagement and disengagement device each forming a flexible piston inner wall portion; a first and second channel system of the respective piston rod engagement and disengagement device for providing fluid communication between the respective cylinder chamber and the respective cavity; the method includes the steps of: moving the piston rod a first distance by controlling the valve device to pressurize the first cylinder chamber of the first cylinder and, via the channel system, simultaneously pressurize the first cavity for expanding the flexible piston inner wall portion providing a radial clamping force onto the piston rod; moving the piston rod second distance, by controlling the valve device to pressurize the first cylinder chamber of the second cylinder and, via the first channel system, simultaneously pressurize the first cavity for expanding the flexible piston inner wall portion providing a radial clamping force onto the piston rod and simultaneously or afterwards controlling the valve device to disengage the piston rod engagement and disengagement device of the first cylinder from the piston rod by pressurizing the first cylinder chamber of the first cylinder with a second pressure being lower than the first pressure; repeating the steps for moving the piston rod further distance.
17. The method according to claim 16, wherein the method comprises the step of: providing the second pressure to all cylinder chambers of the fluid actuator arrangement to disengage all the piston rod engagement and disengagement devices.
18. An apparatus arranged to be infinitely movable, the apparatus includes a fluid actuator arrangement comprising: a first and second cylinder of a cylinder arrangement; a piston rod; a first and second piston device associated with the piston rod; the respective first and second piston device divides respective first and second cylinder into a first and second cylinder chamber provided for connection to a valve device of a fluid supply device; a first and second piston rod engagement and disengagement device of the respective first and second piston device; a first and second cavity of the respective piston rod engagement and disengagement device each forming a flexible piston inner wall portion; a first and second channel system of the respective piston rod engagement and disengagement device for providing fluid communication between the respective cylinder chamber and the respective cavity; wherein the arrangement is provided for moving the apparatus an optional distance by performing the method steps according claim 16.
19. A data medium storing program for moving an apparatus according to claim 18, wherein said program comprises a program code stored on a medium, which is readable on a computer, for causing a control unit to perform the method steps of: moving the piston rod a first distance by controlling the valve device to pressurize the first cylinder chamber of the first cylinder and, via the channel system, simultaneously pressurize the cavity for expanding the flexible piston inner wall portion providing a radial clamping force onto the piston rod; moving the piston rod a second distance, by controlling the valve device to pressurize the first cylinder chamber of the second cylinder and, via the channel system, simultaneously pressurize the cavity for expanding the flexible piston inner wall portion providing a radial clamping force onto the piston rod and simultaneously or afterwards controlling the valve device to disengage the piston rod engagement and disengagement device of the first cylinder from the piston rod by pressurizing the first cylinder chamber of the first cylinder with a second pressure being lower than the first pressure; repeating the steps for moving the piston rod a further distance.
20. A data medium storing program product comprising a program code stored on a medium, which is readable on a computer, for performing the method steps according to claim 16, when a data medium storing program is run on a control unit.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0174] The present invention will now be described by way of examples with references to the accompanying schematic drawings, of which:
[0175] FIGS. 1a to 1d illustrate one aspect of the present invention;
[0176] FIGS. 2a to 2d illustrate a prior art actuator arrangement;
[0177] FIG. 3a shows a flight envelope diagram illustrating needs of performance related to Mach number;
[0178] FIG. 3b shows a graph illustrating a central pump working point relative different fluid actuator arrangements presenting different operational requirements;
[0179] FIGS. 4a to 4b illustrate an example of mounting of a prior art application versus the mounting of an arrangement according to one aspect of the invention;
[0180] FIGS. 5a to 5f illustrate the operating of a hydraulic actuator arrangement, according to one aspect of the present invention;
[0181] FIGS. 6a to 6c illustrate a lift cage and a piston rod device using the arrangement according to one aspect of the present invention;
[0182] FIGS. 7a to 7c illustrate different piston rod engagement and disengagement device according to one aspect;
[0183] FIGS. 8a to 8e illustrate a piston rod engagement and disengagement device according to several aspects of the present invention;
[0184] FIGS. 9a to 9k illustrate a method for operating an arrangement according to one aspect of the present invention;
[0185] FIGS. 10a to 10b illustrate further aspects of the present invention;
[0186] FIGS. 11a to 11f illustrate yet further aspects of the present invention;
[0187] FIGS. 12a to 12k illustrate different aspects of the present invention;
[0188] FIGS. 13a to 13d illustrate further aspects of the present invention;
[0189] FIGS. 14a and 14b illustrate apparatuses according to further aspects of the invention;
[0190] FIGS. 15a and 15b illustrate flowcharts showing alternative methods according to different aspects of the invention; and
[0191] FIG. 16 illustrates a control unit according to one aspect of the invention.
DETAILED DESCRIPTION
[0192] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein for the sake of clarity and understanding of the invention some details of no importance may be deleted from the drawings.
