JP2015227675A - Overload protection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an overload protection device capable of performing a fast and easy returning back operation from a state where a torque transmission is shut off to a normal state where the torque is transmitted.SOLUTION: An overload protection device 11 comprises: an intermediate rotary member 13 holding a first ball 34 in an open hole 31; one side rotary member 14 having one side recess part 32 with which the first ball can engage; the other side rotary member 15 at the other side of the intermediate rotary member that is movable and rotatable in an axial direction; a biasing member 23 for biasing the other side rotary member toward one side; and a second ball member 38 held and pressed between the intermediate rotary member and the other side rotary member in such a way that the first ball displaced from one side recess part to the other side under overloaded state can be restricted against pressing by the other side rotary member. The intermediate rotary member and the one side rotary member are provided with recesses 17 and 18 acting as discrimination parts that can be discriminated as seen from outside to show that the hole and the one side recess part have a returning positional relation where the hole and the one side recess part are axially opposite to each other.

Description

  The present invention relates to an overload protection device that blocks transmission of torque and protects the transmission mechanism when an overload occurs in the torque transmission mechanism.

  Conventionally, for example, an overload protection device described in Patent Document 1 is known as this type of device. This device has a hub flange that rotates by driving a motor in a state where a torque transmitting ball is held in a hole penetrating in the axial direction so that a part of the ball protrudes from the hole, and is opposed to the hub flange in the axial direction. And a drive plate rotatable about an axis by forming a pocket on the surface for releasably engaging the torque transmitting ball. The device also includes a slide plate provided opposite to the drive plate relative to the hub flange from the opposite side in the axial direction so as to be movable in the axial direction and rotatable about the axis, and the slide plate. And a compression coil spring that can press the ball toward the hub flange in the axial direction and press the torque transmitting ball toward the drive plate.

  In addition, this overload protection device includes a strut ball disposed on the inner peripheral side of a pitch circle on which a torque transmitting ball is disposed, and a strut ball partially formed in a hole formed through in an axial direction. And a cage plate that is rotatable about an axis between the slide plate and the hub flange in a state of being held so as to protrude from the center. Furthermore, pocket portions are formed on the surfaces of the slide plate and the hub flange that face each other so that the strut balls held in the holes of the cage plate are detachably engaged.

  In a normal state where torque is transmitted by driving the motor while the torque transmitting ball is pressed by the compression coil spring via the slide plate and engaged with the pocket of the drive plate, the strut ball is Between the pocket portions on the slide plate side and the hub flange side, it is held in a housed state where it does not receive the pressing force of the compression coil spring.

  On the other hand, when an overload occurs, the torque transmitting ball that has been pressed by the compression coil spring through the slide plate and engaged with the pocket of the drive plate is released from the pocket against the pressing force of the compression coil spring. Thus, torque transmission between the hub flange side and the drive plate side is interrupted. In this torque transmission cut-off state, the strut ball is released from the pocket portion and is sandwiched between the opposed surfaces of the slide plate and the hub flange, and the pressing force to the hub flange side of the slide plate is reduced. Take it. By receiving the pressing force with the strut ball in this way, the slide plate is restricted from pressing the torque transmitting ball toward the pocket of the drive plate, and the torque transmission interrupted state is maintained.

JP 2003-194096 Gazette

  By the way, when such an overload protection device is returned from the torque transmission cutoff state to the normal state where torque is transmitted, the drive plate and the hub flange rotate relative to each other due to idling due to the torque transmission cutoff. It is necessary to match the position of the torque transmitting ball and the position of the pocket of the drive plate, which are in a state of being displaced from each other in the circumferential direction. That is, the drive plate and the hub flange rotate relative to each other through a pocket formed on the surface of the hub flange side of the drive plate and a hole formed in the hub flange so as to receive and hold a torque transmitting ball in the axial direction. Need to match.

  However, the position of the pocket on the drive plate side and the hole on the hub flange side should be aligned by rotating the drive plate and the hub flange relatively. It is difficult to grasp the positional relationship between them. Therefore, it takes time for such positioning, and there is a problem that it is difficult to quickly perform a return operation from a torque transmission interruption state to a normal state where torque is transmitted.

  The present invention has been made in view of such circumstances, and an object of the present invention is to quickly and easily perform a return operation from a state where torque transmission is interrupted to a normal state where torque is transmitted. It is to provide an overload protection device.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
An overload protection device that solves the above problem is an intermediate rotating body that is rotatably provided around an axis while holding the first sphere in a hole penetrating in the axial direction so that a part of the first sphere protrudes from the hole; A one-side rotating body provided on a surface facing the intermediate rotating body from one side in the axial direction so that the first sphere can be engaged with the intermediate rotating body and rotatably provided around the axis; A rotating body provided opposite to the other side in the axial direction so as to be movable in the axial direction and rotatable about the axis, and the other side rotating body is connected to one side in the axial direction. The transmission torque between the one side rotating body and the other side rotating body via the biasing member that biases toward the side and the first sphere engaged with the recess is preset. In the event of an overload exceeding the set torque range, the concave portion will resist the biasing force of the biasing member. The first sphere deviated to the other side in the axial direction is clamped between the intermediate rotator and the other rotator so that the pressing of the first sphere to the concave portion by the other rotator is possible. A second spherical body that is in a closed state, and the intermediate rotating body and the one-side rotating body have a return in which the hole of the intermediate rotating body and the concave portion of the one-side rotating body face each other in the axial direction. An identification unit is provided that makes it possible to visually identify that the positional relationship has been reached when the positional relationship has been reached.

