JP2015117784A - Whirl stop device for rotating shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a whirl stop device capable of surely regulating a whirl of a rotating shaft with a simple structure.SOLUTION: A whirl stop device includes: a nut member attached to a fixed part and having an insertion hole through which a rotating shaft is inserted, and having a first region and a second region adjacent in an axial direction on an inner peripheral surface of the through hole; a plurality of rollers disposed between the rotating shaft and the nut member and arranged so that a rotation axis is parallel to an axial direction of the rotating shaft; and a retainer cylindrical formed, arranged between the nut member and the rotating shaft, and moved to the axial direction of the rotating shaft so that the roller is positioned in one of the first region and the second region of the nut member. In the first region, a gap between the inner peripheral surface of the through hole of the nut member and an outer peripheral surface of the rotating shaft is larger than a diameter of the roller, and a locking part having a thickness increasing along a peripheral direction and fastening the roller between the rotating shaft and it is provided on the inner peripheral surface of the through hole in the second region in correspondence with the rollers.

Description

  The present invention relates to a detent device for holding a rotating shaft such as a screw shaft of a ball screw without rotating it.

  For example, as a method of using the ball screw, it is conceivable that not only the screw shaft is used while being matched horizontally, but also the lifting shaft is configured by arranging the screw shaft so as to match the vertical direction. In this case, a motor is connected to the screw shaft, and the nut member screwed to the screw shaft is moved up and down in accordance with the rotation of the motor. However, in a state where the free rotation of the screw shaft is allowed, the screw shaft rotates due to the weight of the nut member or the weight of the movable body mounted on the nut member, and the nut member There is a concern that it will fall to the lower end of the screw shaft.

  If the motor connected to the screw shaft generates a holding torque, or if an electromagnetic brake is provided separately from the motor to stop the rotation of the screw shaft, such a fall of the nut member can be avoided, but suddenly If a power failure occurs, the nut member cannot be prevented from falling. In addition, in order to temporarily lock the nut member at a predetermined position on the screw shaft during the operation of the lifting device, it is necessary to continue energizing the motor and the electromagnetic brake. It is not preferable from the viewpoint.

  As a device for regulating the rotation of a rotating shaft such as the screw shaft without using electric power, a rolling bearing clutch disclosed in JP-A-8-338443 is known.

JP-A-8-338443

  The present invention has been made in view of such a problem, and it is an object of the present invention to provide a detent device capable of reliably regulating the rotation of a rotating shaft with a simple structure without performing continuous energization.

  That is, the present invention is a detent device that is provided between the fixed portion and the rotating shaft and locks the rotating shaft with respect to the fixed portion. This anti-rotation device has a through hole that is attached to the fixed portion and into which the rotating shaft is inserted, and a first region and a second region adjacent to each other in the axial direction are provided on an inner peripheral surface of the through hole. A nut member, a plurality of rollers disposed between the rotating shaft and the nut member, and arranged so that a rotation shaft is parallel to an axial direction of the rotating shaft, and the nut formed in a cylindrical shape A cage that is disposed between the member and the rotating shaft and moves in the axial direction of the rotating shaft to position the roller in either the first region or the second region of the nut member. . In the first region of the nut member, the gap between the inner peripheral surface of the through hole of the nut member and the outer peripheral surface of the rotating shaft is larger than the diameter of the roller, and the inner peripheral surface of the through hole in the second region is Are provided with corresponding locking portions for increasing the thickness along the circumferential direction and sandwiching the rollers between the rotating shafts.

  In the first region of the nut member, the gap between the inner peripheral surface of the through hole of the nut member and the outer peripheral surface of the rotary shaft is larger than the diameter of the rollers arranged in the gap, and the nut member and the rotary shaft When the roller rotates relatively, the roller idles between these two members. Thereby, when a roller exists in the 1st field of a nut member, a rotating shaft can rotate freely to a nut member. On the other hand, in the second region of the nut member, a locking portion is provided for the inner peripheral surface of the through hole of the nut member, and when the roller exists in the second region of the nut member, the roller is engaged. The wedge shaft is sandwiched between the stopper and the rotation shaft, and the rotation of the rotation shaft is restricted by the frictional force with the roller.