[0193] FIG. 1a schematically shows a fluid actuator arrangement 1 comprising a first 3 and second 5 cylinder of a cylinder arrangement 7. The first 3 and second 5 cylinders are arranged in tandem and rigidly fit to each other by using a common cylinder housing. A partition wall 6 is provided between the cylinders 3, 5. The arrangement 1 further comprises a common piston rod 9 and a first 11 and second 13 piston, each being coupled to the piston rod 9. The first piston 11 is arranged in the first cylinder 3 and divides the latter into a first 15 and second 17 chamber. The second piston 13 is arranged in the second cylinder 5 and divides it into a first 15 and second 17 chamber and is rigidly connected to the piston rod 9. The respective chamber 15, 17 is connected for fluid communication with a fluid pump 19 via a valve member 21 comprising a control valve 23 and a logic valve 25. The fluid pump 19 is connected to the control valve 23 by means of a fluid (hydraulic) feeding line 27. The control valve 23 is in turn connected for fluid communication with the first chamber 15 of the second cylinder 5 by means of a first fluid line 29 and also connected to the second chamber 17 of the second cylinder 5 by means of a second fluid line 31. A control unit 33 (such as a CPU) controls the control valve 23 and directs the fluid flow to the second cylinder 5 providing fast motion and low force of the piston rod 9 as is shown in FIG. 1b. In FIG. 1c is shown that the control unit 33 has made a command to the logic valve 25 to open also a third fluid line 35 provided between the first chamber 15 of the first cylinder 3 and the first fluid line 29, thereby activating the arrangement from the state shown in FIG. 1a. The first chamber 15 of the first cylinder 3 will thus also be pressurized. The first piston 11 is provided with a piston rod engagement and disengagement device 37 adapted to engage (secure) or disengage (release) the first piston 11 to/from the piston rod 9. The piston rod engagement and disengagement device 37 comprises a membrane 39 arranged adjacent a wall of an inner piston surface of said first piston 11, which membrane 39 is provided to expand and retract depending upon actual pressure fed into interior fluid guide channels (not shown) of the first piston 11. The piston rod engagement and disengagement device 37 is thus adapted to engage or disengage the first piston 11 to or from the piston rod 9 depending upon actual pressure in the respective chamber 15, 17 in the first cylinder 3. As the first chamber 15 of the first cylinder 3 being pressurized, the membrane 39 will expand and press tightly (clamp) against the piston rod 9. Such tight engagement of the first piston 11 to the piston rod 9 implies that the first piston 11 will contribute adding force (double force area) to the piston rod 9. Such contribution is shown with arrow C marking that the force now generated by the arrangement 1 is larger. In FIG. 1d is shown that the control unit 33 has shut down the feeding of fluid to the first cylinder 3 by closing the logic valve 25. As no pressure prevails in the first chamber 15 of the first cylinder 3, the membrane 39 will retract and the first piston 11 will disengage from the piston rod 9. The first piston 11 is (shortly after disengagement) positioned in symmetrical position (middle position of the second cylinder 5 seen in the longitudinal direction) be means of a spring arrangement 41. The control valve 23 is controlled to feed fluid flow to the second chamber 17 of the second cylinder 5 for pressurizing the second chamber 17 of the second cylinder 5 and returning the piston rod 9 with high motion rate and low force.
[0194] FIG. 2a shows a hydraulic actuator arrangement 100 according to prior art. The arrangement 100 comprises a cylinder 101 and a piston 102 rigidly connected to a piston rod 103. A pump 104 provides a flow of fluid to a control valve 105. The arrangement 100 is designed for highest expected motion force/load. This means that if a lower force has to be generated, a major throttling is made for decreasing the pressure in the pressurized chamber 108. This excess fluid is led to an external reservoir 109. One way to solve this is to decrease the pump action. This is however also ineffective. Especially if another prior art arrangement (not shown) is coupled to the pump 104, which prior art arrangement must perform a high force/load motion adapted to the maximal pump performance. Thereby a not efficient throttling must be performed for the hydraulic actuator arrangement 100. In FIG. 2b is shown that no throttling is performed for achieving that the arrangement 100 is maximally pressurized for motion of a high load.
[0195] FIG. 2c shows another prior art actuator arrangement 200 having two cylinders, each having a piston 201 being rigidly coupled to a common piston rod arrangement 202. In case a lower force is needed, only one cylinder is active. This arrangement is bulky for low force mode involves unnecessary motion of all pistons in the cylinders.
[0196] FIG. 2d shows a further prior art actuator arrangement 300 of a jet fighter wing. An elevator 301 is controlled by the actuator arrangement 300 having two parallel actuators 302. In case of high aircraft speed (e.g. supersonic speed) (high force is required to move the elevator 301), both actuators 302 are activated. At low speed (for example at take-off and landing) there are required a low force and high motion rate to move the elevator 301, wherein high energy losses are present.
[0197] FIG. 3a schematically shows a flight envelope diagram illustrating the performance of an actuator arrangement related to Mach number. It is herein shown that with increasing Mach number (VEL.) and decreasing altitude (ALT.), the control surface motion requirements result in that the pump pressure increases from Low Pump Pressure LPP to High Pump Pressure HPP. At the same time the required motions of an actuator arrangement are different upon actual position of the aircraft in the flight envelope. At low Mach numbers are needed High Rates HR and at high Mach numbers are needed Low Rates LR. Low Hinge Moments are marked with LHM. High Hinge Moments are marked with HHM. There is thus a need for high pump pressure and low rate actuator motion at high velocityand low pump pressure and high rate actuator motion at low velocityof the aircraft. According to one aspect of the present invention there is provided that rapid change of force area of the piston device can be made for achieving high force performance of the arrangement or high rate motion of the arrangement in accordance with actual operation of the aircraft.
[0198] FIG. 3b schematically illustrates a diagram (P=fluid pressure; F=force; Q=fluid flow; v=motion rate) of the working point WP of a central pump relative a set (two) of different fluid actuator arrangements (not shown) having different operational requirements regarding High Force/Low Motion Rate (Requirement R1) and High Motion Rate/Low Force (Requirement R2). For example, a first arrangement (not shown) requires High Force and Low Motion Rate and a second arrangement (not shown) requires High Motion Rate and Low Force, wherein the arrangements are connected to a common central pump proving a constant high pressure P. By means of just changing the cross-sectional force area (active piston area) of each arrangement, the Requirement R1 and Requirement R2 will be possible to full fill in an energy saving way. In such way is provided an effective, intelligent and local/distribution control of motion rate and force for each arrangement independently of each other and providing less CO2 emissions and saving energy. This aspect of the present invention also implies a total lower (relative prior art) power output of the central pump and thus lower energy losses.
[0199] FIGS. 4a to 4b illustrate an example of mounting of a prior art application versus the mounting of an arrangement 1 according to one aspect of the invention. As shown in FIG. 4a the prior art arrangement 400 is designed for only High Pump Pressure HPP, but throttled to Low Hinge Moments LHM for providing lower forces. As shown in FIG. 4b the arrangement 1 according to one aspect of the present invention is less bulky and is of lower weight. By means of the arrangement in FIG. 4b according to one aspect there is thus possible to change between high force and high velocity of the piston 9. There is a possibility to change to double force area and thus double force for a short distance by activating both cylinders in tandem. Large forces and short distance motions of being required for the piston rod in high speed and/or supersonic speed.
