JP2016007998A - Power transmission structure of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration in vehicle mountability accompanied with an increase in the scale of a damper while making a damper function be maintained even when a large impact load is applied to the damper.SOLUTION: In a vehicle in which a universal joint 21 and a damper 30 are provided on a drive shaft 10 at an interval in an axial direction, the damper 30 is provided with: a cylindrical part 32 having an opening portion 32b at the tip; a shaft part 50 with the tip portion accommodated in the cylindrical part 32; an elastic member 60 interposed between the shaft part 50 and the cylindrical part 32; a bearing 38 interposed between the outer periphery of the shaft part 50 and the inner periphery of the cylindrical part 32 at an axial position closer to the opening portion side than the elastic member 60; a diameter expansion part 54 protruding radially outward from the outer periphery of the shaft part 50 at an axial position closer to a side opposite to the opening portion than the bearing 38; and a retaining part 42 protruding radially inward from the inner periphery of the cylindrical part 32 at an axial position closer to the opening portion side than the bearing 38. Retaining strength of the damper 30 by the retaining part 42 is set larger than retaining strength of the universal joint 21.

Description

  The present invention relates to a vehicle power transmission structure in which a drive shaft is provided with a damper, and belongs to the field of vehicle power transmission technology.

  For the purpose of improving the fuel efficiency of the engine, a reduced-cylinder operation may be performed depending on the driving state. Further, development of premixed compression ignition (HCCI) technology for performing self-ignition combustion in a predetermined region in a gasoline engine has been promoted, and fuel efficiency can be improved by performing the HCCI combustion.

  However, if reduced-cylinder operation or HCCI combustion is performed, combustion of the engine becomes unstable, and vibration due to torque fluctuation or the like tends to increase. The vibration of the engine is transmitted to the drive shaft that connects the differential device and the drive wheels via the transmission and the differential device. If the vibration transmitted to the drive shaft is transmitted to the vehicle body via the suspension arm or the like, it will cause unpleasant vibration and noise in the passenger compartment.

  Vibration transmitted from the engine to the transmission can be absorbed by the torque converter, but the engine and the transmission are directly connected in a locked-up state of the torque converter or in a powertrain that is not equipped with a torque converter in the first place. Vibration absorption by a torque converter cannot be realized. Therefore, when the lockup area is expanded for improving fuel efficiency or the torque converter is abolished due to the multistage automatic transmission or the like, the above vibration and noise problems are promoted.

  In addition to the vibration source of the engine as described above, the transmission of the power transmission system includes gear meshing vibrations in transmissions and differentials, and torsion caused by impacts at the time of torque reversal in universal joints on the drive shaft. When there are vibrations and the like and these vibrations are transmitted to the vehicle body via the drive shaft, the same problem as described above occurs.

  In order to suppress the vibration of the power transmission system as described above, Patent Document 1 discloses that a damper is disposed on a drive shaft that couples a differential and a drive wheel, and this damper causes an engine, a transmission, and a difference. A technique is disclosed in which vibration from a power source such as a moving device is absorbed. Specifically, this damper is arranged between a pair of universal joints arranged on the drive shaft, and among these, a shaft portion provided at the tip of a shaft extending from the universal joint on the power source side to the wheel side, and the wheel A cylindrical portion provided at the tip of the shaft extending from the universal joint on the side to the power source side, and the shaft portion and the cylindrical portion are fitted to each other via an elastic member.

JP 2010-181011 A

  However, when the damper is provided on the drive shaft as disclosed in Patent Document 1, the strength of the damper is increased so that the damper function is maintained even when a large impact load is applied to the vehicle. There is a need. As a result, the damper itself increases in size, which may deteriorate the mountability of the damper on the vehicle.

  Therefore, an object of the present invention is to suppress deterioration of vehicle mountability accompanying an increase in the size of a damper while maintaining a damper function even when a large impact load is applied to the damper.

  In order to solve the above-described problems, a power transmission structure for a vehicle according to the present invention is configured as follows.

