JP5544417B2 - Clutch device - Google Patents

Description

  The present invention relates to a clutch device that transmits rotation in a certain direction, and relates to a clutch device that can increase transmission torque capacity and suppress energy loss even if it is small.

  As a clutch device that transmits rotation in a fixed direction, for example, Patent Document 1 discloses that the sprag is disengaged from the inner ring and the outer ring by applying a biasing force to the sprag during low and medium speed rotation. The outer ring rotates relative to the outer ring, and the centrifugal force is applied to the sprags against the urging force during high-speed rotation, so that the sprags are engaged with the inner ring and the outer ring, and the relative rotation between the inner ring and the outer ring is restricted. A sprag type one-way clutch is disclosed.

  However, the sprag type one-way clutch disclosed in Patent Document 1 cannot transmit rotation during low and medium speed rotation, and always transmits rotation in a fixed direction during high speed rotation. Therefore, rotation transmission in a fixed direction and switching between cutoffs cannot be performed as necessary.

  On the other hand, in Patent Document 2, a gap in which the facing interval changes along the circumferential direction is provided between the facing of the input shaft and the output shaft, and the retainer is pressed by a spring so that the friction element is placed in a portion having a large gap. Disclosed is a friction type one-way clutch on / off device in which the frictional engagement between the input shaft and the output shaft is released, the input shaft and the output shaft rotate relative to each other, and the transmission of power is cut off. Yes. In this device, a load greater than the holding force of the spring is applied to the retainer, and the friction element is moved to a portion with a small clearance in the rotational direction, so that the friction element is engaged with the input shaft and the output shaft, and the input shaft and the output shaft are output. Relative rotation with the shaft is restricted, and power is transmitted.

  In Patent Document 3, a wedge-shaped space is formed between the inner ring and the outer ring, and the retainer is pressed by a switch spring to hold the engaging element at the neutral position of the wedge-shaped space. A rotation transmission device is disclosed in which the engagement of the engagement element is released, the inner ring and the outer ring rotate relative to each other, and the transmission of power is interrupted. In this device, a load greater than the holding force by the switch spring is applied to the cage and the engagement element is moved in the rotational direction from the neutral position of the wedge-shaped space, so that the engagement element is engaged with the inner ring and the outer ring, Relative rotation with the outer ring is restricted, and power is transmitted.

  As described above, the devices disclosed in Patent Documents 2 and 3 apply a load to the friction element or the engagement element to move the friction element or the engagement element, thereby transmitting the rotation in a certain direction and switching between the interruptions. Can be done as needed.

Japanese Utility Model Publication No. 62-151440 Japanese Patent Laid-Open No. 5-149351 JP 2005-30443 A

  However, in the apparatus disclosed in Patent Document 2, a gap in which the facing interval changes is provided between the input shaft and the output shaft, and the friction element moves through the gap. Since this gap is provided along the circumferential direction of the input shaft, if the circumferential length of the input shaft, that is, the diameter of the input shaft is reduced, it becomes impossible to provide a large gap. Since power is transmitted through the friction elements accommodated in the gaps, the number of friction elements cannot be increased if the number of gaps decreases. As a result, a small device with a small diameter input shaft has a problem that the torque (transmission torque capacity) transmitted through the friction element cannot be increased.

  Similarly, in the apparatus disclosed in Patent Document 3, a wedge-shaped space is provided between the inner ring and the outer ring facing each other, and the engagement element moves in the wedge-shaped space. Since the wedge-shaped space is provided along the circumferential direction of the inner ring, if the circumferential length of the inner ring, that is, the diameter of the inner ring is reduced, it becomes impossible to provide a large number of wedge-shaped spaces. Since power is transmitted through the engagement elements accommodated in the wedge-shaped spaces, the number of engagement elements cannot be increased when the number of wedge-shaped spaces decreases. As a result, there is a problem that a small device with a small inner ring diameter cannot increase the transmission torque capacity.

  Furthermore, in the apparatuses disclosed in Patent Documents 2 and 3, since the direction in which the load is applied to move the friction element or the engagement element in the circumferential direction is the same circumferential direction as the direction of the holding force by the spring, It was necessary to make the magnitude of the load to be applied larger than the holding force by the spring. For this reason, there is a problem that the apparatus for applying the load is increased in size and a large load needs to be applied, resulting in an increase in energy loss.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a clutch device that can increase the transmission torque capacity and can suppress energy loss even if it is small. .

Means for Solving the Problems and Effects of the Invention

  According to the clutch device of the first aspect, the sprag has two engaging surfaces that are in contact with the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring, respectively, and in the circumferential direction between the outer peripheral surface and the inner peripheral surface. A plurality of arrangements are provided, and a load is applied by the load applying device and tilted in the locking direction, so that the two engaging surfaces engage with the outer peripheral surface and the inner peripheral surface, respectively, and the relative rotation between the inner ring and the outer ring is restricted. To do. A plurality of sprags can be arranged at small intervals between the outer peripheral surface and the inner peripheral surface by securing a distance enough to allow the sprags to tilt. Thereby, even if it is small, there exists an effect which can enlarge transmission torque capacity.

Further, the sprag tilted in the anti-lock direction so that one of the outer peripheral surface or the inner peripheral surface and one of the engagement surfaces is in contact with each other by the biasing force of the biasing member is caused by the load from the load applying device. When tilted in the locking direction so that the two engagement surfaces are in contact with the inner peripheral surface, the moment around the contact due to the biasing force of the biasing member and the moment around the contact due to the load from the load applying device The sprag is tilted in relation. The retainer is disposed at a position where the urging member is sandwiched between one of the outer peripheral surface and the inner peripheral surface with which one of the engagement surfaces is in contact, and one of the outer peripheral surface or the inner peripheral surface and one of the engagement surfaces. When the horizontal distance from the contact A to the contact B between the sprag and the biasing member is Lp, and the vertical distance from the contact A to the contact C between the retainer and the sprag is Lr, Lp <Lr is satisfied. Has been. Therefore, the sprag can be tilted with a load smaller than the biasing force of the biasing member. As a result, the load applying device can be reduced in size, and a small load can be used, so that energy loss can be suppressed.

