JP6643172B2 - Motor torque detector - Google Patents

Description

  The present invention relates to a torque detecting device for a motor in which a helical gear or a worm gear for transmitting torque is attached to a motor shaft.

  As this type of torque detecting device, a device disclosed in Patent Document 1 is known.

  In the torque detecting device of this patent document 1, two flanges are provided at a part of the motor shaft where the motor shaft penetrates the frame and protrudes to the outside, and is located at a distance in the axial direction. On the other hand, on the frame side, when the rotation of the motor rotates in the positive or negative direction and the motor shaft moves toward one or the other in the axial direction, there is provided an operating part which comes into contact with one or the other of the two flanges to operate. There are two switches provided.

  Thus, if the motor torque fluctuates from the normal state in accordance with the load while the motor is rotating forward or negatively, the axis of the transmission force of the helical gear attached to the motor shaft based on the torque. Due to the directional component force, the motor shaft moves in the positive or negative direction.For example, when the torque in the positive rotation direction increases to a predetermined value or more, the motor shaft moves in the positive direction and one flange operates one switch, When the negative rotation direction torque increases by a predetermined value or more, the motor shaft moves in the negative direction and the other flange activates the other switch. By doing so, it is possible to detect that the torque fluctuates beyond a predetermined value by operating the two switches corresponding to the positive and negative rotation directions of the motor.

Patent No. 5609342

  However, in the torque detection device of Patent Document 1, the two flanges rotate with the motor shaft because they are mounted on the rotating motor shaft, while the switch is mounted on the frame side. When in the immobile position, and when the actuating part of the switch abuts against the flange, the actuating part creates friction with the flange rotating relative to the actuating part, resulting in wear. Becomes If the operating portion is turned on and off a large number of times, wear is increased, and the life of the switch itself is shortened and reliability is disadvantageously reduced. In addition, since the operation of the operating portion is performed by the dynamic contact with the flange, the dynamic contact also causes a problem of reliability in the operation of the switch.

  In view of such circumstances, an object of the present invention is to provide a motor torque detecting device that can extend the life of a switch member and improve reliability without causing friction due to contact under relative movement.

  In the motor torque detecting device according to the present invention, a helical gear or a worm gear for transmitting torque is attached to the motor shaft.

In such a motor torque detection device, in the present invention, a motor shaft supported rotatably and axially movable by a bearing having an inner and outer ring,
A motor frame that supports an outer ring on the non-rotating side of the bearing has a slide member slidably supported in the axial direction of the motor shaft, and a switch member attached to a stationary portion of the motor, and the switch member is turned on and off. And an engaging portion for engaging the slide member with the operating portion to turn the operating portion on and off with the sliding movement of the slide member, wherein the switch member is turned on and off when the switch member is turned on and off. It has an output terminal for emitting a corresponding signal.

  According to the present invention configured as described above, the switch member and the slide member for operating the switch member are in the non-rotation state, and the two members do not move relative to each other in the rotation direction, so that friction and eventually wear occur between the two members. There is no.

  In the present invention, the switch member is formed as one switch member, and the engagement portion of the slide member has a first engagement portion that turns off the operation portion of the switch member and the first engagement portion in the movement direction of the slide member. A second engaging portion located on both sides of the joint portion to bring the operating portion into an ON state, and when the motor is rotating forward or negatively, the operating portion of the switch member is in a normal load of the motor. Engage with the first engagement portion, output a signal corresponding to the off state at the output terminal of the switch member, when the positive and negative movement of the motor shaft exceeds a predetermined amount or more due to an increase in load, the switch member The actuating portion is disengaged from the first engaging portion and engages with the positive or negative second engaging portion to output a positive or negative signal corresponding to the ON state at the output terminal of the switch member. Can be

  With this configuration, the switch member is turned off as a normal load even when the motor shaft moves positive or negative within a predetermined amount under a torque fluctuation in an allowable range, and the switch is turned on only when the predetermined amount or more. The member is turned on. Further, under such a configuration, even if the motor rotates in either positive or negative direction, one switch member can perform either positive or negative switch operation.

