JPS6139528B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a vehicle wheel hub assembly.

In the case of drive-and-steering wheels or suspended differentials, the transmission between the output of the differential and the drive wheels is ensured by two constant-velocity rotary joints connected by a transmission shaft and connected to the hub. An outer joint proximate the hub is typically splined and connected to the hub by a shank held in a predetermined axial position by a hat. The hub is further attached to the vehicle structural element by means of rolling bearings.

In such devices, the key problem is to obtain as small radial and axial dimensions as possible. It is an object of the invention to provide a wheel hub assembly whose overall dimensions are smaller than those of conventional types and which are relatively easy to assemble and disassemble.

To achieve the above object, the present invention includes a wheel hub and a constant velocity rotary joint for coupling the hub to a transmission shaft, and the constant velocity rotary joint is capable of rotating three partially spherical rollers. a tripod element that is separate from the hub and has three trunnions attached to the hub; a bowl-shaped element that is connected to the transmission shaft and has three race tracks each accommodating the rollers therein; and an auxiliary joint portion connecting the tripod element and the tripod element to each other, the hub having a case member formed therein with a concave spherical bearing surface, and the bowl-shaped element having a case member having an inner concave spherical bearing surface, and a bowl-shaped element having a case member having an inner concave spherical bearing surface. Cooperative convex bearing surfaces are formed, and the hub is supported on the vehicle structural element via a rolling bearing, the rolling bearing having first and second relatively rotatable rings; 1 ring is fixed between the case member and the hub,
A wheel hub assembly characterized in that the second ring is secured to a structural element of the vehicle.

According to this invention as described above, since the tripod element of the constant velocity rotary joint is connected to the wheel hub itself by the auxiliary joint part, there is no need for a shaft part that is received and fixed in the hub as in the past. Therefore, the overall dimensions of the assembly including the wheel hub are reduced. In addition, the driving torque is transmitted from the transmission shaft to the wheel hub via the bowl-shaped element, tripod element, and auxiliary joint.
The tilting moment of the wheel hub is transmitted from the hub to the structural elements of the vehicle via the case member and the first and second rings of the rolling bearing, that is, the torque and tilting moment transmission paths are different. Therefore, excessive stress is not generated locally in each member.

Another feature of the invention is that the hub or case member is arranged concentrically with the axis of the hub and has a lateral extension forming an axial bearing surface and a lateral extension cooperating with elements adjacent to the rolling bearing. both include one radial shoulder, and the assembly of the bearing is accomplished using a single threaded connection between the hub and the case member; the hub has a lateral extension and is a rolling bearing; a radial shoulder is formed on each of the hub and case member for fixing the elements of the hub and the case member, and a threaded connection is achieved directly between the lateral extension of the hub and the case member; the lateral extension is primarily provided on the case member; the hub and the case member are of one piece; the threaded connection is achieved by a female thread that threads into a male thread provided on the hub or the case member;

The present invention will be explained below with reference to the drawings.

FIG. 1 shows a drive shaft 1 in rigid contact with a bowl-shaped member 2, in which three race tracks 3 with a circular cross-section are arranged, and a trunnion 5 of a tripod element 6 with rotation and rotation. Three slidingly mounted rollers 4 are received. The tripod element 6 is in rigid contact with a short shaft 7 which has at its free end external teeth 8 which mesh with internal teeth 9 formed in the wall 10 of a cavity 11 formed in the wheel hub 12 .

The wheel hub 12 is fixed, for example by a set screw 13, to a case member 14 forming a case and having a concave spherical bearing surface 15, the case member 14 having a convex spherical bearing surface formed in the bowl-shaped element 2. Engages bearing surface 16. The tripod element 6 is held axially relative to the hub by a thrust washer 17 which is held in place by a resilient ring 18 wedged within a groove in member 14. The engagement surfaces of washer 17 and tripod element 6 are preferably spherical. Furthermore, the distal end of the shank 7 also has a generally spherical bearing surface 1 which abuts a side wall 20 which is held in place by a resilient ring 21 fixed to the hub.
It has 9.