  According to the clutch device of the second aspect, since the sprag is tilted in the anti-lock direction, a gap is formed between the other of the outer peripheral surface or the inner peripheral surface and the other of the engagement surfaces of the sprags. When the outer ring and the outer ring rotate relative to each other, it is possible to eliminate friction between the other of the outer peripheral surface or the inner peripheral surface and the other of the engagement surfaces of the sprags. Thereby, in addition to the effect of Claim 1, there exists an effect which can suppress the energy loss by the friction with an outer peripheral surface or an inner peripheral surface, and an engagement surface.

  According to the clutch device of the third aspect, the reaction force acting on the sprag from one of the outer peripheral surface or the inner peripheral surface at the contact point where one of the outer peripheral surface or the inner peripheral surface is in contact with one of the engagement surfaces is caused by the load applying device. Since the direction of the component component of the load direction acting on the sprag is the same direction as the lock direction, when a load is applied to the sprag by the load applying device, the engagement surface slides on the outer peripheral surface or the inner peripheral surface. Is prevented, and the sprag can be reliably tilted about the center. Thereby, in addition to the effect of Claim 1 or 2, there is an effect that the two engaging surfaces of the sprag can be reliably engaged with the outer peripheral surface and the inner peripheral surface by applying a load from the load applying device. is there.

  According to the clutch device of the fourth aspect, the sprags are disposed at equal intervals between the outer peripheral surface and the inner peripheral surface, and are brought into contact with each other by being tilted in the anti-lock direction. Tilt the sprags to restrain each other. By tilting the sprags until they are constrained to each other, a sufficient gap can be secured between the other of the outer peripheral surface or the inner peripheral surface and the other of the engaging surfaces. As a result, in addition to the effects of claim 2 or 3, when the inner ring and the outer ring rotate relative to each other, the other of the outer peripheral surface or the inner peripheral surface and the other of the engaging surfaces come into contact with each other, so Has the effect of preventing the relative rotation from being restricted due to engagement.

  According to the clutch device of the fifth aspect, the cage includes a holding portion that holds the sprag and a load transmission portion that transmits a load from the load applying device, and the load applying device is connected to the sprag via the cage. Thus, in addition to the effect of any one of claims 1 to 4, it is possible to apply a load to a plurality of sprags at once and to effectively apply a load to the sprags.

  In addition, since the holding part extends in the axial direction, the load transmitting part extends in a direction intersecting the axial direction, so that the load transmitting part extends in the axial direction. The size of the cage in the axial direction can be shortened and the clutch device can be reduced in size.

  According to the clutch device of the sixth aspect, since the load transmitting portion is formed in a gear shape and the load is transmitted from the load applying device via the gear mechanism, in addition to the effect of the fifth aspect, the load transmitting portion is held from the load applying device. Energy loss generated in the load transmission path to the cage can be reduced, and the load can be efficiently transmitted to the cage.

  According to the clutch device of the seventh aspect, since the load applying device is constituted by an electric motor, the structure of the load applying device is simplified as compared with the case where the load applying device is constituted by a cylinder, a solenoid or the like. The load applying device can be downsized, and in addition to the effect of any one of claims 1 to 6, there is an effect that the clutch device can be downsized.

  In addition, when the load applying device is configured to apply a load to the sprags via the cage, the cage rotates around the axis along with the rotation of the inner ring and the outer ring when the clutch device transmits the rotation. Therefore, the load applying device serves as the rotational resistance of the cage, but by configuring the load applying device with an electric motor, the rotational resistance of the cage can be reduced, and the inner ring and the outer ring can be rotated at high speed. On the other hand, since the cage does not rotate in a state where the rotation of the clutch device is interrupted, it is possible to apply a load to the sprags with an electric motor having a small driving energy, to suppress energy loss, and to reduce the size of the clutch device. There is an effect that can.

It is the schematic diagram which showed typically the vehicle by which the clutch apparatus in 1st Embodiment of this invention is mounted. It is an axial sectional view of a power transmission device provided with a clutch device. It is sectional drawing of the clutch apparatus in the III-III line of FIG. FIG. 3 is an exploded perspective view of a part of the clutch device. (A) is the elements on larger scale of the clutch apparatus which interrupts transmission of the power shown by enlarging the part shown by V of Drawing 3, and (b) is the elements on larger scale of the clutch apparatus which transmits power. . It is a schematic diagram of the sprag tilted in the anti-lock direction. (A) is the elements on larger scale of the clutch apparatus which interrupts transmission of the power in 2nd Embodiment, (b) is the elements on larger scale of the clutch apparatus which transmits motive power.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. First, a first embodiment will be described with reference to FIGS. FIG. 1 is a schematic diagram schematically showing a vehicle 100 on which the clutch device 1 according to the first embodiment of the present invention is mounted. Note that arrows FB and LR in FIG. 1 indicate the front-rear direction and the left-right direction of the vehicle 100, respectively.

  First, a schematic configuration of the vehicle 100 will be described. As shown in FIG. 1, the vehicle 100 drives a front unit 110 that drives a front wheel 101 (left front wheel 101FL and right front wheel 101FR) and a rear wheel 102 (left rear wheel 102BL and right rear wheel 102BR). The rear unit 120 is configured to be able to drive the front wheel 101 and the rear wheel 102 independently of each other. The front unit 110 mainly includes a motor 111 as a power source and a power transmission device 112 that transmits the power of the motor 111 to the front wheels 101, and is configured to be able to drive the front wheels 101 with the power of the motor 111.

  The rear unit 120 mainly includes a motor 121 as a power source and a power transmission device 122 that transmits the power of the motor 121 to the rear wheel 102, and the motor 121 is controlled according to the driving torque of the front wheel 101. Thus, the rear wheels 102 can be driven so that the driving torques of the front wheels 101 and the rear wheels 102 can be distributed appropriately according to the traveling state of the vehicle 100.

