JP5904064B2 - Power transmission device with torque limiter and method of assembling the same - Google Patents

Description

  The present invention relates to a power transmission device with a torque limiter and an assembly method thereof, and more particularly to a power transmission device with a torque limiter including a differential device and a torque limiter in a power transmission path from a drive source to a drive wheel and an assembly method thereof. .

  In vehicles such as automobiles, in order to improve fuel efficiency, in addition to reducing the weight of vehicle body components, shafts and drives in transmissions that constitute a power transmission path from the engine that is the drive source to the drive wheels It is also required to reduce the weight of shafts such as shafts.

  The shaft that constitutes the power transmission path secures the torque capacity that needs to be transmitted during normal driving, and when the clutch is suddenly engaged with the engine output increased or downshifted to the low speed stage during high-speed driving. If this happens, or if the drive wheel jumps during bumpy road driving and then touches the ground again, it will be necessary to prevent the shaft from being damaged when a shock torque greater than the torque capacity during normal driving is input. Torque is a factor that hinders weight reduction of the shaft.

  Therefore, if the power transmission device that transmits power from the engine to the drive wheels can be configured to absorb shock torque while ensuring the torque capacity during normal travel, the shaft constituting the power transmission path can be reduced in diameter. It is considered that the shaft can be lightened by making it hollow.

  As such, for example, in Patent Document 1, in a differential device in which a final reduction gear is attached to a differential case, a friction plate that meshes with the differential case and a friction plate that meshes with the final reduction gear are provided between the differential case and the final reduction gear. An arrangement is disclosed in which clutches for limiting transmission torque are arranged that are alternately arranged and that press the friction plates with springs extending in the axial direction of the differential.

  With the transmission torque limiting clutch, a torque capacity corresponding to the pressing force of the spring is obtained, and by setting this torque capacity to be larger than the maximum torque during normal driving, the torque during normal driving is reduced. Shock torque that exceeds the torque capacity while transmitting reliably can be absorbed by sliding of the friction plate, avoiding the shock torque acting directly on the shaft that constitutes the power transmission path, and reducing the weight of the shaft Become.

JP-A-53-90334

  In the one disclosed in Patent Document 1, shock torque can be absorbed while securing a torque capacity during normal running by disposing a transmission torque limiting clutch in the differential, so that the weight of the shaft can be reduced. However, since the spring of the transmission torque limiting clutch is provided so as to extend in the axial direction of the differential device, the differential device becomes larger in the axial direction.

  A relatively large spring is used for the transmission torque limiting clutch because a large pressing force is required to transmit the maximum torque during normal driving. In this case, however, the axial dimension of the differential increases. As a result, the differential device becomes larger and the in-vehicle performance deteriorates.

  In particular, in the case of an FF vehicle that is housed in a housing in which a differential, a transmission, and a clutch are integrated at the front of the vehicle body, when the axial dimension of the differential increases, the differential, The layout of the transmission and the clutch becomes difficult, the size of the power transmission device becomes large, and the deterioration of in-vehicle performance becomes a problem.

  Moreover, since the transmission torque limiting clutch is arranged on the outer peripheral side of the differential case, the radial dimension of the differential device increases. In FF vehicles, if the radial dimension of the differential gear increases, the distance between the transmission shaft center and the differential gear shaft center increases, the power transmission device becomes larger, and the onboard performance is further deteriorated. It becomes.

  Therefore, an object of the present invention is to provide a power transmission device with a torque limiter and an assembling method thereof that can reduce the size of the differential transmission device to reduce the size of the power transmission device and improve the onboard performance.

  In order to solve the above problems, the present invention is configured as follows.

First, in the invention according to claim 1 of the present application, a pinion gear supported in a differential case via a pinion shaft and a pair of side gears engaged with the pinion gear are housed in a power transmission path from the driving source to the driving wheel. A power transmission device with a torque limiter, comprising: a differential device that transmits the output of the transmission to the drive wheel; and a torque limiter that limits a torque transmitted between the transmission and the drive wheel. The differential device is connected to the output portion of the transmission and is driven to rotate by the output of the transmission, and is connected to the drive wheel and has the same axis as the first rotation member. A second rotating member disposed opposite to the first rotating member and configured to be engageable with the first rotating member; and a longitudinal direction on a side opposite to the second rotating member of the first rotating member. In the circumferential direction A pressing mechanism that generates a pressing force in the circumferential direction, a first inclined surface provided in the pressing mechanism, and a second inclined surface provided in the first rotating member and in contact with the first inclined surface. A conversion mechanism for converting the circumferential pressing force by the pressing mechanism into an axial pressing force and converting the axial pressing force, the first rotating member, the second rotating member, the pressing mechanism, and the conversion The mechanism constitutes a torque limiter that disengages the first rotating member and the second rotating member when a torque of a predetermined value or more is input to the differential device, and the first rotating member And the second rotating member is disposed in the differential case, the first rotating member rotates integrally with the differential case, the second rotating member supports the pinion shaft, the pressing mechanism and the The conversion mechanism is the first Rolling said the member second rotary member, characterized in that it is arranged on a circumference having an engagement portion substantially the same radius opposite.

Furthermore, the invention according to claim 2 of the present application is the invention according to claim 1 , wherein a bearing member is provided between the outer periphery of the second rotating member and the inner surface of the differential case, and the second rotating member is A differential case is rotatably fitted.

