Hydraulic unit for hydraulic rescue tools, and rescue tool equipped therewith

Abstract

A portable, battery-powered hydraulic unit for hydraulic rescue tools, in particular for spreading or cutting tools, as well as a rescue tool equipped therewith, are disclosed. The hydraulic unit includes at least one hydraulic pump, a hydraulic tank, a compensation device for hydraulic fluid, a manually operated hydraulic control valve, an electromechanical interface for on-demand coupling and decoupling of at least one battery pack, a mechanical-hydraulic interface for connecting a hydraulic tool, and an electric motor operable by the electrical energy of the battery pack for driving the hydraulic pump. The electric motor is formed by a disc-shaped motor whose axial length extending in parallel to the longitudinal axis of its output shaft is shorter than its outer diameter.

Claims

1. A portable, battery-powered hydraulic power unit for hydraulic rescue tools, in particular for spreading or cutting tools, comprising: at least one hydraulic pump; a hydraulic tank; a compensation device for hydraulic fluid; a manually operated hydraulic control valve; an electromechanical interface for on-demand coupling and decoupling of at least one battery pack; a mechanical-hydraulic interface for connecting a hydraulic tool; and an electric motor operable by the electrical energy of the battery pack for driving the hydraulic pump; wherein the electric motor is formed by a disc-shaped motor whose axial length extending in parallel to the longitudinal axis of its output shaft is shorter than its outer diameter; wherein the disc-shaped motor is designed as an external rotor motor with an internal fixed stator and an external, rotationally movable rotor extending at least partially around the stator; wherein the output shaft is formed or mounted on the rotor; and wherein the output shaft passes through the stator in the axial direction of the output shaft.

2. The hydraulic unit according to claim 1, wherein the disc-shaped motor is designed as a bell rotor motor with a substantially bell-shaped or U-shaped rotor.

3. The hydraulic unit according to claim 1, wherein a plurality of distributed permanent magnets is designed in relation to the circumference of the rotor, which permanent magnets interact with coil windings on the stator, and which coil windings are provided for generating electromagnetic rotating fields.

4. The hydraulic unit according to claim 1, wherein the disc-shaped motor is directly attached on the housing of the hydraulic tank.

5. The hydraulic unit according to claim 4, wherein a first end wall of the disc-shaped motor, which is closest to the output shaft, is firmly screwed to the housing of the hydraulic tank via a plurality of fastening screws.

6. The hydraulic unit according to claim 5, wherein a screw connection between the disc-shaped motor and the housing of the hydraulic tank is provided starting from a second end wall of the disc-shaped motor opposite the first end wall, so that screw heads of the plurality of fastening screws are arranged between the disc-shaped motor and the hydraulic tank on an inside of the first end wall facing an interior of the disc-shaped motor.

7. The hydraulic unit according to claim 5, wherein a second end wall of the disc-shaped motor, which is opposite the first end wall, is a constituent of the rotor, the second end wall having at least two breakthroughs or cutouts enabling the plurality of fastening screws to be inserted starting from the second end wall via an inside of the disc-shaped motor towards the inside of the first end wall.

8. The hydraulic unit according to claim 1, wherein the hydraulic tank is arranged between the disc-shaped motor and the hydraulic pump and a connecting shaft is provided which passes through a cavity or a channel which is free of hydraulic fluid in the hydraulic tank and couples the disc-shaped motor rotatably with the hydraulic pump.

9. The hydraulic unit according to claim 1, wherein the compensation device comprises an elastically resilient or elastically adjustable compensation diaphragm which is disposed within the hydraulic tank and is movable relative to an interior of the hydraulic tank depending on a volume of hydraulic fluid in the hydraulic tank.

10. The hydraulic unit according to claim 1, wherein at least a sub-section of a first end wall of the disc-shaped motor forms a boundary section of the hydraulic tank.