  The power transmission device 122 of the rear unit 120 incorporates the clutch device 1 (see FIGS. 2 and 3) according to the first embodiment of the present invention. The power transmission path from 121 to the rear wheel 102 can be cut off.

  Next, a detailed configuration of the clutch device 1 will be described with reference to FIGS. 2 to 4. 2 is an axial cross-sectional view showing a part of the power transmission device 122 including the clutch device 1 as a cross-sectional view, and FIG. 3 is a cross-sectional view of the clutch device 1 taken along line III-III in FIG. FIG. 4 is an exploded perspective view of a part of the clutch device 1.

  As shown in FIGS. 2 and 3, the clutch device 1 includes an inner ring 2, an outer ring 3 surrounding the outer periphery of the inner ring 2, a plurality of sprags 4 disposed between the inner ring 2 and the outer ring 3, The retainer 5 that holds the sprags 4 is mainly provided so that the power of the motor 121 (see FIG. 1) can be transmitted to the rear wheel 102 (see FIG. 1) via the inner ring 2 and the outer ring 3. In the present embodiment, the power of the motor 121 is input to the outer ring 3, and the power of the motor 121 input to the outer ring 3 is transmitted to the rear wheel 102 via the inner ring 2.

  The inner ring 2 is a member having a function of transmitting the power of the motor 121 to the rear wheel 102. As shown in FIGS. 2 and 3, the inner ring 2 includes an outer peripheral surface 2a having a circular cross section and rotates around the axis O. It is configured to be possible. The inner ring 2 in the present embodiment is formed in a substantially cylindrical shape, and is supported by a case 122a that forms an outline of the power transmission device 122 via a ball bearing B1, as shown in FIG.

  The outer ring 3 is a member responsible for the function of transmitting the power of the motor 121 to the rear wheel 102 together with the inner ring 2, and has a circular cross section facing the outer peripheral surface 2a of the inner ring 2 as shown in FIGS. An inner peripheral surface 3 a is provided, and the inner ring 2 is configured to be rotatable around the axis O similarly to the inner ring 2. Note that the outer ring 3 in the present embodiment is formed in a substantially annular shape, and is supported by the inner ring 2 via a roller bearing B2, as shown in FIG.

  The sprag 4 is a member having a function for restricting the relative rotation between the inner ring 2 and the outer ring 3, and engaging surfaces 4a and 4b in contact with the outer peripheral surface 2a and the inner peripheral surface 3a, respectively (see FIGS. 4 and 5). As shown in FIG. 3, a plurality of them are arranged at equal intervals in the circumferential direction between the outer peripheral surface 2a and the inner peripheral surface 3a. Further, as shown in FIG. 4, the sprag 4 has groove portions 4d formed on two side surfaces 4c connecting the two engaging surfaces 4a and 4b. The groove 4d is a part where a biasing member 6 described later is mounted.

  The cage 5 is a member that holds the sprag 4 so as to be tiltable in the circumferential direction of the outer peripheral surface 2a and the inner peripheral surface 3a, and is extended annularly in the direction of the axis O as shown in FIGS. The holding portion 5a and a load transmitting portion 5b extending from the holding portion 5a in a direction intersecting with the direction of the axis O are configured.

  The holding portion 5a is a portion that holds the sprag 4 and is disposed around the outer peripheral surface 2a of the inner ring 2 as shown in FIGS. Moreover, as shown in FIG. 4, the holding | maintenance part 5a is provided with multiple holes 5a1 formed at equal intervals over the circumferential direction. A portion of the sprag 4 (on the engagement surface 4a side) located on the inner ring 2 side is inserted into the hole 5a1, and the two front and rear surfaces 4e connecting the two engagement surfaces 4a and 4b of the sprag 4 and the hole 5a1 A gap of an appropriate size is formed between them. As a result, the sprag 4 is held by the holding portion 5a between the outer peripheral surface 2a and the inner peripheral surface 3a so as to be greatly tiltable in the circumferential direction.

  The load transmitting portion 5b is a portion to which a load is transmitted from a load applying device 10 described later, and is extended in a direction intersecting with the direction of the axis O as shown in FIGS. Thereby, compared with the case where the load transmission part 5b is extended in the axial center O direction, the dimension of the axial direction O of the holder | retainer 5 can be shortened, and size reduction of the clutch apparatus 1 can be achieved.

  Further, as shown in FIG. 3, the load transmitting portion 5b is formed in a gear shape so that a load is transmitted from the load applying device 10 via a gear mechanism configured between the pinion 12 and the pinion 12 described later. It is configured. Thereby, the energy loss produced in the load transmission path from the load applying device 10 to the cage 5 can be reduced, and the load can be efficiently transmitted to the cage 5.

  As shown in FIG. 3, the urging member 6 is formed by an annular coil spring, and is a member that applies an urging force in the direction of expanding the diameter. Here, the sprag 4 urged by the urging member 6 will be described with reference to FIG. FIG. 5A is a partially enlarged cross-sectional view of the clutch device 1 that cuts off the transmission of power shown by enlarging the portion indicated by V in FIG. 3. In FIG. 5, it is assumed that the outer ring 3 is driven by a motor 121 (see FIG. 1) and rotates in the direction of arrow T (counterclockwise in FIG. 5).

  The urging member 6 is mounted in the groove portion 4d of the sprag 4 and causes a frictional force generated between the engagement surface 4b of the sprag 4 and the inner peripheral surface 3a of the outer ring 3 by applying a urging force in the direction of expanding the diameter. , The engagement surface 4a of the sprag 4 is tilted in the direction of arrow S in FIG. 5 (hereinafter referred to as “anti-lock direction”). Thereby, the inner ring 2 and the outer ring 3 can be rotated relative to each other, and the transmission of power from the outer ring 3 to the inner ring 2 is interrupted. Moreover, as shown to Fig.5 (a), a clearance gap produces between the outer peripheral surface 2a and the engagement surface 4a. As a result, friction between the outer peripheral surface 2a and the engagement surface 4a of the sprag 4 can be eliminated, and energy loss due to friction can be suppressed.