[0200] FIG. 5a to 5f schematically shows the operating of a hydraulic actuator arrangement 1 according to one aspect of the present invention. FIG. 5a illustrates the arrangement 1 comprising a first cylinder 3 and a second cylinder 5. A first piston 11 is arranged in the first cylinder 3 and a second piston 13 is arranged in the second cylinder 5. A spring mechanism 42 is arranged in respective cylinder 3, 5 for positioning respective piston 11, 13 symmetrically (seen in a longitudinally direction between end walls of the cylinder) in the cylinder 3, 5, when respective cylinder chamber 15, 17 is not pressurized. Only one of the spring mechanisms is shown in the FIGS. 5a to 5f for sake of clarity. A common piston rod 9 protrudes through the cylinders 3, 5 along a central longitudinal axis X. The cylinders 3, 5 are arranged in a tandem assembly and at outside ends of the assembly there is arranged a respective scraper device (not shown) for removing eventual dust and dirt from the piston rod 9 outside the cylinders 3, 5. Respective piston 11, 13 is provided with a piston rod engagement and disengagement device 37 adapted to engage (secure) or disengage (release) the pistons 11, 13 to/from the common piston rod 9. A pump 19 is connected to a control valve 23, which in turn is connected to respective chamber 15, 17 of the assembly via logic valves 25. The second cylinder 5 is connected to the control valve 23 via the right (as seen in the FIGS. 5a to 5f) positioned logic valve 25 adapted for directing the hydraulic flow to the respective chambers 15, 17 of the second cylinder 5. In FIG. 5b is shown that the first piston 11 is actuated by pressurizing the first chamber 15 of the first cylinder 3. The direction of motion is operated by controlling the control valve 23 and the activating of the respective cylinder 3, 5 is made by operating the respective logic valve 25. Such control of fluid flow to the arrangement promotes for efficient selection of working points regarding motion rate and force of the arrangement. By pressurizing the first chamber 15 of the first cylinder 3, the first piston 11 engages the common piston rod 9 by means of the piston rod engagement and disengagement device 37. The second cylinder 5 is not pressurized and no engagement is performed between the piston rod 9 and the second piston 13. The second piston 13 is not engaged with the common piston rod 9, which slides through the second piston 13 and its piston rod engagement and disengagement device 37, thus slides adjacent the piston bore inner wall of the second piston 13. Low force and high motion of the common piston rod 9 is achieved.
[0201] In FIG. 5c is shown that the control valve 23 is operated to direct the hydraulic flow from the pump 19 to the second chamber 17 of the first cylinder 3. The first piston 11 is again in engagement with the common piston rod 9 for returning the latter with a low force.
[0202] In FIG. 5d is shown that both logic valves 25 are operated to open fluid communication with the second cylinder 5 as well. The first chamber 15 of the second cylinder 5 is pressurized and the second piston 13 will engage with the common piston rod 9 in similar same way as the first piston 11. There will thus be added performance in force F acting onto the piston rod 9. Double load motion/fast accelerating heavy loads is thus achieved by the arrangement 1 in this state.
[0203] In FIG. 5e is shown that the control valve 23 is changed for feeding hydraulic oil to re-direct the common piston rod 9 by means of engagement of the both pistons 11, 13 by pressurizing the second chamber 17 of the first cylinder 3 and the second chamber 17 of the second cylinder 5. In FIG. 5f is shown that the right logic valve 25 is closed and the second piston 13 is disengaged from the common piston rod 9, wherein the second piston 13 is returned to mid-position by means of the spring mechanism 42. The first piston 11 is engaged with the common piston rod 9 and propels the latter with minor force for accurate and fine adjustment of the common piston rod 9.
[0204] FIGS. 6a to 6c schematically illustrate a lift cage 45 and a piston rod 9 for use of an arrangement 1 according to one aspect of the present invention. A further parallel arrangement (not shown) is also adapted to the lift cage 45. The piston rod 9 is arranged through a cylinder arrangement comprising four cylinders 4, 4, 4, 4 (see FIG. 6b). Respective cylinder is provided with a piston comprising a piston rod engagement and disengagement member 37 adapted for releasable engagement with the piston rod 9. As seen in FIG. 6a the arrangement 1 is mounted in a structural portion of the lift cage 45. The operation of the arrangement 1 is performed by a user 8 operating a control unit 33. FIG. 6b illustrates the arrangement 1 in closer view taken instantaneously. The arrangement 1 comprises the first 4, second 4, third 4and fourth 4 cylinder with respective first 11, second 11, third 11 and fourth 11 piston. An upper chamber 15 of the second cylinder 4 is pressurized, wherein the second piston 11 is engaged with the piston rod 9. The arrangement 1 and lift cage 45 will thus be moved in direction L, as the upper wall w of the second cylinder 4 is forced (pressed) in said direction. A spring 44 is arranged in each cylinder in its lower cylinder chamber 15. The spring 44 in the second cylinder 4 being compressed during said pressurization. Optionally, during lift start for accelerating the lift cage 45, all cylinders 4, 4, 4, 4 may be active, generating a large force. In FIG. 6c is shown that the third piston 11 is engaged with the piston rod 9 by pressurizing the upper chamber 15 of the third cylinder 4. The second cylinder 4 is not pressurized and the piston 11 is returned to its upper position in the cylinder 4 by said spring 44. For operating the lift cage 45 going down, the lift cage 45 is provided with a system adapted for such functionality.
[0205] FIGS. 7a to 7c schematically illustrate a piston rod engagement and disengagement device 37 according to one aspect. FIG. 7a shows a piston 11 in a front view. A bore 61 (exhibiting an inner wall section 63) is provided centrally in the piston 11 for encompassing a piston rod 9. An interior channel 65 is arranged in the piston 11, which channel 65 is provided with six tangent section portions. The interior channel 65 is adapted for fluid communication with a fluid pressurized cylinder chamber (not shown) according to one aspect. Pressurized fluid is fed into the interior channel 65 wherein the inner wall 63 expands in a radial direction inwardly according to arrows AR in FIG. 7b. In such way the piston 11 will engage the piston rod 9, when the cylinder chamber (see e.g. FIG. 6c) is pressurized for action. In FIG. 7c is illustrated a cross-section A-A taken in FIG. 7a.