  For this reason, the said cage | basket provided in the clearance gap between a nut member and a rotating shaft is moved to an axial direction, and a roller is set to either a 1st area | region or a 2nd area | region, and free rotation and a stop of a rotating shaft are carried out. And can be selected.

It is sectional drawing which shows embodiment of the anti-rotation apparatus to which this invention is applied. It is sectional drawing which shows the state which set the holder | retainer in the control position in the rotation stopper shown in FIG. It is a perspective view which shows arrangement | positioning of the roller in the circumference | surroundings of a rotating shaft. It is an expanded sectional view which shows the relationship between the nut member in a 1st area | region, a rotating shaft, and a roller. It is an expanded sectional view which shows the relationship between the nut member in a 2nd area | region, a rotating shaft, and a roller. It is the schematic which shows the structure of a roller pushing mechanism. It is the schematic explaining the motion of the roller in the 2nd area | region accompanying operation | movement of a roller pushing mechanism.

  Hereinafter, the rotation stopper device of the rotating shaft according to the present invention will be described in detail.

  FIG. 1 is a sectional view showing a first embodiment of a detent device 1 to which the present invention is applied. The anti-rotation device 1 is provided for a fixed portion of a mechanical device or the like that supports the rotating shaft 2 and can switch between free rotation and fixing of the rotating shaft 2 with a simple operation. For this reason, for example, by installing the rotary shaft 2 that is rotationally driven by the motor, the rotary shaft 2 is prevented from freely rotating even in a state where the holding power of the motor is not exerted during a power failure. Is possible.

  The anti-rotation device 1 includes a nut member 3 having a through hole 30 into which the rotary shaft 2 is inserted, and a plurality of rows arranged between the rotary shaft 2 and the nut member 3 along the circumferential direction of the rotary shaft 2. A roller 4 and a cage 5 that aligns the roller 4 at a predetermined interval between the nut member 3 and the rotary shaft 2 are provided.

  The rotary shaft 2 is a target for restricting the rotational movement by the anti-rotation device 1, and may be a support shaft of a rotating component such as a pulley or a gear, or may be a screw shaft of a screw feeder.

  The nut member 3 is fixed to a fixing part such as a mechanical device by a bolt (not shown). The cross-section of the through hole 30 of the nut member 3 is circular, and the difference between the inner diameter and the outer diameter of the rotary shaft 2 is set to be larger than twice the diameter of the roller 4. As shown in FIG. 1, the inner peripheral surface of the through hole 30 of the nut member 3 is divided into a first region A and a second region B in the axial direction. Details of the first area A and the second area B will be described later.

  On the other hand, the cage 5 is formed in a substantially cylindrical shape, and is manufactured, for example, by injection molding of synthetic resin. The inner diameter of the cage 5 is larger than the outer diameter of the rotary shaft 2, and the outer diameter is smaller than the inner diameter of the through hole 30 of the nut member 3. It is arranged between the nut member 3. In addition, the retainers 5 are provided with accommodation holes for the rollers 4 in a line at equal intervals along the circumferential direction, and the rollers 4 are arranged in the accommodation holes and maintain a constant posture.

  The cage 5 is movable in the axial direction with respect to the nut member 3, and as shown in FIG. 2, a part of the cage 5 protrudes from the axial end of the nut member 3. To do. When the cage 5 moves in the axial direction, the roller 4 disposed in the accommodation hole moves together with the cage 5 in the axial direction of the rotary shaft 2. In this embodiment, the roller 4 exists in the second region B of the nut member 3 in the state shown in FIG. 2, that is, in the state where the cage 5 protrudes from the through hole 30 of the nut member 3. Further, the cage 5 is pushed between the nut member 3 and the rotating shaft 2 from the state shown in FIG. 2, that is, the cage is substantially accommodated between the nut member and the rotating shaft as shown in FIG. In this state, the roller 4 is present in the first region A of the nut member 3.