  Further, there is an appropriate gap between the two front and rear surfaces 4e (see FIG. 4) connecting the two engaging surfaces 4a and 4b of the sprag 4 and the hole 5a1 formed in the holding portion 5a. Since they are formed, as shown in FIG. 5A, the sprags 4 abut against each other by being largely tilted in the anti-lock direction. When the sprags 4 are tilted to the positions where they abut against each other, the sprags 4 restrain each other. Thereby, the clearance gap between the outer peripheral surface 2a and the engagement surface 4a is fully securable. As a result, when the inner ring 2 and the outer ring 3 rotate relative to each other, the outer peripheral surface 2a contacts the engaging surface 4a, and the sprag 4 unintentionally engages with the outer peripheral surface 2a and the inner peripheral surface 3a. Thus, it is possible to prevent the relative rotation of the inner ring 2 and the outer ring from being restricted.

  Further, since the groove portions 4d are formed on the two side surfaces 4c connecting the two engaging surfaces 4a and 4b of the sprag 4, and the urging member 6 is mounted on these groove portions 4d, the urging force of the urging member 6 is provided. Thus, it is possible to tilt the sprag 4 in the anti-lock direction with a good balance.

  According to the clutch device 1 described above, in order to engage the sprag 4 with the inner ring 2 and the outer ring 3, it is necessary to apply an external force to the sprag 4 against the urging force of the urging member 6. Therefore, the clutch device 1 is provided with a load applying device 10 (see FIGS. 2 and 3).

  The load applying device 10 applies a load to the sprag 4 against the urging force of the urging member 6 and tilts the sprag 4 in a direction opposite to the arrow S in FIG. 5 (hereinafter referred to as “lock direction”). As shown in FIGS. 2 and 3, the apparatus includes an actuator 11 and a pinion 12. The actuator 11 is a power source that generates a load to be applied to the sprag 4 and is configured by an electric motor (an AC motor or a DC motor) and is configured to be drivable by electric power supplied from a power source (not shown).

  Thus, since the load application apparatus 10 (actuator 11) is comprised with the electric motor, compared with the case where the load application apparatus 10 (actuator 11) comprises a cylinder, a solenoid, etc., for example, the load application apparatus 10 is comprised. In addition to simplifying the structure, the load applying device 10 can be downsized, and the clutch device 1 can be downsized.

  Further, in a state where the clutch device 1 is transmitting rotation, the cage 5 rotates around the axis O along with the rotation of the inner ring 2 and the outer ring 3, so that the load applying device 10 becomes the rotational resistance of the cage 5. However, by configuring the load applying device 10 (actuator 11) with an electric motor, the rotational resistance of the cage 5 can be reduced, and the inner ring 2 and the outer ring 3 can be rotated at high speed. On the other hand, since the cage 5 does not rotate when the sprag 4 does not revolve, a load can be applied to the sprag 4 with a small drive energy by configuring the load applying device 10 (actuator 11) with an electric motor.

  The pinion 12 is a member for transmitting the power of the actuator 11 to the cage 5, and is formed in a gear shape that meshes with the load transmission portion 5b of the cage 5, as shown in FIG. A gear mechanism is formed between them. When the power of the actuator 11 is transmitted to the cage 5 by the pinion 12, a load is applied to the sprag 4 via the cage 5. As described above, since the load applying device 10 applies a load to the sprags 4 via the cage 5, it is possible to apply a load to the plurality of sprags 4 at a time, and to efficiently apply a load to the sprags 4. Can do.

  According to the load applying device 10 configured as described above, as shown in FIG. 5B, the sprag 4 is locked in the locking direction (see FIG. 5) via the cage 5 against the urging force of the urging member 6. 5 is applied to the sprag 4 in the locking direction about the engaging surface 4b of the sprag 4 as a center. As a result, the engagement surfaces 4a and 4b of the sprag 4 are in contact with the outer peripheral surface 2a and the inner peripheral surface 3a, so that the contact between the inner peripheral surface 3a and the engagement surface 4b and the contact between the outer peripheral surface 2a and the engagement surface 4a. Frictional force is generated, and the sprags 4 are engaged with the inner ring 2 and the outer ring 3 by relative displacement of the respective contacts in the circumferential direction of the outer peripheral surface 2a and the inner peripheral surface 3a. Is regulated. As a result, power is transmitted from the outer ring 3 to the inner ring 2, and the inner ring 2 rotates as the outer ring 3 rotates (counterclockwise in FIG. 5B).

  When the sprag 4 is engaged with the inner ring 2 and the outer ring 3 and the relative rotation between the inner ring 2 and the outer ring 3 is restricted, the outer ring 3 is locked in the locking direction (see FIG. 5). When rotating in the direction of the arrow Lo), the sprag 4 is tilted in the locking direction by the rotation of the outer ring 3 even when the load application by the load applying device 10 is stopped, and the inner ring 2 and the outer ring 3 are engaged with the sprag 4. Is maintained.

  On the other hand, when the sprag 4 is engaged with the inner ring 2 and the outer ring 3 and the relative rotation between the inner ring 2 and the outer ring 3 is restricted, the outer ring 3 is counteracted when viewed from the inner ring 2 side by the relative rotation with the inner ring 2. When rotating in the locking direction (counter arrow Lo direction in FIG. 5), the load applying device 10 is stopped or the load applied by the load applying device 10 is reduced, so that the sprag 4 is applied by the urging force of the urging member 6. Tilts in the anti-lock direction (arrow S direction in FIG. 5). Thereby, the engagement between the inner ring 2 and the outer ring 3 and the sprag 4 is released, and transmission of power from the outer ring 3 to the inner ring 2 is interrupted.

  According to the clutch device 1 configured as described above, when a load is applied to the sprag 4 by the power transmission device 10, the sprag 4 is engaged with the inner ring 2 and the outer ring 3, and the inner ring 2 and the outer ring 3 are engaged. Relative rotation in a constant rotation direction is restricted. On the other hand, when the application of the load by the power transmission device 10 is released, the urging force is applied to the sprag 4 by the urging member 6, so that the engagement of the sprag 4 with the inner ring 2 and the outer ring 3 is released. The inner ring 2 and the outer ring 3 rotate relative to each other in both rotation directions. Thereby, rotation transmission in a fixed direction and switching between cutoffs can be performed.

