JPH10325420A - Drive force transmission unit for wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exchange a first dustproof boot in a state that a second constant velocity joint and a second dustproof boot are mounted on the other end part of a transmission shaft. SOLUTION: A spacer 33 is securely fitted in externally in the vicinity of one end part of a transmission shaft. A first dustproof boot 24a is located between the outer peripheral surface of the spacer 33 and the outer peripheral surface of the outer ring 4 of a first universal velocity joint 2. The outside diameter D36 of a cylinder part 36 on the outside diameter consisting of the spacer 33 is set to a value higher than the outside diameter D27a of the fit-in fixing part 27a of a second dustproof boot 32. The first dustproof boot 24a passes the periphery of the second dustproof boot 32 and in a state that a second constant velocity joint 3 and the second dustproof boot 32 are mounted on the other end part of the transmission shaft, the first dustproof boot 24a is exchangeable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The wheel driving force transmission unit according to the present invention is a front wheel of a front engine front wheel drive vehicle (FF vehicle) or a four wheel drive vehicle (4WD vehicle), or an independent suspension type rear wheel. Front-engine rear-wheel drive vehicle with suspension (F
It is used to transmit driving force to driving wheels such as rear wheels of 4WD vehicles and RWD vehicles.

[0002]

2. Description of the Related Art For example, in order to rotationally drive the front wheels of a front-wheel drive vehicle, a driving force from an engine is transmitted via a transmission while maintaining constant velocity regardless of a steering angle applied to the front wheels. There is a need. Further, it is necessary to continuously transmit the driving force to the front wheels irrespective of a change in the positional relationship between the front wheels and the vehicle body during traveling. For this reason, a driving force transmission unit for wheels as shown in FIG. 3 has been conventionally used.

[0003] This wheel driving force transmission unit is provided with first and second constant velocity joints 2 and 3 at both ends of a transmission shaft 1. In the illustrated example, a first constant velocity joint 2 which is a Barfield constant velocity joint is provided around one end (the left end in FIG. 3) of the transmission shaft 1. Further, in the illustrated example, the outer ring 4 constituting the constant velocity joint 2 is
It has a function as a hub (an inner ring of a wheel supporting rolling bearing unit) that supports a driving wheel such as a front wheel of a car and rotates with the driving wheel. For this purpose, a mounting flange 5 for fixing the driving wheel to the outer ring 4 is provided on the outer peripheral surface of the outer ring 4 at the distal end (the left end in FIG. 3). An inner ring member 6 is fixed around an intermediate portion of the outer ring 4, and the inner ring member 6 is fixed to the outer ring 4 by a nut 7 screwed to an outer peripheral surface of a portion near the base end (rightward portion in FIG. 3). The outer ring 4 is fixed to the outer peripheral surface. These inner ring member 6 and outer ring 4
Constitute a hub that rotates together with the drive wheels.

On the other hand, around the inner ring member 6 and the outer ring 4, a second outer ring 8 constituting a rolling bearing unit for supporting wheels is arranged. A mounting flange 9 for connecting and supporting the second outer ring 8 to a suspension is provided on an outer peripheral surface of the second outer ring 8, and a double-row outer ring raceway 10, 10
Are provided respectively. And these outer ring raceways 1
A second outer race which constitutes the wheel supporting rolling bearing unit by providing rolling elements 12, 12 between the outer races 0, 10 and the inner raceways 11, 11 provided on the outer peripheral surfaces of the outer race 4 and the inner race member 6, respectively. An outer ring 4 constituting the constant velocity joint 2 is rotatably supported inside the inner surface 8. The seal ring 3 is provided between the inner peripheral surfaces of both ends of the second outer ring 8, the outer peripheral surface of the intermediate portion of the outer ring 4 and the outer peripheral surface of the end of the inner ring member 6.
8 and 38 are provided to block the portion where the rolling elements 12 and 12 are installed from the outside.