First, the invention according to claim 1 of the present application is
A universal joint and a damper are provided on the drive shaft that connects the power source and the drive wheel with an axial interval therebetween,
The drive shaft includes a first power transmission shaft that connects the universal joint and the damper, a second power transmission shaft that is connected to one end of the first power transmission shaft via the damper at one end, and one end. A third power transmission shaft connected to the other end of the first power transmission shaft via the universal joint,
The damper is provided at either one end of the first power transmission shaft or one end of the second power transmission shaft, and has a cylindrical portion having an opening at the tip, and one end of the first power transmission shaft or the first power transmission shaft. 2 provided with a shaft portion provided at one of the other ends of the power transmission shaft and having a tip portion accommodated in the tube portion, and an elastic member interposed between the shaft portion and the tube portion, A power transmission structure for a vehicle,
The damper includes a bearing interposed between an outer periphery of the shaft portion and an inner periphery of the cylindrical portion at an axial position closer to the opening than the elastic member, and the opening is on the opposite side of the opening from the bearing A diameter-enlarged portion projecting radially outward from the outer periphery of the shaft portion at a position in the axial direction, and a retaining member projecting radially inward from the inner periphery of the cylindrical portion at an axial position closer to the opening than the bearing And comprising
The release strength of the damper by the release preventing portion is larger than the release strength of the universal joint.

  In this specification, the term “pull-out strength” means that the accommodated portion provided at the end of the second shaft is fitted inside the cylindrical portion provided at the end of the first shaft. In the structure, when the first and second shafts are pulled in the axial direction so as to extract the accommodated part from the cylindrical part, the magnitude of the tensile force immediately before the retaining function of the accommodated part from the cylindrical part is lost. It means.

The invention according to claim 2 is the invention according to claim 1,
The universal joint includes a receiving portion provided at the other end of the first power transmission shaft, a cylindrical portion provided at one end of the third power transmission shaft so as to receive the receiving portion, And a boot portion provided to extend in the axial direction across the outer periphery of the cylindrical portion and the outer periphery of the first power transmission shaft.

Furthermore, the invention according to claim 3 is the invention according to claim 1 or 2,
The power source includes an engine;
The retaining portion is composed of a snap ring that is mounted in a reduced diameter in a circumferential groove formed on the inner periphery of the cylindrical portion,
The damper is disposed rearward of the engine in the vehicle front-rear direction and outside the universal joint in the vehicle width direction,
The cylindrical portion is disposed so as to extend outward from one end of the first power transmission shaft along the vehicle width direction,
The opening is arranged on the outer side in the vehicle width direction than the engine.

The invention according to claim 4 is the invention according to any one of claims 1 to 3,
In addition to the bearing disposed on the opening side in the axial direction from the elastic member, the damper includes a bearing disposed on the side opposite to the opening in the axial direction from the elastic member,
The bearing on the opening side has a larger diameter than the bearing on the side opposite to the opening.

  According to the first aspect of the present invention, a damper having a greater pulling strength than the universal joint is provided on the drive shaft. Therefore, when a large impact load is applied to the vehicle, a bending load or power is applied to the drive shaft. A load that increases the axial distance between the power source and the drive wheel can be applied to the universal joint that has a lower pulling strength than the damper. Therefore, the load acting on the damper can be reduced, and thereby the strength of the damper required for maintaining the damper function can be reduced. Therefore, it is possible to suppress an increase in size of the damper while ensuring a good damper function, and it is possible to suppress deterioration of the mountability of the damper on the vehicle.

  According to the second aspect of the present invention, the universal joint is provided with the extendable boot portion, so that when a large impact load is applied to the vehicle, the drive shaft is subjected to bending load, power source and driving wheel. When the load that expands the axial distance between the two and the universal joint acts on the universal joint, even if the contained part is detached from the cylindrical part in the universal joint, the contained part is accommodated in the boot part. be able to.