Next, the relationship between the urging force and the load acting on the sprag 4 will be described with reference to FIG. FIG. 6 is a schematic view of the sprag 4 tilted in the anti-lock direction. As shown in FIG. 6, the sprag 4 that is disengaged from the inner ring 2 and the outer ring 3 has a contact surface 4 b and an inner peripheral surface 3 a due to a biasing force (load P) applied by the biasing member 6. Around the contact point A, a rotational moment tilted in the anti-lock direction (clockwise in FIG. 6) is generated. Further, when the sprag 4 engages with the inner ring 2 and the outer ring 3 and revolves around the axis O along with the rotation of the inner ring 2 and the outer ring 3, centrifugal force K acts on the sprag 4. Along with these, a pressing load acts on the contact A. As a reaction force against the sprags 4, the reaction force F _A to the normal direction of the inner peripheral surface 3a acts at a contact point A. On the other hand, in order to tilt the sprag 4 in the lock direction, the holding portion 5a applies a load R in the lock direction (the direction of the arrow S in FIG. 6) to the contact C in contact with the sprag 4.

Here, considering the contact A around a rotational moment M _A acting on the sprags 4, the load P in the sprag 4, since the load R and the centrifugal force K acts, rotation moment M _A has the following formula (1) It is represented by

M _A = Lp · P + Lk · K−Lr · R (1)
However, in Formula (1), Lp is a horizontal distance from the contact A to the application point of the load P (groove 4d), and Lk is a horizontal distance from the contact A to the application point of the centrifugal force K (the center of gravity G of the sprag 4). Lr is a vertical distance from the contact A to the point of application of the load R (contact C). The rotational moment M _A is positive in the clockwise direction around the contact A. Strictly speaking, the loads P, K and R need to take into account errors due to the horizontal and vertical components of the load, but the errors are significantly smaller than the magnitudes of the loads P, K and R. The loads P and K act in the vertical direction, and the load R acts in the horizontal direction.

Here, in order to engage the engaging surface 4a of the sprag 4 with the outer peripheral surface 2a, the sprag 4 tilts counterclockwise in FIG. 6 without the engaging surface 4b of the sprag 4 sliding on the inner peripheral surface 3a. It is necessary to be done. That is, it is necessary that M _A <0. In the state shown in FIG. 6, since the engagement between the inner ring 2 and the outer ring 3 and the sprag 4 is released, the outer ring 3 and the inner ring 2 can rotate about the axis O, but the outer ring 3 and the inner ring 2 are driven. The sprag 4 cannot revolve around the axis O with force. Accordingly, the centrifugal force K does not act on the sprag 4 (K = 0). Table from requirement to engage the engagement surface 4a of the sprag 4 on the outer circumferential surface 2a is by substituting M _{A <0,} K = 0 in equation (2), the following equation (2) above Is done.

R> Lp / Lr · P (2)
Here, if Lp <Lr, Lp / Lr <1. Therefore, from the formula (2), the load R> Lp / Lr · P <P. Therefore, the load applying device 10 (see FIG. 3) engages the sprag 4 with the outer ring 3 and the inner ring 2 without applying a load larger than the urging force (load P) of the urging member 6 to the sprag 4. Can do. Thereby, while being able to miniaturize the load provision apparatus 10, since a small load is sufficient, energy loss can be suppressed. As a result, the clutch device 1 can be reduced in size.

In FIG. 6, when the angle between the normal line at the contact A and the vertical direction is α, the magnitude of the component component F _{Ah in} the horizontal direction of the reaction force F _A acting on the sprag 4 from the inner peripheral surface 3a is F _A · sin α, the direction of which is the same as the lock direction (the direction of the arrow S in FIG. 6). Further, if the friction coefficient at the contact A is μ and the component component in the vertical direction of the reaction force F _A is F _Ap , the magnitude of the friction is μ · F _Ap = μ · F _A · cos α, and the direction is also locked. The direction is the same as the direction (the direction of the arrow S in FIG. 6).

As described above, the reaction force F _A acting on the sprag 4 from the inner peripheral surface 3a at the contact point A where the inner peripheral surface 3a contacts the engaging surface 4b acts on the sprag 4 via the holding portion 5a by the load applying device 10. Since the direction of the component component in the load direction of the load R to be applied (the horizontal direction and the left-right direction in FIG. 6) is the same as the lock direction (counter arrow S direction in FIG. 6), the load applying device 10 applies the sprag 4 When the load R is applied, the engagement surface 4b is prevented from sliding on the inner peripheral surface 3a, and the sprag 4 can be reliably tilted about the contact A. Thereby, by applying a load from the load applying device 10, the two engaging surfaces 4a and 4b of the sprag 4 can be reliably engaged with the outer peripheral surface 2a and the inner peripheral surface 3a.

  As described above, according to the clutch device 1, the load application device 10 can perform transmission of rotation in a certain direction and switching between interruptions as necessary. Furthermore, by securing the spacing enough to allow the sprags 4 to tilt, the plurality of sprags 4 can be arranged at small intervals between the outer peripheral surface 2a and the inner peripheral surface 3a. Thereby, even if the clutch apparatus 1 is small, the transmission torque capacity can be increased.

  Next, a second embodiment will be described with reference to FIG. In the first embodiment, the case where the urging member 6 applies a urging force to the sprag 4 in the direction away from the axis O and the power is transmitted from the outer ring 3 to the inner ring 2 has been described. In contrast, in the second embodiment, a case will be described in which the urging member 26 applies a urging force to the sprag 24 in a direction approaching the axis O, and power is transmitted from the inner ring 2 to the outer ring 3.

