JP2015203434A - Load sensitive type change gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a load sensitive type change gear for performing a smooth change-over from a constant velocity transmission state to a reduction transmission state as a load torque acting on an output shaft is increased.SOLUTION: There is provided a change-over mechanism A in which when an oscillation member 20 is kept at a constant velocity transmission attitude, a first engaging part 21 of the oscillation member 20 is engaged with an engaging recess 15 of a carrier 14 so as to integrally rotate a sun gear of a planetary gear reducer mechanism, the carrier 14 and an output shaft 2 and to make a reduction speed transmission state. When a load torque acting on the output shaft 2 is increased, the oscillation member 20 starts to oscillate and the first engaging part 21 is removed from the engaging recess 15, a guide part 15A for moving the oscillation member 20 to the reduction speed transmission attitude is formed in a region communicated with the engaging recess 15.

Description

  The present invention relates to a load-sensitive transmission, and more specifically, when the load acting on the output system is low, transmission is performed at a constant speed, and when the load acting on the output system increases, deceleration is performed by mechanical operation. The present invention relates to a transmission.

  As a load-sensitive transmission configured as described above, Patent Document 1 includes an input shaft that rotates integrally with the sun gear of the planetary gear transmission mechanism, and an output shaft that transmits the driving force from the planetary gear transmission mechanism. A switching mechanism that maintains a constant speed transmission state when the load torque acting on the output shaft is less than a set value and switches to a deceleration transmission state when the load acting on the input shaft exceeds the set value Technology is shown.

  In Patent Document 1, the input shaft rotates integrally with the sun gear, and the output shaft rotates integrally with the carrier. The switching mechanism includes a switching member that can switch between a constant speed transmission posture and a deceleration transmission posture with respect to the ring gear, and includes a spring that maintains the switching member in the constant speed transmission posture.

  In the first embodiment of Patent Document 1, the switching member includes a pair of contact arms and a single engagement pin. When the load torque acting on the output shaft is less than the set value, the engagement pin is engaged with the concave portion on the carrier outer periphery of the planetary reduction mechanism by maintaining the switching member in the constant speed transmission posture. A high-speed transmission state in which the input shaft and the output shaft are rotated together appears. On the other hand, when the load acting on the output shaft reaches the set value or more, the engagement pin is separated from the concave portion by switching the switching member to the deceleration transmission posture against the biasing force of the spring. At the same time, the abutment arm engages with the restraining tooth portion of the fixed system, and a deceleration transmission state in which the driving force decelerated by the planetary deceleration mechanism is transmitted to the output shaft appears.

JP 2013-245786 A

  In the configuration of Patent Document 1, in order to engage the engaging pin of the switching member with the concave portion on the outer periphery of the carrier in a state where the switching member is in the constant speed transmission posture, the biasing force of the spring causes the carrier and the ring gear to It acts in the direction of maintaining the relative rotational phase.

  In this configuration, when the load torque acting on the output shaft increases, the relative rotational phase between the carrier and the ring gear is displaced, and the positional relationship between the concave portion and the engagement pin changes with this displacement. Swinging in the direction of the transmission posture is performed.

  In addition, when the switching member swings to the deceleration transmission posture, the force acting between the recess and the engagement pin also acts in the direction of the deceleration transmission posture, so that there is a surface that facilitates the oscillation. However, in the configuration of Patent Document 1, the switching member swings in accordance with the displacement of the relative rotational phase between the carrier and the ring gear, and the engagement pin comes out of the recess before reaching the state where the contact arm engages the restraining tooth portion. Due to the separation, it is difficult to continue the posture change, and there is room for improvement from the viewpoint of smooth switching.

  Further, in the configuration of Patent Document 1, when the contact arm is engaged with the restraining tooth portion, the tip portion of the contact arm needs to be fitted into the valley portion of the restraining tooth portion. Depending on the timing, it may come into contact with the crest portion of the restraining tooth portion and may not be engaged. When the engagement cannot be achieved in this manner, the swing toward the deceleration transmission posture is performed at a predetermined cycle, and depending on this cycle, the contact arm repeatedly abuts against the mountain-shaped portion of the restraining tooth portion. It sometimes took time to reach the final state.

  An object of the present invention is to rationally configure a load-sensitive transmission that can smoothly switch from a constant speed transmission state to a deceleration transmission state as the load torque acting on the output shaft increases.

