Rotary actuator with position feedback device and process valve module

Abstract

A fluid-actuated rotary actuator includes a housing having a tubular body extending in an axial direction, in which is provided a drive piston assembly for driving a rotatably mounted output shaft, which extends perpendicular to the axial direction through the tubular body and the axial end of which is routed out of the tubular body at an upper wall section of the tubular body, further including a magnet assembly associated with the axial end of the output shaft and receiving a rotary movement of the output shaft, and further including a position feedback device configured to detect the magnetic field generated by the magnet assembly and to provide, in accordance with the detected magnetic field, a position signal corresponding to a position of the output shaft, wherein the position feedback device is located in a receptacle chamber formed in the upper wall section of the tubular body.

Claims

1. A fluid-actuated rotary actuator comprising a housing having a tubular body extending in an axial direction, in which is provided a drive piston assembly for driving a rotatably mounted output shaft, which extends perpendicular to the axial direction through the tubular body and the axial end of which is routed out of the tubular body at an upper wall section of the tubular body, further comprising a magnet assembly associated with the axial end of the output shaft and receiving a rotary movement of the output shaft, and further comprising a position feedback device configured to detect the magnetic field generated by the magnet assembly and to provide, in accordance with the detected magnetic field, a position signal corresponding to a position of the output shaft, wherein the position feedback device is located in a receptacle chamber formed in the upper wall section of the tubular body, the receptacle chamber having a first section open at the upper wall section and a second section extending from the first section, the first section corresponding to a head section of the position feedback device and the second section corresponding to a shaft section of the position feedback device.

2. The fluid-actuated rotary actuator according to claim 1, wherein the receptacle chamber is open towards an end face and/or a longitudinal side of the tubular body.

3. The fluid-actuated rotary actuator according to claim 1, wherein the receptacle chamber is open towards an end face of the tubular body, and wherein a housing cover is placed on the end face, the housing cover having a recess through which a connector and/or a cable is/are routed to the position feedback device.

4. The fluid-actuated rotary actuator according to claim 1, wherein a housing cover, which covers the receptacle chamber towards the end face and holds the position feedback device in the receptacle chamber, is placed on the end face.

5. The fluid-actuated rotary actuator according to claim 1, wherein the position feedback device comprises an oblong shaft section, which comprises a magnetic field sensor element, and a head section, the cross-section of the head section being wider and/or higher than the cross-section of the shaft section.

6. The fluid-actuated rotary actuator according to claim 1, further comprising a position indicator, which is placed on the axial end of the output shaft and in which the magnet assembly is located.

7. The fluid-actuated rotary actuator according to claim 6, wherein the position indicator has an indicating element for the visual indication of a position of the output shaft.

8. The fluid-actuated rotary actuator according to claim 1 further comprising a position indicator, which is fitted to the axial end of the output shaft and in which the magnet assembly is located, wherein the position indicator is removably mounted on the output shaft and the rotary actuator is configured to adopt a predetermined operating state, if the position feedback device detects a removal and/or replacement of the position indicator.

9. The fluid-actuated rotary actuator according to claim 1, wherein the magnet assembly comprises a permanent magnet which is designed to be an annular segment.

10. The fluid-actuated rotary actuator according to claim 1, wherein the magnet assembly comprises one or more magnet bars.

11. The fluid-actuated rotary actuator according to claim 1, wherein the position feedback device comprises a Hall sensor.

12. The fluid-actuated rotary actuator according to claim 1, wherein the receptacle chamber is open towards an end face at an axial end of the tubular body, and wherein a functional module assembly is placed on the end face, and wherein a receptacle chamber into which the position feedback device projects is formed in the functional module assembly.

13. A process valve unit, comprising a fluid-actuated rotary actuator according to claim 1 and a valve fitting with a spindle and a valve member, wherein the fluid-actuated rotary actuator is mounted on the valve fitting and the valve member is mechanically coupled to the output shaft of the fluid-actuated rotary actuator via the spindle, so that the position of the valve member is determined by the position of the output shaft.