  Here, FIG. 7A is a partially enlarged sectional view of the clutch device 21 that cuts off the transmission of power in the second embodiment, and FIG. 7B is a partially enlarged sectional view of the clutch device 21 that transmits power. It is. In addition, the same code | symbol is attached | subjected about the part same as 1st Embodiment, and the description is abbreviate | omitted. In FIG. 7, it is assumed that the inner ring 2 is driven by a motor 121 (see FIG. 1) and rotates in the direction of arrow T (clockwise in FIG. 7). As shown in FIG. 7, the holding portion 25 a that constitutes the cage 25 of the clutch device 21 in the second embodiment is disposed inside the inner peripheral surface 3 a of the outer ring 3 and is positioned on the outer ring 3 side of the sprag 24. The part to be held is held.

  The urging member 26 is formed by an annular coil spring, and is attached to the groove portion 24d of the sprag 24 to apply an urging force in the direction of reducing the diameter. As a result, the sprag 24 is tilted in the direction of the arrow S in FIG. 7 (hereinafter referred to as “anti-locking direction”) using the frictional force generated between the engagement surface 24 a of the sprag 24 and the outer peripheral surface 2 a of the inner ring 2. . Thereby, the inner ring 2 and the outer ring 3 can be rotated relative to each other, and the transmission of power from the inner ring 2 to the outer ring 3 is interrupted. Further, as shown in FIG. 7A, a gap is generated between the inner peripheral surface 3a and the engagement surface 24b. As a result, friction between the inner peripheral surface 3a and the engagement surface 24b of the sprag 24 can be eliminated, and energy loss due to friction can be suppressed.

  Similarly to the first embodiment, the sprags 24 are greatly tilted in the anti-lock direction (arrow S direction), so that they come into contact with each other as shown in FIG. When the sprags 24 are tilted to a position where they abut against each other, the sprags 24 restrain each other. Thereby, a sufficient gap can be secured between the inner peripheral surface 3a and the engagement surface 24b. As a result, when the inner ring 2 and the outer ring 3 rotate relative to each other, the inner peripheral surface 3a and the engaging surface 24b come into contact with each other, and the sprags 24 are unintentionally engaged with the outer peripheral surface 2a and the inner peripheral surface 3a. Thus, it is possible to prevent the relative rotation of the inner ring 2 and the outer ring 3 from being restricted.

  As shown in FIG. 7B, the load applying device 10 locks the sprag 26 in the locking direction (reverse arrow S in FIG. 7) via the retainer 25 (holding portion 25a) against the biasing force of the biasing member 26. By applying a load in the direction, the sprag 24 can be tilted in the locking direction (counter arrow S direction) about the engaging surface 24a of the sprag 26. As a result, the engagement surfaces 24a and 24b of the sprag 24 are in contact with the outer peripheral surface 2a and the inner peripheral surface 3a, so that the contact between the inner peripheral surface 3a and the engagement surface 24b and the contact between the outer peripheral surface 2a and the engagement surface 24a. Frictional force is generated at the same time, and the sprags 24 engage with the inner ring 2 and the outer ring 3 due to the displacement of the respective contacts in the circumferential direction of the outer peripheral surface 2a and the inner peripheral surface 3a, so that the relative rotation between the inner ring 2 and the outer ring 3 occurs. Is regulated. As a result, power is transmitted from the inner ring 2 to the outer ring 3, and the outer ring 3 rotates as the inner ring 2 rotates (in the direction of arrow T in FIG. 7).

  When the sprags 24 are engaged with the inner ring 2 and the outer ring 3 and the relative rotation between the inner ring 2 and the outer ring 3 is restricted, the inner ring 2 is locked in the locking direction (see FIG. 7). When rotating in the direction of arrow Li), even if the load application by the load applying device 10 is stopped, the sprag 24 is tilted in the locking direction by the rotation of the inner ring 2, and the inner ring 2 and the outer ring 3 are engaged with the sprag 24. Is maintained.

  On the other hand, when the sprag 24 is engaged with the inner ring 2 and the outer ring 3 and the relative rotation between the inner ring 2 and the outer ring 3 is restricted, the inner ring 2 is counteracted when viewed from the outer ring 3 side by the relative rotation with the outer ring 3. When rotating in the locking direction (counter arrow Li direction in FIG. 7), the sprag 24 is stopped by the urging force of the urging member 26 by stopping the load applying device 10 or reducing the load applied by the load applying device 10. Tilt in the anti-lock direction (arrow S direction in FIG. 7). As a result, the engagement between the inner ring 2 and the outer ring 3 and the sprag 24 is released, and the transmission of power from the inner ring 2 to the outer ring 3 is interrupted. As described above, according to the clutch device 21, transmission of rotation in a certain direction and switching between cutoffs can be performed as in the first embodiment.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed. For example, the numerical values and shapes given in the above embodiment are merely examples, and other numerical values and shapes can naturally be adopted.

  In the above-described embodiment, the case where the clutch devices 1 and 21 are incorporated in the power transmission device 122 of the vehicle 100 has been described. However, the present invention is not necessarily limited to this. For example, other vehicles (locomotives, passenger vehicles) Naturally, it can be incorporated into a power transmission device such as a traveling device, a working device, and a machine tool of a cargo vehicle and a special vehicle.

  In each of the above-described embodiments, the case where the actuator 11 is configured by an electric motor (AC motor or DC motor) has been described. However, the present invention is not necessarily limited to this, and other power sources can naturally be employed. . Examples of other power sources include a hydraulic motor, a pneumatic cylinder, a hydraulic cylinder, an AC solenoid, and a DC solenoid.

  Here, when the actuator 11 is configured by a solenoid, it is not limited to the case where a load is applied to the sprags 4 and 24 by a gear mechanism or the like. For example, the load is applied to the sprags 4 and 24 using electromagnetic force. You may comprise.

  In each of the above-described embodiments, the case where the urging members 6 and 26 are configured by coil springs has been described. However, the present invention is not necessarily limited to this, and other urging members can naturally be employed. As another urging member, for example, a ribbon spring formed by applying a wave-like bending process to a metal material and configured to apply a load as an urging force to the sprags 4 and 24 by using the elasticity thereof can be cited. It is done.