A feature of the present invention is that a case main body includes a sun gear provided on an input shaft that rotates only in one direction, a carrier that supports a planetary gear that engages with the sun gear, an output shaft, and a ring gear that meshes with the planetary gear. And on the same axis of rotation inside
In the ring gear, a swing member that is loosely fitted to a support shaft parallel to the rotation shaft core and operates around the support shaft, and is fixed to the case body in a state of being located on the inner peripheral side of the swing member. A regulating gear having a plurality of convex portions provided intermittently along the circumferential direction so that the rocking member is engaged and disengaged, and the rocking member is intermittently provided along the circumferential direction at an outer edge portion of the carrier. A first engaging portion that can be engaged with and disengaged from a plurality of engaging recesses provided on the base, and a second engaging portion that can be engaged and disengaged from the convex portion of the restriction gear,
A guide portion is formed on the edge portion between the plurality of engagement recesses in the carrier, and the first engagement portion separated from the engagement recess is in sliding contact. It is formed with a larger diameter on the upper side along the relative rotation direction,
The first engagement portion is engaged with the engagement recess by the urging member, and the second engagement portion is in a constant speed transmission posture separated from the projection, so that the input shaft, the output shaft, When the ring gear rotates integrally and the load acting on the output shaft increases, the ring gear rotates relative to the carrier in the direction opposite to the carrier and resists the biasing force of the biasing member. And the second engaging portion engages with the convex portion, so that the swinging member is in a deceleration transmission posture and the rotation of the ring gear is stopped. is there.

According to this configuration, the load torque acting on the output shaft increases, and after the first engagement portion is released from the engagement recess due to a change in the relative rotation phase between the carrier and the ring gear, the first engagement portion is Displaces along the guide. Since the guide portion is formed to have a larger diameter toward the upper side along the relative rotation direction of the carrier, the guide portion swings with respect to the first engagement portion when the change in the relative rotation phase continues. A force for continuously moving the member toward the deceleration transmission posture is continuously applied, and after this movement, the transition to the deceleration transmission posture in which the second engagement portion is engaged with the restriction gear is smoothly performed.
In particular, in this configuration, since the input shaft is driven and rotated in one direction, the guide portion can be formed over the entire region between the adjacent engaging recesses and the engaging recesses. Smooth movement of the moving member is realized.
Therefore, a load-sensitive transmission is configured that can smoothly switch from the constant speed transmission state to the deceleration transmission state as the load torque acting on the output shaft increases.

  In the present invention, a plurality of the convex portions are formed so that the restriction gear protrudes outward from a circumferential surface having the rotation axis as a center, and the plurality of convex portions are formed on the circumferential surface. They may be arranged at unequal intervals in the direction along.

  According to this, since the plurality of convex portions are formed to protrude outward from the circumferential surface, and the plurality of convex portions are formed at unequal intervals in the circumferential direction, the swing member is moved to the deceleration transmission posture. Is performed at a period determined from the positional relationship between the first engagement portion and the engagement recess, even if the second engagement portion abuts the protruding portion (vertex portion) of the protrusion, At the time of contact, the second engaging portion comes into contact with the convex portion, and the state can be reliably shifted to the restricted state.

  In the present invention, the hole portion through which the support shaft is inserted is formed in a long hole shape that allows displacement in a direction approaching the rotating shaft core in a state where the swinging member is in a constant speed transmission posture. May be.

  According to this, the swing member can be switched between the constant speed transmission posture and the deceleration transmission posture by swinging around the axis of the support shaft. Further, the swing member can be shifted in a direction approaching the rotation axis with respect to the support shaft and a direction away from the rotation axis. As a result, in the constant speed transmission posture, the swing member is shifted in a direction approaching the rotation axis, and the first engagement portion is reliably engaged with the engagement recess. Further, immediately after the tip of the second engaging portion comes into contact with the convex portion due to the swing of the swing member, the ring gear and the carrier rotate relative to each other, so that the swing member has the second engagement portion of the second engagement portion. A force that rotates around the tip acts. Thus, the rotational force acts and the first engaging portion moves along the guide portion. As a result, the swinging member shifts to the deceleration transmission posture while being displaced along the hole portion. As a result, in the deceleration transmission posture, the swinging member is displaced to a position shifted in a direction away from the rotation axis, and the first engagement portion is greatly separated from the engagement recess, thereby avoiding interference with the carrier. It becomes possible.