  According to the third aspect of the present invention, the opening portion of the cylinder portion of the damper is disposed on the outer side in the vehicle width direction than the engine, and is disposed in a portion farthest from the engine in the cylinder portion. Therefore, for example, when a large impact load is applied to the vehicle from the front of the vehicle, the engine is retracted, and the damper is configured with a snap ring mounted on the opening side portion of the tube portion and, consequently, the circumferential groove on the inner periphery of the tube portion. It is possible to prevent an impact load from being directly applied to the retaining portion of the. Therefore, since the strength required for the damper is reduced, it is possible to suppress the increase in size of the damper, and it is possible to suppress the deterioration of the mountability of the damper on the vehicle.

  According to the invention described in claim 4, the opening-side bearing and the non-opening-side bearing provided in the damper are moved in the direction in which the diameter-enlarged portion is removed by the bearing on the opening side having a larger diameter. Therefore, the damper can be more reliably prevented from coming off.

It is a top view which shows the power transmission device of the vehicle which concerns on one Embodiment of this invention. It is sectional drawing which shows the structure of the differential side constant velocity joint provided in the power transmission device shown in FIG. It is sectional drawing which looked at the structure of the damper provided in the power transmission device shown in FIG. 1 from the axial direction. FIG. 4 is a cross-sectional view taken along line AA of FIG. 3 when the structure of the damper shown in FIG. 3 is viewed from another direction.

  Hereinafter, embodiments of the present invention will be described. In the following description, terms indicating directions such as “front”, “rear”, “front / rear”, “right”, “left”, “left / right”, etc. It shall refer to the direction seen with the posture facing the direction of travel.

  FIG. 1 is a plan view showing a power transmission device 1 for a vehicle according to the present embodiment.

  As shown in FIG. 1, the power transmission device 1 is mounted on a front engine / front drive type vehicle (FF vehicle), for example, a power source 2 mounted in an engine room, and left and right drive wheels. And a pair of left and right drive shafts 10 (10a, 10b) for connecting the motor 28 to the power source 2.

  The power source 2 includes a horizontally installed engine 3 and a transaxle 4 arranged in parallel on the left side of the engine 3 in the vehicle width direction, for example. The transaxle 4 includes, for example, a transmission 6 connected to the output shaft of the engine 3 via a torque converter (not shown), and a differential device 8 that transmits the output of the transmission 6 to the left and right drive shafts 10. It has. The transmission 6 and the differential device 8 are arranged offset to the left of the center in the vehicle width direction. The differential device 8, the left and right drive shafts 10a, 10b connected to the differential device 8, and various components provided on these drive shafts 10a, 10b are rearward of the engine 3 in the vehicle longitudinal direction. Arranged on the side.

  Each drive shaft 10 is arranged to extend in the vehicle width direction over the entire length. On each drive shaft 10, a differential side constant velocity joint 21 and a wheel side constant velocity joint 22 are provided in this order from the differential device side at intervals in the vehicle width direction. As a result, a portion of the drive shaft 10 closer to the drive wheel than the differential-side constant velocity joint 21 can swing up and down around the differential-side constant velocity joint 21 in accordance with the unevenness of the road surface.

  Each drive shaft 10 includes a differential side shaft 11 (11a, 11b) extending from the differential 8 to the differential side constant velocity joint 21, a wheel side shaft 12 extending from the drive wheel 28 to the wheel side constant velocity joint 22, and a pair of And an intermediate shaft 15 that connects the constant velocity joints 21 and 22. The intermediate shaft 15 includes a first intermediate shaft 13 that extends from the differential-side constant velocity joint 21 toward the driving wheel, and a second intermediate shaft 14 that extends from the wheel-side constant velocity joint 22 toward the differential device. ing.

  The constant velocity joints 21 and 22 on the differential side and the wheel side are arranged symmetrically, so that the length of the left and right intermediate shafts 15 and the length of the left and right wheel side shafts 12 are equal. ing. Therefore, regarding the swinging of the drive shaft 10 according to the road surface unevenness described above, the left and right drive shafts 10a and 10b can perform the same behavior.

  On the other hand, the lengths of the differential-side shafts 11a and 11b are different on the left and right, and the right-side differential-side shaft 11a is longer than the left-side differential-side shaft 11b. The right differential shaft 11 a is fixed to the vehicle body via a bracket 29.