Still further, in the invention according to claim 3 of the present application, in the invention according to claim 1 or 2 , the differential device is provided on the opposing surfaces of the first rotating member and the second rotating member, respectively. A first tooth surface and a second tooth surface having teeth extending radially in mesh with each other, and the teeth on the first tooth surface and the teeth on the second tooth surface exert a circumferential pressing force in a circumferential direction; An engagement mechanism configured to increase the pressure force and convert the pressure, and the first rotation member, the second rotation member, the pressing mechanism, the conversion mechanism, and the engagement mechanism are connected to the differential device. A torque limiter configured to release the engagement between the first rotating member and the second rotating member when a torque of a predetermined value or more is input.

Furthermore, in the invention according to claim 4 of the present application, the pinion shaft is provided in the differential case formed by dividing the power transmission path from the driving source to the driving wheel by the first case structural body and the second case structural body. And a pair of side gears that engage with the pinion gear are housed, and are transmitted between the transmission and the driving wheel, and a differential that transmits the output of the transmission to the driving wheel. A torque limiter for limiting torque to be transmitted, and the differential is coupled to a first rotating member coupled to the output of the transmission and driven to rotate by the output of the transmission; And a second rotating member disposed on the same axis as the first rotating member so as to face the first rotating member and configured to be engageable with the first rotating member; and On the side opposite to the second rotating member A pressing mechanism that is arranged with its longitudinal direction oriented in the circumferential direction and generates a pressing force in the circumferential direction, a first inclined surface provided in the pressing mechanism, and a first inclined surface provided in the first rotating member A first inclined member, a second inclined member, and a conversion mechanism that converts the circumferential pressing force of the pressing mechanism into an axial pressing force. The pressing mechanism and the conversion mechanism constitute a torque limiter that releases the engagement between the first rotating member and the second rotating member when a torque of a predetermined value or more is input to the differential device. A method for assembling a power transmission device with a torque limiter, comprising: a first subassembly forming step of forming the first subassembly by assembling the pressing mechanism to the first case component; and the second case component. The pin The conversion mechanism is formed by a second subassembly forming step of assembling the on gear, the side gear, the first rotating member, and the second rotating member to form a second subassembly, and the pressing mechanism and the first rotating member. And combining the first subassembly and the second subassembly to assemble the differential device.

  With the above configuration, according to the invention of each claim of the present application, the following effects can be obtained.

  First, according to the first aspect of the present invention, in the power transmission device with a torque limiter provided with the differential device and the torque limiter, the differential device is a first rotating member that is rotationally driven by the output of the transmission. A second rotating member coupled to the drive wheel and configured to be engageable with the first rotating member, and a pressing mechanism that is arranged with the longitudinal direction oriented in the circumferential direction and generates a pressing force in the circumferential direction And a first inclined surface provided in the pressing mechanism and a second inclined surface provided in the first rotating member and in contact with the first inclined surface, and the circumferential pressing force by the pressing mechanism is increased to the axial pressing force. The first rotating member and the second rotating member are engaged with each other when a torque greater than a predetermined value is input by the first and second rotating members, the pressing mechanism, and the converting mechanism. A torque limiter to be released is configured.

  By setting the predetermined value to be larger than the maximum torque during normal running, the shock torque is absorbed when a shock torque greater than the predetermined value is input while securing the torque capacity during normal running. Can do. In addition, since the pressing mechanism is arranged with the longitudinal direction oriented in the circumferential direction, the differential size of the differential device is reduced by reducing the axial dimension of the differential device as compared with the case of being arranged in the axial direction. Can be Thereby, a power transmission device can be reduced in size and vehicle-mounted property can be improved. Furthermore, since the converting mechanism converts the circumferential pressing force of the pressing mechanism by increasing the pressing force in the axial direction, the pressing mechanism can be reduced, and the above-described effect can be more effectively achieved. . In particular, in the FF vehicle, the above effect can be obtained effectively.

The first rotating member and the second rotating member are disposed in the differential case, the first rotating member rotates integrally with the differential case, the second rotating member supports the pinion shaft, a pressing mechanism and a conversion mechanism. Compared to the case where the torque limiter is disposed on the outer peripheral side of the differential case by disposing the first rotating member and the second rotating member on a circumference having substantially the same radius as the engaging portion facing each other. Thus, the radial dimension of the differential device can be shortened to reduce the size of the differential device, and the power transmission device can be reduced in size.

According to the second aspect of the present invention, the bearing member is provided between the outer periphery of the second rotating member and the inner surface of the differential case, and the second rotating member is rotatably fitted to the differential case. Thus, when a torque of a predetermined value or more is input, the engagement between the first rotating member and the second rotating member can be released, and the second rotating member and the differential case can be reliably rotated relative to each other. Can be effectively obtained.

Still further, according to the invention according to claim 3 of the present application, the first tooth surface and the second tooth surface having teeth extending in the radial direction that mesh with each other provided on the opposing surfaces of the first rotating member and the second rotating member, respectively. And the tooth of the first tooth surface and the tooth of the second tooth surface are provided with an engagement mechanism formed to increase the axial pressing force into the circumferential pressing force and convert it. Thus, the pressing mechanism can be further reduced, and the above-described effect can be more effectively achieved.

Furthermore, according to the invention according to claim 4 of the present application, a pressing mechanism is assembled to the first case structure forming the differential case to form the first subassembly, and the pinion gear is formed on the second case structural body forming the differential case, The side gear, the first rotating member, and the second rotating member are assembled to form a second subassembly, and the first subassembly and the second subassembly are combined so as to form a conversion mechanism by the pressing mechanism and the first rotating member. By assembling the differential device, the pressing mechanism can be assembled in advance to the first case structure, so that the differential device can be assembled relatively easily, and the invention according to claim 1 of the present application. It is possible to assemble a power transmission device that achieves the above effects relatively easily.