11. A hydraulic rescue tool, in particular a portable spreading or cutting tool, which is suitable for operation by only one rescuer, with a portable, battery-powered hydraulic unit, and a hydraulic tool attached thereto wherein the hydraulic unit is designed according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other objects and features of the invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

(2) In the drawings,

(3) Each shows in a simplified, schematic representation:

(4) FIG. 1 shows an embodiment of a hydraulic rescue tool in plan view.

(5) FIG. 2 shows the hydraulic unit of the rescue tool of FIG. 1 in a perspective view;

(6) FIG. 3 shows the hydraulic unit of FIG. 2 in sub-sectional view;

(7) FIG. 4a-d shows an embodiment of a disc-shaped motor, as installed in the hydraulic unit of FIG. 2;

(8) FIG. 5 shows a simplified half-section of a first embodiment of a fastening between a disc-shaped motor and the hydraulic tank of the hydraulic unit;

(9) FIG. 6 shows a simplified half-section of another embodiment of a fastening between a disc-shaped motor and the hydraulic tank of the hydraulic unit.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(10) Firstly, it should be pointed out that the same parts described in the different embodiments are denoted by the same reference numbers and the same component names and the disclosures made throughout the description can be transposed in terms of meaning to same parts bearing the same reference numbers or same component names. Furthermore, the positions chosen for the purposes of the description, such as top, bottom, side, etc., relate to the drawing specifically being described and can be transposed in terms of meaning to a new position when another position is being described.

(11) FIG. 1 shows in plan view an embodiment of a hydraulic spreading tool, as it is often used to recover people from accident vehicles. Such a tool is also used for other enforced or spreading operations. In addition to the illustrated spreading tool, cutting tools are known to belong to the same generic group of tools. As a superordinate, such tools can be referred to as hydraulic rescue tools 1.

(12) The apparatus designated in its entirety as a rescue tool 1 in FIG. 1 essentially comprises a hydraulic unit 2 and a hydraulically actuated or controllably actuated tool 3 attached thereto in the form of the said spreading device, cutting device, lifting device or the like. According to the example, the mechanical-hydraulic tool 3 is coupled to the hydraulic unit 2 via a mechanical-hydraulic interface 4, as can also be seen in FIG. 2. This coupling is preferably a fixed or permanent coupling, which can only be disengaged with the aid of tools or only by dismantling operations. Alternatively, a tool-free activatable and deactivatable interface is possible, but measures are provided to avoid the loss of hydraulic fluid or to avoid inclusions of air in the hydraulic circuit between the hydraulic tool 3 and the hydraulic unit 2.

(13) An overall length 5 of the rescue tool 1 is made up of the length 6 of the hydraulic unit 2 and the length 7 of the hydraulic tool 3. Hereby, the length 7 of the hydraulic tool 3 is typically greater than the length 6 of the hydraulic aggregate 2. While the length 7 of the hydraulic tool 3 is essentially influenced by its performance or robustness, for example, due to lever transmissions or the underlying lever rules, the length 6 of the hydraulic unit 2 is not necessarily in interdependency with its performance. Accordingly, the handling or ergonomics of the rescue tool 1 can be improved in particular by the shortest possible constructive lengths of the hydraulic unit 2, without causing any loss of performance, in particular with respect to the mechanical pressure or cutting forces of the tool 3. Therefore, the present solution is based on being able to design the hydraulic unit 2 with the shortest possible length 6, without affecting the performance of the rescue tool 1 or without affecting the performance of the hydraulic unit 2.

(14) The spreading tool 3 shown by way of example comprises two spreading arms 8, 9, which are hinged to a base body 10 and can perform opening and closing movement via a hydraulic cylinder, not shown. At least one handle 11, 12 provided for the most ergonomic and secure guiding or holding of the rescue tool 1 by a rescuer is advantageously formed on the base body 10 of the tool 3.