In each of the above-described embodiments, the case where the sprags 4 and 24 tilted in the anti-lock direction (arrow S direction) contact each other and restrain each other has been described. However, the present invention is not limited to this. Depending on the shape of 24, for example, the sprags 4 and 24 tilted in the anti-locking direction may be brought into contact with the holding portions 5a and 25a (retainers 5 and 25) to restrict further tilting. Is possible. In this case, the same effect can be obtained.
<Others>
<Means>
The clutch device described in the technical idea 1 has an inner ring having an outer circumferential surface having a circular cross section and configured to be rotatable around an axis, and an inner circumferential surface having a circular cross section facing the outer circumferential surface of the inner ring. And an outer ring configured to be rotatable about the axis, and two engagement surfaces in contact with the outer peripheral surface and the inner peripheral surface, respectively, and the engagement surfaces are engaged with the outer peripheral surface and the inner peripheral surface. A plurality of sprags arranged in the circumferential direction between the outer peripheral surface and the inner peripheral surface, and the sprags can be tilted in the circumferential direction of the outer peripheral surface and the inner peripheral surface. And a biasing force is applied to the sprag so that one of the outer peripheral surface or the inner peripheral surface and one of the engaging surfaces is in contact with each other to contact the sprag in the circumferential direction. Biasing member that tilts in the direction and biasing of the biasing member The sprag is applied with a load against the outer peripheral surface and the inner peripheral surface so that the two engagement surfaces are in contact with each other in a direction opposite to the anti-lock direction and in the circumferential lock direction. A load applying device that tilts the sprag, and a load is applied to the sprag against the biasing force of the biasing member by the load applying device, and the sprag tilts in the locking direction, whereby the outer peripheral surface And the two engagement surfaces of the sprags are engaged with the inner peripheral surface, respectively, and the relative rotation between the inner ring and the outer ring is restricted.
The clutch device described in the technical idea 2 is the clutch device described in the technical idea 1, wherein the sprag is tilted in the anti-lock direction so that the other of the outer peripheral surface or the inner peripheral surface and the engaging surface A gap is formed on the other side.
The clutch device described in the technical idea 3 is the clutch device described in the technical idea 1 or 2, in which the outer peripheral surface or the inner surface is at the contact point where one of the outer peripheral surface or the inner peripheral surface is in contact with one of the engagement surfaces. The reaction force acting on the sprag from one of the peripheral surfaces is such that the direction of the component component in the load direction acting on the sprag by the load applying device is the same as the locking direction.
The clutch device described in the technical idea 4 is the clutch device described in the technical idea 2 or 3, in which the sprags are arranged at equal intervals between the outer peripheral surface and the inner peripheral surface facing each other in the anti-lock direction. They are in contact with each other by being tilted.
The clutch device according to the technical idea 5 is the clutch device according to any one of the technical ideas 1 to 4, wherein the retainer extends in the axial direction and holds the sprag, and the shaft. A load transmitting portion that extends in a direction intersecting the center direction and transmits a load from the load applying device, and the load applying device applies a load to the sprags via the cage.
The clutch device described in the technical idea 6 is the clutch device described in the technical idea 5, wherein the load transmission portion is formed in a gear shape, and a load is transmitted from the load applying device by a gear mechanism.
The clutch device described in the technical idea 7 is the clutch device described in the technical ideas 1 to 6, wherein the load applying device is constituted by an electric motor.
<Effect>
According to the clutch device described in the technical idea 1, the sprag has two engaging surfaces that are in contact with the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring, respectively, and the circumferential direction is between the outer peripheral surface and the inner peripheral surface. And a plurality of engagement surfaces are engaged with the outer peripheral surface and the inner peripheral surface to cause relative rotation between the inner ring and the outer ring. regulate. A plurality of sprags can be arranged at small intervals between the outer peripheral surface and the inner peripheral surface by securing a distance enough to allow the sprags to tilt. Thereby, even if it is small, there exists an effect which can enlarge transmission torque capacity.
Further, the sprag tilted in the anti-lock direction so that one of the outer peripheral surface or the inner peripheral surface and one of the engagement surfaces is in contact with each other by the biasing force of the biasing member is caused by the load from the load applying device. When tilted in the locking direction so that the two engagement surfaces are in contact with the inner peripheral surface, the moment around the contact due to the biasing force of the biasing member and the moment around the contact due to the load from the load applying device The sprag is tilted in relation. Therefore, the sprag can be tilted with a load smaller than the biasing force of the biasing member. As a result, the load applying device can be miniaturized and a small load can be used, so that energy loss can be suppressed.
There are fruits.
According to the clutch device described in the technical idea 2, since the sprag is tilted in the anti-lock direction, a gap is formed between the other of the outer peripheral surface or the inner peripheral surface and the other engagement surface of the sprag. When the inner ring and the outer ring rotate relative to each other, friction between the outer peripheral surface or the other of the inner peripheral surfaces and the other of the engaging surfaces of the sprags can be eliminated. Thereby, in addition to the effect of the technical idea 1, there exists an effect which can suppress the energy loss by the friction with an outer peripheral surface or an internal peripheral surface, and an engagement surface.
According to the clutch device described in the technical idea 3, the reaction force acting on the sprag from one of the outer peripheral surface or the inner peripheral surface at the contact point where one of the outer peripheral surface or the inner peripheral surface is in contact with one of the engagement surfaces is the load applying device. Since the direction of the component component of the load direction acting on the sprag is the same as the lock direction, the engagement surface slides on the outer peripheral surface or the inner peripheral surface when a load is applied to the sprag by the load applying device. This prevents the sprags from being tilted around them. Thereby, in addition to the effect of the technical idea 1 or 2, the effect that the two engagement surfaces of the sprag can be reliably engaged with the outer peripheral surface and the inner peripheral surface by applying the load from the load applying device. There is.
According to the clutch device described in the technical idea 4, the sprags are disposed at equal intervals between the outer peripheral surface and the inner peripheral surface and are in contact with each other by being tilted in the anti-lock direction. If the sprags are tilted to each other, they will restrain each other. By tilting the sprags until they are constrained to each other, a sufficient gap can be secured between the other of the outer peripheral surface or the inner peripheral surface and the other of the engaging surfaces. As a result, in addition to the effects of the technical idea 2 or 3, when the inner ring and the outer ring rotate relative to each other, the outer peripheral surface or the other of the inner peripheral surface and the other of the engaging surface come into contact with each other unintentionally This has the effect of preventing the sprags from engaging and restricting relative rotation.
According to the clutch device described in the technical idea 5, the cage includes a holding portion that holds the sprag and a load transmission portion that transmits a load from the load applying device, and the load applying device is interposed via the cage. Since the load is applied to the sprags, in addition to any one of the technical ideas 1 to 4, it is possible to apply a load to a plurality of sprags at once and to effectively apply a load to the sprags.
In addition, since the holding part extends in the axial direction, the load transmitting part extends in a direction intersecting the axial direction, so that the load transmitting part extends in the axial direction. The size of the cage in the axial direction can be shortened and the clutch device can be reduced in size.
According to the clutch device described in the technical idea 6, the load transmitting unit is formed in a gear shape, and the load is transmitted from the load applying device via the gear mechanism. In addition to the effect of the technical idea 5, the load applying device The energy loss that occurs in the load transmission path from the cage to the cage can be reduced, and the load can be efficiently transmitted to the cage.
According to the clutch device described in the technical idea 7, since the load applying device is configured by an electric motor, the structure of the load applying device is simplified as compared with a case where the load applying device is configured by a cylinder, a solenoid, or the like. In addition, the load applying device can be reduced in size, and in addition to the effects of any one of the technical ideas 1 to 6, there is an effect that the clutch device can be reduced in size.
In addition, when the load applying device is configured to apply a load to the sprags via the cage, the cage rotates around the axis along with the rotation of the inner ring and the outer ring when the clutch device transmits the rotation. Therefore, the load applying device serves as the rotational resistance of the cage, but by configuring the load applying device with an electric motor, the rotational resistance of the cage can be reduced, and the inner ring and the outer ring can be rotated at high speed. On the other hand, since the cage does not rotate in a state where the rotation of the clutch device is interrupted, it is possible to apply a load to the sprags with an electric motor having a small driving energy, to suppress energy loss and to reduce the size of the clutch device. There is an effect that can.