It is a schematic diagram which shows the front part of the vehicle body provided with the power transmission device which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the differential of the power transmission device which concerns on 1st Embodiment. FIG. 3 is a cross-sectional view of the differential device along line Y3-Y3 in FIG. 2. FIG. 3 is a cross-sectional view of the differential device taken along line Y4-Y4 in FIG. 2. It is a top view of the 1st rotation member of a differential. It is explanatory drawing for demonstrating the pressing force by a pressing mechanism. It is explanatory drawing for demonstrating operation | movement when shock torque is input into the differential gear. It is explanatory drawing for demonstrating the assembly method of a differential gear. It is explanatory drawing for demonstrating the differential of the power transmission device which concerns on 2nd Embodiment of this invention. Explanation for explaining the differential of the power transmission device according to the third embodiment of the present invention. It is sectional drawing which shows the differential of the power transmission device which concerns on 4th Embodiment of this invention. It is explanatory drawing for demonstrating the differential of the power transmission device which concerns on 5th Embodiment of this invention.

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

(First embodiment)
FIG. 1 is a schematic diagram showing a front portion of a vehicle body provided with a power transmission device according to an embodiment of the present invention. A vehicle body 1 shown in FIG. 1 includes an engine 2 as a drive source, a clutch 3, a transmission 4, a differential device 5, a drive shaft 6 connected to the differential device 5, and a drive at the front of the vehicle body. And a front wheel 7 as a driving wheel attached to the shaft 6.

  The vehicle body 1 is an FF vehicle housed in a housing 8 in which an engine 2 is disposed at the front of the vehicle body and a clutch 3, a transmission 4, and a differential device 5 are integrated. In the vehicle body 1, the engine 2 is disposed such that the output shaft faces the vehicle width direction, the clutch 3 and the transmission 4 are disposed adjacent to each other in the vehicle width direction, and the transmission 4 and the differential device 5 are It is arranged adjacent to the longitudinal direction of the vehicle body.

  The output of the engine 2 is transmitted to the differential device 5 through the clutch 3 and the transmission 4, and is transmitted from the differential device 5 to the front wheel 7 through the drive shaft 6. In the vehicle body 1, a differential device 5 is provided in a power transmission path from the engine 2 to the front wheel 7, and power that transmits power from the engine 2 to the front wheel 7 by the clutch 3, the transmission 4, the differential device 5, and the drive shaft 6. A transmission device is configured.

  2 is a cross-sectional view showing the differential device of the power transmission device according to the first embodiment, FIG. 3 is a cross-sectional view of the differential device along line Y3-Y3 in FIG. 2, and FIG. 2 is a cross-sectional view of the differential device along line Y4-Y4 in FIG. In FIG. 3, the output gear, ring gear, bolts and nuts of the transmission are omitted.

  As shown in FIG. 2, the differential case 10 of the differential device 5 is divided and formed by a first case structure 11 formed in a substantially disc shape and a second case structure 21 formed in a substantially cylindrical shape. The flange portion 11a of the first case component 11 and the flange portion 21a of the second case component 21 are fastened and fixed using bolts B1 and nuts N1.

  A ring gear 9 that meshes with an output gear 4 a that is an output portion of the transmission 4 is fastened and fixed to the differential case 10, and the output of the transmission 4 is transmitted to the differential device 5. The ring gear 9 is fastened and fixed to the flange portion 11 a of the first case component 11 and the flange portion 21 a of the second case component 21. The differential case 10 is provided to be rotatable around an axis C1 extending in the vehicle width direction.

  In the differential case 10, specifically, in the side wall portion 21 b of the second case structure 21, a pinion shaft 22 extending in a direction orthogonal to the axis C <b> 1 is disposed and is rotatable to the pinion shaft 22. A pair of pinion gears 23 that are supported by each other and that face each other are disposed. A pair of left and right side gears 24 that mesh with the pair of pinion gears 23 are also disposed in the differential case 10.

  The first case structure 11 and the second case structure 21 are provided with shaft insertion portions 11c and 21c corresponding to the side gears 24, respectively. The drive shaft 6 is inserted into each of the shaft insertion portions 11c and 21c, and the tip of the drive shaft 6 is splined to the side gear 24. As a result, the drive shaft 6 can rotate relative to the differential case 10 together with the side gear 24.

  In the present embodiment, the differential device 5 also includes a first rotating member 30 that is rotationally driven by the output of the transmission 3 in the differential case 10, and the first rotating member 30 on the same axis as the first rotating member 30. And a second rotating member 35 configured to be able to engage with the first rotating member 30, and a circumferential pressing force disposed on the side opposite to the second rotating member 35 of the first rotating member 30. And a conversion mechanism 45 that converts the circumferential pressing force of the pressing mechanism 40 into an axial pressing force for conversion.

  FIG. 5 is a plan view of the first rotating member of the differential device, and FIG. 5 shows a view of the first rotating member 30 as viewed from the second rotating member 35 side. As shown in FIGS. 2 and 5, the first rotating member 30 is formed in a ring shape, and teeth 31 extending in the axial direction of the first rotating member 30 are formed on the outer periphery thereof. Teeth 21d that mesh with the teeth 31 of the first rotating member 30 are formed on the inner surface of the side wall portion 21b of the second case constituting body 21 on the first case constituting body 11 side, and the first rotating member 30 is the first case. The structure 21 is spline-fitted. As a result, the first rotating member 30 is rotationally driven together with the first case component 21 by the output of the transmission 3 and rotates integrally with the differential case 10.

  The first rotating member 30 is also configured to be movable in the axial direction with respect to the second case component 21 in a state of being spline fitted to the first case component 21. The first case component 11 is formed with a first groove 11 d that is recessed in a concave shape so as to allow the first rotating member 30 to move in the axial direction.