  In general, the overload protection device is configured such that in a state where torque transmission is interrupted, the intermediate rotating body and the one-side rotating body rotate relative to each other so that the position of the hole that holds the first sphere and the recess that can engage the first sphere The position may be displaced in the circumferential direction. However, even if it is misaligned as described above, according to this configuration, the hole and the recess are opposed to each other in the axial direction by using the identification portions provided on the intermediate rotating body and the one-side rotating body. It becomes possible to align quickly and easily so as to satisfy the positional relationship.

  In the overload protection device, the identification unit includes a hole position identification unit provided in the intermediate rotator and a recess position identification unit provided in the one-side rotator, and the hole and the recess include the hole In the case of a return positional relationship, the hole position identifying portion and the recessed portion identifying portion are visually recognized from the outside in a relative positional relationship set in advance in the circumferential direction around the axis. Is preferred.

  According to this configuration, the intermediate rotating body and the one of the intermediate rotating body and the one of the one so that the hole position identifying section provided in the intermediate rotating body and the concave position identifying section provided in the one rotating body have a preset relative positional relationship. By rotating at least one of the side rotators, the position of the hole in the intermediate rotator and the position of the recess in the one side rotator can be easily made into a positional relationship for return.

  In the overload protection device, the hole position identification portion is provided in a shape that allows a jig for alignment to be externally locked to an outer surface of the intermediate rotating body, and the concave position identification portion is formed on the one side. It is preferable that the outer surface of the rotating body is provided in a shape that allows the jig locked to the hole position identification portion from the outside to be locked.

  According to this configuration, since the hole position identifying portion of the intermediate rotating body and the concave position identifying portion of the one-side rotating body are both shaped to be able to lock the alignment jig from the outside, they are positioned from the outside. It becomes possible to lock the jig for alignment. Therefore, with such a positioning jig locked, either the one-side rotating body or the other-side rotating body is rotated in the opposite direction to that in the normal state to restore the hole and the recess. While maintaining this positional relationship, it is possible to easily perform a return operation from the torque transmission interruption state to the normal state.

  In the overload protection device, the hole position identification unit is provided in the shape of a concave line or a convex line on the outer surface of the intermediate rotating body up to a surface facing the one-side rotating body, and the concave position identifying unit is Of the concave strip and the convex strip, the same shape as that of the hole position identifying portion is provided in a shape that is connected to the hole position identifying portion by extending to the outer surface of the one side rotating body to the surface facing the intermediate rotating body. It is preferable.

  According to this configuration, when the hole position identification unit of the intermediate rotator and the recess position identification unit of the one-side rotator are aligned in a preset relative positional relationship, the outer surface of the intermediate rotator and the one-side rotator On the outer surface, there are formed a ridge or a ridge extending across the opposing surfaces of both rotating bodies. Therefore, the position of the hole in the intermediate rotating body and the position of the recess in the one-side rotating body in the axial direction can be obtained by fitting a jig from the outside to the concave or convex strip extending across the opposing surfaces of both rotating bodies. It can be maintained in the state of being opposed.

  In the overload protection device, it is preferable that the hole position identification unit and the recess position identification unit are provided so as to have a positional relationship facing each other in the axial direction in the relative positional relationship.

  According to this configuration, at least one of the intermediate rotator and the one-side rotator is arranged so that the hole position identifying unit of the intermediate rotator and the concave position identifying unit of the one-side rotator are opposed in the axial direction. If it rotates, the hole of an intermediate | middle rotary body and the recessed part of a one-side rotary body will face in an axial direction. Therefore, it becomes easier to align the position of the hole in the intermediate rotator with the position of the recess in the one-side rotator.

  According to the present invention, it is possible to quickly and easily perform a return operation from a state where torque transmission is interrupted to a normal state where torque is transmitted.

The perspective view of the overload protection device of an embodiment. FIG. 2 is a half sectional view of the overload protection device shown in FIG. 1. The front view at the time of seeing the other side rotary body of the overload protection apparatus in the normal state which can transmit torque in the state which projected the 1st sphere and the 2nd sphere from the one side of an axial direction. The fragmentary sectional view of the overload protection device immediately after overload occurs. The partial front view at the time of seeing the other side rotary body of the overload protection apparatus in FIG. 4 in the state which projected the 1st sphere and the 2nd sphere from the one side of an axial direction. The fragmentary sectional view of the overload protection device in the state of interruption of torque transmission at the time of overload. The partial front view at the time of seeing the other side rotary body of the overload protection apparatus in FIG. 6 in the state which projected the 1st sphere and the 2nd sphere from the one side of an axial direction. The fragmentary sectional view of the overload protection device when returning from the interruption state of torque transmission. The partial front view at the time of seeing the other side rotary body of the overload protection apparatus in FIG. 8 in the state which projected the 1st sphere and the 2nd sphere from the one side of an axial direction.

Hereinafter, an embodiment of an overload protection device will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the overload protection device 11 of this embodiment is connected to a rotation source (not shown) of a drive source such as a motor or a driven device such as a speed reducer via a key groove 12a. In this state, a substantially cylindrical hub 12 that can rotate about the axis P is provided. On the outer periphery of the hub 12, the intermediate rotating body 13, the one-side rotating body 14, and the other-side rotating body 15, each having a ring shape with substantially the same diameter, are arranged around an axis centering on the axis P. It is provided so as to be relatively rotatable.

  That is, an intermediate rotating body 13, also called a center plate, is disposed at a substantially central position in the axial direction of the hub 12. One intermediate rotary member 14, also called a drive plate, is disposed at a position on one side (left side in FIG. 2) of the intermediate rotary member 13 from both sides in the axial direction. At the position on the other side in the axial direction (right side in FIG. 2), the other-side rotating body 15 also called a slide plate is arranged.