  On each drive shaft 10, a damper 30 is disposed between the pair of constant velocity joints 21 and 22, that is, on the intermediate shaft 15. The damper 30 absorbs the vibration transmitted from the power source 2 to the drive shaft 10, thereby suppressing vibration transmission to the vehicle body via a suspension arm (not shown) or the like, and unpleasant vibration and noise in the vehicle interior. . The arrangement of these dampers 30 is bilaterally symmetric, and the vibration absorbing effect by the dampers 30 can be obtained in the same way for both the left and right drive shafts 10a, 10b.

  The structure of the differential side constant velocity joint 21 will be described with reference to FIG. FIG. 2 is a cross-sectional view showing the differential-side constant velocity joint 21 provided on the right drive shaft 10a. The differential-side constant velocity joint 21 provided on the left drive shaft 10b has a symmetrical structure with the differential-side constant velocity joint 21 shown in FIG.

  As shown in FIG. 2, the differential side constant velocity joint 21 includes an outer ring 70 provided at a driving wheel side end portion of the differential side shaft 11 a and an inner ring attached to a differential device side end portion of the first intermediate shaft 13. 74, a plurality of balls 78 interposed between the outer ring 70 and the inner ring 74, and a cage 80 that holds these balls 78.

  The outer ring 70 is configured by a cylindrical portion extending in the axial direction so as to open to the drive wheel side. On the inner periphery of the outer ring 70, the same number of ball grooves 72 as the number of balls 78 extend in the axial direction. Further, a circumferential groove 82 is provided on the inner circumference of the outer ring 70 over the entire circumference at an axial position on the drive wheel side of the ball groove 72, and a C-shaped snap ring 84 is provided in the circumferential groove 82. It is mounted in an elastically deformed state so as to reduce the diameter. The snap ring 84 is held in the circumferential groove 82 by being pressed against the bottom of the circumferential groove 82 by a restoring force acting in the diameter expansion direction.

  The inner ring 74 is provided with an insertion hole 75 penetrating the inner ring 74 in the axial direction. The differential hole side end of the first intermediate shaft 13 is press-fitted into the insertion hole 75, and the inner periphery of the insertion hole 75 and the outer periphery of the first intermediate shaft 13 are spline-fitted. On the outer periphery of the inner ring 74, the same number of ball grooves 76 as the number of balls 78 extend in the axial direction. Each ball 78 is fitted into a ball groove 72 of the outer ring 70 and a ball groove 76 of the inner ring 74, and can roll in the axial direction along these ball grooves 72 and 76.

  Various parts including the inner ring 74 fixed to the differential device side end of the first intermediate shaft 13 as described above, and the ball 78 and the cage 80 engaged with the inner ring 74 as described above, The to-be-accommodated portion 81 made of these components is prevented from dropping from the outer ring 70 by the ball 78 interfering with a snap ring 84 as a retaining portion.

  The pull-out strength of the differential side constant velocity joint 21 is preferably, for example, 900 N or more and 1100 N or less, and the circumferential groove 82 and the snap ring 84 are configured so as to realize such a pull-out strength. The “stripping strength of the differential-side constant velocity joint 21” here refers to the snap ring 84 when the differential-side shaft 11 a and the first intermediate shaft 13 are pulled in the axial direction so as to extract the accommodated portion 81 from the outer ring 70. This means the magnitude of the tensile force immediately before the function of preventing the portion 81 to be removed from the outer ring 70 is lost.

  Further, the differential side constant velocity joint 21 includes a boot 86 provided across the outer periphery of the outer ring 70 and the outer periphery of the first intermediate shaft 13. The boot 86 is fixed to the outer periphery of the outer ring 70 and the outer periphery of the first intermediate shaft 13 using boot bands 88 and 89, respectively. The boot 86 is formed in a bellows shape so that it can expand and contract in the axial direction.