  As shown in FIGS. 4 and 5, a tooth surface 32 (first tooth surface) is formed on the surface of the first rotation member 30 facing the second rotation member 35. The tooth surface 32 has a tooth 33 extending in the radial direction, and the tooth 33 has a trapezoidal cross section in the circumferential direction, and its side surface 33a is formed at an angle of 45 degrees as shown in FIG. Has been.

  The first rotating member 30 also includes four projecting portions 34 that project in a substantially quadrangular prism shape on the side opposite to the second rotating member 35 of the first rotating member 30. The four protrusions 34 are arranged at equal intervals of 90 degrees in the circumferential direction. The tip of the projecting portion 34 is formed by an inclined surface 34 a that is inclined at a predetermined angle θ <b> 1 with respect to a direction orthogonal to the axis of the first rotating member 30. In the present embodiment, the predetermined angle θ1 is set to an angle between 0 degrees and 45 degrees.

  The second rotating member 35 is formed in a ring shape so as to have substantially the same length in the radial direction as the first rotating member 30, and is disposed on the same axis as the first rotating member 30 and the first rotating member 30. Are arranged opposite to each other.

  The second rotating member 35 is formed with a pinion shaft insertion hole 35a. The pinion shaft 22 is inserted into the pinion shaft insertion hole 35a, and the second rotation member 35 supports the pinion shaft 22. Thereby, the second rotating member 35 is rotated around the axis C <b> 1 together with the pinion shaft 22 and the pinion gear 23, and is connected to the front wheel 7 via the pinion shaft 22, the pinion gear 23, the side gear 24 and the drive shaft 6.

  The inner surface of the second rotation member 35 is curved and supports the pinion gear 23. The outer surface of the second rotating member 35 is rotatably fitted to the inner surface of the side wall portion 21 b of the second case component 21. The second rotating member 35 is also rotatably supported at one end face in the axial direction by the bottom wall portion 21e of the second case constituting body 21.

  The second rotating member 35 is also formed with a tooth surface (second tooth surface) 36 on the other end surface in the axial direction, that is, the surface facing the first rotating member 30. The tooth surface 36 has a tooth 37 extending in the radial direction, and the tooth 37 has a trapezoidal cross section in the circumferential direction, and its side surface is formed at an angle of 45 degrees.

  The teeth 33 of the first rotating member 30 and the teeth 37 of the second rotating member 35 are formed so as to mesh with each other, and the first rotating member 30 and the second rotating member 35 are configured to be engageable. When the first rotating member 30 and the second rotating member 35 are engaged, the output of the transmission 3 is the differential case 10, the first rotating member 30, the second rotating member 35, the pinion shaft 22, the pinion gear 23, the side gear 24, and the drive shaft. 6 is transmitted to the front wheel 7 via 6.

  The pressing mechanism 40 provided on the side opposite to the second rotating member 35 of the first rotating member 30 is provided corresponding to the protruding portion 34 of the first rotating member 30. The pressing mechanism 40 includes a spring 41 that is spirally formed as an elastic member, and a pressing member 42 that is biased by the spring 41. The spring 41 and the pressing member 42 are the second of the first case component 11. It arrange | positions in the 2nd groove part 11e formed in a rectangular shape from the end surface by the side of the case structure 21 side.

  The pressing member 42 is disposed in the second groove portion 11e so that the tip portion 44 formed in a substantially quadrangular prism shape with the pin portion 43 inserted into the spring 41 is in contact with the protruding portion 34 of the first rotating member 30. Has been. The tip 44 of the pressing member 42 has an inclined surface 44a that is inclined at a predetermined angle θ1 with respect to a direction orthogonal to the axis of the first rotating member 30 so as to contact the inclined surface 34a of the protruding portion 34 of the first rotating member 30. Is formed. In the present embodiment, the predetermined angle θ1 is set to an angle between 0 degrees and 45 degrees.

  The pressing member 42 is disposed so as to contact the protruding portion 34 of the first rotating member 30 in a state where the spring 41 is compressed. The pressing member 42 is also configured to be able to move within the second groove portion 11e by compressing the spring 41 when a force of a predetermined value or more is input.

  The pressing mechanism 40 thus configured has a longitudinal axis C2 and is arranged with the longitudinal direction directed in the circumferential direction. Accordingly, the pressing mechanism 40 generates a pressing force in the circumferential direction by the spring 41 and causes the pressing force in the circumferential direction to act on the inclined surface 34 a of the first rotating member 30.

Here, the pressing force by the pressing mechanism 40 will be described with reference to FIG.
FIG. 6 is an explanatory diagram for explaining the pressing force by the pressing mechanism. As shown in FIG. 6, when the pressing force by the pressing mechanism 40 is F1, that is, when the pressing force in the circumferential direction by which the pressing member 42 presses the first rotating member 30 by the spring 41 is F1, the pressing force by the pressing mechanism 40 is as follows. Due to the pressure F1, the first rotating member 30 is pressed with a pressing force F2 in a direction perpendicular to the inclined surface 34a of the first rotating member 30 through the inclined surface 44a of the pressing member 42 and the inclined surface 34a of the first rotating member 30. . The pressing force F2 is represented by the following formula: F2 = F1 / sin θ1.