  Further, a torque adjusting nut 16 is screwed onto a male screw portion (not shown) formed on the outer periphery of the hub 12 at a position further on the other side (right side in FIG. 2) than the other side rotating body 15 in the axial direction. In the combined state, the position adjustment in the axial direction is possible. In the following description, unless otherwise specified, “one side in the axial direction” indicates the left side in FIG. 2, and “the other side in the axial direction” indicates the right side in FIG. It shall be shown.

  In addition, at a plurality of circumferential locations (for example, three locations at intervals of 120 degrees; only one location is shown in FIG. 1) on the outer surface of the intermediate rotator 13, the one-side rotator 14 of the intermediate rotator 13 is provided. A linear concave line 17 extending along the axial direction is formed so as to connect the opposite surface to the opposite surface to the other-side rotating body 15. Similarly, at a plurality of locations in the circumferential direction on the outer surface of the one-side rotating body 14 (for example, three places having an interval of 120 degrees as shown in FIG. 1), the intermediate rotating body 13 in the one-side rotating body 14 is connected. A linear recess 18 extending along the axial direction is formed so as to connect between the opposing surface and the surface on the opposite side.

  As shown in FIGS. 1 and 2, the recess 17 of the intermediate rotating body 13 and the recess 18 of the one-side rotating body 14 are formed in a groove shape having substantially the same opening width along the circumferential direction. The recess 17 and the recess 18 are in a positional relationship facing each other in the axial direction based on relative rotation between the intermediate rotating body 13 and the one-side rotating body 14, that is, in a circumferential direction centered on the axis. In the case of the target positional relationship, one concave groove 19 is formed that is connected across the opposing surfaces of the intermediate rotator 13 and the one-side rotator 14. Further, as shown in FIG. 2, a rod-like member 20 which is an example of a positioning jig can be fitted into the concave groove 19 from the outside. In a state where the rod-like member 20 is fitted in the concave groove 19, the relative rotation of the intermediate rotating body 13 and the one-side rotating body 14 is restricted.

  As shown in FIG. 2, a hub flange 12b having a hook shape is formed on the outer peripheral surface of the hub 12, and a ring shape having the same diameter as the hub flange 12b is formed on the other side of the hub flange 12b in the axial direction. Is disposed so as to face the other surface of the hub flange 12b in the axial direction. The intermediate rotating body 13 described above is arranged on the other side of the needle bearing 21 in the axial direction so as to face the surface of the needle bearing 21 on the other side in the axial direction. That is, on the outer periphery of the hub 12, the intermediate rotator 13 that functions as a center plate is disposed so as to be rotatable about the axis in a manner in which the needle bearing 21 is sandwiched between the hub flange 12 b in the axial direction.

  In addition, as shown in FIG. 2, on one surface of the torque adjusting nut 16 in the axial direction, springs are provided at a plurality of circumferential locations around the axis P (for example, 8 locations at 45 ° intervals). A receiving hole 22 is formed. And in each spring accommodation hole 22, the urging member 23 which urges | biases the other side rotary body 15 which functions as a slide plate toward the one side of the axial direction in which the intermediate | middle rotary body 13 is located in the state accumulated pressure. The tip is housed in a state where it abuts against the other rotating body 15. The urging member 23 is configured by a compression coil spring as an example.

  Further, as shown in FIG. 2, an annular stepped portion 24 connected to the inner peripheral surface side is formed on one axial surface of the other-side rotating body 15. The stepped portion 24 accommodates a backup ring 25 having a smaller diameter than the other-side rotating body 15 and a smaller thickness in the axial direction than the other-side rotating body 15. That is, while the backup ring 25 is housed in the stepped portion 24, the surface on one side in the axial direction contacts the intermediate rotating body 13, while the surface on the other side in the axial direction contacts the other side rotating body 15. It is accommodated in the level difference part 24 in the aspect which contacts.

  In addition, as shown in FIG. 2, on the outer periphery of the hub 12, the one-side rotating body 14 that functions as a drive plate is located on the outer peripheral side of the hub flange 12 b and the needle bearing 21, and the other side surface in the axial direction is It arrange | positions so that the surface of the one side of the axial direction of the intermediate | middle rotary body 13 may be opposed. Further, on the outer peripheral surface of the hub 12, a ball bearing 26 is assembled on one side in the axial direction with respect to the hub flange 12 b by a retaining ring 28 with a washer 27 interposed. That is, the one-side rotating body 14 is rotatable around the axis on the outer periphery of the hub 12 via the ball bearing 26.

  Further, as shown in FIG. 2, a plurality of screw holes 14a (only one is shown by a broken line in FIG. 2) are formed on one surface in the axial direction of the one-side rotating body 14, and these screw holes 14a are formed. A drive connection attachment (not shown) is fixed to the one-side rotating body 14 by using a mounting screw (not shown) screwed onto the one side. Further, a key groove 29 extending along the axial direction is formed on the inner peripheral surface of the other-side rotating body 15, while the key groove 29 is slidable in the axial direction on the outer peripheral surface of the hub 12. A key 30 to be fitted is formed. That is, when the key groove 29 on the inner peripheral surface is slidably fitted to the key 30 on the outer peripheral surface of the hub 12, the other-side rotating body 15 can rotate integrally with the hub 12, while intermediate rotation In the state facing the body 13 from the other side in the axial direction, the body 13 is movable in the axial direction and rotatable around the axis.