[0206] FIG. 8a schematically illustrates a piston rod engagement and disengagement device 37 of a piston 11 according to one aspect. The device 37 comprises a membrane device 39 adapted for providing releasable engagement for the piston 11 with a piston rod 9. The device 37 further comprises a pressure strengthening device 67, which is provided for strengthening the engagement of the piston 11 to the piston rod 9. The pressure strengthening device 67 is arranged within the piston 11 and is shown in an enlarged view in FIG. 8c according to one aspect. It comprises a movable micro piston rod 69 having a first micro pressure area mpa1 and a second micro pressure area mpa2. The first micro pressure area mpa1 being larger than the second micro pressure area mpa2, and is in fluid communication with the pressurized fluid of the pressurized cylinder chamber 15. The second micro pressure area mpa2 is arranged in communication with a pressure strengthening fluid provided in a cavity 65for acting upon the membrane device 39 of the piston 11. FIG. 8b schematically illustrates one aspect of the invention, wherein a piston 11 is provided with two piston rod engagement and disengagement devices 37, each adapted for fluid communication with respective first 15 and second 17 chamber of a cylinder. FIG. 8d schematically shows a front view of a portion of a piston 11 having a central bore 61 forming an inner wall section 63. An interior circular cavity 65 is provided in the piston 11 extending parallel with the inner wall section 63 extension. The interior circular cavity 65 is arranged for fluid communication with corresponding cylinder chamber for pressurizing the interior circular cavity 65, thereby expanding the inner wall section 63 for engagement functionality. FIG. 8e schematically illustrates a piston 11 comprising a common membrane using a channel system (alternatively at least one channel) adapted for a respective micro piston for alternately actuating said common membrane. The use of a common membrane involves the benefit of an optimal friction area (clamping area) of the membrane.
[0207] FIGS. 9a to 91 schematically illustrate a method for operating the motion of a piston rod 9 of an arrangement 1 according to one aspect of the present invention. FIG. 9a illustrates that first chamber 15 of respective cylinder (first 3 and second 5) being pressurized for accelerating a heavy load F. FIG. 9b shows that the overall force area is smaller, as the second cylinder 5 is not pressurized. However, the motion of the piston rod 9 is performed by pressurizing the first cylinder 3. FIG. 9c shows when both first 11 and second 13 pistons are in engagement with the piston rod 9. The first piston 11 is shortly held in engagement with the piston rod 9 during change of engagement to the second piston 13.
[0208] FIG. 9c thus shows a way to manage operation of the arrangement to engage the piston rod 9 and simultaneously propel the latter without faltering during switch between pistons 11 and 13.
[0209] FIG. 9d shows that the second piston 13, which is in engagement with the piston rod 9, has moved the latter, at the same time as the first piston 11 is disengaged (as the first cylinder chamber 15 not being pressurized) and has been moved to a mid-portion of the first cylinder 3 by means of a spring arrangement (not shown). Further motion of the piston rod 9 is performed in FIG. 9e, wherein the controlled pressure acts onto the piston rod 9 via the first piston 11. FIG. 9f shows further motion the first piston 11. FIG. 9g shows complementary motion by means of providing pressure to the second cylinder 5. FIG. 9h shows that yet further motion is achieved by means of the first cylinder 3. FIGS. 9i and 9j shows return of the piston rod 9 by activating the first cylinder 3 second chamber 17 and fine adjustment by activating the first chamber 15 of the first cylinder 3 to an accurate position of the piston rod 9. A major force F is generated onto the piston rod 9 as shown in FIG. 9k by pressurizing the second chambers 17 of the respective first 3 and the second 5 cylinder.
[0210] FIG. 10a schematically illustrates a further aspect of the present invention. The arrangement 1 comprises a first and a second cylinder. The first cylinder is shorter than the second cylinder.
[0211] FIG. 10b schematically illustrates a further aspect of the present invention. The arrangement 1 comprises a plurality of cylinders arranged in tandem and with a distance there between.
[0212] FIGS. 11a to 11f schematically illustrate yet further aspects of the present invention. FIG. 11a shows an arrangement 1 comprising two cylinders 3, 5 with a respective piston 11, 13. By pressurizing both first chambers 15, the pressure makes the cylinder arrangement 7 to move providing a major force F. For providing less force and higher motion rate of the cylinder arrangement 7, only one cylinder is pressurized. The respective piston being symmetrically positioned in the respective cylinder by means of an electro-magnetic device E. FIG. 11b illustrates an aspect wherein four cylinders 3, 3, 3, 3 are used for propelling a piston rod arrangement 9 comprising four piston rods 9 and a four-armed-wheel 10. In FIG. 11b only two cylinders 3, 3 are pressurized. FIG. 11c shows a further aspect wherein the arrangement 1 is provided for telescope functionality. FIG. 11d shows an arrangement 1 comprising an integrated logic valves unit VU. The valve unit VU transforms an electrical signal to an analogous hydraulic quantity. In the figure is shown that fluid F is fed into a first cylinder 3 via a port 91 and at the same time into a second cylinder 3 via a port 92. Return fluid is fed from the first cylinder 3 via port 93 and from the second cylinder 3 via port 94. For changing direction of motion a control valve (not shown) is operated to change fluid to be fed into ports 93 and 94. The integrated logic valves unit VU is for changing direction not operated. For changing a force/motion rate of the arrangement 1, the integrated logic valves unit VU is operated to change so that port 92 is opened for feeding fluid to the second cylinder 3 at the same time as port 91 not being fed with fluid and the piston of the first cylinder 3 is disengaged.