  Next, the structure of the damper 30 will be described with reference to FIGS. 3 and 4. 3 is a cross-sectional view of the damper 30 provided on the right intermediate shaft 15 as viewed from the axial differential device side, and FIG. 4 is a cross-sectional view of the damper 30 shown in FIG. The left damper 30 has a symmetrical structure with the right damper 30.

  As shown in FIGS. 3 and 4, the damper 30 has a cylindrical portion 32 provided at the tip of the first intermediate shaft 13 on the driving wheel side so as to extend in the vehicle width direction, and is accommodated in the cylindrical portion 32. And a shaft portion 50 provided integrally with the second intermediate shaft 14.

  As shown in FIG. 3, a plurality of concave portions 34 are provided on the inner periphery of the cylindrical portion 32 at intervals in the circumferential direction. A plurality of partition portions 36 projecting radially inward are provided on the inner periphery of the cylindrical portion 32. Each partition part 36 is arrange | positioned in the intermediate part between a pair of recessed parts 34 adjacent in the circumferential direction. A radially inner end portion of the partition portion 36 is disposed in the vicinity of the outer periphery of the shaft portion 50.

  A plurality of fin portions 52 project from the outer periphery of the shaft portion 50 at intervals in the circumferential direction. Each fin part 52 is arrange | positioned in the intermediate part between a pair of partition parts 36 adjacent in the circumferential direction. The radially outer end of the fin portion 52 is disposed in the recess 34. A gap 46 is provided between the fin portion 52 and the side wall of the recess 34. Thereby, relative rotation between the cylindrical portion 32 and the shaft portion 50 is allowed in a predetermined angle range, and relative rotation exceeding the range is prevented by interference between the fin portion 52 and the side wall of the concave portion 34. The rotation of the first intermediate shaft 13 transmitted from the power source side can be reliably transmitted to the second intermediate shaft 14 via the damper 30.

  Between the fin part 52 and the partition part 36 which adjoin in the circumferential direction, the cross-section fan-shaped elastic member 60 is interposed, for example. The elastic member 60 is made of rubber, for example. The elastic member 60 is positioned on the side surface of the fin portion 52 and the side surface of the partition portion 36 by adhesion or other methods. The elastic member 60 is elastically deformable so as to allow relative rotation between the shaft portion 50 and the tube portion 32. Specifically, when the shaft portion 50 rotates relative to the cylindrical portion 32, one elastic member 60 sandwiching the fin portion 52 is compressed and deformed. Various vibrations such as torsional vibration transmitted from the power source 2 to the drive shafts 10a and 10b can be attenuated by the elastic member 60 configured as described above.

  As shown in FIG. 4, the cylinder part 32 is provided with the bottom part 32a which obstruct | occludes the axial direction proximal end, and the opening part 32b which open | releases an axial direction terminal end. Note that the opening 32 b is sealed by a seal member 44.

  The cylinder part 32 is arrange | positioned along the vehicle width direction on the vehicle width direction outer side rather than the engine 3 (refer FIG. 1). Since the cylinder part 32 is opened to the outer side in the vehicle width direction, the opening part 32b is arranged in a part of the cylinder part 32 farthest from the engine 3. By arranging the cylindrical portion 32 in this way, the engine 3 moves backward when a large impact load is applied to the vehicle from the front of the vehicle, for example, in the cylindrical portion 32 of the damper 30, particularly in the peripheral portion of the opening 32b. It is possible to suppress the impact load from directly acting on the attached snap ring (preventing part) 42.

  It should be noted that the entire cylinder portion 32 does not necessarily have to be arranged outside the engine 3 in the vehicle width direction, and the engine 3 and the cylinder portion are arranged so that at least the opening 32b is arranged outside the engine 3 in the vehicle width direction. 32 may be arranged overlapping in the vehicle width direction.

  Between the outer periphery of the shaft portion 50 and the inner periphery of the cylindrical portion 32, there is a first bearing 37 that supports the differential device side end of the shaft portion 50, and the shaft portion on the drive wheel side relative to the first bearing 37. A second bearing 38 that supports 50 is interposed. The concave portion 34, the partition portion 36, the fin portion 52, and the elastic member 60 described above are provided so as to extend in the axial direction between the first and second bearings 37 and 38.