[0005] An inner ring 13 constituting the constant velocity joint 2 is externally fitted to one end of the transmission shaft 1 by spline engagement, and is further separated from the transmission shaft 1 by a retaining ring 14 called a circlip. It is trying to keep it from falling out. A plurality of balls 17 are inserted between a plurality of grooves 15 provided on the outer peripheral surface of the inner ring 13 and a plurality of grooves 16 provided on the inner peripheral surface of the outer ring 4 to form a pair of concave grooves 15, 16. Each is provided so as to be able to roll one by one so that the rotational force from the inner ring 13 to the outer ring 4 can be transmitted. When the steering angle is given to the front wheels, which are the driving wheels, or when the positional relationship between the driving wheels and the vehicle body changes due to the displacement of the suspension device during traveling, the central axes of the transmission shaft 1 and the outer wheel 4 are changed. Will not match. Even in such a case, the ball 17 rolls inside the concave grooves 15 and 16, so that the rotational speed of the transmission shaft 1 and the outer ring 4 is kept constant. Such a function of the first constant velocity joint 2 is well known in the related art, and a detailed description thereof will be omitted.

In the illustrated example, a second constant velocity joint 3, which is a tripod constant velocity joint, is provided around the other end (the right end in FIG. 3) of the transmission shaft 1. The second constant velocity joint 3 includes a tripod 18 externally fitted to the outer peripheral surface of the other end portion of the transmission shaft 1 by spline engagement, and a driving shaft 19 at a distal end portion (left end portion in FIG. 3) of a driving shaft 19. And a housing 20 fixed concentrically. In the case of the illustrated example, the housing 20 corresponds to a member serving as an outer ring of the second constant velocity joint 3. The above tripod 1
8 has three trunnions 21 radially provided at equal intervals in the circumferential direction, and a roller 22 around each trunnion 21.
Is rotatably supported. The housing 20
Are provided with recesses 23 at three equally-spaced positions on the inner peripheral surface, each extending in the axial direction (the left-right direction in FIG. 3). The second constant velocity joint 3 is configured by rollingly engaging the rollers 22 inside the recesses 23. In the assembled state to the vehicle, the base end (the right end in FIG. 3) of the drive shaft 19 to which the housing 20 is connected and fixed is connected and fixed to an output portion of a differential gear (not shown). With the displacement of the suspension device during traveling, the positional relationship between the transmission shaft 1 and the drive shaft 19 changes, and the center axis of the transmission shaft 1 and the center axis of the drive shaft 19 become inconsistent or the transmission shaft Even when the shaft 1 is displaced in the axial direction (the left-right direction in FIG. 3), the rollers 22 roll inside the recesses 23 so that the rotational motion between the transmission shaft 1 and the outer ring 4 is uniform. And the displacement of the transmission shaft 1 in the axial direction is absorbed. Since the function of the second constant velocity joint 3 is well known in the related art, detailed description thereof will be omitted.

A first dustproof portion is provided between a portion of the transmission shaft 1 near one end of the transmission shaft 1 and a base end portion (right end portion in FIG. 3) of the outer race 4 of the first constant velocity joint 2. A boot 24 is provided to prevent foreign matters such as rainwater and dust from entering the first constant velocity joint 2. The first dustproof boot 24 made of an elastic material such as rubber is provided with a bellows-like elastically deformable portion 25 at an intermediate portion, and short cylindrical fitting and fixing portions 26 and 27 at both end openings. I have. The fitting fixed portions 26 and 27 are respectively engaged with the outer peripheral surface of a portion near one end of the intermediate portion of the transmission shaft 1 and the outer peripheral surface of the base end of the outer ring 4 of the first constant velocity joint 2. Engagement grooves 28 and 29 are provided over the entire circumference. When the first dust-proof boot 24 is provided between the transmission shaft 1 and the outer ring 4, the fitting / fixing portion 26 is
Then, the fitting fixing portions 27 are respectively engaged with the engaging grooves 29, and the outer peripheral surfaces of the fitting fixing portions 26, 27 are held down by holding bands 30, 31.

Further, a second dustproof boot 32 is provided between a portion of the transmission shaft 1 near the other end and the outer peripheral surface of the end of the housing 20 of the second constant velocity joint 3. Foreign substances such as rainwater and dust are prevented from entering the one constant velocity joint 3. This second dustproof boot 32
Also, similarly to the above-described first dustproof boot 24, a bellows-like elastically deforming portion 25a is provided at an intermediate portion, and short cylindrical fitting fixing portions 26a and 27a are provided at both end openings. Such a second dust-proof boot 32 is provided between the transmission shaft 1 and the housing 20 so as to connect the fitting / fixing portion 26 a to the transmission shaft 1.
The fitting fixing portion 27a is engaged with an engaging concave groove 29a provided on an outer peripheral surface of an end portion of the housing 20, respectively. Band 30 for suppressing the outer peripheral surface of mating fixing portions 26a and 27a
a, 31a for mounting.