  In the present invention, it is preferable that the slide member has an adjusting member capable of adjusting the predetermined amount.

  By the adjustment by the adjusting member, it is possible to appropriately change and set the predetermined amount range for the movement in which the switch maintains the off state even when the torque due to the load fluctuates.

  As described above, the present invention makes it possible to rotate and axially move a motor shaft on which a helical gear or worm gear for transmitting torque is mounted when the motor is rotating forward or negatively. When the torque fluctuates according to the load of the motor supported by the bearing, the torque is detected using the fact that the motor shaft moves due to the axial component of the transmission force of the helical gear or the worm gear. In the apparatus, a slide member supported movably in the axial direction by a motor frame, and a switch member attached to an immobile portion of the motor, wherein the slide member and the switch member that do not rotate, the axis of the motor shaft, Since the torque detection is performed based on the switch operation by the directional movement, any friction and eventually wear occur in the operating portion of the switch member. DOO without, prolonging the life of the switch member and it is possible to improve the reliability of the switch actuation.

FIG. 1 is a schematic configuration diagram of a motor device including a motor torque detection device as one embodiment of the present invention. It is sectional drawing which expands and shows the part of the torque detection apparatus in the apparatus of FIG. FIG. 3 is a cross-sectional view illustrating a state where the slide member has moved in a forward direction in the apparatus in FIG. 2. FIG. 3 is a cross-sectional view illustrating a state where the slide member has moved in a negative direction in the apparatus in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows a motor device provided with the torque detecting device of the present embodiment. The upper half of the figure is a front view, and the lower half is a cross-sectional view taken along a plane including the axis of the motor shaft.

  In a motor device (hereinafter, referred to as “motor”) 1, a rotor 12 is attached to a motor shaft 11 having an axis X, and the motor shaft 11 is provided with rolling bearings (hereinafter, “bearings”) at two positions separated in an axis X direction. 13) and 14 so as to be rotatable. One bearing 13 located on the right side and the other bearing 14 located on the left side have an inner ring 13A; 14A, a ball 13B; 14B, and an outer ring 13C; 14C, and the inner ring 13A; And rotates integrally with the motor shaft 11. An outer ring 13C of one bearing 13 is supported by a disk-shaped support 21 described later, and an outer ring 14C of the other bearing 14 is supported by a stationary lid 22 forming a motor frame 20 of the motor 1. A leaf spring 23 for preload is disposed between the bearing 21 and the support 21 that supports one of the bearings 13, and a torque detection device 30 is attached to the support 21. The torque detecting device 30 will be described later in detail. On the other hand, in the lid 22 supporting the other bearing 14, an oil seal 22A is provided between the lid 22 and the motor shaft 11, and a preload is provided between the lid 22 and the bearing 14. Is disposed.

  The lid 22 and the support 21 are held at their outer periphery by a cylindrical body 25 that forms a part of the motor frame 20, and the support 21 and the body 25 are provided with the torque detecting device. Another lid 26 that covers 30 is attached. A helical gear or a worm gear (not shown) is attached to the left end side of the motor shaft 11, and is connected to a reduction gear (not shown).

  Next, the torque detection device 30 will be described together with the one bearing 13. FIG. 2 is an enlarged view showing the torque detection device 30 in FIG. 1 and its periphery.

  FIG. 2 shows a case where the torque detection device 30 is in a neutral state within a permissible range with respect to torque fluctuation.

  The torque detecting device 30 includes a slide member 31 and a switch member 32.

  The slide member 31 is supported by a support 21 that supports the outer ring 13 </ b> C of the one bearing 13. The outer race 13C of the bearing 13 supported by the stationary support 21 held by the motor frame 20 is therefore non-rotating. The bearing 13 is provided with a preloading leaf spring 23 having a corrugated cross section disposed between a side plate portion 21B extending in the radial direction from the main portion 21A of the support body 21 and the outer ring 13C. The bearing 13 has a rotating inner ring 13 </ b> A fitted and mounted on a step portion 11 </ b> A of the motor shaft 11 via a spacer 26.