  In the present invention, the first engaging portion is formed of an engaging pin that is in a posture parallel to the rotating shaft core, and the swinging member is in the constant speed transmission posture in a direction along the rotating shaft core. In view, the engagement pin is in the engagement recess at a position where the carrier moves away in the direction of relative rotation by the increase of the load with reference to a virtual straight line connecting the rotation axis and the support shaft. May be engaged.

  According to this, in a situation where the swinging member is in the constant speed transmission posture, it can be said that the engagement position of the engagement pin is in a positional relationship that already precedes the direction of the deceleration transmission posture from the constant speed transmission posture. Because of this positional relationship, the load acting on the output shaft increases, the relative rotational phase of the carrier and the ring gear changes, and the swinging member is caused by the force acting on the engagement pin from the engagement recess of the carrier. When starting to swing in the direction of the deceleration transmission posture, the moving component in the direction of pulling out from the engaging recess acts on the engaging pin from the initial stage of the swinging, so that it is easy to detach from the engaging recess. And allowing smooth transition to the reduced speed transmission posture of the swing member.

  According to the present invention, the plurality of swing members are formed with a first support arm and a second support arm extending in a direction away from each other in the circumferential direction of the ring gear, and the first support arm in the circumferential direction of the ring gear. The arm length of the support arm and the arm length of the second support arm are set to different values, and span the first support arm of the swing member and the second support arm of the swing member adjacent thereto. A tension type coil spring may be provided as the biasing member.

  In this configuration, a plurality of coil springs having the same urging force are used, and the swinging member is maintained in a constant speed transmission posture by the urging forces of the plurality of coil springs. Also, when shifting from the constant speed transmission state to the deceleration transmission state, or conversely, when shifting from the deceleration transmission state to the constant speed transmission state, the postures of the plurality of oscillating members are changed via coil springs. Can be changed in conjunction with each other. For example, in a design in which the arm length of the first support arm is equal to the arm length of the second support arm, the arm length when setting the threshold value of the switching torque from the constant speed transmission state to the deceleration transmission state, Setting the biasing force is difficult. On the other hand, by setting the arm length of the first support arm and the arm length of the second support arm to different values, the degree of freedom in design increases, and the threshold value of the switching torque can be easily set.

It is sectional drawing of a load sensitive type transmission. It is the II-II sectional view taken on the line of FIG. It is the III-III sectional view taken on the line of FIG. It is a figure which shows the relationship between the engagement pin and engagement recessed part in a constant-speed transmission state. It is a figure which shows the rocking | swiveling member in the transition process from a constant speed transmission attitude | position to a deceleration transmission attitude | position. It is a figure which shows the relationship between the control arm of a deceleration transmission state, and a convex part. It is a disassembled perspective view of a load sensitive transmission.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Basic configuration]
As shown in FIGS. 1 to 3 and 7, the input shaft 1 driven by external power, the planetary gear reduction mechanism P to which the driving force of the input shaft 1 is transmitted, and the drive from the planetary gear reduction mechanism P An output shaft 2 to which force is transmitted and a switching mechanism A for controlling the planetary gear reduction mechanism P by a load torque T acting on the output shaft 2 are housed in the case body 3 to constitute a load-sensitive transmission. Yes.

  In this load-sensitive transmission, the driving force is transmitted to the input shaft 1 in the direction indicated by the driving direction R. The switching mechanism A performs transmission in a constant speed transmission state in which the input shaft 1, the ring gear 12, and the carrier 14 are integrally rotated in the driving direction R when the load torque T acting on the output shaft 2 is less than a threshold value. When the load torque T acting on the output shaft 2 reaches the deceleration threshold value or more, the rotation in the deceleration transmission state in which the rotational force decelerated by the planetary gear reduction mechanism P is transmitted to the output shaft 2 by blocking the rotation of the ring gear 12 is performed. . Note that the load torque T shown in the drawing indicates the direction of the torque, and the input shaft 1 and the output shaft 2 rotate in the driving direction R regardless of the value of the load torque T.

  The switching mechanism A returns to the constant speed transmission state again when the load torque T acting on the output shaft 2 in the deceleration transmission state falls below the above-described threshold. The operation mode when the automatic shift is performed by the load torque T acting on the output shaft 2 will be described later.