[0213] FIG. 11e shows an embodiment wherein the force area of the arrangement 1 can be changed in an optimal way. For reaching fast piston motion and minor force, a first force area A1 (e.g. 1 area unit) is activated by alternating engagement of the first 18 and second actuator 18 to the piston rod 9. For achievement of slow piston motion with major force, all activators 18, 18, 18, 18 are activated. This major force can be achieved by activating all four force areas A1, A2, A3 and A4. This means that eight area units are used, i.e. the force areas of the first, second, third, fourth actuators 18, 18, 18, 18 are all used together. This implies an optimal combination of eight different force area units, which can be selected from required piston motion rate and force of the piston device.
[0214] FIG. 11f shows an aspect wherein four cylinder arrangements 7, 7, 7, 7 of a fluid actuator arrangement 1 share one common fluid pump 19. If the first arrangement 7 must provide high force and the second must provide high velocity, this is possible by the arrangement using the common fluid pump 9 by changing force area of the respective arrangement 7 and 7.
[0215] FIG. 12a schematically shows a supersonic fighter aircraft 70, which comprises the arrangement 1 according to one aspect. A canard 71 of the fighter aircraft 70 is adapted for one aspect of the arrangement 1 providing the left and right canard 71 with fast motion rate and low force in low aircraft velocity and low motion rate and high force in supersonic speed. FIG. 12b schematically illustrates a forestry machine 72 comprising a lift arm which is adapted with the arrangement 1 according to one aspect of the invention. FIG. 12c schematically shows a portion of a container terminal 73 comprising a container crane adapted to further arrangements 1 according to further aspects, offering shorter time for container ships in harbour. FIG. 12d schematically shows a commercial aircraft 74 designed for long distance flights. The landing gear retraction system 75 of the aircraft 74 is adapted for a hydraulic actuator arrangement 1 according to one aspect of the present invention. By using the arrangement, the weight of the aircraft 74 can be saved whereby improved performance is achieved, especially fuel consumption of the aircraft 74 is reduced which can be a part of Green aviation concept, aiming at the reduction of the operational environmental footprint of the aircraft 74. FIG. 12e schematically shows a mobile crane 76 adapted with an arrangement 1 according to yet a further aspect of the present invention. FIG. 12f schematically shows an offshore platform 77 including jacking systems used to raise and lower oil well drilling. The jacking system comprises an arrangement 1 according to one aspect. FIG. 12g schematically illustrates a forklift 78 comprising an arrangement 1 according to a further aspect. By using more compact arrangement 1, a driver will have better view which increases certainty and reduces risks. FIG. 12h schematically illustrates a bascule bridge 79 adapted with the arrangement 1 according to a further aspect. The bridge counterweight chamber 80 is adapted for encompassing the piston rod arrangement of the hydraulic actuators and thus protected from outdoor environment. FIG. 12i schematically shows a further aspect used in a 3D-printing apparatus 81 for printing of entire buildings. FIG. 12j schematically shows an automated storage and retrieval system 82 for car parking DP3, which system comprises an arrangement 1 according to a further aspect. FIG. 12k schematically shows a mobile scissor lift 83 comprising a hydraulic actuator arrangement 1 according to a further aspect.
[0216] FIG. 13a shows a fluid actuator arrangement 1 comprising a first 104, a second 104 and a third 104' cylinder of a cylinder arrangement 107. All cylinders 104, 104, 104 comprise a respective piston rod engagement and disengagement device 137 (first), 137 (second), 137 (third), each of which being adapted to engage or disengage a respective piston device 111 (first), 111 (second), 111 (third) of the respective cylinder 104, 104, 104 to/from a piston rod 109. Each cylinder 104, 104, 104 comprises a cylinder sleeve 201, each of which being provided with a first 203 and second 203 flange member. The three cylinders 104, 104, 104 are rigidly coupled to each other in axial direction along a cylinder axis X by means of bolts 204 to form the common cylinder arrangement 107.
[0217] Each cylinder 104, 104, 104 defines a cylinder space 205 in which the respective piston device 111, 111, 111 is slidingly provided. The respective piston device 111, 111, 111 is slidingly provided along the cylinder axis X and around the common piston rod 109 arranged along the cylinder axis X. The respective piston device 111, 111, 111 sealingly divides the cylinder space 205 into a first 115 and second 117 cylinder chamber. Each cylinder chamber 115, 117 comprises a fluid channel 210 provided in the cylinder sleeve 201 for permitting pressurized fluid to flow in or out to/from the respective cylinder chamber 115, 117.
[0218] The respective piston rod engagement and disengagement device 137, 137, 137 being controlled by the pressurized fluid of the actual cylinder chamber 115, 117. Alternately pressurizing of the respective cylinder chamber 115, 117 of the first cylinder 104 with a fluid pressure P will imply that the fluid pressure P, via a first channel system 165 of the first piston device 111, also directly and momentary will pressurize a first cavity 139 of the piston rod engagement and disengagement device 137 formed in the first piston device 111. Upon such pressurization of the cavity 139, an expandable membrane (an inner wall portion 163 of the first piston device 111 will expand and press tightly (clamp) against the piston rod 109 with an inwardly directed radial force. Thus, by pressurizing the cylinder chamber 115 of the first cylinder 104, the first piston device 111 will directly engage the piston rod 109 by means of the piston rod engagement and disengagement device 137 utilizing the same pressure P being applied to the first cylinder chamber 115 of the first cylinder 104. As the first cylinder chamber 115 of the first cylinder 104 being pressurized, the expandable membrane (first inner wall portion 163) will expand and engage the piston device 111 to the piston rod 109. The engagement of the first piston device 111 to the piston rod 109 outer envelope surface 206 plus the pressurized first cylinder chamber 114, implies that the first piston device 111 will propel the piston rod 109 a cylinder stroke length as part of an infinite and continuous motion of the piston rod.