14. A fluid-actuated rotary actuator comprising a housing having a tubular body extending in an axial direction, in which is provided a drive piston assembly for driving a rotatably mounted output shaft, which extends perpendicular to the axial direction through the tubular body and the axial end of which is routed out of the tubular body at an upper wall section of the tubular body, further comprising a magnet assembly associated with the axial end of the output shaft and receiving a rotary movement of the output shaft, and further comprising a position feedback device configured to detect the magnetic field generated by the magnet assembly and to provide, in accordance with the detected magnetic field, a position signal corresponding to a position of the output shaft, wherein the position feedback device is located in a receptacle chamber formed in the upper wall section of the tubular body, and wherein the position feedback device comprises an oblong shaft section, which comprises a magnetic field sensor element, and a head section, the cross-section of the head section being wider and/or higher than the cross-section of the shaft section, and wherein the receptacle chamber has a first section, which is open towards the end face of the tubular body and accommodates the head section, and a second section, which opens out at a rear wall of the first section and accommodates the shaft section.

15. The fluid-actuated rotary actuator according to claim 14, wherein the cross-section of the head section is wider and/or higher than the cross-section of the second section, so that the head section abuts the rear wall of the first section.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Exemplary embodiments of the invention are shown in the drawing, of which:

(2) FIG. 1 is a perspective view of a rotary actuator according to a first embodiment,

(3) FIG. 2 is a perspective view of the rotary actuator according to the first embodiment,

(4) FIG. 3 is a perspective sectional view of the rotary actuator according to the first embodiment,

(5) FIG. 4 is a perspective view of a tubular body of the rotary actuator according to the first embodiment,

(6) FIG. 5 is an exploded view of a tubular body of the rotary actuator according to the first embodiment,

(7) FIG. 6 is a perspective view of the rotary actuator according to a second embodiment,

(8) FIG. 7 is a perspective sectional view of a tubular body of the rotary actuator according to the second embodiment,

(9) FIG. 8 is a perspective sectional view of a position indicator of a rotary actuator according to the first and second embodiments,

(10) FIG. 9 is a bottom view of a position indicator of a rotary actuator according to the first and second embodiments,

(11) FIG. 10 is a perspective view of a process valve unit according to a third embodiment, and

(12) FIG. 11 is a perspective view of a process valve unit according to a fourth embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(13) In the following description of the figures, identical designations are used for functionally identical components of the illustrated embodiments, and a repeated description of functionally identical components is omitted.

(14) FIGS. 1 to 5 are perspective views of a rotary actuator 40 according to a first embodiment. FIG. 1 shows the rotary actuator 40 with a position indicator 23 mounted at an axial end of an output shaft 6, while FIG. 2 shows the rotary actuator 40 without the position indicator 23.

(15) The rotary actuator 40 of the first embodiment is suitable for mounting on a valve fitting 24 for the actuation of a valve member of the valve fitting 24, thereby controlling a fluid flow.

(16) The rotary actuator 40 of the first embodiment is fluid-actuated and comprises a housing 1 with a tubular body 44 extending in an axial direction 26. In the tubular body 44 there is provided a drive piston assembly 19 for driving a rotatably mounted output shaft 6, which extends through the tubular body 44 perpendicular to the axial direction 26 and the axial end of which emerges from the tubular body 44 in an upper wall section 35 of the tubular body 44.

(17) The fluid-actuated rotary actuator further comprises a magnet assembly 34 located at its axial end and receiving a rotary movement of the output shaft 6. In the illustrated embodiment, the magnet assembly 34 is mounted in a position indicator 23, which is likewise mounted to the axial end of the output shaft 6. The magnet assembly 34 is therefore non-rotatably connected to the output shaft 6 by means of the position indicator 23.

(18) The fluid-actuated rotary actuator 40 further comprises a position feedback device 36, which is designed to detect the magnetic field generated by the magnet assembly 34 and to provide, in accordance of the detected magnetic field, a position signal corresponding to a position of the output shaft 6. In the illustrated embodiment, the position feedback device 36 has a connector 43, via which the position signal can preferably be output.

(19) The position feedback device 36 is located in or inserted into a receptacle chamber 38 formed in the upper wall section 35 of the tubular body 44. The receptacle chamber 38 can be seen in the exploded view of the rotary actuator 40 shown in FIG. 5, for example.

(20) The location of the position feedback device 36 in the receptacle chamber 38 in the wall section 35 results in a very compact design of the rotary actuator 40. Preferably, the installation space of the rotary actuator 40 is hardly, if at all, increased by the position feedback device 36.