  The load-sensitive transmission of the present invention can be used for all automobiles, such as a drive system that adjusts the angle of the seat back of the automobile and a drive system that opens and closes the door glass. Note that the load-sensitive transmission of the present invention can be used for other than automobiles.

[Planetary gear reduction mechanism]
The planetary gear reduction mechanism P includes a sun gear 11, a ring gear 12, a plurality of planetary gears 13 that mesh with these, and a carrier 14 that supports the plurality of planetary gears 13. In this planetary gear speed reduction mechanism P, an input shaft 1, a planetary gear speed reduction mechanism P, and an output shaft 2 are rotatably provided on a rotation axis X and a coaxial axis.

  The sun gear 11 is formed integrally with the input shaft 1. The carrier 14 is formed integrally with the output shaft 2 in a plate shape in a posture orthogonal to the rotational axis X. The output shaft 2 is formed in a cylindrical shape having a hexagonal hole 2A that is coaxial with the rotational axis X.

  The output shaft 2 protrudes from both sides of the carrier 14 in the direction along the rotation axis X, and the input shaft 1 is supported by one projecting portion of the output shaft 2 through the first bush 16 so as to be relatively rotatable. A restriction gear 18 is supported on the other protrusion of the shaft 2 via a second bush 17 so as to be relatively rotatable.

  A needle bearing may be used in place of the first bush 16 and the second bush 17. Further, although the restriction gear 18 is connected and fixed to the case body 3, the restriction gear 18 may be integrally formed with the case body 3.

  The ring gear 12 is disposed at a position surrounding the sun gear 11. The carrier 14 is provided with a plurality of gear support shafts 19 in a posture parallel to the rotation axis X, and the planetary gear 13 is rotatably supported by these gear support shafts 19.

  In this load-sensitive transmission, since the input shaft 1 is formed in a cylindrical shape, a driving force is transmitted to the outer periphery of the input shaft 1 from a driving source such as an external electric motor. Moreover, since the hexagon hole 2A is formed in the output shaft 2, motive power is taken out by the hexagon shaft fitted to this.

[Switching mechanism]
The switching mechanism A includes a plurality of (three) swinging members 20 that are supported on the flange portion 12A of the ring gear 12 by the support shaft 27, and a plurality of biasing members that act on the swinging members 20 to apply a biasing force. (Three) tension type coil springs 28 are provided. Each coil spring 28 has the same urging force.

  The switching mechanism A includes an engaging pin 21 (an example of a first engaging portion) provided in the swing member 20 and a plurality of intermittently formed outer edges of the carrier 14 because the engaging pin 21 is engaged. The engaging recess 15, a regulating arm 22 (an example of a second engaging portion) integrally formed with the swing member 20, and a regulating gear 18 supported by the case body 3 so as to abut against the regulating arm 22. I have.

  The oscillating member 20 functions to exhibit a constant speed transmission state when in the constant speed transmission posture illustrated in FIGS. 2 and 4 and to exhibit a deceleration transmission state when in the deceleration transmission posture illustrated in FIG. 6. To do.

  The support shaft 27 is screwed and fixed to the flange portion 12A of the ring gear 12 in a posture parallel to the rotation axis X. A hole 20 </ b> A through which the support shaft 27 is inserted is formed at the center position of the swing member 20. The hole 20A is formed in a long hole shape extending in a direction along a virtual center straight line C connecting the hole 20A and the engagement pin 21.

  The engagement pin 21 (an example of a first engagement portion) is fixed to the swing member 20 in a posture parallel to the rotation axis X. A contact pin 25 is fixed to the flange portion 12A of the ring gear 12 in a posture parallel to the rotation axis X, and a contact surface 20B on which the contact pin 25 can contact is formed on the swing member 20. . Further, since the hole portion 20A is formed in a long hole shape and the swinging member 20 can be displaced to the outer peripheral side of the ring gear 12, the inner periphery of the flange portion 12A of the ring gear 12 is brought into contact with the engagement pin 21. A cutout portion 12B to be avoided is formed.

  The swing member 20 is integrally formed with a first support arm 23 and a second support arm 24 that extend in directions away from each other in the circumferential direction of the ring gear 12. A first hook portion 23 </ b> A is formed at the extended end of the first support arm 23, and a second hook portion 24 </ b> A is formed at the extended end of the second support arm 24.