[0219] A control unit 133 controls the valve device 121 comprising a first 125, a second 125 and a third 125 logic valve and a control valve 123 to pressurize respective cylinder chamber and at the same time the belonging piston engagement and disengagement device 137, 137, 137. In FIG. 13a is shown that the first cylinder chamber 115 of the first cylinder 104 is pressurized and, via the first channel system 165, simultaneously pressurize the first cavity 139 for expanding the first flexible piston inner wall portion 163 providing a radial clamping force onto the piston rod 109. The motion of the piston rod 109 is made by controlling the valve device 121 to pressurize the first cylinder chamber 115 of the first cylinder 104 and, via the first channel system 165, simultaneously pressurize the first cavity 139 for expanding the first flexible piston inner wall portion 163 providing a radial clamping force onto the piston rod 109. The motion of the piston rod 109 (a second distance) is made by controlling the valve device 121 to pressurize the first cylinder chamber 115 of the second cylinder 104 and, via the second channel system 165, simultaneously pressurize the second cavity 139 for expanding the second flexible piston inner wall portion 163 providing a radial clamping force onto the piston rod 109 and simultaneously (or shortly afterwards or any time there between) controlling the valve device 121 to disengage the piston rod engagement and disengagement device 137 from the piston rod 109 by pressurizing the first cylinder chamber 115 of the first cylinder 104 with a second pressure being lower than the first pressure so that the first flexible piston inner wall portion 163 take its original condition (state) not engaging the piston rod 109. At the same time the second piston device 111 (comprising the second flexible piston inner wall portion 163) provides a radial clamping force onto the piston rod 109 and moves the piston rod 109. The steps are repeated for infinitely and continuously moving the piston rod 109.
[0220] According to one aspect the method comprises the step of providing the second pressure to all cylinder chambers 15, 17 of the fluid actuator arrangement 1 to disengage all the piston rod engagement and disengagement devices 137, 137, 137 for performing a disengagement of all piston devices 111, 111, 111, so that the arrangement 1 momentary disengage all piston devices 111, 111, 111 from the piston rod 109 in case the piston rod 109 propels a large mass using the kinetic energy of the mass (in a way reminding of a freewheel clutch).
[0221] Alternatively, a locking mode is possible, wherein a piston-like clamping device using the fluid supply system or external fluid supply systems (or wherein both chambers of respective cylinder may optionally be pressurized for activating the piston engagement and disengagement device in a locked position) is used. Such application may be advantageous in case of error in operation.
[0222] FIG. 13b shows a piston of the fluid actuator arrangement in closer detail. The piston 111 comprises the piston rod engagement and disengagement device 137. The first cavity 139 is formed by an outer surface of an inner sleeve 198 and an inner surface of an outer housing 199. The inner sleeve 198 is open at its ends. The inner sleeve 198 is surrounded by the outer housing 199 and being coaxially arranged around the inner sleeve 198 and encompassing the inner sleeve 198. A cavity 139 (or cavities) is coupled to a channel system 165 comprising a first opening entering the cavity 139 and a second opening entering the outer envelope surface of the outer housing 199 for fluid communication with the first cylinder chamber 115 via a passage 211 provided in the piston.
[0223] The passage 211 may have a shuttle valve 209 arranged to obstruct the fluid fed to the first cylinder chamber 115 from entering the second cylinder chamber 117. The shuttle valve 209 is tube-formed comprising three openings and a ball or other blocking valve element that moves freely within the tube (or other valve member). The shuttle valve 209 prevents the fluid from travelling from one cylinder chamber to the other, but allows the fluid to flow through a middle opening coupled to the channel system 165. The first cylinder chamber 115 is pressurized with a pressure P for moving the piston 111 in the direction of arrow A. The fluid fed into the first cylinder chamber 115 also enters the first channel system 165 via the passage 211 and the shuttle valve 209 and further to the first cavity 139. The first cavity 139 of the piston rod engagement and disengagement device 137 is formed by an inner side of a piston inner wall portion 163 (i.e. outer side of the inner sleeve 198) and the inner side of the outer housing 199. The cavity (or cavities) thus extends parallel with and in a direction circumferentially around the envelope surface of the piston rod 109 and in an direction along the cylinder axis X (the cavity or cavities being e.g. cylindrical shaped and coaxially arranged within the piston rod engagement and disengagement device 137). The mass of material forming the inner sleeve 198 adjacent the first cavity 139 is so flexible that the increased pressure in the first cavity 139 will expand the mass of material of the inner wall portion 163. The piston inner wall portion 163 is expanded by means of the pressure P and being pressed in radial direction (with a force F) towards the piston rod 109 envelope surface for engagement with the piston rod 109. By means of the pressurization of the first cylinder chamber 115 there is thus also achieved that the first cavity 139 per se is pressurized. This is achieved by that the pressurized fluid will enter also the passage 211 of the first piston 111 and the channel system 165 and further to the first cavity 139. The pressurization of the first cavity 139 will instantaneously expand the piston inner wall portion 163 for providing engagement between the piston device 111 and the piston rod 109 for moving the piston rod 109.
[0224] FIG. 13c shows a piston 11 in closer detail. The piston 11 comprises a membrane 240 being designed as an inner sleeve 221 open at its ends. The inner sleeve 221 is surrounded by an outer housing 222 coaxial arranged around the inner sleeve 221 and encompassing the inner sleeve 221. A cavity 239 or a plurality of cavities being formed between an outer surface 223 of the inner sleeve 221 and an inner surface 224 of the surrounding outer housing 222. Alternatively, the outer housing 222 comprises a fluid channel 265 comprising a first end 266 entering the cavity 239 and a second end 267 entering an outer envelope surface 225 of the outer housing 222 for fluid communication with the cylinder chamber 115 via a passage 211 comprising a return valve (arranged for directing the fluid from one of the cylinder chambers to the cavity 239) provided in the piston 11. Suitably, the inner sleeve 221 is made flexible and comprises e.g. bronze-based material or other suitable materials. The open ends of the outer housing 222 is covered by a respective support ring 230 for fixation of the inner sleeve 221 to (within) the outer housing 222. Seals (O-rings) 231 are arranged in end positions of the membrane 240 between the outer surface 223 of the inner sleeve 221 and the inner surface 224 of the outer housing 222 for providing a seal between the inner sleeve 221 and the outer housing 222. Suitably, the membrane 240 (outer housing, inner sleeve and support ring) is mounted in the piston 11 with a suitable bias to the piston. Alternatively, an inner surface 250 (facing the piston rod 109 envelope surface) of the inner sleeve 221 is provided with a helical groove 252 (not shown) or grooves for achieving smooth operation of the piston 11 and uniform friction between the inner sleeve 221 and the piston rod 109 envelope surface for effective sliding of the piston 11 along the piston rod 109 when the piston 11 is disengaged from the piston rod 109. Such helical groove 252 or grooves will also provide rigid engagement of the piston 11 to the piston rod 109 when the membrane 240 is pressurized for engagement.