DESCRIPTION OF SYMBOLS 1,21 Clutch device 2 Inner ring 2a Outer peripheral surface 3 Outer ring 3a Inner peripheral surface 4,24 Sprag 4a, 4b, 24a, 24b Engagement surface 5,25 Cage 5a, 25a Holding part 5b Load transmitting part 6,26 Energizing member 10 Load applying device 11 Actuator (a part of load applying device, electric motor)
A contact O axis

Claims (7)

An inner ring having an outer peripheral surface having a circular cross section and configured to be rotatable about an axis;
An outer ring having a circular inner peripheral surface facing the outer peripheral surface of the inner ring and configured to be rotatable about the axis;
The outer peripheral surface and the inner peripheral surface have two engaging surfaces, and the engaging surfaces are configured to be engageable with the outer peripheral surface and the inner peripheral surface, and the outer peripheral surface and the inner peripheral surface A plurality of sprags arranged in the circumferential direction between the opposing faces;
In the sprags by applying a biasing force to the outer peripheral surface or the like with one of the inner circumferential surface and one of said engaging surface is in contact with the contact A sprag that tilting the counter locking direction of the circumferential direction there are, with each annular the formed biasing member to grant the biasing force the counter-locking direction around the contact point a via the contact B in contact with the contact B of the sprags,
The sprag is held so as to be able to tilt in the circumferential direction of the outer peripheral surface and the inner peripheral surface, and the attachment between the outer peripheral surface or one of the inner peripheral surfaces that is in contact with one of the engagement surfaces. A holding portion that is annularly extended at a position sandwiching the biasing member and is rotatable about the axis, and a plurality of openings in the circumferential direction of the holding portion that are opposite to one of the engagement surfaces of the sprags A retainer having a hole into which an end of the hole is inserted ;
The anti-locking direction is opposite to the anti-locking direction so that the two engaging surfaces are in contact with the outer peripheral surface and the inner peripheral surface by applying a load to the sprag against the urging force of the urging member. The sprag is tilted in a circumferential locking direction, and is connected to the retainer and rotates the holding portion in the locking direction to contact the edge of the hole and the sprag through a contact C. And a load applying device that applies the load in the locking direction around the contact A, and the load applying device applies a load against the urging force of the urging member so that the sprag is locked. By tilting in the direction, the two engagement surfaces of the sprag are engaged with the outer peripheral surface and the inner peripheral surface, respectively, and relative rotation between the inner ring and the outer ring is restricted , From A A clutch device , wherein Lp <Lr is satisfied, where Lp is a horizontal distance to point B and Lr is a vertical distance from the contact A to the contact C.   2. The clutch according to claim 1, wherein the sprag is tilted in the anti-lock direction to form a gap between the other of the outer peripheral surface or the inner peripheral surface and the other of the engagement surfaces. apparatus.   The reaction force acting on the sprag from one of the outer peripheral surface or the inner peripheral surface at the contact point where one of the outer peripheral surface or the inner peripheral surface is in contact with one of the engagement surfaces is applied to the sprag by the load applying device. The clutch device according to claim 1 or 2, wherein the direction of the component component of the acting load direction is the same direction as the lock direction.   4. The clutch according to claim 2, wherein the sprags are disposed at equal intervals between the outer peripheral surface and the inner peripheral surface and are in contact with each other by being tilted in the anti-lock direction. apparatus. The retainer includes a holding portion that extends in the axial direction and holds the sprag, and a load transmission portion that extends in a direction intersecting the axial direction and transmits a load from the load applying device. ,
The clutch device according to any one of claims 1 to 4, wherein the load applying device applies a load to the sprags via the cage.   The clutch device according to claim 5, wherein the load transmission unit is formed in a gear shape, and a load is transmitted from the load applying device by a gear mechanism. The clutch device according to claim 1, wherein the load applying device is configured by an electric motor.

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