  The arm length of the first support arm 23 in the circumferential direction of the ring gear 12 (distance from the hole portion 20A to the first hook portion 23A) is the arm length of the second support arm 24 (from the hole portion 20A to the second hook portion 24A). The distance is set shorter than Note that, by making the arm length of the first support arm 23 different from the arm length of the second support arm 24, the degree of freedom in design is increased and the threshold value of the switching torque can be easily set.

  A coil spring 28 is provided across the first hook portion 23 </ b> A of the adjacent first support arm 23 and the second hook portion 24 </ b> A of the second support arm 24 among the plurality of swing members 20. When the load torque T acting on the output shaft 2 is less than the set value, the coil spring 28 maintains the swing member 20 in a constant speed transmission posture and engages the engagement pin 21 with the engagement recess 15. And function to maintain a constant speed transmission state.

  In this configuration, since the arm length of the second support arm 24 is longer than the arm length of the first support arm 23, the force acting on the swing member 20 from the coil spring 28 via the second support arm 24 is A large force acts on the swing member from the coil spring 28 via the first support arm 23. As a result, the force for maintaining the swinging member 20 in the constant speed transmission posture is exerted strongly by the biasing force of the coil spring 28, and the torque at which the transition of the swinging member 20 from the constant speed transmission posture to the deceleration transmission posture is started. It is high.

  The engaging recess 15 is formed in a posture that cuts along the radial direction of the carrier 14 at equal intervals with respect to the outer edge of the carrier 14 and opens outward. Further, when the swinging member 20 swings from the constant speed transmission posture to the deceleration transmission posture while the input shaft 1 rotates in the driving direction R, the swinging member 20 is brought into contact with the engagement pin 21 to contact the swinging member. A guide portion 15 </ b> A that promotes the swinging of the 20 is formed. The guide portion 15A is formed to have a larger diameter toward the upper side along the relative rotation direction of the carrier 14 as the load torque T increases. As a result, the guide portion 15 </ b> A is inclined with respect to a virtual circle centered on the rotation axis X in a region continuous with the plurality of engagement recesses 15. In particular, in the load-sensitive transmission of the present invention, since the driving direction R of the input shaft 1 is determined, the guide portion 15A can be formed with a gentle gradient in the entire region between the adjacent engagement recesses 15. Smooth swing of the swing member 20 is realized.

  The restriction gear 18 includes a circumferential surface 18S centered on the rotational axis X and a plurality of convex portions 18T protruding outward from the circumferential surface 18S, and the plurality of convex portions 18T are formed on the circumferential surface 18S. Are arranged at unequal intervals in the direction along.

  2 and 4 to 6 show two types of intervals in the direction along the circumferential surface 18S of the convex portion 18T, but even if the interval is set to three or more types. Alternatively, three or more intervals may be set randomly in the circumferential direction. Since the switching mechanism A includes the three oscillating members 20, the three convex portions 18 </ b> T that are in contact with the corresponding convex portions 18 </ b> T at the same time are arranged in a predetermined positional relationship. For this reason, it is possible to set the intervals between the plurality of protrusions 18T to different values by providing three pairs of protrusions 18T as one set and providing a plurality of sets of protrusions 18T with different relative angles around the rotation axis X. It becomes possible.

  In this switching mechanism A, the constant speed transmission posture is maintained by the engagement pin 21 provided in the swing member 20 engaging with one of the plurality of engagement recesses 15 on the outer edge of the carrier 14. However, when the swinging member 20 is in the constant speed transmission posture, as shown in FIGS. 2 and 4, the contact pin 25 contacts the contact surface 20B.

  Further, as shown in FIG. 4, the carrier 14 increases the load torque T with reference to the virtual straight line L connecting the rotation axis X and the support shaft 27 in a state where the swinging member 20 is in a constant speed transmission posture. As a result, the engagement pin 21 engages with the engagement recess 15 at a position disengaged toward the side that advances in the relative rotation direction. Specifically, assuming an engagement straight line M connecting the rotation axis X and the engagement pin 21, the angle θ formed by the engagement straight line M and the above-described virtual straight line L is set to about 5 degrees. ing.