  The pressing force F2 in the direction orthogonal to the inclined surface 34a of the first rotating member 30 is decomposed into a circumferential pressing force F3 and an axial pressing force F4, and the first rotating member 30 is subjected to the axial pressing force F4. It is pressed in the axial direction. The pressing force F4 is expressed by the following formula: F4 = F2 cos θ1, and when the pressing force F1 is used, the pressing formula F4 is expressed by the following formula: F4 = F1 / tan θ1. Since the angle θ1 is set to an angle between 0 degrees and 45 degrees, the circumferential pressing force F1 by the pressing mechanism 40 is increased and converted into the axial pressing force F4.

  In the present embodiment, the conversion mechanism 45 includes a slope 44 a provided on the pressing mechanism 40, specifically, the pressing member 42, and a slope 34 a provided on the first rotating member 30 and in contact with the slope 44 a of the pressing mechanism 40. The circumferential pressing force F1 by the pressing mechanism 40 is increased and converted to an axial pressing force F4.

  Then, due to the axial pressing force F <b> 4 against which the first rotating member 30 is pressed, the second rotating member 35 has the side surface 33 a of the tooth 33 of the first rotating member 30 and the side surface 37 a of the tooth 37 of the second rotating member 35. Is pressed by a pressing force F5 in a direction perpendicular to the side surface 37a of the tooth 37 of the second rotating member 35. The pressing force F5 is represented by the following formula: F5 = F4 / sin45 °.

  The pressing force F5 in the direction orthogonal to the side surface 37a of the tooth 37 of the second rotating member 35 is decomposed into an axial pressing force F6 and a circumferential pressing force F7, and the second rotating member 35 is It is pressed in the circumferential direction by the pressing force F7. The pressing force F7 is expressed by the following formula: F7 = F5 cos 45 °, and when the pressing force F4 is used, it is expressed by the following formula: F7 = F4 / tan 45 °. Therefore, the axial pressing force F4 for pressing the first rotating member 30 is converted into a circumferential pressing force F7 having the same magnitude as the pressing force F4.

  When the circumferential radius of the first rotating member 30 at the position P1 shown in FIG. 6 is R1, the torque capacity that can be transmitted between the first rotating member 30 and the second rotating member 35 is the circumferential direction. This is expressed by the product F7 · R1 of the pressing force F7 and the radius R1 in the circumferential direction. When the pressing force F1 is used, it is expressed by F1 / tan θ1 · R1.

  When the torque T acts on the differential 5 and the torque T acts on the second rotating member 35 as shown in FIG. 6, the circumferential direction of the second rotating member 35 toward the first rotating member 30 at the position P1. When the circumferential load F is equal to or less than the circumferential pressing force F7 on the second rotating member 30, the first rotating member 30 and the second rotating member 35 face each other. The first rotating member 30 and the second rotating member 35 are engaged with each other at the engaging portion 49.

  In this embodiment, the pressing mechanism 40 sets the circumferential pressing force F1 so that the circumferential pressing force F7 is slightly larger than the circumferential load corresponding to the maximum torque during normal travel. . As a result, when a torque equal to or less than the maximum torque during normal driving is input to the differential device 5, the engagement state between the first rotating member 30 and the second rotating member 35 is maintained, and the output of the transmission 4 is increased. The differential case 10, the first rotating member 30, the second rotating member 35, the pinion shaft 22, the pinion gear 23, the side gear 24, and the drive shaft 6 are transmitted to the front wheel 7.

  On the other hand, when the torque T acts on the second rotating member 35, the circumferential load F applied to the first rotating member 30 by the second rotating member 35 at the position P <b> 1 is increased in the circumferential direction to the second rotating member 35. When larger than the pressing force F7, the first rotating member 30 moves in the axial direction toward the pressing mechanism 40, and the engagement between the first rotating member 30 and the second rotating member 35 is released.

  FIG. 7 is an explanatory diagram for explaining the operation when shock torque is input to the differential device. When a shock torque greater than the circumferential load F shown in FIG. 6 is input, the first rotating member 30 moves toward the pressing mechanism 40 as shown by an arrow A1 as shown in FIG. By moving in the axial direction, the engagement between the first rotating member 30 and the second rotating member 35 is released. In the pressing mechanism 40, the pressing member 42 is moved in the circumferential direction as indicated by the arrow A2 along with the movement of the first rotating member 30, and the spring 41 is compressed.

  In this way, when a shock torque of a predetermined value or more is input to the differential device 5, the engagement between the first rotating member 30 and the second rotating member 35 is released, and the differential device 5 is connected to the transmission 4. The shock torque is not transmitted between the first rotating member 30 and the second rotating member 35 connected to the wheel 7.

  In the present embodiment, the first rotating member 30, the second rotating member 35, the pressing mechanism 40, and the conversion mechanism 45 receive the first rotating member 30 and the second rotating member when a torque greater than a predetermined value is input to the differential device 5. A torque limiter 50 is configured to limit the torque transmitted between the transmission 4 and the front wheel 7 by disengaging the rotating member 35.

  As described above, the differential device 5 is connected to the first rotating member 30 that is rotationally driven by the output of the transmission 4 and the driving wheel 7 and is configured to be engageable with the first rotating member 30. The rotating member 35, the longitudinal direction of the pressing mechanism 40 that is arranged in the circumferential direction and generating the circumferential pressing force F 1, the first inclined surface 44 a provided in the pressing mechanism 40, and the first rotating member 30 A second slope 34a that is provided and is in contact with the first slope 44a, and a conversion mechanism 45 that converts the circumferential pressing force F1 by the pressing mechanism 40 into an axial pressing force F4 for conversion. 1. Torque that disengages the first rotating member 30 from the second rotating member 35 when a torque greater than a predetermined value is input by the first rotating member 30, 35, the pressing mechanism 40, and the converting mechanism 45. A limiter 50 is configured.