[0009]

Among the constituent members of the above-described wheel driving force transmission unit, the first member made of an elastic material,
In many cases, the second dustproof boots 24 and 32 are damaged earlier than other metal parts. In particular, the first dustproof boot 24 provided on the side close to the drive wheels often receives a large vibration while being largely displaced due to the provision of a steering angle, and the need for replacement and repair is relatively high. However, the first dustproof boot 24 provided at a portion sandwiched between the first and second constant velocity joints 2 and 3 remains in a state where the two constant velocity joints 2 and 3 are attached to both ends of the transmission shaft 1. Cannot be replaced.

On the other hand, since the disassembly and assembly of the first constant velocity joint 2 of the Barfield type is troublesome, in order to replace the first dustproof boot 24, the disassembly and assembly is relatively easy. The second constant velocity joint 3 that is a mold
Needs to be removed from the other end of the transmission shaft 1.
When disassembling and assembling the second constant velocity joint 3 in this manner, one of the fitting and fixing portions 26a and 27a of the second dustproof boot 32, which does not need to be removed, is inserted into the engaging groove 28.
a, 29a, which requires disassembly and assembly of the second constant velocity joint 3, and the cost required for replacing the first dustproof boot 24 increases. In order to eliminate such inconvenience, the driving force transmission unit for a wheel of the present invention has one end of the transmission shaft with the second constant velocity joint and the second dustproof boot attached to the other end of the transmission shaft. The invention has been made in order to realize a structure in which a first dustproof boot provided between a section and a first constant velocity joint can be replaced.

[0011]

According to the present invention, there is provided a wheel driving force transmitting unit, similar to the above-described conventional wheel driving force transmitting unit, including a transmission shaft and a first shaft provided around one end of the transmission shaft. A constant velocity joint, a second constant velocity joint provided around the other end of the transmission shaft, an end of the transmission shaft near the one end and an end of a member to be an outer ring of the first constant velocity joint A first dustproof boot provided between the outer peripheral surface and a first dustproof boot provided between an intermediate portion of the transmission shaft near the other end and an end outer peripheral surface of a member serving as an outer ring of the second constant velocity joint; And two dustproof boots.

In particular, in the driving force transmission unit for a wheel according to the present invention, the annular portion having an outer diameter equal to or larger than the maximum outer diameter of the second dustproof boot is provided at a portion near one end of the intermediate portion of the transmission shaft. The seat is externally fitted and fixed, and one end of the first dustproof boot is externally fitted and fixed to the outer peripheral surface of the spacer.

[0013]

According to the wheel driving force transmission unit of the present invention configured as described above, by providing the spacer, the inner diameter of the first dustproof boot can be made larger than the maximum outer diameter of the second dustproof boot. Can be. Therefore, while the second constant velocity joint and the second dustproof boot are mounted on the other end of the transmission shaft, the first dustproof member provided between the one end of the transmission shaft and the first constant velocity joint. Replace boots.

[0014]

FIG. 1 shows a first embodiment of the present invention. The feature of the present invention is that the second constant velocity joint 3 and the second dustproof boot 3 are attached to the other end of the transmission shaft 1.
The first dust-proof boot 24a provided between one end of the transmission shaft 1 and the first constant velocity joint 2 with the mounting of the second dustproof boot 2a.
There is a structure that allows the exchange of Since the structure and operation of the other parts are the same as those of the conventional structure shown in FIG. 3 described above, the same parts are denoted by the same reference numerals, and duplicated description is omitted or simplified. The following description focuses on the characteristic portions of the above.

At a portion near one end of the intermediate portion of the transmission shaft 1,
By bending a corrosion-resistant metal plate such as a galvanized steel plate or a stainless steel plate, a spacer 33 having a U-shaped cross section and an annular shape as a whole is externally fitted and fixed by interference fitting. That is, the spacer 33 has an inner cylindrical portion 35 bent at a right angle from the inner peripheral edge of the annular portion 34, and an outer cylindrical portion 35 bent at a right angle from the outer peripheral edge of the annular portion 34 in the same direction as the inner cylindrical portion 35. And a radial side cylindrical portion 36. In addition, a continuous portion between the base end of the outer diameter side cylindrical portion 36 and the outer peripheral edge of the circular ring portion 34 protrudes diametrically outward from the outer peripheral surface of the outer diameter side cylindrical portion 35, The ridge 37 is continuous over the entire circumference of the spacer 33. The ridge 37 is provided to prevent the short cylindrical fitting and fixing portion 26b formed at the opening end of the first dustproof boot 24a from coming out of the outer diameter side cylindrical portion 36 carelessly. ing.