(15) A housing 13 of the hydraulic unit 2, which preferably consists of plastic, may also have at least one handle 14 for the most ergonomic support or handling of the rescue tool 1. The portable and network-independent rescue tool 1, in particular its hydraulic unit 2, has at least one electromechanical interface 15, which is provided for on-demand coupling and decoupling of at least one battery pack 16, as this was exemplified in FIGS. 2, 3. In the properly attached or plugged-in state, as can be seen in FIGS. 2, 3, the at least one battery pack 16 is provided for the electrical power supply of the hydraulic rescue tool 1.

(16) As can be seen above all from a summary of FIGS. 2, 3, the portable, battery-operated hydraulic unit 2 comprises an electric motor 17, which can be driven by the electrical energy of the battery pack 16, for driving a hydraulic pump 18 of the hydraulic unit 2. According to the invention, this electric motor 17 is formed by a disc-shaped motor 19. Such a disc-shaped motor 19 has an axial length 22 extending in parallel to the longitudinal axis 20 of its output shaft 21, which is smaller or shorter than an outer diameter 23 of the disc-shaped motor 19, as shown in FIG. 3 or FIG. 4d. In particular, such disc-shaped motors 19 have a relatively large ratio between outer diameter 23 and axial length 22 compared to conventional electric motors. Typically, this ratio between the outer diameter 23 of the utilized disc-shaped motor 19 and its axial length 22 is larger than 1, in particular greater than 1.5. In accordance with a practicable design, this ratio is approximately 2.

(17) Preferably, the disc-shaped motor 19 is connected directly that is without an intermediate gearbox to the hydraulic pump 18 in a rotationally movable manner. To this end, a drive shaft 24 of the hydraulic pump 18, the drive shaft 24 being, for example, designed as a hollow shaft, is non-rotatably connected to the output shaft 21 of the disc-shaped motor 19. The hydraulic pump 18 serves as a high-pressure pump for hydraulic fluids, in particular for hydraulic oil, and may be formed, for example, by an eccentric pump or the like. A hydraulic tank 25, which is provided for storing or receiving a sufficient amount of hydraulic fluid, and in particular for supplying the hydraulic tools 3 with the working medium, is positioned between the disc-shaped motor 19 and the hydraulic pump 18 in relation to the longitudinal axis of the hydraulic rescue tool 1. In other words, in relation to the longitudinal direction of rescue tool 1, at the opposite ends of hydraulic tank 25, the hydraulic pump 18 is located directly adjacent to the hydraulic tank 25 on one hand and on the other hand the disc-shaped motor 19 is located directly adjacent to the hydraulic tank 25. Preferably, the hydraulic tank 25 defines the central holding or fastening element for the disc-shaped motor 19 on the one hand and for the hydraulic pump 18 that is on the opposite site on the other hand.

(18) In order to enable a position-independent operation of the hydraulic unit 2 or of the rescue tool 1, the hydraulic tank 25 is assigned a compensation device 26 for hydraulic fluid, in particular arranged within the hydraulic tank 25. As is well known, such a compensation device 26 typically includes an elastically resilient or elastically adjustable balancing diaphragm 27 disposed within the hydraulic tank 25 and movable relative to the interior of the hydraulic tank 25 depending on the volume of hydraulic fluid in the hydraulic tank 25. As a result, elastically variable volumes are created within the hydraulic tank 25, which prevent an undesired discharge of hydraulic fluid from vents during the filling and discharge operations of hydraulic fluid with respect to the hydraulic tank 25.

(19) For manually controlled influencing of opening and closing movements or of ejection and retraction movements of the tool 3, at least one manually operated hydraulic control valve 28—FIG. 3—is provided on the hydraulic unit 2. This hydraulic control valve 28 can be transferred by at least one actuating element 29, for example, a rocker switch, to the respective valve positions, in particular to alternating flow and blocking positions. Typically, the at least one actuating element 29 changes piston or shutter slide positions in the control valve 28. The hydraulic pressure which can be generated via the hydraulic pump 18 can thereby be supplied in a controlled manner via the control valve 28 and via fluid passages 30 of the hydraulic unit 2 to a hydraulic cylinder of the tool 3 (not shown) or can be returned therefrom.