  As shown in FIG. 2, a hole 31 penetrating the intermediate rotator 13 in the axial direction is formed at a portion near the outer periphery of the intermediate rotator 13. In addition, the surface of the one-side rotating body 14 facing the intermediate rotating body 13 from one side in the axial direction is intermediate when the one-side rotating body 14 and the intermediate rotating body 13 have a predetermined relative angle positional relationship. A concave portion (hereinafter also referred to as “one-side concave portion”) 32 that is opposed to the hole 31 penetratingly formed in the rotating body 13 in the axial direction is formed. Further, the surface of the other side rotating body 15 facing the intermediate rotating body 13 from the other side in the axial direction is intermediate when the other side rotating body 15 and the intermediate rotating body 13 are in a positional relationship of a predetermined relative angle. Concave portions (hereinafter, also referred to as “other-side concave portions”) 33 and 33 a that are axially opposed to the holes 31 that are formed through the rotating body 13 are formed. The other-side recesses 33, 33a are two types of recesses having different axial depths, that is, the other-side recess 33 having a relatively shallow axial depth and an axial depth relatively. The other recesses 33 on the other side and the other recesses 33 a on the deeper side are formed alternately in the circumferential direction of the other side rotating body 15.

  A first sphere 34 made of, for example, a steel ball is accommodated and held in the hole 31 of the intermediate rotator 13 so that a part of the first sphere 34 protrudes from the hole 31. When the operation is stopped or in a normal state where torque can be transmitted, a portion of the first sphere 34 that protrudes from the hole 31 to the one side in the axial direction engages with the one-side recess 32 formed in the one-side rotating body 14. On the other hand, the portion of the first sphere 34 that protrudes from the hole 31 to the other side in the axial direction is engaged with the shallower concave portion 33 formed on the other side rotating body 15.

  As shown in FIG. 2, the backup ring 25 is formed with a holding hole 35 penetrating the backup ring 25 in the axial direction. Further, the surface of the intermediate rotator 13 facing the backup ring 25 from one side in the axial direction penetrates the backup ring 25 when the intermediate rotator 13 and the backup ring 25 are in a positional relationship of a predetermined relative angle. A concave portion (hereinafter also referred to as “one-side holding concave portion”) 36 that is opposed to the formed holding hole 35 in the axial direction is formed. In addition, the backup ring 25 when the other-side rotating body 15 and the backup ring 25 are in a positional relationship with a predetermined relative angle on the surface of the other-side rotating body 15 facing the backup ring 25 from the other side in the axial direction. A recess 37 (hereinafter also referred to as “the other-side holding recess”) that is opposed to the holding hole 35 formed in the axial direction in the axial direction is formed.

  A second sphere 38 made of, for example, a steel ball is accommodated and held in the holding hole 35 of the backup ring 25 so that a part of the second sphere 38 protrudes from the holding hole 35. When the operation is stopped or in a normal state where torque can be transmitted, a portion of the second sphere 38 that protrudes from the holding hole 35 to one side in the axial direction is engaged with a one-side holding recess 36 formed in the intermediate rotating body 13. On the other hand, the portion of the second sphere 38 that protrudes from the holding hole 35 to the other side in the axial direction is engaged with the other side holding recess 37 formed in the other side rotating body 15.

  As shown in FIG. 3, an arc groove 39 having a radius approximately the same as the length from the axis P serving as the center of rotation to the center of the other-side recesses 33 and 33a is formed on one surface of the other-side rotator 15. Is formed. The other-side recesses 33 and 33a described above are formed at a plurality of locations on the arc groove 39 (18 locations in the case of FIG. 3 at intervals of 20 degrees). As shown in FIG. 3, in the present embodiment, a plurality (9 in FIG. 3) of first spheres 34 are provided on the other recesses in the circumferential direction around the axis P (in this case, the shallower one). The other side recess 33) is engaged. Therefore, in the case of the present embodiment, the intermediate rotating body 13 is formed with a plurality of (9) holes 31 that can accommodate and hold the plurality (9) of first spheres 34 one by one.

  As shown in FIG. 3, the surface facing the one side of the stepped portion 24 of the other-side rotating body 15 has a length substantially the same as the length from the axis P serving as the rotation center to the center of the other-side holding recess 37. An arc groove 40 having a radius of is formed. And the other side holding | maintenance recessed part 37 is formed in the multiple places (in the case of FIG. 3 10 places) on this circular arc groove 40. As shown in FIG. As shown in FIG. 3, in the present embodiment, the same number (second in FIG. 3) of second spheres 38 as the number of places where the other-side holding recesses 37 are formed individually engages with the other-side holding recesses 37. It is configured. Therefore, in the case of this embodiment, the backup ring 25 is formed with holding holes 35 that can accommodate and hold the plurality (10) of second spheres 38 at a plurality of locations (10 locations).

  Note that FIG. 3 shows the positional relationship between the first sphere 34 and each of the other concave portions 33 and 33a and the second state when the overload protection device 11 is stopped or in a normal state, as in FIG. In order to show the positional relationship between the sphere 38 and each of the other-side holding recesses 37, the first sphere 34 and the second sphere 38 are projected and displayed on one surface of the other-side rotating body 15. In this state, as shown by a broken line and a two-dot chain line in FIG. 3, the alignment hole 15 a formed on the outer peripheral surface of the other-side rotating body 15 and the recess formed on the outer peripheral surface of the intermediate rotating body 13. The position in the circumferential direction centering on the axis line P of the strip 17 and the concave strip 18 formed in the outer peripheral surface of the one side rotating body 14 coincide. As shown in FIG. 3, in the case of the present embodiment, the alignment holes 15 a, the concave stripes 17, and the concave stripes 18 are formed at three positions that are spaced 120 degrees in the circumferential direction around the axis P. .