The outer diameter D ₃₆ of the outer diameter side cylindrical portion 36 is the maximum outer diameter of the second dustproof boot 32.
Have an outer diameter D _{27 a} more fitted fixed fit fixing part _27a (D ₃₆ ≧ D 27a) on the end portion outer peripheral surface of the 0. The first dustproof boot 24a for preventing foreign matter from entering the first constant velocity joint 2 is provided at the end of the outer diameter side cylindrical portion 36 and the outer ring 4 constituting the first constant velocity joint 2. It is provided between the outer peripheral surface of the unit. Therefore, the first dustproof boot 24a
The short cylindrical fitting and fixing portion 26b provided at the end of the outer cylindrical portion 36 has an inner diameter that can be externally fitted to the outer diameter side cylindrical portion 36. The fitting and fixing portion 26b is held down by the holding band 30b in a state of being externally fitted to the outer diameter side cylindrical portion 36. In this state, the ridge 37 prevents the fitting and fixing portion 26b from being displaced toward the first constant velocity joint 2, and the fitting and fixing portion 26b comes off from the outer diameter side cylindrical portion 35. To reliably prevent

Although not related to the gist of the present invention, in the case of the illustrated example, the outer half of the outer race 4 (the half that is located outside in the width direction when assembled to a vehicle, and is referred to as FIG. 1). Left half)
The second spacer 39 is internally fixed by interference fit. A part of the second spacer 39 projects outward (to the left in FIG. 1) from the outer end surface of the outer race 4 (to the left in FIG. 1). When a drive wheel is connected to the outer wheel 4, a circular hole provided at the center of a wheel constituting the drive wheel is fitted into a part of the second spacer 39, and the outer wheel 4 is connected to the outer wheel 4. The drive wheel is aligned with the drive wheel, and a part of the radial load of the drive wheel is supported by the second spacer 39.

Further, a slinger 40 is provided on a portion of the outer peripheral surface of the outer race 4 which is outside the outer end surface of the second outer race 8.
The outer fitting is fixed by interference fitting. The slinger is formed by bending a corrosion-resistant metal plate, such as a galvanized steel plate or a stainless steel plate, so as to have an overall U-shaped cross section, and is in a state of being close to the second outer ring 8. The outer ring 4 is externally fitted and fixed to the outer peripheral surface. Such a slinger 40 constitutes a labyrinth seal between the slinger 40 and the second outer ring 8, and at the time of rotation of the outer ring 4, shakes foreign substances adhered by centrifugal force outward in the diametrical direction, thereby forming a seal ring 38. At the same time, it is possible to reliably prevent foreign matters such as rainwater from entering the portion where the rolling elements 12 and 12 are installed.

According to the wheel driving force transmission unit of the present invention configured as described above, by providing the spacer 33, the inner diameter of the first dustproof boot 24a can be reduced by the second dustproof boot 32. The outer diameter D _27a of the fitting and fixing portion 27a externally fitted and fixed to the outer peripheral surface of the end of the housing 20, which is the maximum outer diameter of the housing 20.
More than that. That is, the inner diameter of the first fitting fixing portion 26b provided at an end portion of the dust-proof boot 24a is in conformity with the outer diameter D ₃₆ of the outer diameter side cylindrical portion 36 constituting the spacer 33, the outer diameter D _27a More than that. Also, the first constant velocity joint 2
The inner diameter of the fitting fixing portion 27 that fits into the engaging concave groove 29 formed at the inner end (the right end in FIG. 1) of the outer race 4 can also be made _larger than the outer diameter _D27a . Further, the two fitting fixing portions 26
The inner diameter of the elastically deforming portion 25b existing between the b and 27 can be elastically expanded by increasing the distance between the two fitting and fixing portions 26b and 27, and can be greater than the outer diameter _D27a . Therefore, as long as the connection between the drive shaft 19 and the output portion of the differential gear is released, the second constant velocity joint 3 and the second dustproof boot 32 are attached to the other end of the transmission shaft 1.
The first dustproof boot 24 provided between one end of the transmission shaft 1 and the first constant velocity
a can be exchanged. In this case, in the case of this example, the fitting and fixing portion 2 is used.
The outer diameter D _27a of the holding band 31a is the same as the outer diameter of the holding band 31a for externally fitting and fixing the fitting / fixing portion 27a to the engaging groove 29a of the housing 20.
the outer diameter of a large, the and when made may interfere when removing the first dustproof boot 24a, larger than the outer diameter of the band 31a to suppress the outer diameter D ₃₆ of the outside diameter side cylindrical part 36.