  In the following description, the position of the cage 5 when the roller 4 is located in the first area A is the “standby position”, and the position of the cage 5 when the roller 4 is located in the second area B. The position is expressed as “regulated position”.

  FIG. 3 shows the arrangement of the rollers 4 around the rotating shaft 2. Around the rotating shaft 2, a plurality of rollers 4 are arranged at equal intervals. The rotation axis of each roller 4 coincides with the axial direction of the rotation axis 2. Although not shown in the figure, since the rollers 4 are arranged in the accommodation holes of the cage 5 as described above, the distance between the rollers 4 does not change. Then, when the cage 5 is moved in the axial direction with respect to the nut member 3, the roller 4 present in the first region A of the nut member 3 is pulled in the axial direction as it is, and the nut member 3 is It will move to the 2nd field B.

  FIG. 4 is an enlarged cross-sectional view showing the relationship among the nut member 3, the roller 4, and the rotating shaft 2 in the first region A. In the first region A, the inner peripheral surface of the through hole 30 of the nut member 3 has a uniform inner diameter. Since the difference between the inner diameter of the nut member 2 and the outer diameter of the rotating shaft 2 is set to be larger than twice the diameter of the roller 4, each roller 4 is attached to both the nut member 3 and the rotating shaft 2 at the same time. Not touching. For this reason, even if the said rotating shaft 2 rotates in the state which set the said holder | retainer to the stand-by position, this roller 4 can rotate freely inside the accommodation hole of the holder | retainer 5. FIG.

  A key 51 is provided on the outer peripheral surface of the cage 5, and a sliding groove 52 into which the head of the key 51 enters is provided on the inner peripheral surface of the through hole 30 of the nut member 3. The key 51 is freely movable in the axial direction of the nut member 3 in the sliding groove 52. When the retainer 5 moves between the standby position and the restriction position, the key 51 is also moved accordingly. It moves to the 1st field A or the 2nd field B. Since the key 51 is inserted into the sliding groove 52, the retainer 5 is restricted from rotating in the circumferential direction with respect to the nut member 3.

  On the other hand, in the second region B of the nut member 3, the same number of locking portions 31 as the number of the rollers 4 are provided at equal intervals in the circumferential direction with respect to the inner peripheral surface of the through hole 30. FIG. 5 is a cross-sectional view of the locking portion 31 observed from the axial direction of the nut member 3, more specifically from the left side of FIG. Each locking portion 31 gradually increases in thickness along the circumferential direction of the nut member 3 and protrudes from the inner peripheral surface of the through hole 30. The locking portion 31 has a tapered surface facing the rotating shaft 2. 32 is provided. The tapered surface 32 is smoothly continuous from the inner peripheral surface of the through hole 30. Therefore, the distance between the tapered surface 32 and the outer peripheral surface of the rotary shaft 2 becomes narrower as the thickness of the locking portion 31 increases. At the portion where the thickness of the locking portion 31 is maximum, the distance between the tapered surface 32 and the outer peripheral surface of the rotary shaft 2 is set to be smaller than the diameter of the roller 4. In the second region B, the inner diameter of the through hole 30 is the same as that of the first region A except where the locking portion 31 is provided.

  Further, in the detent device 1 of this embodiment, a cage push-out mechanism for setting the cage 5 from the standby position to the restricted position is provided. The cage push-out mechanism includes a coil spring 33 provided inside the nut member 3 and a locking pin 34 that sets the cage 5 at a standby position.

  As shown in FIG. 1, the coil spring 33 is disposed inside the through hole 30 of the nut member 3 so as to wind around the rotating shaft 2. One end of the coil spring 33 is fixed to the axial end surface of the retainer 5, and the other end is fixed to a holding plate 35 attached to the nut member 3. The holding plate 35 has a through hole of the rotating shaft 2 in the center and is formed in a disc shape, and is fixed to the end surface of the nut member 3 on the side opposite to the direction in which the cage 5 protrudes. . In the state where the cage 5 is set at the standby position, the coil spring 33 is compressed between the cage 5 and the holding plate 35, and the biasing force of the coil spring 33 is strong against the cage 5. It is working.

