Drive device for a movable tappet

Abstract

The disclosure relates to a drive device (V) for producing a translational motion of a movable tappet (8) by means of an electromagnetic rotating machine. The drive device includes an inner rotor (4) and an outer coaxial stator (5) and has a movement-thread pair integrated coaxially in the stator. The movement-thread pair comprising a lead screw (6), which is coupled to the rotor for conjoint rotation, and a threaded nut (7), which is linearly guided in a stator sleeve (2) in a rotationally fixed manner and is rigidly coupled to the tappet. The rotor is guided for rotation around the stator and a torque being transferred from the rotor to the lead screw by means of a thin-walled flange (10). A rotational fixation (11) of the threaded nut in the cavity of the stator sleeve is provided as a result of interlocking joining of the two.

Claims

1. A drive device (1′) for generating a translational movement of a movable tappet (8) by means of an electromagnetic rotating machine, wherein the drive device (1′) is formed as an outer rotor type drive device, comprising: a rotor (4); and a stator (5) arranged coaxially to the rotor (4), the stator having at least one movement-thread pair integrated coaxially therein, comprising a lead screw (6), which is coupled in a rotationally fixed manner to the rotor (4), and a threaded nut (7) guided linearly in a stator sleeve (2) by anti-twist locking, the nut being rigidly coupled to the tappet (8), spaced bearings seated between an outer surface of said stator sleeve (2) and an inner surface of the rotor (4) wherein the rotor (4) is guided in a rotational movement around an outer surface of the stator (5), wherein the transfer of a torque from the rotor (4) to the lead screw (6) takes place by means of a flange (10) having a wall thickness T<0.1 D, wherein D equals a diameter of the flange (10), and wherein an anti-twist lock (11) of the threaded nut (7) is provided in the recess of the stator sleeve (2) by a form-fitting interlocking of guide tabs (7′) provided on the threaded nut (7) with guide grooves (2′) provided in the stator sleeve (2), the guide tabs (7′) being formed on a head of the threaded nut (7) which extends over an end of the tappet (8), the threaded nut (7) having a usable travel path Vw which extends from an inner surface I.sub.F of the flange (10) to at least an outer surface A.sub.G of the drive device (1′).

2. The drive device (1′) according to claim 1 further characterized in that the electromagnetic rotating machine of the drive device (1′) is actuated without a sensor.

3. The drive device (1′) according to claim 1, further characterized in that the drive device (1′) is selected from the group of motor types consisting of: synchronous motors including transverse flux motors and reluctance motors and stepper motors; asynchronous motors; electronics-commutated DC motors; and brush-commutated DC motors.

4. The drive device (1′) according to claim 3 further characterized in that the electromagnetic rotating machine of the drive device (1′) is actuated without a sensor.

5. The drive device (1′) according to claim 3 further characterized in that in a housing flange (1) is arranged an electrical connection (9) for a power supply and/or signal transmission for the magnetic and/or optical contact or contact-free detection of the linear movement of the tappet (8) and/or the rotational movement of the rotor (4).

6. The drive device (1′) according to claim 5, further characterized in that a sensor system (13) is provided for detecting the rotational movement of the rotor (4).

7. The drive device (1′) according to claim 1 further characterized in that in a housing flange (1) is arranged an electrical connection (9) for a power supply and/or signal transmission for the magnetic and/or optical contact or contact-free detection of the linear movement of the tappet (8) and/or the rotational movement of the rotor (4).

8. The drive device (1′) according to claim 7 further characterized in that the electromagnetic rotating machine of the drive device (1′) is actuated without a sensor.

9. The drive device (1′) according to claim 7, further characterized in that a sensor system (13) is provided for detecting the rotational movement of the rotor (4).

10. The drive device (1′) according to claim 9 further characterized in that the electromagnetic rotating machine of the drive device (1′) is actuated without a sensor.