FIG. 2 shows a second embodiment of the present invention.
An example is shown. In the case of the structure of this example, the first constant velocity joint 2a is formed, and a double row is formed on the outer peripheral surface of the outer ring 4a which also functions as an inner ring of a rolling bearing unit for rotatably supporting the wheels. Inner raceway 11, 11
Is formed directly. The inner ring member 6 and the nut 7 (FIG. 1) as in the case of the first example described above are omitted. In this way, both of the double-row inner raceways 11, 11 are connected to the outer race 4a.
When the rigidity of the outer ring is the same, by forming the inner ring member 6 (see FIG. 1) on the outer ring 4 as in the first example, the rolling elements 12 and Twelve pitch circle diameters (PCD) can be reduced.

In the case of this embodiment, a cylindrical portion 41 for externally fitting an inner peripheral edge of a wheel constituting a driving wheel is integrally formed with an outer end (left end in FIG. 2) opening of the outer ring 4a. The second spacer 39 (see FIG. 1) formed and used in the first example described above is omitted. Further, in the case of the present example, a partition 42 for closing the inside of the intermediate portion of the outer ring 4a and preventing foreign matter from entering the first constant velocity joint 2a through the inside of the outer ring 4a is provided with the outer ring 4a. Is formed separately from the outer ring 4a, and is fixedly fitted inside the intermediate portion of the outer ring 4a by interference fitting. Other configurations and operations are the same as those in the first example described above, and therefore, the same parts are denoted by the same reference numerals, and redundant description will be omitted.

[0022]

The wheel driving force transmission unit of the present invention is
Since the configuration and operation are performed as described above, the replacement work of the first dustproof boot, which is the member with the least durability, is facilitated, and the cost required for repair work can be reduced.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing a first example of an embodiment of the present invention.

FIG. 2 is a half sectional view showing the second example.

FIG. 3 is a half sectional view showing one example of a conventional structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmission shaft 2, 2a First constant velocity joint 3 Second constant velocity joint 4, 4a Outer ring 5 Mounting flange 6 Inner ring member 7 Nut 8 Second outer ring 9 Mounting flange 10 Outer ring raceway 11 Inner ring raceway 12 Rolling element 13 Inner ring Reference Signs List 14 retaining ring 15 concave groove 16 concave groove 17 ball 18 tripod 19 drive shaft 20 housing 21 trunnion 22 roller 23 concave portion 24, 24a first dustproof boot 25, 25a, 25b elastically deforming portion 26, 26a, 26b fitting fixing portion 27 , 27a Fitting fixing portion 28, 28a Engaging concave groove 29, 29a Engaging concave groove 30, 30a, 30b Suppression band 31, 31a Suppression band 32 Second dustproof boot 33 Spacer 34 Circular ring 35 Inner diameter cylindrical part 36 Outer Diameter Side Cylindrical Portion 37 Ridge 38 Seal Ring 39 Second Spacer 40 Slinger 41 Cylindrical Portion 42 Spacing

Claims (1)

[Claims] A transmission shaft; a first constant velocity joint provided around one end of the transmission shaft; a second constant velocity joint provided around the other end of the transmission shaft; A first dust-proof boot provided between an intermediate portion one end portion and an end outer peripheral surface of a member to be an outer ring of the first constant velocity joint,
A driving force transmission unit for a wheel including a second dustproof boot provided between a portion near the other end of the transmission shaft at the other end and an outer peripheral surface of an end portion of a member serving as an outer ring of the second constant velocity joint. In this case, an annular spacer having an outer diameter equal to or larger than the maximum outer diameter of the second dustproof boot is externally fitted and fixed to a portion near one end of the transmission shaft, and one end of the first dustproof boot is fixed. , Which is externally fitted and fixed to an outer peripheral surface of the spacer.