  By setting the predetermined value to be larger than the maximum torque during normal running, the shock torque is absorbed when a shock torque greater than the predetermined value is input while securing the torque capacity during normal running. Can do. Further, since the pressing mechanism 40 is arranged with the longitudinal direction thereof being directed in the circumferential direction, the axial direction dimension of the differential device 5 is reduced as compared with the case where it is arranged in the axial direction. 5 can be reduced in size. Thereby, a power transmission device can be reduced in size and vehicle-mounted property can be improved. Furthermore, since the converting mechanism 45 converts the circumferential pressing force F1 by the pressing mechanism 40 into the axial pressing force F4 for conversion, the pressing mechanism 40 can be made smaller, and the above effect is more effective. Can be played. In particular, in the FF vehicle, the above effect can be obtained effectively.

  In the present embodiment, the pressing mechanism 40 and the conversion mechanism 45 are disposed on a circumference having substantially the same radius as the engaging portion 49 where the first rotating member 30 and the second rotating member 35 face each other. . Thereby, compared with the case where the torque limiter 50 is disposed on the outer peripheral side of the differential case 10, the differential device 5 can be reduced in size by reducing the radial dimension of the differential device 5. It can be downsized.

Next, an assembling method of the differential device 5 configured as described above will be described.
FIG. 8 is an explanatory diagram for explaining a method of assembling the differential device. When assembling the differential 5, first, as shown in FIG. 8, the first case assembly 11 is assembled with the pressing mechanism 40, that is, the spring 41 and the pressing member 42 to form the first subassembly S <b> 1.

  In addition, one side gear 24, the pinion gear 23 and the second rotating member 35 integrally assembled with the pinion shaft 22, the other side gear 24, and the first rotating member 30 are sequentially assembled to the second case structural body 21. A subassembly S2 is formed.

  Then, the first subassembly S1 and the second subassembly S2 are overlapped and fastened so as to form the conversion mechanism 45 by the pressing mechanism 40 and the first rotating member 30, thereby fixing the first subassembly S1 and the first subassembly S1. The differential device 5 is assembled by combining the two subassemblies S2.

  Thereby, since the pressing mechanism 40 can be assembled in advance to the first case structure 11 when the differential device 5 is assembled, the differential device 5 can be assembled relatively easily, and the power transmission device can be It can be assembled relatively easily.

(Second Embodiment)
Next, a power transmission device according to a second embodiment of the present invention will be described. In addition, about the power transmission device which concerns on 2nd Embodiment, only a different part from the differential device 5 of the power transmission device which concerns on 1st Embodiment is demonstrated, and description is abbreviate | omitted about the structure similar to the differential device 5. FIG. .

  FIG. 9 is an explanatory diagram for explaining a differential gear of the power transmission device according to the second embodiment of the present invention. As shown in FIG. 9, the differential device 55 of the power transmission device according to the second embodiment is the opposite surface of the first rotation member 30 and the second rotation member 35 in the differential device 5 according to the first embodiment. Are formed in a planar shape.

  In the differential device 55, the first rotating member 30 and the second rotating member 35 are configured to be engageable with each other by a flat facing surface. Also in the differential device 55, the first rotating member 30 is pressed by the pressing mechanism 40 with the axial pressing force F4, and the first rotating member 30 and the second rotating member 35 are engaged. When a torque of a predetermined value or more is input, slip occurs between the first rotating member 30 and the second rotating member 35, and the engagement between the first rotating member 30 and the second rotating member 35 is released.

  Also in the power transmission device according to the second embodiment, by setting the predetermined value to be larger than the maximum torque during normal traveling, the predetermined value or more is secured while ensuring the torque capacity during normal traveling. The shock torque can be absorbed when the shock torque is input. Also in the differential device 55, the pressing mechanism 40 is disposed with the longitudinal direction thereof being directed in the circumferential direction. Therefore, by reducing the size of the differential device 55, the power transmission device can be miniaturized and the onboard performance can be improved. Can do.

(Third embodiment)
Next, a power transmission device according to a third embodiment of the present invention will be described. In addition, about the power transmission device which concerns on 3rd Embodiment, only a different part from the differential device 5 of the power transmission device which concerns on 1st Embodiment is demonstrated, and description is abbreviate | omitted about the structure similar to the differential device 5. FIG. .

  FIG. 10 is an explanatory diagram for explaining a differential gear of the power transmission device according to the third embodiment of the present invention. As shown in FIG. 10, the differential device 65 of the power transmission device according to the third embodiment is the same as the differential device 5 according to the first embodiment, in which the side surface 33a of the tooth 33 of the first rotating member 30 is 0 degrees. The side surface 37a of the tooth 37 of the second rotating member 35 is formed at a predetermined angle θ2 between 0 degrees and 45 degrees, with a predetermined angle θ2 between 45 degrees.

  In the differential device 65, the second rotating member 35 causes the side surface 33 a of the tooth 33 of the first rotating member 30 and the tooth 37 of the second rotating member 35 by the axial pressing force F <b> 4 that presses the first rotating member 30. Is pressed with a pressing force F5 ′ in a direction perpendicular to the side surface 37a of the tooth 37 of the second rotating member 35. The pressing force F5 'is expressed by the following formula: F5' = F4 / sin θ2.

  The pressing force F5 ′ in the direction orthogonal to the side surface 37a of the tooth 37 of the second rotating member 35 is decomposed into an axial pressing force F6 ′ and a circumferential pressing force F7 ′, and the second rotating member 35 is circular. It is pressed in the circumferential direction by the circumferential pressing force F7 ′. The pressing force F7 'is expressed by the following formula: F7 = F5' cos θ2, and when the pressing force F4 is used, the pressing formula F7 'is expressed by the following formula: F7' = F4 / tan θ2. Since the angle θ2 is set to an angle between 0 degrees and 45 degrees, the axial pressing force F4 is increased and converted into the circumferential pressing force F7 '.