The inner ring 22 of the ball bearing 23 has a spacer 24
It is fixed between the hub 12 and the member 14 via. The outer ring 25 of this ball bearing is fixed by a threaded collar 26 to an element 27 of the structure of the vehicle. Although the illustrated ball bearing is of the type that includes two rows of balls 28 on each side of a central ring, it will be appreciated that any other type of bearing may be used.

With the above structure, the torque is transmitted from the transmission shaft 1 through the main rotary joint part 2 and the auxiliary rotary joint parts 8, 9 between the tripod element 6 and the hub 12, so that this joint It performs the function normally performed by a spline arranged between a driven shaft in rigid contact with the tripod element and a spline provided in the wheel hub.

As a result, this wheel hub assembly is particularly compact and compact in its shape. Axis line AB is shown in the drawing
is shown, which is the axis of the wheel,
From the drawings it can be seen that a constant velocity rotary joint can be placed considerably outside this axis, subject to a very slight extension of the sliding section provided by this joint located at the output of the differential at the opposite end of shaft 1. , it is found that it is possible to allow an increase in the rotation or steering angle of the wheel without maximum damage to the joint, yet requiring a rotation angle exceeding the normal value.

FIG. 2 shows a wheel hub assembly including a main rotary joint J, a wheel hub M, and a ball bearing R. FIG. This joint connects the drive shaft 101 to which the bowl-shaped element 102 is rigidly connected.
three race tracks 103 are formed in the element in a known manner to receive therein three rollers 104 rotatably and slidably mounted on the trunnion 105 of the tripod element 106. This tripod element is rigidly mounted with a short shaft 107, which at its free end has a cavity 1 formed in the wheel hub M.
It has external teeth 108 that mesh with internal teeth 109 provided on the wall of 10.

As previously mentioned, the assembly of this joint is completed by side walls 111 and washers 112 held by elastic rings 113, 114, respectively, and which hold and guide the tripod element. Also, bowl-shaped element 1
A member 11 forming a concave spherical bearing surface 116 that engages a convex spherical bearing surface 117 formed in 02
5 is provided.

An important feature here is that this member 115 terminates adjacent the hub by a generally cylindrical section 120 having an internal thread 121. The hub also has a lateral extension 122 that extends toward the joint and includes male threads 123 that mate with female threads on the case member. The lateral extension 122 of the hub has a cylindrical bearing surface 124 for an inner ring 125 of ball bearings;
The outer ring 126 of this bearing is fixed to a structural element 127 of the vehicle in a known manner. Inner ring 125 is axially secured between two radial shoulders 128, 129 formed on the axial extension of the hub and on the end face of member 115, respectively.

By mounting in this manner, assembly and disassembly operations can be performed such that the assembly of the hub, the adjacent portion of the joint, and the inner ring of the ball bearing has a relatively large diameter and is aligned with the axis X-X of the hub. It is particularly simple to implement since it is achieved by a single screw connection coaxial with the . Furthermore, this threaded connection is provided in the area of the axial extension of the hub, and since the torque is transmitted directly to the hub via the auxiliary joints 108, 109, no forces are exerted on this area. Torques with ramps are also transmitted in a particularly satisfactory manner.

The wheel hub assembly shown in FIG. 3 is similar to the wheel hub assembly of FIG. 2, except that the lateral extension 122a of the hub is more shortened while the member 115a is longer and cylindrical. It extends to the tube-shaped portion 120a.
This threaded connection is therefore located closer to the hub and on the one hand also has the advantages mentioned for the previous embodiment. A radial shoulder for securing the inner ring of the ball bearing is provided on the hub and on the member 115a, and this member is in particular attached to the retaining ring 11.
4a, the number of components is further reduced.

In the case of FIG. 4, the wheel hub assembly has been modified to allow the diameter of the ball bearing R to be reduced. For this purpose, the toothed part carried on the shank 107b in rigid contact with the tripod element 106b is constituted by a toothed ring 130, which is connected to the distal part of the shank and the toothed part 130. The shank has intermeshed frusto-conical splines 131, 132, the axial connection being achieved by a nut 133 and washer 134 disposed at the distal end of the shank. The toothed wheel 130 and hub have two mating spherical bearing surfaces 135, 136;
The shaft portion 137 of the hub through which the shaft portion 107 passes has a frusto-conical shape, and these various devices allow the angular movement and positioning of the tripod element by the auxiliary joint formed by the two tooth profiles 108b and 109b. can be implemented.