  Further, the locking pin 34 penetrates the nut member 3 in the radial direction and can be freely inserted into and removed from the nut member 3. When the locking pin 34 is pushed into the nut member 3, the tip of the locking pin 34 projects from the inner peripheral surface of the through hole 30 of the nut member 3. Further, the retainer 5 is provided with a setting hole 50 into which the tip of the locking pin 34 is fitted, and when the retainer 5 is set at the standby position, the engagement hole 50 is engaged with the engagement hole 50. The front end of the stop pin 34 enters. That is, when the locking pin 34 is pushed into the nut member 3 with the cage 5 set at the standby position, the movement of the cage 5 in the axial direction is restricted by the locking pin 34, and the cage 5 The coil spring 33 can be stopped at the standby position against the urging force of the coil spring 33.

  On the other hand, when the locking pin 34 is pulled out from the nut member 3, the tip of the locking pin 34 comes out of the setting hole 50 of the cage 5, so that the cage 5 is regulated from the standby position by the urging force of the coil spring 33. The rollers 4 forcibly moved to the position and arranged in the cage 5 are positioned from the first area A to the second area B.

  Furthermore, in the detent device 1 of this embodiment, when the retainer 5 is set from the standby position to the restricting position, a roller pushing mechanism that displaces the retainer 5 in the circumferential direction of the rotating shaft 2 in accordance with the movement. 6 is provided. This roller push-in mechanism 6 presses the roller 4 set from the first area A to the second area B of the nut member 3 against the engaging portion 31 to prevent the roller 4 from slipping in the second area B. In this embodiment, the cage 5 is displaced in the circumferential direction by using the biasing force of the coil spring 33.

  This roller push-in mechanism 6 is configured using a key 51 formed in the cage and a sliding groove 52 formed in the nut member 3. FIG. 6 schematically shows the relationship between the sliding groove 52 formed in the nut member 3 and the key 51 moving in the sliding groove 52. The sliding groove 52 is provided with a length corresponding to the moving distance from the standby position of the cage 5 to the restricting position, and an inclined surface in which the groove width of the sliding groove 52 gradually changes in the center in the longitudinal direction. 53 is provided. That is, the groove width on the first region A side of the nut member 3 is narrower than the inclined surface 53 on the second region B side. For this reason, when the cage 5 is moved from the restricting position to the standby position and the key 51 existing in the second area B is moved to the first area A, the key 51 is moved into the slip groove 52 by the inclined surface 53. It is designed to be brought to one side. The positional relationship between the key 51 and the sliding groove 52 in FIG. 4 also indicates this.

  The direction in which the inclined surface 53 approaches the key 51 (the lower direction in FIG. 6) coincides with the direction in which the coil spring 33 is twisted to accumulate the urging force. That is, when the cage 5 is set from the restriction position to the standby position while the coil spring 33 is being compressed, the key 51 is guided by the inclined surface 53 so that the cage 5 is placed around the rotating shaft 2. A slight rotation is given. Accordingly, the coil spring 33, one end of which is fixed to the cage, is compressed to accumulate an urging force, and at the same time, while being slightly twisted, the urging force is also accumulated. As a result, when the urging force of the coil spring 33 is released and the cage 5 set at the standby position is moved to the restricting position, the key 51 moves in the direction opposite to the arrow direction shown in FIG. The retainer 5 moves to the restricting position while slightly rotating. The positional relationship between the key 51 and the sliding groove 52 in FIG. 5 indicates this, and in comparison with FIG. 4, it can be seen that the cage 5 has slightly rotated in the circumferential direction.