  Also in the power transmission device according to the third embodiment, when the torque T acts on the second rotating member 35, the circumferential load F applied to the first rotating member 30 by the second rotating member 35 at the position P1 is the first. When the circumferential pressing force F7 ′ on the two rotating members 30 is greater, the first rotating member 30 moves in the axial direction toward the pressing mechanism 40 and the first rotating member 30 and the second rotating member 35 The engagement is released.

  As described above, the differential device 65 includes the tooth surfaces 32 and 36 having the teeth 33 and 37 that are provided on the opposing surfaces of the first rotating member 30 and the second rotating member 35 and extend in the radial direction and mesh with each other. There is provided an engagement mechanism 66 formed such that the teeth 33 of the surface 32 and the teeth 37 of the tooth surface 36 increase and convert the axial pressing force F4 to the circumferential pressing force F7 ′.

  Further, in the differential device 65, when a torque greater than a predetermined value is input to the differential device 5 by the first rotating member 30, the second rotating member 35, the pressing mechanism 40, the converting mechanism 45, and the engaging mechanism 66. The engagement between the first rotating member 30 and the second rotating member 35 is released, and a torque limiter 50 that limits the torque transmitted between the transmission 4 and the front wheel 7 is configured.

  Also in the power transmission device according to the third embodiment, by setting the predetermined value so as to be larger than the maximum torque during normal running, the torque capacity during normal running is ensured to be equal to or greater than the predetermined value. The shock torque can be absorbed when the shock torque is input. Also in the differential device 65, since the pressing mechanism 40 is arranged with the longitudinal direction oriented in the circumferential direction, downsizing the differential device 65 reduces the size of the power transmission device and improves in-vehicle performance. Can do.

  Furthermore, a first tooth surface 32 and a second tooth surface 33 having radially extending teeth 33, 37 provided on opposite surfaces of the first rotating member 30 and the second rotating member 35 and engaging with each other are provided. The tooth 33 of the tooth surface 32 and the tooth 37 of the second tooth surface 36 are provided with an engagement mechanism 66 formed so as to increase the axial pressing force F4 and convert it into a circumferential pressing force F7 ′. As a result, the pressing mechanism 40 can be further reduced.

(Fourth embodiment)
Next, a power transmission device according to a fourth embodiment of the present invention will be described. In addition, about the power transmission device which concerns on 4th Embodiment, only a different part from the differential device 5 of the power transmission device which concerns on 1st Embodiment is demonstrated, and description is abbreviate | omitted about the structure similar to the differential device 5. FIG. .

  FIG. 11 is a cross-sectional view showing a differential gear of the power transmission device according to the fourth embodiment of the present invention. As shown in FIG. 11, the differential device 75 of the power transmission device according to the fourth embodiment is the same as the differential device 5 according to the first embodiment, between the outer periphery of the second rotating member 35 and the inner surface of the differential case 10. A bearing member 76 is disposed on the surface.

  In the differential device 75, a metal ring-shaped bush 76 is disposed as a bearing member between the outer periphery of the second rotating member 35 and the inner surface of the side wall portion 21 a of the second case component 21. The two bushes 76 are spaced from each other in the axial direction of the differential device 75 and press-fitted into the inner surface of the side surface portion 21 a of the second case structure 21, and the second rotating member 35 is connected to the differential case 10 via the bush 76. Specifically, the second case component 21 is rotatably fitted.

  As a result, when a torque greater than a predetermined value is input to the differential device 75, the engagement between the first rotating member 30 and the second rotating member 35 is released and the second rotating member 35 and the differential case 10 are securely connected. Relative rotation can be achieved, and shock torque can be absorbed reliably.

  In the differential device 75, the bearing member 76 is disposed between the outer periphery of the second rotating member 35 and the inner surface of the side wall portion 21 a of the second case component 21. It is also possible to dispose a bearing member between the first rotating member 30 side and the bottom wall portion 21e of the second case structure 21.

(Fifth embodiment)
Next, a power transmission device according to a fifth embodiment of the present invention will be described. In addition, about the power transmission device which concerns on 5th Embodiment, only a different part from the differential device 5 of the power transmission device which concerns on 1st Embodiment is demonstrated, and description is abbreviate | omitted about the structure similar to the differential device 5. FIG. .

  FIG. 12 is an explanatory diagram for explaining a differential gear of the power transmission device according to the fifth embodiment of the present invention. As illustrated in FIG. 12, the differential device 85 of the power transmission device according to the fifth embodiment is the same as the differential device 5 according to the first embodiment, in which the contact surface and the pressure between the pressing member 42 and the first rotating member 30 are pressed. Metal balls 86 and 87 are disposed on the contact surface between the member 42 and the first case structure 11, respectively.

  In the differential device 85, a concave ball receiving portion 44 b is formed on the inclined surface 44 a of the pressing member 42, and a concave concave ball receiving portion 34 b is formed on the inclined surface 34 a of the projecting portion 34 of the first rotating member 30. ing. A metal ball 86 is accommodated between the ball accommodating portion 44b of the pressing member 42 and the ball accommodating portion 34b of the first rotating member 30, and the pressing member 42 and the first rotating member 30 come into contact with each other by rolling contact. ing.