(21) As FIG. 5 shows by way of example, the receptacle chamber 38 is open towards the end face 3 of the tubular body 44. As a result, the position feedback device 36 can be inserted into the receptacle chamber 38 in a particularly simple way. As an alternative to the illustrated configuration, the receptacle chamber 38 can be open towards a side wall 46 of the tubular body 44.

(22) As FIGS. 3 and 5 show, the receptacle chamber 38 is oblong in design and oriented towards the axial end of the output shaft 6. In the illustrated embodiment, in which the receptacle chamber 38 is open towards the end face 3, the receptacle chamber 38 extends in the axial direction 26 of the tubular body.

(23) In the embodiment shown in FIG. 5, the receptacle chamber opens out around the corner both at the upper wall section 35 and at the end face 3. This makes the installation of the position feedback device 36 particularly simple, and the connector 43 can emerge from the receptacle chamber 38 in an upward direction, i.e. in a direction parallel to the output shaft. FIG. 4 shows this design of the receptacle chamber 38 from another perspective.

(24) A housing cover 4, which covers the receptacle chamber 38 towards the end face 3 and thus holds the position feedback device 36 in the receptacle chamber 38, is fitted to the end face 3. As an alternative or in addition thereto, the position feedback device 36 can be secured in the receptacle chamber 38 or on the tubular body 44 by its own fastening means.

(25) As can be seen in FIG. 3, the position feedback device 36 has an oblong shaft section 36B and a head section 36A. The cross-section of the head section 36A is wider and higher than the cross-section of the shaft section 36B. A magnetic field sensor element for measuring a magnetic field strength of the magnetic field generated by the magnet assembly 34 is preferably arranged at the shaft section 36B. The head section 36A preferably comprises evaluation electronics for processing a magnetic field measurement value detected by the magnetic field sensor element and for providing or outputting a position signal based on the magnetic field measurement value.

(26) In correspondence to the sections of the position feedback device 36, the receptacle chamber 38 has an oblong second section 38B and a first section 38A which is wider and higher than the second section 38B. The first section 38A is oriented towards the end face 3 of the tubular body 44 and the second section 38B is located between the first section 38A and the axial end of the output shaft 6 and extends towards the axial end of the output shaft 6. The first section 38A accommodates the head section 36A and the second section 38B accommodated the shaft section 36B.

(27) As FIG. 5 further shows, the second section 38B opens out at a rear wall 47 of the first section 38A. The remaining section of the rear wall 47 forms a contact surface for the head section 36A. The head section 36A can therefore be clamped between the housing cover 4 and the rear wall 47.

(28) As FIG. 1 shows, a cylindrical or disc-shaped position indicator 23 is placed on the axial end of the output shaft 6. The magnet assembly 34 designed as an annular segment is located in the position indicator 23 concentric with the axial direction of the output shaft 6. The magnet assembly 34 is located at a bottom section of the position indicator 23 and thus close to the upper wall section 35 and to the position feedback device 36 located therein.

(29) The position indicator 23 further comprises a bracket-shaped indicating element 39, which extends transversely across the surface of the position indicator 23. As the position indicator 23 is non-rotatably connected to the output shaft 6, the position of the output shaft 6 can be indicated visually by means of the indicating element 39.

(30) The position indicator 23 is preferably removable from the output shaft 6. A removal or replacement of the position indicator 23 at the output shaft 6 can be detected by means of the position feedback device 36 and interpreted as a user input by this or by another control unit associated with the rotary actuator. The rotary actuator 40 is in particular designed to adopt, if it detects that the position indicator 23 is fitted to the output shaft 6, a calibration state in which the magnetic field measurement values corresponding to the end positions of the output shaft are determined and stored.

(31) FIG. 3 shows the drive piston assembly 19 located in a piston space 11 and consisting of two drive pistons. Each of the two drive pistons comprises a toothed rack not shown in the drawing, which is oriented in the axial direction and meshes with an output pinion mounted on the output shaft 6 for converting a linear movement of the drive pistons into a rotary movement of the output shaft 6. The toothed racks are in particular located on opposite sides of the output shaft 6, so that opposing linear movements of the drive pistons are converted into corresponding rotary movements of the output shaft 6. In this manner, the output shaft 6 turns in a first direction of rotation if the drive pistons approach one another and in a second direction of rotation if the drive pistons move away from one another. As an alternative to the toothed rack and output pinion arrangement, a tumbler yoke (Scotch yoke) can be used to convert the linear movement of the drive piston assembly 19 into a rotary movement of the output shaft 6.