  An end portion on the differential device side of the shaft portion 50 is a small-diameter portion 51 that is reduced in diameter as compared with the remaining portion. The cylindrical portion 32 is supported via the first bearing 37.

  An annular diameter-enlarged portion 54 that protrudes radially outward from the outer periphery of the shaft portion 50 is provided at a position in the axial direction closer to the drive wheel than the elastic member 60. The enlarged diameter portion 54 is provided integrally with the shaft portion 50. However, the configuration of the enlarged diameter portion is not limited to this, and may be constituted by, for example, a snap ring that is mounted in an expanded state in a circumferential groove provided on the outer periphery of the shaft portion 50.

  The second bearing 38 is disposed at an axial position on the opening 32b side with respect to the enlarged diameter portion 54. The second bearing 38 has a larger diameter than the first bearing 37. More specifically, the inner diameter of the second bearing 38 is larger than the outer diameter of the first bearing 37.

  A C-shaped snap ring 42 is provided at a position in the axial direction on the opening 32b side of the second bearing 38 as a retaining portion that protrudes radially inward from the inner periphery of the cylindrical portion 32. The snap ring 42 is attached to a circumferential groove 40 provided on the inner circumference of the cylindrical portion 32 over the entire circumference in a state of being elastically deformed so as to reduce the diameter. The snap ring 42 is held in the circumferential groove 40 by being pressed against the bottom of the circumferential groove 40 by a restoring force acting in the diameter expansion direction.

  By the way, for example, it is conceivable that the snap ring is attached to a circumferential groove formed on the outer peripheral surface of the shaft portion 50 in an elastically deformed state so as to expand the diameter, and the retaining portion of the damper 30 is configured by the snap ring. However, the snap ring 42 mounted in the circumferential groove 40 of the cylindrical portion 32 has a larger diameter than such a snap ring. The retaining portion of the present embodiment configured with the relatively large-diameter snap ring 42 can exhibit a higher retaining function than a relatively small-diameter portion.

  As described above, the second bearing 38 is disposed so as to be sandwiched from both sides in the axial direction by the enlarged-diameter portion 54 and the snap ring (preventing portion) 42. The movement of the shaft portion 50 toward the opening portion 32b is restricted by the interference between the enlarged diameter portion 54 and the inner ring of the second bearing 38. Here, since the second bearing 38 has a larger diameter than the first bearing 37 as described above, it is possible to reliably prevent the second bearing 38 from coming off due to interference between the enlarged diameter portion 54 and the inner ring of the second bearing 38. Further, the movement of the second bearing 38 and the shaft portion 50 toward the opening 32 b is restricted by the interference between the outer ring of the second bearing 38 and the snap ring (preventing portion) 42. As described above, the movement restriction (prevention of retaining) of the shaft part 50 toward the opening 32b is finally realized by the snap ring (preventing part) 42.

  Further, as described above, the opening 32b is disposed in a portion of the cylindrical portion 32 farthest from the engine 3, so that, for example, when a large impact load is applied to the vehicle from the front of the vehicle, the engine 3 moves backward, It is possible to suppress the impact load from acting on the opening 32b side portion of the cylindrical portion 32, in particular, the snap ring (preventing portion) 42. As a result, the strength of the damper 30 can be lowered, and the damper 30 can be downsized, so that the vehicle mountability can be improved.

  The pull-out strength of the damper 30 by the snap ring (prevention portion) 42 is larger than the pull-out strength of the above-mentioned differential side constant velocity joint 21 (see FIG. 2), specifically, for example, not less than 1200N and not more than 1400N. preferable. Specific configurations such as dimensions and materials of the second bearing 38, the enlarged diameter portion 54, the snap ring 42 (the retaining portion), and the circumferential groove 40 are determined so as to realize such a removal strength of the damper 30. ing.