Description

(1) The invention will be explained in the following based on figures, wherein the invention is not limited thereto:

(2) Herein:

(3) FIG. 1 shows schematically a drive device 1′ for generating a translational movement of a movable tappet 8 by means of an electromagnetic rotating machine;

(4) FIG. 2 shows schematically a recess 14 inside the drive device 1′ from FIG. 1; and

(5) FIG. 3 shows schematically an excerpt from a sectional view A-A of the drive device 1′ from FIG. 1 in the region of the threaded nut 7.

(6) FIG. 1 shows schematically a drive device 1′ for generating a translational movement of a movable tappet 8 by means of an electromagnetic rotating machine.

(7) The drive device 1′ can comprise, for example, the following components: a housing flange 1 with a stator tube or a stator sleeve 2, a covering hood 3, a rotor 4, a stator 5 or a laminated stator core 5, on which are disposed windings 12, which are connected to a sensor system 13, a lead screw 6 with a threaded nut 7 and a tappet 8, as well as a connection 9 for a control and power electronics.

(8) The stator 5 is arranged coaxially to the rotor 4 and comprises at least one movement-thread pair 6. 7 integrated coaxially therein, comprising a lead screw 6, which is coupled in a rotationally fixed manner to the rotor 4, and a threaded nut 7, which is guided linearly by an anti-twist locking in the stator sleeve 2 and which is rigidly coupled to the preferably tube-shaped tappet 8, wherein the rotor 4 is guided in rotational movement around the stator 5, for example outside the stator 5, and thus, on the one hand, offers a large interaction surface facing the stator 5 and thus a cohesive large driving force can be generated.

(9) On the other hand, this arrangement makes possible a recess 14 for the internal transfer mechanism 6, 7, 8, wherein the transfer of a torque from the rotor 4 to the lead screw 6 is produced by means of a thin-walled flange 10, which takes up only a minimum installation length in the axial direction.

(10) The usable travel path V.sub.W of the threaded nut 7 with the tappet 8 is maximized thereby, in such a way that it extends through at least the total length of the drive device 1′ with the exception of the flange 10, although shorter designs may also be considered and these are completely exploitable for a usable travel path of the tappet 8.

(11) Also, an anti-twist lock 11 of the threaded nut 7 is provided in the guide groove 2′ of the stator tube 2 or the stator sleeve 2 by way of a form-fitting interlocking of the stator tube 2 with the threaded nut 7. In this way, the cross section of the tappet 8 can be designed as round, wherewith it is ensured that an optimal sealing of the drive device 1′ against external influences is present.

(12) In this embodiment of the drive device 1′, the rotor and the stator are joined to an electrical machine in such a way that the latter is designed as an outer rotor, wherein the drive device 1′ can be arranged in one of the following motor types: synchronous motors including transverse flux motors and reluctance motors and stepper motors; asynchronous motors; electronics-commutated DC motors; or brush-commutated DC motors.

(13) In the housing flange 1 is found an electrical connection 9 for a measurement system and/or a power supply and/or a signal transmission for the magnetic and/or optical contact or contact-free detection of the linear movement of the tappet 8 and/or the rotational movement of the rotor 4.

(14) The electromagnetic rotating machine can be actuated without a sensor with the drive device 1′ according to the invention.

(15) FIG. 2 shows schematically a recess 14 inside the drive device 1′ from FIG. 1.

(16) FIG. 3 shows schematically an excerpt from a sectional view A-A of the drive device 1′ from FIG. 1 in the region of the threaded nut 7. The lead screw 6 with the threaded nut 7 having guide tabs 7′ that engage in guide grooves 2′ of the stator tube 2 can be recognized.

LIST OF REFERENCE CHARACTERS

(17) 1′ Drive device 1 Housing flange 2 Stator tube, 2′ Guide groove of the stator tube 2 3 Covering hood 4 Rotor 5 Stator 6 Lead screw 7 Threaded nut, 7′ Guide tabs of the threaded nut 7 8 Tappet 9 Connection for electronics 10 Flange 11 Anti-twist lock 12 Winding 13 Sensor system 14 Recess V.sub.W Travel path X X-Axis I.sub.F Inner surface of the flange 10 A.sub.G Outer surface of the housing flange 1