  Further, as shown in FIG. 3, pin portions 41 are arranged in the axial direction at a plurality of locations (for example, two locations having an interval of 180 degrees) on the arc groove 40 formed in the stepped portion 24 of the other side rotating body 15. It protrudes toward one side (the front side in the direction orthogonal to the paper surface in FIG. 3). These pin portions 41 have a shape along the circular arc groove 40 of the other-side rotating body 15, and are elongated holes 42 (see FIG. 3) that are formed through a plurality of locations (for example, 4 locations at intervals of 90 degrees) of the backup ring 25. A pair of pin portions 41 that are positioned point-symmetrically are inserted into two long holes 42 that are positioned point-symmetrically among the four long holes 42.

  In the remaining two long holes 42, pin portions projecting from a plurality of locations (for example, two locations having an interval of 180 degrees) on the other side of the intermediate rotating body 13 toward the other side in the axial direction. 43 (shown by a two-dot chain line in FIG. 3) is inserted. These pin portions 41 and 43 and the long hole 42 have a rotatable range when the other side rotating body 15 and the backup ring 25 are relatively rotated and a rotatable range when the intermediate rotating body 13 and the backup ring 25 are relatively rotated. It is something to regulate.

Next, the operation of the overload protection device 11 configured as described above will be described with reference to the drawings as appropriate.
As a premise, the overload protection device 11 in this case has a hub 12 coupled to a motor (not shown) serving as a drive source, and a driven device serving as a drive load on the one-side rotating body 14 serving as a drive plate. (Not shown) is connected. Further, during normal operation, torque is transmitted while rotating in the A direction indicated by the solid arrow in FIGS. 2 to 7, and when returning from the torque cutoff state, the torque is transmitted in the B direction indicated by the solid arrow in FIGS. Shall be. Then, it is assumed that the rotation of the one-side rotator 14 connected to the driven device is stopped during an overload when the driving load becomes large.

  Now, as shown in FIG. 2, the overload protection device 11 is in the first sphere that is engaged with the one-side recess 32 and the shallower-side recess 33 in the normal state where the drive load is not overload. Torque from the motor is transmitted via 34. That is, when the hub 12 is driven and rotated in the direction A in FIG. 2, the other-side rotating body 15 in which the key groove 29 is fitted to the key 30 also rotates in the same direction. In this case, since the other side rotator 15 is urged to one side in the axial direction by the urging member 23, the other side rotator 15 is engaged with the shallower side recess 33. The first spherical body 34 maintains the engaged state in pressure contact with the one-side concave portion 32 of the one-side rotating body 14. Therefore, the torque transmitted from the motor via the hub 12, the other side rotator 15 and the first sphere 34 is transmitted from the first sphere 34 to the one side rotator 14. To the driven device.

On the other hand, during overload, the torque transmission is cut off as shown in FIGS.
When an overload occurs, the intermediate rotator 13 and the other-side rotator 15 (and the backup ring 25) continue to rotate, but the one-side rotator 14 stops its rotation. Therefore, in the normal state, as shown in FIG. 3, the intermediate rotating body 13 and the other side rotation in which the respective positions in the circumferential direction of the concave line 17 and the alignment hole 15 a coincide with the concave line 18 of the one side rotating body 14. The body 15 rotates relative to the one-side rotating body 14 in the A direction.

  First, immediately after the occurrence of an overload, the intermediate rotating body 13 is rotated on one side so that the groove 17 is slightly displaced in the A direction from the groove 18 (for example, about 5 degrees) as shown in FIG. Rotates relative to the body 14. Therefore, the first sphere 34 accommodated and held in the hole 31 of the intermediate rotator 13 also moves in the A direction according to the rotation of the intermediate rotator 13. As a result, the first spherical body 34 comes out from the one side recess 32 of the one side rotating body 14 to the other side in the axial direction, and the other side rotating body 15 is attached to the biasing member 23 as shown in FIG. Push back against the force to the other side in the axial direction (that is, the right side in the figure). At this time, as shown in FIG. 5, the first sphere 34 rolls in the circumferential direction along the arc groove 39 on the surface on one side of the other-side rotating body 15 and has been shallowly engaged until then. It moves to the position between the other side recessed part 33 and the other side recessed part 33 of the deeper one side next to it.

  At this time, the backup ring 25 also initially rotates in the A direction together with the other-side rotating body 15, so that the second sphere 38 accommodated and held in the holding hole 35 of the backup ring 25 also moves in the A direction according to the rotation of the backup ring 25. Move to. As a result, the second spherical body 38 comes out from the one side holding recess 36 of the intermediate rotating body 13 to the other side in the axial direction. At this time, as shown in FIG. 5, the second sphere 38 rolls in the circumferential direction along the arc groove 40 on the surface on one side of the other side rotating body 15, and has engaged with the other side until then. A position state immediately after coming out of the side holding recess 37 is obtained.

  In this state, as shown in FIGS. 4 and 5, the second sphere 38 is in a position along the arc groove 40 in the other side rotator 15, and is still in the middle rotator 13 and the other side rotator 15. It is not in the state of being pinched between the mutually opposing surfaces. Therefore, in this state, the first sphere 34 is sandwiched between the other side rotator 15 and the one side rotator 14 based on the urging force of the urging member 23. Then, the first spherical body 34 rolls in such a state that the pressure is sandwiched between the other-side rotating body 15 and the one-side rotating body 14, so that the other-side rotating body 15 and the one-side rotating body 14 are turned around. Rotate in directions opposite to each other. As a result, as shown in FIG. 5, the other-side rotating body 15 has a positioning hole 15 a slightly in the A direction (for example, about 5 degrees) from the concave strip 17 and further in the A direction from the concave strip 18 ( For example, about 10 degrees), relative rotation is performed with respect to each of the intermediate rotating body 13 and the one-side rotating body 14 so as to be displaced.