  Further, in the differential device 85, a ball housing portion 44 c that is recessed in the recess is formed in the distal end portion 44 of the pressing member 42 at a portion of the distal end portion 44 of the pressing member 42 that contacts the first case constituent body 11. A ball housing portion 11 f that is recessed in a concave shape is formed in the second groove portion 11 e of the first case structure 11. A metal ball 87 is accommodated between the ball accommodating portion 44c of the pressing member 42 and the ball accommodating portion 11f of the first case component 11, and the pressing member 42 and the first case component 11 are brought into rolling contact with each other. In contact.

  Accordingly, the frictional force between the pressing member 42 and the first rotating member 30 and the friction amount between the pressing member 42 and the first case constituting body 11 can be reduced and smoothly moved. When the shock torque is input to the device 85, the engagement between the first rotating member 30 and the second rotating member 35 can be quickly released to absorb the shock torque.

  The present invention is not limited to the illustrated embodiments, and various improvements and design changes can be made without departing from the scope of the present invention.

  As described above, according to the present invention, in the power transmission device with a torque limiter, the power transmission device can be miniaturized by reducing the size of the differential device, and the in-vehicle performance can be improved. It can be used for a power transmission device.

2 Engine 4 Transmission 4a Output gear 5, 55, 65, 75, 85 Differential gear 7 Front wheel 10 Differential case 11 First case component 21 Second case component 22 Pinion shaft 23 Pinion gear 24 Side gear 30 First rotating member 32, 37 tooth surfaces 33, 37 teeth 34a, 44a slope 35 second rotating member 40 pressing mechanism 41 spring 42 pressing member 45 converting mechanism 49 engaging portion 66 engaging mechanism 76 bearing member S1 first subassembly S2 second subassembly

Claims (4)

A power transmission path from the drive source to the drive wheel accommodates a pinion gear supported in the differential case via a pinion shaft and a pair of side gears engaged with the pinion gear, and transmits the output of the transmission to the drive wheel. A power transmission device with a torque limiter, comprising: a differential device; and a torque limiter that limits torque transmitted between the transmission and the drive wheel,
The differential is
A first rotating member connected to the output of the transmission and driven to rotate by the output of the transmission;
A second rotating member coupled to the drive wheel and disposed opposite to the first rotating member on the same axis as the first rotating member and configured to be engageable with the first rotating member; ,
A pressing mechanism that is arranged with the longitudinal direction facing the circumferential direction on the side opposite to the second rotating member of the first rotating member, and generates a pressing force in the circumferential direction;
A first inclined surface provided in the pressing mechanism; and a second inclined surface provided in the first rotating member and in contact with the first inclined surface, wherein the pressing force in the circumferential direction by the pressing mechanism is axially applied. A conversion mechanism for increasing the pressure to convert, and
With
The first rotating member, the second rotating member, the pressing mechanism, and the converting mechanism cause the first rotating member and the second rotating member when the torque greater than a predetermined value is input to the differential device. A torque limiter that disengages is configured ,
The first rotating member and the second rotating member are disposed in the differential case,
The first rotating member rotates integrally with the differential case;
The second rotating member supports the pinion shaft,
The pressing mechanism and the conversion mechanism are disposed on a circumference having substantially the same radius as an engaging portion where the first rotating member and the second rotating member face each other.
A power transmission device with a torque limiter. A bearing member is provided between the outer periphery of the second rotating member and the inner surface of the differential case;
The second rotating member is rotatably fitted to the differential case.
The power transmission device with a torque limiter according to claim 1 . The differential includes a first tooth surface and a second tooth surface, which are provided on opposing surfaces of the first rotating member and the second rotating member and have teeth extending in the radial direction and meshing with each other, and the first tooth surface. An engagement mechanism formed so that the tooth of the tooth surface and the tooth of the second tooth surface are converted by increasing the axial pressing force to a circumferential pressing force;
The first rotating member, the second rotating member, the pressing mechanism, the converting mechanism, and the engaging mechanism cause the first rotating member and the first rotating member when a torque greater than a predetermined value is input to the differential device. A torque limiter that is disengaged from the two-rotating member is configured.
The power transmission device with a torque limiter according to claim 1 , wherein the power transmission device has a torque limiter. A pinion gear supported via a pinion shaft in a differential case formed by dividing the first case component and the second case component in a power transmission path from the drive source to the drive wheel and engages with the pinion gear. A differential device that houses a pair of side gears and that transmits the output of the transmission to the drive wheel; and a torque limiter that limits the torque transmitted between the transmission and the drive wheel. The moving device is connected to the output portion of the transmission and is driven to rotate by the output of the transmission, and is connected to the driving wheel and on the same axis as the first rotating member. A second rotating member arranged opposite to the first rotating member and configured to be engageable with the first rotating member, and a longitudinal direction on the side opposite to the second rotating member of the first rotating member, the circumferential direction Placed towards the A pressing mechanism that generates a pressing force in the circumferential direction; a first inclined surface provided in the pressing mechanism; and a second inclined surface provided in the first rotating member and in contact with the first inclined surface. And a conversion mechanism that converts the circumferential pressing force to an axial pressing force to convert the differential force by the first rotating member, the second rotating member, the pressing mechanism, and the converting mechanism. A method of assembling a power transmission device with a torque limiter, in which a torque limiter is configured to release the engagement between the first rotating member and the second rotating member when a torque of a predetermined value or more is input to the device. And
A first subassembly forming step of forming the first subassembly by assembling the pressing mechanism to the first case structure;
A second subassembly forming step of forming the second subassembly by assembling the pinion gear, the side gear, the first rotating member and the second rotating member to the second case structure;
A merging step of assembling the differential device by merging the first subassembly and the second subassembly so as to form the conversion mechanism by the pressing mechanism and the first rotating member;
A method for assembling a power transmission device with a torque limiter.