(32) FIGS. 6 and 7 show a fluid-actuated rotary actuator 50 according to a second embodiment of the invention. The second embodiment substantially corresponds to the first embodiment, but in particular differs therefrom insofar as in the second embodiment the connector or a connecting cable 42 of the position feedback device 36 emerges from the receptacle chamber 38 through an opening in the end face 3. For this purpose, the housing cover is provided with a recess 41, which exposes the opening in the end face 3 towards the receptacle chamber 38.

(33) FIGS. 8 and 9 show the position indicator 23. As described above, the position indicator 23 comprises a bracket-shaped indicating element 39 and the magnet assembly 34 designed as an annular segment. The magnetisation of the magnet assembly 34 preferably varies along the circumference of the annular segment.

(34) FIG. 10 shows a process valve unit 60 according to a third embodiment. In the illustrated embodiment, the process valve unit 60 comprises a rotary actuator 40 according to the first embodiment. Alternatively, the process valve unit 60 can comprise a rotary actuator 50 according to the second embodiment.

(35) The rotary actuator 40 sits on a valve fitting 24 comprising a spindle and a valve member. The output shaft 6 is non-rotatably connected to the valve member of the valve fitting 24 via the spindle. The angular position of the valve member is accordingly determined by the angular position of the output shaft 6. In this manner, it is possible to derive the position of the valve member from the position signal provided by the position feedback device 36, which corresponds to the position of the output shaft 6.

(36) FIG. 11 shows a process valve unit 70 according to a fourth embodiment. In the illustrated embodiment, the process valve unit 70 comprises a rotary actuator 50 according to the second embodiment. Alternatively, the process valve unit 70 can comprise a rotary actuator 40 according to the first embodiment.

(37) The fourth embodiment substantially corresponds to the third embodiment, but in particular differs therefrom insofar as a functional module assembly 7 is located between the end face 3 of the tubular body 44 and the housing cover 4. In addition, the housing cover 4 has no recess in this case and is secured to the functional module assembly 7 by means of the mounting screws 9.

(38) The receptacle chamber 38 is here open towards the functional module assembly 7, and the position feedback device 36 extends into the functional module assembly 7. For this purpose, a receptacle chamber is preferably provided in an upper wall section of the functional module assembly 7.

(39) The functional module assembly 7 lengthens the installation space of the rotary actuator 50 in the axial direction. The valve fitting 40, on which the rotary actuator 50 is placed, has two pipe connectors 31A and 31B, which are arranged coaxially along a pipework direction 32. The pipework direction 32 runs parallel to the axial direction 26. This results in a process valve unit of a particularly compact design.

(40) In operation, the process valve unit 70 is supplied with compressed air from a line connected to an external pressure port of the rotary actuator 50. The compressed air is looped through a control valve assembly, which is provided in the functional module assembly 7, for example, and which is in particular designed as a 5/3-way valve. The outlets of the control valve assembly are connected to chambers of the piston space 11 via suitable working passages. In accordance with a control command, the outlets of the control valve assembly are switched to a pressure or venting state in order to hold the drive pistons of the drive piston assembly 19 in their current position or in a defined position or to move them towards or away from one another. The control command is, for example, output to the control valve assembly by an electronics assembly which is preferably located in the functional module assembly 7. As an alternative, the control command can be output by the position feedback device 36. The movement of the drive pistons of the drive piston assembly 19 turns the output shaft 6, whereby the spindle of the valve fitting 24 and finally the valve member of the valve fitting 24 are turned or actuated.

(41) The position indicator 23, which is non-rotatably connected to the output shaft 6, receives the rotary movement of the output shaft 6, so that the position of the magnet assembly 34 relative to the position feedback device 36 is changed. The magnetic field detected by the position feedback device changes accordingly. On the basis of the detected magnetic field, the position feedback device 36 provides a position signal corresponding to the position of the output shaft 6 and/or of the valve member.