  An outer ring 13C on the non-rotating side of the bearing 13 is loosely fitted in a concave portion 21B-1 formed corresponding to the side plate portion 21B of the support 21, and is axially moved with respect to the concave portion 21B-1 in the direction of the axis X. It is supported in a movable state. A hole 21A-1 extending in the direction of the axis X is formed in the main portion 21A of the support 21 located outside the recess 21B-1 so as to be adjacent to the outer peripheral edge of the recess 21B-1. The slide member 31 is supported by the hole 21A-1 via a bush 28 so as to be slidable in the axis X direction.

  The slide member 31 includes a rod 33 having a cylindrical portion 33A at an intermediate portion and threaded portions 33B and 33C formed at both ends, and two engagements screwed to a threaded portion 33B at one end located to the right. A member 34 (34A and 34B), a nut member 35 as an adjusting member for pressing one of the engagement members 34A, a compression spring 36 disposed between the other engagement member 34B and the bush 28, A flange-shaped pressure plate 37 attached to the rod 33 at a boundary position between the screw portion 33C and the cylindrical portion 33A at the other end, and a nut member 38 screwed to the screw portion 33C to press the pressure plate 37; have.

  The two engagement members 34A and 34B cooperate to form an engagement portion 34 for the switch member 32. The two ring-shaped engaging members 34A and 34B form tapered surfaces 34A-1 and 34B-1 in opposing directions, and form a V-groove opened by both tapered surfaces 34A-1 and 34B-1. The distance L between the engagement members 34A and 34B can be changed and set by adjusting the screwing position of the one engagement member 34A with the screw portion 33B. The nut member 35 as an adjustment member fixes the adjusted position of the engagement member 34A.

  Thus, the sliding member 31 receives the force of the compression spring 36 disposed between the bush 28 and the left engaging member 34B, and pushes the pressure plate 37 of the bearing 13 while the rod 33 is pressed rightward. It is located in contact with the side end surface of the outer ring 13C. In this position, the engaging portion 34 is in the neutral position. In the neutral position, the operating portion 32A of the switch member 32 described later is positioned within the range of the distance L between the two engaging members 34A and 34B of the engaging portion 34. Then, when the range forms the first engaging portion and the operating portion 32A exceeds the above range, the engaging members 34A and 34B come into contact with the operating portion 32A of the switch member 32 and The part 34 is formed.

  The switch member 32 is attached to an immobile portion of the motor device 1, for example, a part of the motor frame 20, and is in an immobile position. The switch member 32 has a protruding operating portion 32A, and the operating portion 32A is immersed by receiving a pressing force. The switch member 32 issues an off signal at the output terminal 32B when the operating portion 32A is protruding and an on signal when the operating portion 32A is immersed.

  The slide member 31 moves rightward (positive direction) or leftward (negative direction) while sliding with respect to the bush 28, and the switch member 32 is configured such that the operating portion 32 </ b> A When riding on the member 34B, the operating portion 32A is pressed by the engaging member 34B and is immersed (see FIG. 3). The engagement member 34A is pressed and immersed (see FIG. 4), and a negative ON signal is generated at the output terminal 32B. When the operating portion 32A is located between the two engaging members 34A and 34B, that is, in the range of the distance L and is in the neutral state, the operating portion 32A is in the protruding state, and the switch member 32 outputs an OFF signal. It occurs at terminal 32B.

  Next, the operation of this embodiment having such a configuration will be described.

  When the motor device is driven, the motor shaft 1 rotates and rotationally drives the driven rotary body via a helical gear or a worm gear (not shown). When the motor shaft 1 rotates forward or negatively, the motor shaft 1 receives an axial component of the load via a helical gear or a worm gear for transmitting the load and moves (shifts) in the axial direction. The direction of this movement is positive or negative depending on the direction of rotation.