  When the other side rotator 15 further rotates in the A direction from that state, as shown in FIGS. 6 and 7, the first sphere 34 has the other side recess 33 engaged in the normal state of FIG. 3. It will be in the state which engaged with the other other side recessed part 33a of the next one, and will be in a non-contact state with respect to the one side rotary body 14 which has stopped rotation. Further, at the same time that the first sphere 34 engages (accommodates) the deeper second recess 33a, the other rotator 15 moves to one side in the axial direction by the urging force of the urging member 23. Then, the second sphere 38 is sandwiched between the opposing surfaces of the intermediate rotator 13 and the other rotator 15 by the movement of the other rotator 15 to one side, and the first sphere 34 In a state where the urging force of the urging member 23 does not reach, the non-contact state with respect to the one-side rotating body 14 is maintained. Therefore, the other-side rotating body 15 and the intermediate rotating body 13 are idled with respect to the one-side rotating body 14 whose rotation is stopped, and as a result, the transmission of torque via the first sphere 34 is interrupted. . During this idling, there is no portion that slides with respect to the one-side rotating body 14 that has stopped rotating in the other-side rotating body 15 and the intermediate rotating body 13, so that, for example, idling continues in a state where the motor is directly connected. Even if it happens, there is no problem such as wear.

  As shown in FIG. 7, at this time, the other-side rotating body 15 has the pin portion 41 locked to one end of the long hole 42 of the backup ring 25, and the intermediate rotating body 13 has the pin portion 43 having the length of the backup ring 25. The other end of the hole 42 is locked. That is, the other-side rotating body 15 rotates relative to the intermediate rotating body 13 so that the alignment hole 15a is slightly displaced in the A direction from the concave strip 17 of the intermediate rotating body 13 (for example, about 20 degrees). In this state, the idling of the one-side rotator 14 is continued together with the intermediate rotator 13.

  In this case, the intermediate rotating body 13 is integrally formed on the outer periphery of the hub 12, and the other-side rotating body 15 is not key-connected to the hub 12 and is rotatable with respect to the hub 12. (Hereinafter referred to as “comparison configuration”), it may be impossible to obtain a torque transmission interruption state. That is, in order to obtain an interrupted state of torque transmission with the occurrence of overload, the intermediate rotator 13 holding the first sphere 34 in the hole 31 and the other rotator 15 having the other recesses 33 and 33a are provided. It is necessary to rotate in the direction opposite to the circumferential direction. However, in the case of the comparative configuration, the rolling of the first sphere 34 changes to slip with respect to the other rotating body 15 that is rotatable, and the first sphere 34 is inserted into the relatively deeper recess 33a. May not be engaged, and if that happens, the idle state cannot be obtained. In this regard, in the case of the present embodiment, the other-side rotating body 15 can rotate integrally with the hub 12, while the intermediate rotating body 13 is moved in the axial direction while facing the other side in the axial direction. Since it is freely rotatable around the axis, there is no such inconvenience.

  Further, the hole 31 for accommodating and holding the first sphere 34 is formed through the intermediate rotating body 13, while the holding hole 35 for accommodating and holding the second sphere 38 is a backup ring having a separate structure from the intermediate rotating body 13. 25 is formed through. That is, a plurality of types of holes (in this case, the hole 31 for the first sphere 34 and the holding hole 35 for the second sphere 38) are mixed for one rotating body such as the intermediate rotating body 13 and the backup ring 25. Thus, a single type of hole is formed through. Therefore, it is possible to suppress a decrease in the strength of the rotating body (intermediate rotating body 13, backup ring 25) due to the through-holes being formed, and it is not necessary to form a plurality of types of holes that are displaced in the radial direction. Concerns that compactness is hindered by space constraints can also be reduced.

Next, when returning from the torque transmission interrupted state to the normal state where torque is transmitted again, the following returning operation is performed.
First, as shown in FIGS. 8 and 9, in a state where the rotation of the hub 12 is stopped, the intermediate rotator 13 and the one-side rotator 14 are manually rotated relative to each other, so that the recess 17 of the intermediate rotator 13 is obtained. And the concave strip 18 of the one-side rotator 14 are matched so as to face each other in the axial direction. That is, by setting the concave line 17 and the concave line 18 to have a predetermined relative positional relationship, the concave line 17 and the concave line 18 extend in a straight line across the opposing surfaces of the rotating bodies 13 and 14. A groove 19 is formed. Then, the position of the hole 31 that accommodates and holds the first sphere 34 in the intermediate rotator 13 that cannot be visually recognized from the outside, and the position of the one-side recess 32 that can also engage the first sphere 34 in the one-side rotator 14. The positional relationship for return is opposite in the axial direction.

  As a result, the user of the overload protection device 11 can visually recognize the groove 19 formed by aligning the groove 17 and the groove 18 so that the hole of the intermediate rotating body 13 cannot be visually recognized. It can be identified that the position of 31 and the position of the one-side concave portion 32 of the one-side rotating body 14 are in a positional relationship for return facing in the axial direction. In this regard, when the recess 17 and the recess 18 are in a positional relationship for return in which the hole 31 of the intermediate rotating body 13 and the one side recess 32 of the one side rotating body 14 face each other in the axial direction, It functions as an identification part (a hole position identification part, a concave part position identification part) that makes it possible to visually identify that the positional relationship has been reached.

