JP2018112290A - Power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission device which can prevent or suppress an increase of a rotation outside diameter and weight, and can prevent or suppress the generation of noise and vibration accompanied by the deformation of an outer race.SOLUTION: A power transmission device 1 comprises a constant velocity joint 4 for connecting a first shaft 2 and a second shaft 3 in series. The constant velocity joint 4 comprises: a cylindrical outside joint part 9 connected to the first shaft 2 by friction-welding; an inside joint part 10 slidably arranged in the outside joint part 9 in an axial direction so as to be regulated in movement in a peripheral direction, and connected to the second shaft 3; a boot 11 for blocking a clearance between the outside joint part 9 and the second shaft 3; and a seal plate 12 for blocking the inside of the outside joint part 9 at the first shaft 2 side rather than the inside joint part 10. The inside joint part 10 is formed while having a magnitude for allowing insertion in a connection part 16 for connecting the first shaft 2 and the outside joint part 9, and the seal plate 12 is formed of a fractural resin.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power transmission device in which a first shaft and a second shaft are connected by a constant velocity joint.

  As a power transmission device, for example, a device described in Patent Document 1 is known.

  This power transmission device is applied to a two-part, three-joint type propeller shaft of a four-wheel drive vehicle (4WD) or a rear wheel drive vehicle (FR). The propeller shaft is configured by connecting a stub shaft to a first shaft connected to a transmission via an intermediate bearing and connecting a pipe shaft portion to the stub shaft via a constant velocity joint.

  The tube shaft portion is coupled to the outer race of the constant velocity joint by friction welding. Moreover, the joint part of a pipe shaft part and an outer race is expanded in diameter from the center part of the outer race. This allows the inner race, ball, cage, etc. of the constant velocity joint to pass through the curled joint and enter the tube shaft when the engine or transmission moves backward, such as during a vehicle collision. Can absorb shock. Further, the coupling portion is formed to have a larger diameter than the seal plate for retaining the lubricating grease provided in the outer race, and allows the seal plate pushed from the inner race or the like to pass therethrough.

JP 2003-146098 A

  However, since the coupling portion is formed with a large diameter, there has been a problem that an increase in the outer diameter and weight of the outer race is inevitable.

  In addition, since the seal plate is generally made of steel, the outer race may be deformed by a high load when it is press-fitted into the outer race, and abnormal noise and vibration may occur when the ball rolls along the groove of the outer race. was there.

  Accordingly, the present invention has been created in view of such circumstances, and its purpose is to prevent or suppress an increase in the outer diameter and weight of the outer race, and to prevent or suppress the generation of abnormal noise and vibration associated with the deformation of the outer race. It is to provide a transmission device.

  According to one aspect of the present invention, a cylindrical shape having a constant velocity joint for connecting a first shaft and a second shaft in series, the constant velocity joint being coupled to the first shaft by friction welding. An outer joint portion, an inner joint portion that is slidable in the axial direction in the outer joint portion and that is restricted from moving in the circumferential direction, and is coupled to the second shaft, the outer joint portion, and the second A power transmission device comprising a boot for closing a space between a shaft and a seal plate for closing an inside of an outer joint portion closer to the first shaft than the inner joint portion, wherein the inner joint portion includes the first shaft and the outer joint. The seal plate is formed of a resin that can be broken. Force transmission apparatus is provided.

  Preferably, the seal plate has a lid body formed in a bottomed cylindrical shape.

  Preferably, a mounting groove extending in a circumferential direction is formed on an inner peripheral surface of the outer joint portion, and the seal plate is formed on the outer periphery of the lid body on the open end side and is fitted into the mounting groove. Have

  Preferably, the outer diameter of the lid body is formed larger than the inner diameter of the coupling portion.

  Preferably, the attachment groove and the claw portion are formed so as to be detached when the lid body is pushed in the axial direction from the inner joint portion.

  According to the present invention, it is possible to prevent or suppress an increase in the outer diameter and weight of the outer race, and to prevent or suppress the generation of abnormal noise and vibration associated with the deformation of the outer race.

It is sectional drawing of the power transmission device which concerns on one embodiment of this invention. It is a principal part enlarged view of FIG. It is sectional drawing of the power transmission device in the state where the inner race etc. were pushed back. It is sectional drawing of the power transmission device of the state which the inner race etc. pushed further back and the seal plate fractured | ruptured. It is a principal part enlarged view of FIG. It is sectional drawing of the power transmission device of the state in which the inner race etc. was pushed further back and was inserted in the coupling part. It is a principal part expanded sectional view of the power transmission device which shows other embodiment.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In addition, the front-back direction in embodiment mentioned later shall mean the front-back direction of a vehicle.