  The movement amount and the direction of the motor shaft 1 change with the fluctuation of the motor load. With the movement of the motor shaft 1 and the change in the movement amount and direction, the slide member 31 moves, and the movement amount and direction also change. When the load of the motor, that is, the change in the movement of the slide member 31 is within a predetermined movement range within an allowable range, the operating portion 32A of the switch member 32 is connected to the two engagement members 34A and 34B of the engagement portion 34. , That is, within the range of the distance L, the operating portion 32A is in the protruding state, and the switch member 32 emits an off signal. Therefore, the motor device 1 maintains the operating state as it is.

  When the motor shaft 11 is rotating in one rotation direction (forward rotation direction), the load on the motor increases, and the slide member 31 moves rightward (forward direction) in FIG. In this case, when the load increases beyond the allowable range, the motor shaft 11 and, consequently, the slide member 31 move rightward beyond the above-mentioned predetermined movement amount range, and as shown in FIG. The slide member 32 rides on the left engagement member 34B of the engagement portion 34 and enters, and the slide member 32 emits a positive ON signal at the output terminal 32B. A control device (not shown) receives the output signal and controls the driven rotating body in a direction to reduce the load.

  Further, when the motor shaft 11 is rotating in the other rotation direction (negative rotation direction) and the load increases beyond an allowable range, as shown in FIG. Move so as to be out of the movement range. At that time, the operating portion 32A of the switch member 32 rides on and goes into the engagement member 34A on the right side of the engagement portion 34, and the slide member 32 emits a negative ON signal to the output terminal 32B. The control device receives the output signal and controls the driven rotating body in a direction to reduce the load.

  The predetermined range related to the amount of movement of the slide member 31 for bringing the slide member 31 into the neutral state, that is, the range of the distance L between the two engagement members 34A and 34B is reduced by loosening the nut 35 as an adjustment member. Can be changed and set by fixing the position with the nut 35.

DESCRIPTION OF SYMBOLS 11 Motor shaft 13 Bearing 13C Outer ring 30 Torque detection device 31 Slide member 32 Switch member 32A Actuation part 32B Output terminal 34 Engagement part 34A, 34B Second engagement part 35 Adjustment member (nut)
L First engagement part (range of distance L)

Claims (3)

A helical gear or a worm gear that transmits torque is a motor torque detector that is attached to a motor shaft.
A motor shaft rotatably and axially movably supported by bearings having inner and outer rings,
A slide member supported slidably in the axial direction of the motor shaft by a motor frame that supports an outer ring that is a non-rotating side of the bearing;
A switch member attached to a stationary part of the motor,
The switch member includes an operating portion that performs an on-off operation, and the slide member includes an engagement portion that engages with the operating portion and performs an on-off operation of the operating portion with the sliding movement of the slide member.
The switch member has an output terminal that emits a signal corresponding to on / off when the switch member is turned on / off,
A torque detecting device for a motor, characterized in that:   The switch member is formed as one switch member, and the engagement portion of the slide member has a first engagement portion that turns off the operation portion of the switch member, and both sides of the first engagement portion in the moving direction of the slide member. And a second engaging portion for bringing the operating portion to an on state, wherein the operating portion of the switch member is engaged with the first engaging portion when the motor is normally loaded, and an output terminal of the switch member is provided. A signal corresponding to the OFF state is output at the time of positive / negative movement of the motor shaft exceeding a predetermined amount due to increase or decrease of the load, the operating portion of the switch member is disengaged from the first engagement portion and the positive side or the negative side. The motor torque detection device according to claim 1, wherein the motor torque detection device is engaged with the second engagement portion and outputs a positive or negative signal corresponding to the ON state at an output terminal of the switch member.   3. The torque detecting device for a motor according to claim 1, wherein the slide member has an adjusting member capable of adjusting the predetermined amount.

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