[0225] FIG. 13d shows a piston 11 according a further aspect. A first non-return valve NR1 prevents the fluid from travelling from a first 15 cylinder chamber to a second cylinder chamber 17. The first non-return valve NR1 permits the fluid from the second cylinder chamber 17 to enter the membrane cavity 39 via a common channel 66. A second non-return valve NR2 prevents the fluid from travelling from the second 17 cylinder chamber to the first cylinder chamber 15. The second non-return valve NR2 permits the fluid from the first cylinder chamber 15 to enter the membrane cavity 39. Each non-return valve NR1, NR2 thus allows the fluid of the respective pressurized cylinder chamber to flow through the common channel 66 to the membrane cavity 39 providing actuating of the piston rod engagement and disengagement device 37.
[0226] FIG. 14a illustrates an apparatus 400 arranged to be infinitely movable by means of a fluid actuator arrangement 107 comprising a first and second 104, 104 cylinder, a piston rod 9, a first 11 and second 13 piston device associated with the piston rod 9. The respective first 11 and second 13 piston device divides respective first and second cylinder 104, 104 into a first 15 and second 17 cylinder chamber provided for connection to a valve device 21 of a fluid supply device 19. The fluid actuator arrangement 107 further comprises a first and second piston rod engagement and disengagement device 137, 137 of the respective first 11 and second 13 piston device, a first and second cavity (not shown) of the respective piston rod engagement and disengagement device 137, 137 each forming a flexible piston inner wall portion (not shown), a first and second channel system (not shown) of the respective piston rod engagement and disengagement device 137, 137 for providing fluid communication between the respective cylinder chamber 15, 17 and the respective cavity.
[0227] FIG. 14b illustrates an arrangement (e.g. for an elevator apparatus 100) having at least two cylinders 3, 5, each of them comprising a piston 11, 13 arranged around a stationary common piston rod 9. Respective piston 11, 13 comprises a piston rod engagement and disengagement device 37. In this embodiment, there is provided a channel system 65 between a first cylinder chamber 15 and the membrane cavity 39 for direct fluid communication between the cavity 39 and the chamber 15. Since the lifting force for lifting the elevator 100 (and cylinder arrangement), in a direction D, is achieved by alternately pressurizing (with a first pressure) the respective first cylinder chamber 15 (upper chamber) and cavity 39 via fluid ports 210, it will not be needed any channel system between the second cylinder chamber 17 and the cavity 39. There is even not needed any shuttle valve. The alternately pressurizing of the respective upper cylinder chamber 15 comprises interchange actuating of respective chamber 15 repeatedly and regularly with one another in time for lifting the elevator 100 along the stationary piston rod 9. The second chamber 17 of each cylinder 3, 5 may be pressurized via port PZ for returning of the piston to a starting point SP.
[0228] FIGS. 15a and 15b illustrate flowcharts showing methods according to different aspects of the invention. FIG. 15a illustrates a flow chart of the method according to one aspect of the invention. The method starts in a Step 1001. In Step 1002 is provided a method for controlling a fluid actuator arrangement comprising a first and second piston rod engagement and disengagement device of a respective first and second piston device. In Step 1003 the method is fulfilled and stopped. The step 1002 comprises the steps of moving a piston rod a first distance by controlling a valve device to pressurize a first cylinder chamber of the first cylinder and, via a channel system, simultaneously pressurize a first cavity for expanding a flexible piston inner wall portion providing a radial clamping force onto the piston rod; moving the piston rod a second distance, by controlling the valve device to pressurize a first cylinder chamber of a second cylinder and, via a second channel system of the second cylinder, simultaneously pressurize a second cavity for expanding a flexible piston inner wall portion providing a radial clamping force onto the piston rod and simultaneously (or shortly afterwards) controlling the valve device to disengage the piston rod engagement and disengagement device of the first cylinder from the piston rod by pressurizing the first cylinder chamber of the first cylinder with a second pressure being lower than the first pressure; and repeating the steps for moving the piston rod further distance.
[0229] FIG. 15b illustrates a flow chart of the method according to a further aspect of the invention. The method starts in a Step 2001. In Step 2002 is provided a method for controlling a fluid actuator arrangement comprising a first and second piston rod engagement and disengagement device of a respective first and second piston device corresponding to Step 1002 in FIG. 15a. The method comprises a further Step 2003 of providing the second pressure to all cylinder chambers of the fluid actuator arrangement to disengage all the piston rod engagement and disengagement devices from the common piston rod. In Step 2004 the method is fulfilled and stopped.
[0230] FIG. 16 illustrates a CPU device 900 according to one aspect of the invention. The control unit 133 of the fluid actuator arrangement 1 described in FIG. 13a may comprise the CPU device 900. The CPU device 900 comprises a non-volatile memory NVM 920 which is a computer memory that can retain stored information even when the computer is not powered. The CPU device 900 further comprises a processing unit 910 and a read/write memory 950. The NVM 920 comprises a first memory unit 930.
[0231] A computer program (which can be of any type suitable for any operational data) is stored in the first memory unit 930 for controlling the functionality of the CPU device 900.
[0232] Furthermore, the CPU device 900 comprises a bus controller (not shown), a serial communication port (not shown) providing a physical interface, through which information transfers separately in two directions. The device 900 also comprises any suitable type of I/O module (not shown) providing input/output signal transfer, an A/D converter (not shown) for converting continuously varying signals from detectors (not shown) of the production line and other monitoring units (not shown) of the production line into binary code suitable for the computer.