(20) FIGS. 4a to 4d illustrate an advantageous embodiment of a disc-shaped motor 19 for driving the hydraulic pump 18 of the hydraulic unit 2.

(21) This disc-shaped motor 19 is designed as a so-called external rotor motor. That is, it has an at least partially internal, fixed stator 31, which is at least partially surrounded by an external, rotationally movable rotor 32, as best seen in FIG. 4d. The output shaft 21 of the disc-shaped motor 19 which is formed or mounted on the rotationally movable rotor 32 passes through its stator 31 with respect to the axial direction or longitudinal axis 20 of its output shaft 21. It is appropriate in this context if the disc-shaped motor 19 is designed as a so-called bell rotor motor which in cross-section has a substantially bell-shaped or substantially U-shaped rotor 32. The substantially hollow-cylindrical shell portion of the rotor 32 surrounds the cylindrical shell surface or outer contour of the stator 31, as best seen in FIGS. 4a-d.

(22) According to an advantageous embodiment, the disc-shaped motor 19 has a plurality of distributed permanent magnets 33 with respect to the circumference or with respect to the circumferential direction of the rotor 32. This plurality of permanent magnets 33 on the rotor 32 are in this case interacting with excitation or coil windings (not shown) on the stator 31. The coil windings (not shown), which are associated with the pole shoes of the stator 31 shown in FIGS. 4a, 4b and 4c, serve to generate electromagnetic rotating fields, thereby determining the respective rotational speed and direction of rotation of the disk-shaped motor 19. As is known per se, these rotary fields or the corresponding three-phase currents are generated by an electronic commutation circuit 34 shown schematically in FIG. 3. The disc-shaped motor 19 is thus designed preferably brushless or without sliding contacts and is therefore of very low maintenance.

(23) As best seen in FIG. 3 it can be provided according to an appropriate embodiment that the disc-shaped motor 19 is attached to the preferably metallic housing 35 of the hydraulic tank 25. According to a typical embodiment, a separate holding plate 36 can be provided thereby, which is screwed to the disc-shaped motor 19 on the one hand and on the other hand is connected to the housing 35 of the hydraulic tank 25, in particular positively-locked and/or screwed, as can be best seen in FIG. 3. The holding plate 36 acts as a separate adapter or coupling element between the disc-shaped motor 19 and the housing 35 of the hydraulic tank 25. According to a preferred development or improvement, however, it is provided that the disc-shaped motor 19 is directly attached to the housing of the hydraulic tank 25, that is it is mounted without an intermediate adapter or holding plate 36, as can be seen in FIGS. 5, 6. This results in further weight savings and advantages in terms of minimizing the required number of components.

(24) In particular, as best seen in FIGS. 5, 6, it can be provided that the first end wall 37 of the disc-shaped motor 19, which is closest to the output shaft 21, can be firmly screwed to the housing 35 of the hydraulic tank 25. This first end wall 37 of the disc-shaped motor 19 is a constituent of the stator 31 and is thus penetrated by the output shaft 21 of the disc-shaped motor 19, as can be seen schematically in FIGS. 5 and 6. Preferably, several fastening screws 38 distributed over the circumference or around the output shaft 21 are provided, which serve to connect the disc-shaped motor 19 or its stator 31 with the hydraulic tank 25. It is appropriate if the screw connection between the disc-shaped motor 19 and the housing 35 of the hydraulic tank 25 is mounted or is provided starting from the second end wall 39 of the disc-shaped motor 19 opposite the first end wall 37. In this context, screw heads 40 of the fastening screws 38 for the disc-shaped motor 19 are then arranged on the inside 41 of the first end wall 37 facing the interior or the inside of the disc-shaped motor 19. This makes it possible to avoid the need for additional adapter or retaining plates to connect the disc-shaped motor 19 to the hydraulic tank 25.