  FIG. 1 is a cross-sectional view of a power transmission device according to a first embodiment of the present invention, and FIG. 2 is an enlarged view of a main part of FIG.

  As shown in FIGS. 1 and 2, the power transmission device 1 includes a first shaft 2, a second shaft 3 disposed in front of the first shaft 2, and the first shaft 2 and the second shaft 3 in series. And a constant velocity joint 4 connected to.

  The 1st shaft 2 consists of a pipe axis part which constitutes a propeller shaft of vehicles. The first shaft 2 is formed in a cylindrical shape and is connected to a final gear (not shown).

  The 2nd shaft 3 makes the stub axis | shaft which comprises the propeller shaft of a vehicle. The second shaft 3 is formed to be solid and smaller in diameter than the inner diameter of the first shaft 2. The second shaft 3 is coaxially coupled to an output shaft extending from a transmission (not shown) via a shaft, a universal joint, or the like. The second shaft 3 has a spline 5a for attaching an inner race 18 to be described later on the outer periphery of the front end portion (outer periphery of the rear end portion), and has a front end surface 6 perpendicular to the axial direction at the front end. Further, a groove 8 for attaching the snap ring 7 is formed on the tip side of the spline 5a so as to extend in the circumferential direction. The snap ring 7 functions as a stopper for the inner race 18.

  The constant velocity joint 4 is provided with a cylindrical outer joint portion 9 coupled in series to the first shaft 2, and is slidable in the axial direction within the outer joint portion 9 and restricted in movement in the circumferential direction. The inner joint part 10 coupled to the two shafts 3, the boot 11 that closes between the outer joint part 9 and the second shaft 3, and the seal that closes the inside of the outer joint part 9 on the first shaft 2 side from the inner joint part 10. Plate 12.

  The outer joint portion 9 forms an outer race. The outer joint portion 9 is formed at the center in the axial direction and is engaged with the inner joint portion 10, and is formed on one end side (rear end side) of the central tube portion 13 and coupled to the first shaft 2. A first shaft side cylinder portion 14 and a second shaft side cylinder portion 15 that is formed on the other end side (front end side) of the central cylinder portion 13 and into which the second shaft 3 is inserted.

  The central cylinder portion 13 is formed thick and has an engagement groove 13a extending in the axial direction on the inner periphery. A plurality of engaging grooves 13a are formed in the circumferential direction, and are respectively engaged with a ball 19 of the inner joint portion 10 to be described later so as to be axially movable but not circumferentially movable.

  The first shaft side cylinder portion 14 is formed such that the inner diameter and the outer diameter are the same as those of the first shaft 2. Specifically, the first shaft side cylinder portion 14 is formed to have a smaller outer diameter and a larger inner diameter than the central cylinder portion 13. Thereby, the 1st shaft side cylinder part 14 is formed thinly and lightweight. Further, the first shaft side cylinder portion 14 and the first shaft 2 are joined to each other by friction welding with their end faces abutting each other. Thereby, the thermal influence on each member which comprises the constant velocity joint 4 can be suppressed very small, and the deflection | deviation accuracy when a propeller shaft rotates can be raised. Further, the coupling portion 16 formed by friction welding the first shaft side tube portion 14 and the first shaft 2 projects and curls radially inward and curls by projecting radially outward. It is formed into a shape. Further, an attachment groove 17 for attaching the seal plate 12 is formed on the inner periphery of the base end (front end) of the first shaft side cylinder portion 14 as will be described later. The mounting groove 17 extends in the circumferential direction and is formed in an annular shape. Further, the mounting groove 17 is formed so that the opening on the inner periphery slightly extends rearward, and allows the seal plate 12 described later to be detached from the mounting groove 17 when receiving a strong rearward force. ing.

  The second shaft side cylinder portion 15 is for holding the boot 11 apart from the central cylinder portion 13 in the axial direction, and is formed thinner and lighter than the first shaft side cylinder portion 14. A boot 11 is attached to the tip (front end) of the second shaft side cylinder portion 15.

  The inner joint portion 10 is made of steel and is arranged in a circumferentially spaced manner on the outer periphery of the inner race 18 and a cylindrical inner race 18 attached around the front end portion (rear end portion) of the second shaft 3. A ball 19 and a cage 20 provided on the inner race 18 and rotatably holding the ball 19 are provided. The inner race 18 has a spline 5b on the inner periphery, and is fitted to the spline 5a formed on the second shaft 3. The cage 20 has a window hole 21 for exposing the ball 19 on the outer peripheral surface, and projects a part of the ball 19 outward in the radial direction. That is, the maximum radial dimension D1 / 2 of the inner joint portion 10 is the dimension from the center of the inner race 18 to the protruding end of the ball 19. The cage 20 is disposed in front of the front end (rear end) of the second shaft 3.