  Next, as shown in FIG. 8 and FIG. 9, the rod-shaped member 20 is fitted into the groove 19 formed by connecting the groove 17 and the groove 18, and the hole 31 and the one-side recess 32 are axially formed. The relative rotation between the intermediate rotating body 13 and the one-side rotating body 14 in a state of facing each other is restricted. Then, in this state, the hub 12 is rotated in the direction B in FIGS. That is, the other-side rotating body 15 is rotated together with the hub 12 in the direction opposite to that in the normal state of FIGS. At this time, the other side rotator 15 is in a state in which the urging force of the urging member 23 is exerted on the intermediate rotator 13 via the second sphere 38. While rolling with respect to the intermediate rotating body 13, the needle bearing 21 between the hub 12 and the intermediate rotating body 13 also rolls with respect to the intermediate rotating body 13. Therefore, the other side rotator 15 can be rotated together with the hub 12 by hand without a heavy load, and a quick and easy return operation can be realized.

  Then, when the other side rotator 15 is rotated in this way, the second sphere 38 moves along the arc groove 40 in the direction opposite to the time when the overload occurs in the circumferential direction, and the intermediate rotator 13 is held on one side. It will be in the state engaged between the recessed part 36 and the other side holding recessed part 37 of the other side rotary body 15. FIG. Therefore, the second sphere 38 is released from the state in which the second sphere 38 is sandwiched between the intermediate rotator 13 and the other rotator 15 and receives the urging force of the urging member 23. Then, the other side rotator 15 is pressed and moved toward one side in the axial direction by the urging force of the urging member 23, and presses the first sphere 34 toward the one side rotator 14.

  At this time, since the other-side rotating body 15 rotates in the B direction together with the hub 12, the relatively shallow other-side concave portion 33 on the one-side surface faces the hole 31 of the intermediate rotating body 13 in the axial direction. It becomes like this. Then, since the hole 31 of the intermediate | middle rotary body 13 which accommodates and hold | maintains the 1st spherical body 34 and the one side recessed part 32 of the one side rotary body 14 are facing the 1st spherical body 34 in the axial direction, the other side rotary body 15 is engaged with the concave portion 32 on one side. As a result, as shown in FIG. 2, the first spherical body 34 is formed by the biasing force of the biasing member 23 with the one-side recess 32 of the one-side rotating body 14 and the relatively shallow other-side recess 33 of the other-side rotating body 15. The pressure is sandwiched between the two, and the normal state where torque can be transmitted is restored.

According to said embodiment, the following effects can be acquired.
(1) In the state where torque transmission is interrupted, the intermediate rotator 13 and the one-side rotator 14 rotate relative to each other so that the position of the hole 31 holding the first sphere 34 and the first sphere 34 can be engaged with each other. The position of the recess 32 may be displaced in the circumferential direction. However, even if it is misaligned, the hole 31 and the one-side recess 32 are axially formed using the recess 17 and the recess 18 provided in the intermediate rotating body 13 and the one-side rotating body 14. Thus, it is possible to quickly and easily perform the alignment so as to obtain a positional relationship for returning opposite to each other. Therefore, it is possible to quickly and easily perform a return operation from the state where the torque transmission is interrupted to the normal state where the torque is transmitted.

  (2) The intermediate rotator 13 is provided with a recess 17 as a hole position identification portion, and the one-side rotator 14 is provided with a recess 18 as a recess position identification portion. Therefore, by rotating at least one of the intermediate rotator 13 and the one-side rotator 14 so that the recesses 17 and 18 have a preset relative positional relationship, holes in the intermediate rotator 13 are obtained. The position of 31 and the position of the one-side recess 32 in the one-side rotating body 14 can be simply set in a positional relationship for return.

  (3) Since the concave strip 17 as the hole position identifying portion of the intermediate rotating body 13 and the concave strip 18 as the concave position identifying portion of the one-side rotating body 14 are both in a shape having irregularities, they are used for alignment from the outside. It becomes possible to lock the rod-shaped member 20 as the jig. Therefore, the hole 31 and the one-side recess 32 are restored by rotating the other-side rotating body 15 in the direction opposite to that in the normal state in a state where the rod-shaped member 20 as such a positioning jig is locked. Thus, it is possible to easily perform the return operation from the torque transmission interruption state to the normal state while maintaining the positional relationship.

  (4) When the groove 17 as the hole position identifying portion of the intermediate rotating body 13 and the groove 18 as the recessed position identifying portion of the one-side rotating body 14 are aligned in a preset relative positional relationship, The outer surface of the rotating body 13 and the outer surface of the one-side rotating body 14 are provided with a groove 19 that is a kind of a groove extending across the opposing surfaces of the rotating bodies 13 and 14. Therefore, the position of the hole 31 in the intermediate rotating body 13 and the one-side rotating body 14 are fitted by fitting a rod-shaped member 20 as a jig from the outside into the concave groove 19 extending across the opposing surfaces of both the rotating bodies 13 and 14. Can be maintained in a state in which the position of the one-side recess 32 is opposed in the axial direction.

  (5) The intermediate rotator so that the groove 17 as the hole position identifying portion of the intermediate rotator 13 and the groove 18 as the recess position identifying portion of the one-side rotator 14 face each other in the axial direction. If at least one of 13 and the one-side rotating body 14 is rotated, the hole 31 of the intermediate rotating body 13 and the one-side recess 32 of the one-side rotating body 14 face each other in the axial direction. Therefore, it becomes easier to align the position of the hole 31 in the intermediate rotating body 13 and the position of the one-side recess 32 in the one-side rotating body 14 for returning.

In addition, you may change said embodiment as follows.
In the above embodiment, the preset relative positional relationship between the hole position identification part (concave 17) of the intermediate rotator 13 and the concave position identification part (concave 18) of the one-side rotator 14 is the axial direction It is not necessary to have a positional relationship facing each other. In short, the positional relationship between the hole position identification part (concave line 17) and the concave part position identification part (concave line 18) on the appearance is such that the hole 31 and the one-side concave part 32 that are not visible from the outside face each other in the axial direction. Anything that can be identified as being in the positional relationship for return is acceptable. For example, the relative positional relationship may be a positional relationship shifted in the circumferential direction by a preset distance.