The threaded connection between the hub M and the case member 115b is similar to that shown in FIG.

The fact that the toothed ring 130 can be disassembled actually makes it possible to reduce the diameter of the axial extension of the hub and thus of the inner ring of the ball bearing, with generally similar advantages in other respects. It should be noted that this is obtained.

In the embodiment shown in FIG. 5, a threaded connection between the hub lateral extension 122c and the case member 115c is provided. This wheel hub assembly includes a thin plate collar 140 that also functions as a curved plate to protect the bearing. A sealing element 141 seals the bearing and an outer ring 142 of the bearing has an inner bore 143.
Press fit inside. Spacers 144 ensure precise adjustment between inner rings 145, 146 and transmission of axial forces to firmly connect ball bearings, hubs and coupling members.

In FIG. 6, assembly of the hub, bearing and coupling member is accomplished in a manner similar to that described in FIG. The modification point in this embodiment is the auxiliary joint between the tripod element, the rigidly installed shaft portion 107d, and the hub M. This joint is in this example elastically deformable, formed by a tube 150 connected to the shaft 107d by a conical spline 151, which tube has a radius formed in the cavity 154 of the hub. radial vanes 152 embedded within an integral elastic member 153 provided within the directional recess;
It has The number of blades and recesses can be eight, for example. Elastic members 153 extend axially beyond the vanes on both sides 155, 156 and are retained by side walls 157 to ensure axial positioning of the tripod element. Since such elastically deformable joints exhibit a cushioning effect,
This has the advantage of insulating the wheel hub from torsional vibrations generated in the engine body and transmitted via the main joint J.

The apparatus shown in FIG. 7 aims to shorten the overall axial dimensions of the hub, bearing, and joint members. For this purpose, the hub M and the case member have an integral structure, and the inner ring 12
5e is tightened between the shoulder 128e of the hub and the internal thread 160 that meshes with the external thread 161. The fact that the overall axial dimension of this joint is reduced allows the distance d between the center O of the main joint member J and the axis Y-Y of the wheel to be increased, so that the steering angle of the wheel is can further increase the angular movement capacity provided by

In FIG. 8, two inner rings 170,1
71 are provided, which are secured similarly to the embodiment shown in FIG. 6 by nuts 172 and separated by spacers 173. On the other hand, outer ring 174 includes holes 175 for being fixed to pivot bearing member 177 by bolts 176.
Curved plates 178, 179 protect the ball bearings and at the same time serve to maintain the inner rings 170, 171 and spacer 173 in the assembled condition prior to overall assembly.

In the embodiment shown in FIG. 9, the auxiliary joint is similar to that described with respect to FIG. 4, but the assembly is different. The case 115f of the joint has a radial step 180 and a tube 18 passing through the hub M.
Contains 1. The distal end of this tube 181 is provided with male threads and receives a shaft nut 182 for securing the hub. A pin 183 inserted into a step or radial shoulder 180 and cooperating with a recess 184 in the hub prevents relative rotation between the case 115f and the hub, thereby facilitating screwing of the nut 182. .

It is to be understood that the various subarrangements contemplated with respect to the various embodiments presented herein may be assembled in different combinations depending on the particular intended use, without departing from the scope of the claims of the invention. .

[Brief explanation of the drawing]