[Operating form]
The load-sensitive transmission of the present invention has a constant speed transmission state and a deceleration according to a load torque T acting on the input shaft 1 in a situation where the input shaft 1 is driven and rotated in the driving direction R as shown in FIGS. It is configured to automatically switch to the transmission state.

  From the configuration described above, when the load torque T acting on the output shaft 2 is less than the threshold value, each of the plurality of oscillating members 20 assumes a constant speed transmission posture by the urging force of the coil spring 28, and FIG. As shown in FIG. 4, the engagement pin 21 engages with the engagement recess 15 of the carrier 14. Thus, when the swinging member 20 is in the constant speed transmission posture, the swinging member 20 is moved until reaching the position where the support shaft 27 contacts the outer end side of the hole 20A by the biasing force of the coil spring 28. Since it is displaced (the oscillating member 20 is displaced in the direction approaching the rotation axis X), the engagement pin 21 is deeply fitted into the engagement recess 15 and this constant velocity transmission posture is maintained. Further, when the swing member 20 is in the constant speed transmission posture, the contact pin 25 contacts the contact surface 20B of the swing member 20.

  Thus, by maintaining the state in which the engagement pin 21 is engaged with the engagement recess 15, the input shaft 1, the sun gear 11, the plurality of planetary gears 13, the ring gear 12, the carrier 14, and the output shaft 2. Then, transmission is performed in a constant speed transmission state that rotates integrally in the driving direction R.

  Next, when the load torque T acting on the output shaft 2 increases beyond a threshold value, the planetary gear 13 starts to revolve around the rotation axis X, and the urging force of the coil spring 28 as shown in FIG. Against this, the ring gear 12 starts relative rotation in the direction opposite to the driving direction R. Thereby, the relative rotational phase of the ring gear 12 and the carrier 14 changes, and the engagement pin 21 is detached from the engagement recess 15. After this detachment, the engaging pin 21 is guided by the guide portion 15A, and the plurality of swinging members 20 are interlocked by the coil spring 28. Therefore, any swinging member 20 swings toward the deceleration transmission posture. Is promoted.

  As described above, in a state where the swing member 20 is in the constant speed transmission posture, the carrier 14 is deviated to the side delayed in the direction of relative rotation by the load torque T with reference to the virtual straight line L as shown in FIG. The engagement pin 21 is engaged with the engagement recess 15 at the position. This engagement position can be said to be a position preceding the direction in which the swing member 20 is displaced to the deceleration transmission posture. Accordingly, the load torque T acting on the output shaft 2 increases, the relative rotational phase between the carrier 14 and the ring gear 12 changes, and the rocking is caused by the force acting on the engagement pin 21 from the engagement recess 15 of the carrier 14. When the member 20 starts swinging in the direction of the deceleration transmission posture, the moving component in the direction of extracting from the engagement recess 15 acts on the engagement pin 21 from the initial stage of the swing, and the engagement recess 15 Can be easily detached from the swinging member 20 and the swinging member 20 can be smoothly shifted to the deceleration transmission posture.

  Further, the tip end (extension end) of the restriction arm 22 is displaced in a direction approaching the restriction gear 18 by swinging, and finally comes into contact with the convex portion 18T of the restriction gear 18 (strictly speaking, the circumferential surface 18S and Abuts on the boundary portion with the convex portion 18T). Thus, immediately after the tip of the restriction arm 22 contacts the convex portion 18T, the ring gear 12 and the carrier 14 rotate relative to each other, so that the swinging member 20 rotates around the tip of the restriction arm 22. A moving force is applied. When the rotational force acts in this manner, the swinging member 20 shifts to the deceleration transmission posture by swinging while being displaced along the longitudinal direction of the hole 20A. In this deceleration transmission posture, the swinging member 20 is displaced to a position shifted in a direction away from the rotation axis X, so that the engagement pin 21 is largely separated from the engagement recess 15 to avoid interference with the carrier 14. .

  Along with this swinging, the swinging member 20 is displaced generally along the longitudinal direction of the hole 20A in the outer peripheral direction of the ring gear 12, but the engaging pin 21 moves in the internal space of the notch 12B of the flange 12A. Therefore, the engagement pin 21 does not contact the inner periphery of the flange portion 12A.