(25) In order to enable this screw connection of the disc-shaped motor 19 through its interior, without having to disassemble the disc-shaped motor 19 into individual parts, it is provided that the second end wall 39 of the disc-shaped motor 19 opposite the first end wall 37, which second end wall 39 is a constituent of the rotor 32, has at least two breakthroughs 41, 42, in particular at least two diametrically opposite breakthroughs 41, 42 or corresponding cutouts, as can also be seen from FIG. 4b. These at least two breakthroughs 41, 42 or corresponding cutouts in the second end wall 39 of the disc-shaped motor 19 are provided for insertion of the fastening screws 38, starting from the second end wall 39 in the direction parallel to the output shaft 21. In particular, the fastening screws 38 can be inserted into the interior of the disc-shaped motor 19 via these breakthroughs 41, 42 and ultimately abut on the inside 41 of the first end wall 37 in a load-transmitting manner, as can be seen in FIGS. 4d, 5 and 6.

(26) As best seen in FIG. 5, the first end wall 37, which functions as a constituent of the stator 31, can also be designed as a boundary wall or as a sub-section of the hydraulic tank 25.

(27) On the other hand, according to FIG. 6, a split design of the first end wall 37 is provided, which forms a positive-locking motor flange in order to be able to couple this disc-shaped motor 19 with the hydraulic tank 25 in a centered manner.

(28) As further best seen in FIGS. 5, 6, it can also be appropriate if at least one sub-section or individual zones of the first end wall 37 of the disc-shaped motor 19 forms a boundary section of the hydraulic tank 25. In particular, the first end wall 37 of the disc-shaped motor 19 can thereby define at least one sub-section of the cover or another boundary wall of the housing 35 of the hydraulic tank 25. In context of the compensation device 26 or the corresponding compensation diaphragm 27—FIG. 3—it is not absolutely necessary that the transition between the disc-shaped motor 19 or between the first end wall 37 and the housing 35 of the hydraulic tank 25 is made liquid-tight. The tightness with respect to the hydraulic fluid kept in stock is ensured in a simple manner by the compensation membrane 27, as shown by way of example in FIG. 3.

(29) The embodiments show possible design variants and it should be pointed out at this stage that the invention is not limited to the specifically illustrated embodiments thereof, and instead the individual variants may be used in different combinations with one another and these possible variants lie within the reach of the person skilled in this technical field given the disclosed technical teaching.

(30) The scope of protection is determined by the claims. However, the description and drawings shall be used for the interpretation of the claims. Individual features or combinations of features from the various embodiments shown and described may be inventive solutions in their own right. The task on which the independent inventive solutions are based can be found in the description

(31) For the sake of order, it should finally be pointed out that, for a better understanding of the structure, elements are illustrated to a certain extent out of scale and/or on an enlarged scale and/or on a reduced scale.

(32) Although only a few embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.

REFERENCE LIST

(33) 1 Rescue Tool 2 hydraulic unit 3 tool 4 mechanical-hydraulic interface 5 Overall Length 6 Length 7 Length 8 Spreading Arm 9 Spreading Arm 10 Base 11 Handle 12 Handle 13 Housing 14 Handle 15 Electromechanical Interface 16 Battery Pack 17 Electric Motor 18 Hydraulic Pump 19 Disc-shaped motor 20 Longitudinal Axis 21 Output Shaft 22 Axial Length 23 Outer Diameter 24 Drive Shaft 25 Hydraulic Tank 26 Compensation Device 27 Compensation Membrane 28 Control Valve 29 Actuating Element 30 Fluid Channel 31 Stator 32 Rotor 33 Permanent Magnet 34 Commutation Circuit 35 Housing 36 Holding Plate 37 First End Wall 38 Fastening Screw 39 Second End Wall 40 Screw Head 41 Inside 42 Breakthrough 43 Breakthrough