1 to 9 are longitudinal sectional front views of portions of different embodiments of the invention. 1,101... Drive shaft, 2,102... Bowl-shaped member, 3,103... Race track, 4,104...
Roller, 5,105...Trunion, 6,106
... Tripod element, 7,107 ... Short shaft part, 8,10
8... Free end tooth, 9,109... Internal tooth, 11,1
10... Cavity, 12... Wheel hub, 13... Set screw, 14... Case member, 15, 116...
Concave bearing surface, 16,117... Convex bearing surface,
17,112...Thrust washer, 18,2
2,113,114...Elastic ring, 19...Bearing surface, 20,111...Side wall, 21...Elastic ring, 22,125,145,146,170,
171...Inner ring, 23...Ball bearing, 24,
144,173...Spacer, 25,126,1
42,174...outer ring, 115...member,
120...Cylindrical part, 121...Female thread, 12
2... Lateral extension part, 123... Male thread, 124...
... Cylindrical bearing surface, 128, 129 ... Radial shoulder, 130 ... Toothed wheel body, 131, 132 ...
Spline, 133...Natsuto, 135,136
... Bearing surface, 137 ... Axial cavity, 150 ...
Tube, 151... Nut, 152... Radial vane, 153... Elastic member, 154... Cavity, 1
55, 156... Elastic member extension portion, 157... Side wall, 160, 172, 182... Nut, 161
...Male thread.

Claims (1)

[Claims] 1. A wheel hub, and a constant velocity rotary joint for coupling the hub to a transmission shaft, the constant velocity rotary joint having three partially spherical rollers rotatably attached thereto. a tripod element having three trunnions and separate from the hub; a bowl-shaped element connected to a transmission shaft and having three race tracks each accommodating the rollers therein; and a hub and a tripod element. an auxiliary joint portion connecting the hubs to each other; the hub is formed with a case member having an inner concave spherical bearing surface;
The bowl-shaped element is also formed with a convex bearing surface that engages and cooperates with said concave spherical bearing surface, and the hub is supported on a structural element of the vehicle via a rolling bearing, said rolling bearing being It has first and second rings that are relatively rotatable, the first ring being fixed between the case member and the hub, and the second ring being fixed to a structural element of the vehicle. Wheel hub assembly. 2. A wheel hub assembly according to claim 1, wherein the hub is formed with a cavity for receiving the auxiliary joint and carries a side wall against which the end of the tripod element abuts. 3. A wheel hub assembly according to claim 1, wherein the case member carries a member for axially maintaining the tripod element. 4. The assembly of the hub, the case member, and the first ring of the rolling bearing is achieved by a single screw connection arranged concentrically with the axis of the hub. Wheel hub assembly. 5. The hub or case member has a lateral extension arranged concentrically with the axis of the hub and forming an axial bearing surface and at least one radial shoulder cooperating with the first ring of the rolling bearing. A wheel according to claim 4, wherein the assembly of the first ring of the rolling bearing, the hub and the case member is achieved by a single threaded connection between the hub and the case member. hub assembly. 6 The hub has a lateral extension and the first of the rolling bearings
A wheel according to claim 5, in which a radial shoulder for fixing the ring is formed on each of the hub and the case member, and the lateral extension of the hub and the case member are connected directly by screws. hub assembly. 7. A wheel hub assembly according to claim 5, wherein the lateral extension is provided primarily in the case member. 8. A wheel hub assembly according to claim 7, wherein a washer axially retaining the tripod element is secured between the distal end of the lateral extension of the case member and the shoulder of the hub. 9. The wheel hub assembly according to any one of claims 1 to 5, wherein the hub and the case member are made of a single member. 10. Claim 4 or 6, wherein the threaded connection is achieved by a female thread that engages with a male thread provided on either the hub or the case member.
The wheel hub assembly according to any one of items 9 to 9. 11. Claims 4 to 4, in which the auxiliary joint part is removably attached to the end of the shaft that is in rigid contact with the tripod element, and includes an externally toothed member that meshes with internal teeth formed in the cavity of the hub. The wheel hub assembly according to any one of clauses 10 to 10. 12. Axial retention of the tripod element is achieved by means of a toothed member, an end of the shaft, a spherical surface on the hub, and a retaining wall of the hub. Wheel hub assembly as described in. 13. The wheel hub assembly according to claim 11 or 12, wherein the axial cavity of the hub, through which the shaft portion rigidly connected to the tripod element passes, has a truncated conical shape. 14 The auxiliary joint part is fixed to the end of the shaft part that is in rigid contact with the tripod element, and includes a member having wings embedded in an elastic member provided in a recess formed in the cavity of the hub, and the elastic member is Wheel hub assembly according to any one of claims 4 to 10, which ensures preferably axial retention of the shank in rigid contact with the tripod element.