  The “stripping strength of the damper 30” here refers to the inner ring of the second bearing 38 when the first intermediate shaft 13 and the second intermediate shaft 14 are pulled in the axial direction so as to extract the shaft portion 50 from the cylindrical portion 32. Since the restriction of the movement of the shaft portion 50 due to the interference with the enlarged diameter portion 54 and the interference between the outer ring of the second bearing 38 and the snap ring 42 cannot be achieved, the function of preventing the shaft portion 50 from coming off from the cylindrical portion 32 is lost. It means the magnitude of the previous tensile force.

  Since the pull-out strength of the damper 30 is greater than the pull-out strength of the differential side constant velocity joint 21, for example, when a large impact load is applied to the vehicle from the front of the vehicle, the bending load or the differential device 8 and the drive wheels 28 are applied to the drive shaft 10. It is possible to apply a load that increases the axial distance between the differential-side constant velocity joint 21 that has a lower pulling strength than the damper 30. Therefore, it is possible to reduce the strength of the damper 30, thereby suppressing an increase in size of the damper 30, and thus suppressing deterioration of the mountability of the damper 30 on the vehicle.

  Further, when a large impact load is applied to the vehicle, a bending load on the drive shaft 10 or a load that expands the axial distance between the differential 8 and the drive wheel 28 acts on the differential side constant velocity joint 21. Even if various parts including the accommodated portion 81 are dropped from the outer ring 70 of the differential side constant velocity joint 21, the parts can be accommodated in the boot 86.

  While the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments.

  For example, in the above-described embodiment, the cylindrical portion 32 of the damper 30 is provided at the front end of the first power transmission shaft (first intermediate shaft 13) on the driving wheel side, and the shaft portion 50 is configured to be the second power transmission shaft (second shaft). The case where the intermediate shaft 14) is provided at the front end of the power source side has been described, but the present invention provides a shaft portion of a damper at the front end of the drive wheel side of the first power transmission shaft, and the power source side of the second power transmission shaft. The present invention can also be applied to a case where a damper cylinder is provided at the tip.

  Moreover, the structure of the damper 30 shown in FIG.3 and FIG.4 is only an example, and the specific structure of the damper containing a retaining structure is not specifically limited in this invention. Therefore, in the present invention, various known retaining structures can be employed instead of the retaining structure including the second bearing 38, the enlarged diameter portion 54, and the snap ring 42 described above.

  Furthermore, in the above-described embodiment, when a large impact load is applied to the vehicle, a bending load or a load that increases the axial distance between the differential 8 and the drive wheel 28 is applied to the drive shaft 10. In the present invention, the case where the accommodated portion 81 can be accommodated in the boot 86 when acting on the speed joint 21 and the accommodated portion 81 is detached from the outer ring 70 of the differential side constant velocity joint 21 has been described. A form in which the accommodated portion 81 is not accommodated in the boot 86 is also included. In this case, for example, by increasing the allowable relative movement amount between the outer ring 70 in the axial direction and the accommodated portion 81 in the fitted state between the outer ring 70 and the accommodated portion 81, the fit between the outer ring 70 and the accommodated portion 81 is achieved. It becomes easy to maintain the combined state. Therefore, in this case, the boot 86 can be omitted.

  Furthermore, in the above-described embodiment, the case where the constant velocity joint 21 shown in FIG. 2 is used as the universal joint provided on the drive shaft has been described. However, the universal joint in the present invention is of a type different from that described above. It may be a universal joint other than a speed joint or a constant velocity joint.

  In the present invention, the retaining structure of the universal joint is not limited to the one composed of the snap ring 84 as described above, and various known retaining structures such as caulking may be adopted. The universal joint is not necessarily provided with a retaining structure.

  Furthermore, in the above-described embodiment, a case has been described in which the pull-out strength of the universal joint (difference-side constant velocity joint 21) disposed on the drive shaft on the drive shaft side is smaller than the pull-out strength of the damper. In the present invention, the pull-out strength of the universal joint (in the above-described embodiment, the wheel-side constant velocity joint 22) arranged on the drive wheel side of the damper may be made smaller than the pull-out strength of the damper. The same effect can be obtained.