  The boot 11 is made of an elastic material such as rubber. The boot 11 is formed in a ring shape that closes the space between the second shaft side cylinder portion 15 and the second shaft 3 and has a shape that bends the intermediate portion between the second shaft side cylinder portion 15 and the second shaft 3 backward. Formed. A lubricant made of grease or the like is accommodated in the outer joint portion 9 between the boot 11 and the seal plate 12.

  The seal plate 12 is integrally formed of a breakable resin such as nylon. The seal plate 12 includes a lid main body 22 formed in a bottomed cylindrical shape, and a claw portion 23 formed on the outer periphery of the lid main body 22 and fitted in the mounting groove 17.

  The lid body 22 includes a guide tube portion 22a formed in a cylindrical shape and a cover plate portion 22b that closes the rear end of the guide tube portion 22a.

  The guide cylinder portion 22a is formed so that the outer diameter D2 is larger than the inner diameter D3 of the coupling portion 16, and the inner diameter D4 is smaller than the diameter D1 of a circle whose radius is the maximum radial dimension D1 / 2 of the inner joint portion 10. (D4 <D1 <D3 <D2). As a result, the seal plate 12 hits the coupling portion 16 when it is pushed by the inner joint portion 10 and moved rearward.

  Further, the outer peripheral corner portion of the cover plate portion 22b is rounded in an arc shape in cross section, and when it comes into contact with the coupling portion 16, it is in contact with the coupling portion 16 over the entire circumference and is coaxial with the coupling portion 16. Is held by the coupling portion 16.

  The claw portion 23 protrudes radially outward from the guide tube portion 22a. The claw portion 23 is formed in an annular shape over the entire circumference of the guide tube portion 22a. The claw portion 23 includes an inclined surface 23a that protrudes forward in the radial direction and a rear end surface 23b that is perpendicular to the axial direction. Note that a plurality of claw portions may be formed at a certain interval in the circumferential direction. In this case, the mounting groove may also be formed at a plurality of intervals in the circumferential direction according to the arrangement of the claw portions.

  Next, the operation of this embodiment will be described.

  When the engine and the transmission (not shown) are pushed backward due to a frontal collision of the vehicle or the like, the second shaft 3 and the inner joint portion 10 are pushed backward and moved as shown in FIG. As a result, the boot 11 is easily stretched and broken to allow the second shaft 3 to move. And the front end surface 6 of the 2nd shaft 3 contact | abuts to the cover-plate part 22b of the seal plate 12, and pushes the seal plate 12 back.

  The seal plate 12 pressed at the center in the radial direction of the cover plate portion 22 b bends so as to move the claw portion 23 inward in the radial direction, and the claw portion 23 is detached from the mounting groove 17. Thereby, the seal plate 12 is pushed by the second shaft 3 and moves backward. At this time, since the guide tube portion 22a is interposed between the ball 19 of the inner joint portion 10 and the first shaft side tube portion 14, the inner joint portion 10 is moved to the first shaft side by the guide function of the guide tube portion 22a. It is moved along the central axis of the cylindrical portion 14. Thereafter, when the outer peripheral corner portion of the cover plate portion 22b contacts the curled joint portion 16, the outer peripheral corner portion of the cover plate portion 22b contacts the curled joint portion 16 over the entire circumference, It is held by the coupling portion 16.

  Thereafter, as shown in FIGS. 4 and 5, when the seal plate 12 is further pushed backward by the second shaft 3, the seal plate 12 is, for example, at the position of the outer peripheral end portion of the lid plate portion 22 b as shown in the illustrated example. Shear fracture. At this time, since the inner joint portion 10 is restricted from moving in the radial direction by the guide tube portion 22a, the inner joint portion 10 continues to push the center portion of the lid plate portion 22b stably and breaks the lid plate portion 22b.

  Thereafter, as shown in FIGS. 5 and 6, the inner joint portion 10 passes through the inner peripheral side of the coupling portion 16 and can absorb the impact from the engine and the transmission well.