  FIG. 7 is a schematic diagram showing the positional relationship of the rollers 4 in both the first region A and the second region B as observed from the axial direction of the nut member 3, specifically from the left side of FIG. Is omitted. In a state where the cage 3 is set to the standby position, the roller 4 (the roller 4 drawn with a one-dot chain line in the drawing) in the first region A is slightly displaced from the engaging portion 31 of the nut member 3. Existing. When the cage 5 is set at the restriction position, the roller 4 moves from the first region A to the second region B of the nut member 3 together with the cage 5. At this time, since the cage 5 is slightly rotated by the urging force of the coil spring 33 as described above, the roller 4 moves to the second region B while moving around the nut member 3 as indicated by an arrow in FIG. Move in the direction as well. Thereby, the roller 4 (roller 4 drawn with a solid line in the drawing) moved to the second region B is pushed between the tapered surface 32 of the locking portion 31 and the outer peripheral surface of the rotating shaft 2.

  The roller push-in mechanism 6 of this embodiment uses the urging force generated by the torsion of the coil spring 33 and slightly rotates the cage 5 set from the standby position to the restricting position in the circumferential direction. Then, the cage 5 may be rotated. For example, a cam groove is formed on the outer peripheral surface of the cage 5, and the tip of the locking pin 34 inserted into the nut member 3 is inserted into the cam groove, so that the cage 5 is biased by the coil spring 33. When moving from the standby position to the restricting position, the cage 5 may rotate in the circumferential direction by the action of the cam groove.

  The retainer 5 holds the roller 4 in a non-contact manner with the rotation shaft in the first region A of the nut member 3, but in the second region B, the retainer 5 itself is bent. The roller 4 and the rotating shaft 2 are in contact with each other. That is, in the second region B, the roller 4 comes into contact with the locking portion 31 and is pressed against the outer peripheral surface of the rotary shaft 2, so that the cage 5 is elastically deformed by the pressing force, and the roller 4 is rotated. 2 will be contacted. On the other hand, when the roller 4 is moved from the second region B to the first region A, the pressing force applied to the roller 4 by the locking portion 31 is removed, so that the cage 5 is restored to its original shape, thereby The roller 4 is separated from the rotating shaft.

  The anti-rotation device 1 of the present embodiment configured as described above operates as follows.

  First, when it is desired to freely rotate the rotary shaft 2 with respect to the anti-rotation device 1, the cage 5 is pushed into the nut member 3 against the urging force of the coil spring 33, and the cage 5 is put on standby. The position is set (the state shown in FIG. 1). The cage 5 set at the standby position is stopped at the position by the locking pin 34, and the coil spring 3 is pressed and contracted between the cage 5 and the holding plate 35.

  At this time, the roller 4 is located in the first region A of the nut member 3, but in the first region A, the gap between the nut member 3 and the rotary shaft 2 is larger than the diameter of the roller 4 as shown in FIG. 4. It is set large enough. For this reason, the roller 4 does not contact both the nut member 3 and the rotating shaft 2 at the same time, and can rotate freely inside the accommodation hole of the cage 5 even if it contacts the rotating shaft 2. Is possible. Therefore, the rotating shaft 2 can freely rotate without being restricted.

  Further, in the first region A, the gap between the nut member 3 and the rotary shaft 2 is sufficiently larger than the diameter of the roller 4, so that the roller 4 can be held in non-contact with the rotary shaft 2 by the cage 5. . By doing so, the rotating shaft can freely rotate without receiving any resistance from the anti-rotation device 1.

  On the other hand, when the rotation of the rotating shaft 2 is locked and the rotating shaft 2 is fixed to the anti-rotation device 1, the locking pin 34 is extracted from the nut member 3, and the cage 5 is moved to the standby position. To the restricted position. The retainer 5 is pushed from the standby position to the restricting position by the urging force of the coil spring 33, and the rollers 4 arranged in the retainer 5 move from the first region A to the second region B of the nut member 3. (State shown in FIG. 2). Along with this movement, the cage 5 slightly rotates in the circumferential direction around the rotating shaft 2.

  As a result, as shown in FIG. 5, the roller 4 is sandwiched between the tapered surface 32 of the locking portion 31 provided in the second region B and the outer peripheral surface of the rotating shaft 2. Since the space between the taper surface 32 and the outer peripheral surface of the rotating shaft 2 is a wedge-shaped space, when the rotating shaft 2 tries to rotate leftward in FIG. A large frictional force acts between the roller 4 and the outer peripheral surface of the rotating shaft 2 and between the roller 2 and the tapered surface 32. As a result, the roller 4 is in a state of being caught between the locking portion 31 and the rotating shaft 2, and the rotating shaft 2 cannot be rotated. That is, when the cage 5 is set from the standby position to the restricting position, the rotating shaft 2 can be fixed to the anti-rotation member 1.