  In the above-described embodiment, the power transmission device mounted on the engine-side-mounted FF vehicle has been described. However, the present invention is a vehicle other than the FF type, such as a front engine / rear drive type vehicle (FR vehicle). It can also be applied to a power transmission device mounted on a vertical engine-type vehicle.

  As described above, according to the present invention, it is possible to suppress the deterioration of the vehicle mountability accompanying the increase in the size of the damper while maintaining the damper function even when a large impact load is applied to the damper. Therefore, there is a possibility of being suitably used in the manufacturing industry of vehicles in which a damper is disposed on a drive shaft.

1: Power transmission device 2: Power source 3: Engine 4: Transaxle 6: Transmission 8: Differential device 10: Drive shaft 11: Differential shaft (third power transmission shaft)
12: Wheel side shaft 13: First intermediate shaft (first power transmission shaft)
14: Second intermediate shaft (second power transmission shaft)
15: Intermediate shaft 21: Differential side constant velocity joint (universal joint)
22: Wheel side constant velocity joint 28: Drive wheel 30: Damper 32: Tube portion 32a: Bottom portion of the tube portion 32b: Opening portion of the tube portion 37: First bearing (bearing on the side opposite to the opening)
38: Second bearing (opening side bearing)
40: Circumferential groove 42: Snap ring (preventing part)
54: Expanded diameter part 60: Elastic member 70: Outer ring (cylindrical part)
74: Inner ring 78: Ball 81: Contained part 82: Circumferential groove 84: Snap ring 86: Boots

Claims (4)

A universal joint and a damper are provided on the drive shaft that connects the power source and the drive wheel with an axial interval therebetween,
The drive shaft includes a first power transmission shaft that connects the universal joint and the damper, a second power transmission shaft that is connected to one end of the first power transmission shaft via the damper at one end, and one end. A third power transmission shaft connected to the other end of the first power transmission shaft via the universal joint,
The damper is provided at either one end of the first power transmission shaft or one end of the second power transmission shaft, and has a cylindrical portion having an opening at the tip, and one end of the first power transmission shaft or the first power transmission shaft. 2 provided with a shaft portion provided at one of the other ends of the power transmission shaft and having a tip portion accommodated in the tube portion, and an elastic member interposed between the shaft portion and the tube portion, A power transmission structure for a vehicle,
The damper includes a bearing interposed between an outer periphery of the shaft portion and an inner periphery of the cylindrical portion at an axial position closer to the opening than the elastic member, and the opening is on the opposite side of the opening from the bearing A diameter-enlarged portion projecting radially outward from the outer periphery of the shaft portion at a position in the axial direction, and a retaining member projecting radially inward from the inner periphery of the cylindrical portion at an axial position closer to the opening than the bearing And comprising
The power transmission structure for a vehicle according to claim 1, wherein a pull-out strength of the damper by the retaining portion is greater than a pull-out strength of the universal joint.   The universal joint includes a receiving portion provided at the other end of the first power transmission shaft, a cylindrical portion provided at one end of the third power transmission shaft so as to receive the receiving portion, 2. The vehicle according to claim 1, further comprising: a boot portion that is provided so as to extend and contract in an axial direction across an outer periphery of the cylindrical portion and an outer periphery of the first power transmission shaft. Power transmission structure. The power source includes an engine;
The retaining portion is composed of a snap ring that is mounted in a reduced diameter in a circumferential groove formed on the inner periphery of the cylindrical portion,
The damper is disposed rearward of the engine in the vehicle front-rear direction and outside the universal joint in the vehicle width direction,
The cylindrical portion is disposed so as to extend outward from one end of the first power transmission shaft along the vehicle width direction,
The power transmission structure for a vehicle according to claim 1, wherein the opening is disposed on the outer side in the vehicle width direction than the engine. In addition to the bearing disposed on the opening side in the axial direction from the elastic member, the damper includes a bearing disposed on the side opposite to the opening in the axial direction from the elastic member,
4. The power transmission structure for a vehicle according to claim 1, wherein the bearing on the opening side has a larger diameter than the bearing on the side opposite to the opening. 5.

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