  Thus, the inner joint portion 10 is formed to have a size that can be inserted through the curled joint portion 16 that joins the first shaft 2 and the outer joint portion 9, and the seal plate 12 is formed from a breakable resin. As a result, a sufficient buffering effect of the constant velocity joint 4 at the time of a vehicle collision can be obtained without making the inner diameter D3 of the coupling portion 16 larger than the outer diameter D2 of the guide cylinder portion 22a. It is possible to prevent or suppress an increase in the outer diameter and weight of the outer joint portion 9 as in the case where D3 is larger than the outer diameter of the guide cylinder portion 22a. Further, if the seal plate 12 is made of steel, the outer joint portion 9 can be prevented or suppressed from being deformed by a high load applied from the seal plate 12, and abnormal noise or vibration due to the deformation of the outer joint portion 9 can be prevented. Occurrence can also be prevented or suppressed.

  Further, since the seal plate 12 has the lid main body 22 formed in a bottomed cylindrical shape, the seal plate 12 can move while maintaining the posture when pushed backward, and the broken pieces (guide cylinder portion 22a) after breaking. ) To guide the inner joint part 10.

  Moreover, since the seal plate 12 has the claw part 23 formed in the outer periphery of the open end side of the lid body 22 and fitted in the attachment groove 17, it can be attached to the outer joint part 9 with a simple structure.

  Since the outer diameter D2 of the lid body 22 is formed larger than the inner diameter D3 of the coupling portion 16, the lid body 22 can be reliably applied to the coupling portion 16, and the lid body 22 can be stably sheared and broken.

  Note that a seal such as an O-ring may be provided in the mounting groove 17 at the front or rear of the claw portion 23.

  Moreover, although the seal plate 12 shall have the nail | claw part 23 fitted by the attachment groove 17 of the outer side joint part 9, it is not restricted to this. For example, the seal plate does not have the claw portion 23 and may be bonded to the outer joint portion 9 or may be caulked to the outer joint portion 9. It may be locked by a claw (not shown) provided protruding inward in the direction, or may be fastened to the outer joint portion 9 with a screw or the like.

  The seal plate may be formed of a resin other than nylon. Then, the seal plate may be formed of a hard resin and may be damaged before it is detached from the mounting groove 17.

  Further, as shown in FIG. 7, the seal plate 30 may be formed in a plate shape, or may have a fitting portion 31 fitted to the tip portion of the second shaft 3. Good.

  The constant velocity joint may be a tripod type.

  Further, when the second shaft 3 moves rearward, the front end surface 6 is brought into contact with the seal plate 12. However, the cage 20 or the like is positioned behind the second shaft 3, and the cage 20 or the like is sealed. It may be abutted against the plate 12.

  Further, the second shaft 3 is connected to the transmission side and the first shaft 2 is connected to the final gear. However, the second shaft 3 is connected to the final gear, and the first shaft 2 is connected to the transmission side. It is good also as a thing.

  Furthermore, the above-described shock absorbing structure can also be applied to a power transmission device other than the propeller shaft.

  Each of the embodiments described above can be combined partially or wholly unless there is a particular contradiction. The embodiment of the present invention is not limited to the above-described embodiment, and includes all modifications, applications, and equivalents included in the concept of the present invention defined by the claims. Therefore, the present invention should not be construed as being limited, and can be applied to any other technique belonging to the scope of the idea of the present invention.

DESCRIPTION OF SYMBOLS 1 Power transmission device 2 1st shaft 3 2nd shaft 4 Constant velocity joint 9 Outer joint part 10 Inner joint part 11 Boot 12 Seal plate 16 Joint part

Claims (5)

Having a constant velocity joint connecting the first shaft and the second shaft in series;
The constant velocity joint is provided with a cylindrical outer joint portion coupled to the first shaft by friction welding, and is slidable in the axial direction within the outer joint portion and restricted in movement in the circumferential direction. An inner joint portion coupled to the second shaft; a boot for closing between the outer joint portion and the second shaft; and a seal plate for closing the inside of the outer joint portion on the first shaft side from the inner joint portion. A power transmission device,
The inner joint portion is formed in a size that can be inserted through a curled coupling portion that couples the first shaft and the outer joint portion,
The power transmission device, wherein the seal plate is formed of a breakable resin.   The power transmission device according to claim 1, wherein the seal plate has a lid body formed in a bottomed cylindrical shape. A mounting groove extending in the circumferential direction is formed on the inner peripheral surface of the outer joint portion,
The power transmission device according to claim 2, wherein the seal plate has a claw portion that is formed on the outer periphery of the open end side of the lid body and is fitted into the mounting groove.   4. The power transmission device according to claim 1, wherein an outer diameter of the lid main body is formed larger than an inner diameter of the coupling portion. 5.   The power transmission device according to claim 3, wherein the attachment groove and the claw portion are formed so as to be detached when the lid body is pushed in the axial direction from the inner joint portion.

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