[0233] The CPU device 900 also comprises an input/output unit (not shown) for adaption to time and date. The CPU device 900 also comprises an event counter (not shown) for counting the number of event multiples that occur from independent events in operation. Furthermore, the CPU device 900 includes interrupt units (not shown) associated with the computer for providing a multi-tasking performance and real time computing in said production line. The NVM 920 also includes a second memory unit 940 for external controlled operation.
[0234] A data medium storing program P comprising routines adapted for controlling the control valves and provided for operating the CPU device 900 for performing the present method described herein. The data medium storing program P comprises routines for providing smooth motion of the fluid actuator arrangement in an automatic or semi-automatic way. The data medium storing program P comprises a program code stored on a medium, which is readable on the computer, for causing the control unit 200 to perform the operation of the fluid actuator arrangement by controlling the fluid actuator arrangement comprising a first and second piston rod engagement and disengagement device of a respective first and second piston device in moving a piston rod a first distance by controlling a valve device to pressurize a first cylinder chamber of the first cylinder and, via a channel system, simultaneously pressurize a first cavity for expanding a flexible piston inner wall portion providing a radial clamping force onto the piston rod; moving the piston rod a second distance, and by controlling the valve device to pressurize a first cylinder chamber of a second cylinder and, via a second channel system of the second cylinder, simultaneously pressurize a second cavity for expanding a flexible piston inner wall portion providing a radial clamping force onto the piston rod and simultaneously (or shortly afterwards) controlling the valve device to disengage the piston rod engagement and disengagement device of the first cylinder from the piston rod by pressurizing the first cylinder chamber of the first cylinder with a second pressure being lower than the first pressure; and repeating the steps for moving the piston rod further distance.
[0235] The data medium storing program P further may be stored in a separate memory 960 and/or in a read/write memory 950. The data medium storing program P is in this embodiment stored in executable or compressed data format.
[0236] It is to be understood that when the processing unit 910 is described to execute a specific function that involves that the processing unit 910 executes a certain part of the program stored in the separate memory 960 or a certain part of the program stored in the read/write memory 950.
[0237] The processing unit 910 is associated with a data port 999 for communication via a first data bus 915. The non-volatile memory NVM 920 is adapted for communication with the processing unit 910 via a second data bus 912. The separate memory 960 is adapted for communication with the processing unit 910 via a third data bus 911. The read/write memory 950 is adapted to communicate with the processing unit 910 via a fourth data bus 914. The data port 999 is preferably connectable to data links of the fluid actuator arrangement.
[0238] When data is received by the data port 999, the data will be stored temporary in the second memory unit 940. After that the received data is temporary stored, the processing unit 910 will be ready to execute the program code, according to the above-mentioned procedure. Preferably, the signals (received by the data port 999) comprise information about operational status of the fluid actuator arrangement, such as operational status regarding the position of the piston rod relative the cylinder arrangement. It could also be operational data regarding the speed and brake performance of the fluid actuator arrangement. According to one aspect, signals received by the data port 999 may contain information about actual positions of the apparatus 400 in FIG. 14 by means of a sensor means (not shown). The received signals at the data port 999 can be used by the device 900 for controlling and monitoring the operation in a cost-effective way. The signals received by the data port 999 can be used for automatically moving the piston rod between two end positions. The signals can be used for different operations of a single fluid actuator arrangement or a plurality of fluid actuator arrangements, being adapted to various industrial apparatuses, such as autonomous robot assemblies, holding devices etc. The information is preferably measured by means of suitable sensor members of the fluid actuator arrangement. The information can also be manually fed to the control unit 133 via a suitable communication device, such as a personal computer display.
[0239] Parts of the method can also be executed by the device 900 by means of the processing unit 910, which processing unit 910 runs the data medium storing program P being stored in the separate memory 960 or the read/write memory 950. When the device 900 runs the data medium storing program P, suitable method steps disclosed herein will be executed. A data medium storing program product comprising a program code stored on a medium is also provided, which product is readable on a suitable computer, for performing the method steps according to any of claims 16 to 17, when the data medium storing program P according to claim 19 is run on the control unit 133.
[0240] The arrangement may according to different aspects be adapted to one or several of following industrial segments; construction industry, jacking systems for oil well drilling and service platforms, agricultural equipment industry, marine industry, crane manufacture industry. The arrangement is not limited to be used in such segments, but also other industrial segments are possible.
[0241] The present invention is of course not in any way restricted to the preferred embodiments described above, but many possibilities to modifications, or combinations of the described embodiments, thereof should be apparent to a person with ordinary skill in the art without departing from the basic idea of the invention as defined in the appended claims. One aspect involves that the arrangement can be adapted for momentary disengaging all pistons from the piston rod in case the piston rod propels a large mass using the kinetic energy of the mass (in a way reminding of a freewheel clutch). The valve device may comprise a logic valve of suitable type. The valve member may comprise a 5 ports/2 valve positions, so called 5/2 valve or others. The valve member may comprise a two-way valve of any type suitable for the arrangement. The manoeuvring of the valve member may be performed by means of a solenoid connected to a control unit adapted for controlling the valve member and thereby the arrangement. The arrangement may be adapted for fast and high clamp force engagement of the piston device for propelling the latter accurate also for acceleration of heavy loads. By manoeuvring the valve member, such as a logical valve, the same arrangement can perform also lower force and slow motion rate of the piston rod arrangement. A logical valve can be manoeuvred by the control unit to shut down the fluid flow to excluded cylinder/cylinders and only direct fluid flow to only one cylinder. There are different types of valves that can be used for providing the above-mentioned aspects and other aspects. Electro-hydraulic controlled valves, other types of directly controlled electro-hydraulic logical valves, etc. The arrangement can be used in civil and military, manned and unmanned aircraft: Leading/Trailing Edge Flap Actuators; Landing Gear Actuators; Air Brakes; Primary Servo Actuators (PSA); Electro-Hydrical Actuator (EHA) applications etc.