  In the state where the swing member 20 has reached the deceleration transmission posture, the rotation of the ring gear 12 is blocked and the swing member 20 is maintained in the deceleration transmission posture as shown in FIG. In this manner, the ring gear 12 is maintained in a state in which the ring gear 12 is engaged and held with the restriction gear 18 formed integrally with the case main body 3, and the rotational force decelerated by the planetary gear reduction mechanism P is transmitted to the output shaft 2 in the reduction transmission state. Doing transmission.

  In particular, since the plurality of convex portions 18T are formed at unequal intervals in the circumferential direction, for example, even when the movement of the swinging member 20 to the deceleration transmission posture is performed at a fixed cycle, the tip of the restriction arm 22 Even when it comes into contact with the protruding portion (vertex portion) of the convex portion 18T, the tip of the restricting arm 22 is reliably brought into contact with the convex portion 18T during the subsequent contact, and the transition to the restricted state is ensured. To.

  The present invention can be used for a load-sensitive transmission that shifts to a decelerating state by a mechanical operation as the load torque acting on the output shaft increases.

DESCRIPTION OF SYMBOLS 1 Input shaft 2 Output shaft 3 Case main body 11 Sun gear 12 Ring gear 13 Planetary gear 14 Carrier 15 Engaging recessed part 15A Guide part 18 Restricting gear 18S Circumferential surface 18T Convex part 20 Oscillating member 20A Hole part 21 First engaging part / engagement Pin 22 Second engagement portion / regulator arm 23 First support arm 24 Second support arm 27 Support shaft 28 Biasing member / coil spring L Virtual straight line X Rotation axis

Claims (5)

A sun gear provided on an input shaft that rotates only in one direction;
A carrier that supports the planetary gear engaged with the sun gear and has an output shaft;
A ring gear meshing with the planetary gear is provided on the same rotational axis inside the case body, and
An oscillating member that is loosely fitted to a support shaft parallel to the rotation shaft in the ring gear and operates around the support shaft;
A restriction gear fixed to the case body in a state of being located on the inner peripheral side of the swing member, and having a plurality of convex portions provided intermittently along the circumferential direction so that the swing member is engaged and disengaged. Prepared,
The swinging member can be engaged with and disengaged from a first engaging part that can be engaged with and disengaged from a plurality of engaging recessed parts intermittently provided along the circumferential direction at the outer edge of the carrier, and a convex part of the restriction gear. A second engaging portion,
A guide portion is formed on the edge portion between the plurality of engagement recesses in the carrier, and the first engagement portion separated from the engagement recess is in sliding contact. It is formed with a larger diameter on the upper side along the relative rotation direction,
The first engagement portion is engaged with the engagement recess by the urging member, and the second engagement portion is in a constant speed transmission posture separated from the projection, so that the input shaft, the output shaft, The ring gear rotates integrally;
When the load acting on the output shaft increases, the ring gear rotates relative to the carrier in the opposite direction, and the first engaging portion moves away from the engaging recess against the urging force of the urging member. A load-sensitive transmission configured to be disengaged and configured so that the second engaging portion engages with the convex portion, whereby the swinging member assumes a deceleration transmission posture and the rotation of the ring gear stops.   The plurality of convex portions are formed so that the restriction gear protrudes outward from a circumferential surface centered on the rotation axis, and the plurality of convex portions are not aligned in a direction along the circumferential surface. The load-sensitive transmission according to claim 1, which is arranged at equal intervals.   The hole portion through which the support shaft is inserted is formed in a long hole shape that enables displacement in a direction approaching the rotating shaft core in a state where the swinging member is in a constant speed transmission posture. Item 3. A load-sensitive transmission according to item 1 or 2. The first engagement portion is configured by an engagement pin that is parallel to the rotation axis,
When the swinging member is in the constant speed transmission posture, the carrier increases the load with reference to a virtual straight line connecting the rotating shaft core and the support shaft in a direction view along the rotating shaft core. The load-sensitive transmission according to any one of claims 1 to 3, wherein the engagement pin engages with the engagement recess at a position that is disengaged in the direction of relative rotation due to rotation. The plurality of swing members are formed with a first support arm and a second support arm extending in a direction away from each other in the circumferential direction of the ring gear, and the arm of the first support arm in the circumferential direction of the ring gear. The length and the arm length of the second support arm are set to different values,
5. A tension-type coil spring is provided as the biasing member across the first support arm of the swing member and the second support arm of the swing member adjacent thereto. The load sensitive transmission according to one item.

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