  Therefore, in the detent device 1 of the present embodiment, the rotary shaft 2 can be selectively fixed by simply pulling out the locking pin 34 from the nut member 3. For example, the detent device is secured to one end of the screw shaft of the screw feeder. If an apparatus is provided, the rotation and fixing of the screw shaft can be easily switched by a simple operation.

  The locking pin 34 may be moved manually. For example, the locking pin 34 is pulled out of the nut member 3 when the electromagnetic solenoid is de-energized due to a power failure or the like in conjunction with an electromagnetic solenoid. You may do it. With this configuration, even when the motor that drives the rotating shaft 2 loses its holding power during a power failure, the rotation of the rotating shaft 2 can be restricted and unintended operation of the mechanical device can be prevented.

  Further, the anti-rotation device 1 described in this embodiment restricts only the rotation of the rotating shaft 2 in one direction, and cannot restrict the rotation in the opposite direction. However, by providing a pair of locking portions 31 in which the inclined direction of the tapered surface 32 is different from the inner peripheral surface of the through hole 30 of the nut member 3, they can be attached to any rotational direction of the rotary shaft 2. It becomes possible to regulate.

  Furthermore, in the detent device 1 of this embodiment, the roller 4 is directly disposed around the rotation shaft 2 to be regulated. For example, a hollow cylindrical rotation sleeve is provided, and the rotation sleeve and the nut member 3 are provided. The rotating shaft 2 may be inserted into the hollow hole of the rotating sleeve so as to rotate integrally with the rotating sleeve.

  Furthermore, in the detent device 1 of the embodiment, the urging force of the coil spring 33 is applied to the retainer 5, and the retainer 5 is moved from the standby position to the restricting position by the urging force. However, the cage 5 may be manually set to either the standby position or the restriction position without providing the coil spring 33.

DESCRIPTION OF SYMBOLS 1 ... Detent | locking device, 2 ... Rotating shaft, 3 ... Nut member, 4 ... Roller, 5 ... Cage, 6 ... Roller pushing mechanism

Claims (4)

In the detent device provided between the fixed portion and the rotating shaft and locking the rotating shaft to the fixed portion,
A nut member attached to the fixed portion and having a through-hole into which the rotating shaft is inserted, and an inner peripheral surface of the through-hole provided with a first region and a second region adjacent in the axial direction;
A plurality of rollers arranged between the rotating shaft and the nut member, and arranged so that a rotating shaft is parallel to an axial direction of the rotating shaft;
A cylindrical shape is disposed between the nut member and the rotating shaft, and moves in the axial direction of the rotating shaft to position the roller in either the first region or the second region of the nut member. A cage, and
In the first region of the nut member, the gap between the inner peripheral surface of the through hole of the nut member and the outer peripheral surface of the rotating shaft is larger than the diameter of the roller,
The inner peripheral surface of the through hole in the second region is provided with a locking portion corresponding to each roller that increases the thickness along the circumferential direction and sandwiches the roller between the rotating shaft. Anti-rotation device characterized.   When the retainer moves in the axial direction and positions the roller from the first region to the second region, the retainer is displaced in the circumferential direction along with the movement and presses the roller against the locking portion. The detent device according to claim 1, further comprising a roller pushing mechanism.   The roller pushing mechanism includes a coil spring that urges the retainer in the axial direction to move the roller from the first region toward the second region, and the coil spring urges the retainer in the axial direction. The anti-rotation device according to claim 2, wherein the anti-rotation device is also biased in the circumferential direction.   The retainer holds a roller located in the first region in a non-contact manner with the rotation shaft, while bringing the roller located in the second region into contact with the rotation shaft by its own elastic deformation. Item 4. A detent device according to Item 2 or 3.

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