  In the above-described embodiment, the concave line 17 as the hole position identifying unit and the concave line 18 as the concave position identifying unit may not extend to the opposing surfaces of the intermediate rotating body 13 and the one-side rotating body 14. For example, in the outer peripheral surface of each rotary body 13 and 14, the short groove which does not connect between each one side surface and the other side surface may be sufficient.

  -In the said embodiment, you may comprise a hole position identification part and a recessed part position identification part with a convex strip instead of a concave strip. In short, any shape having irregularities capable of locking the jig may be used. Therefore, it is not limited to a recess or protrusion, but may be a recess such as a simple hole or a protrusion such as a protrusion.

  In the above embodiment, the hole position identifying portion and the recessed portion position identifying portion are not the outer peripheral surfaces of the intermediate rotating body 13 and the one-side rotating body 14, but an outer surface portion that is perpendicular to the axial direction as long as it is visible from the outside. It may be. For example, in the case of the intermediate rotator 13, if the outer diameter is larger than that of the one-side rotator 14, the hole position identification unit is provided in the outer surface portion orthogonal to the axial direction instead of the outer peripheral surface of the intermediate rotator 13. be able to.

  In the above embodiment, the hole position identification part and the concave part position identification part are not limited to the shape having irregularities such as the concave stripes 17 and 18, but can be visually recognized as long as they are visible on the plane. It may be provided by various notations.

  In the above embodiment, when the intermediate rotating body 13 and the one-side rotating body 14 are manually rotated relative to each other so that the hole position identifying portion and the recessed portion position identifying portion have a preset relative positional relationship, Both of the side rotating bodies 14 may be rotated with each other, or only one of them may be rotated.

  In the above embodiment, in the state in which the hole position identification unit and the recess position identification unit are set in a predetermined relative positional relationship to return from the torque transmission interruption state to the normal state, the other-side rotating body 15 is in the normal state. Instead of rotating in the opposite direction, the one-side rotating body 14 may be rotated in the direction opposite to the direction B in FIG.

  In the above embodiment, the other-side recesses 33 and 33a in the other-side rotating body may be only the deeper other-side recess 33a. That is, the first sphere 34 may be in contact with one surface of the other-side rotator 15 in the normal state of FIG. Even in such a configuration, when an overload occurs, the first sphere 34 engaged with the deeper second recess 33a can easily take a state away from the one-side rotator 14 that has stopped rotating. It is suppressed that the 1st spherical body 34 hits the one side recessed part 32 of the one side rotary body 14 at the time of idling.

  DESCRIPTION OF SYMBOLS 11 ... Overload protective device, 13 ... Intermediate | middle rotary body, 14 ... One side rotary body, 15 ... Other side rotary body, 17 ... Concave (identification part, hole position identification part), 18 ... Concave (identification part, recessed part) (Position identification part), 19 ... concave groove (identification part), 23 ... urging member, 31 ... hole, 32 ... one side concave part (concave part), 34 ... first sphere, 38 ... second sphere.

Claims (5)

An intermediate rotating body provided in a hole penetrating in the axial direction, the first sphere being held so that a part of the first sphere protrudes from the hole, and being rotatable around the axis;
A one-side rotating body provided on the surface facing the intermediate rotating body from one side in the axial direction and having a recess that allows the first sphere to engage with the intermediate rotating body;
The other side rotating body provided to be movable in the axial direction and to be rotatable about the axis facing the intermediate rotating body from the other side in the axial direction;
An urging member for urging the other-side rotating body toward one side in the axial direction;
At the time of overload when the transmission torque between the one-side rotator and the other-side rotator via the first sphere engaged with the recess exceeds a preset torque range, The intermediate rotator is capable of restricting the first sphere, which is disengaged from the recess toward the other side in the axial direction against the urging force of the urging member, from being pressed toward the recess by the other rotator. And a second sphere that is sandwiched between the rotating body on the other side and
With
When the intermediate rotating body and the one-side rotating body have a return positional relationship in which the hole of the intermediate rotating body and the concave portion of the one-side rotating body face each other in the axial direction, An overload protection device provided with an identification unit that makes it possible to visually identify that a relationship has been established.   The identification unit includes a hole position identification unit provided in the intermediate rotator and a recess position identification unit provided in the one-side rotator, and the hole and the recess have a positional relationship for the return. 2. The overload according to claim 1, wherein the hole position identification unit and the recess position identification unit are visually recognized from the outside in a relative positional relationship set in advance in a circumferential direction around the axis. Protective device. The hole position identification unit is provided in a shape that allows a positioning jig to be locked from the outside on the outer surface of the intermediate rotating body,
3. The overload according to claim 2, wherein the recess position identifying portion is provided in a shape that allows the jig locked to the hole position identifying portion from the outside to be locked on an outer surface of the one-side rotating body. Protective device. The hole position identification unit is provided in the shape of a concave or convex line extending to the outer surface of the intermediate rotating body up to a surface facing the one-side rotating body,
The recess position identification unit has the same shape as the hole position identification unit among the recesses and the protrusions, and extends to the outer surface of the one-side rotating body up to a surface facing the intermediate rotating body, thereby identifying the hole position. The overload protection device according to claim 3, wherein the overload protection device is provided in a shape connected to the portion.   The hole position identifying portion and the recess position identifying portion are provided so as to be in a positional relationship facing each other in the axial direction in the relative positional relationship. The overload protection device described in 1.