GB2066172A

GB2066172A - Vehicle wheel assembly

Info

Publication number: GB2066172A
Application number: GB8038909A
Authority: GB
Original assignee: Goodyear Tire and Rubber Co
Current assignee: Goodyear Tire and Rubber Co
Priority date: 1979-12-28
Filing date: 1980-12-04
Publication date: 1981-07-08
Also published as: JPS5699802A; FR2472483A1; BR8008426A; DE3048062C2; JPS6215001U; FR2472483B1; CA1138916A; CH642913A5; DE3048062A1; MX153590A; GB2066172B

Abstract

A wheel assembly 10, e.g. for a truck or earthmover, has a rim 12 with a well whose base consists of a cylindrical first part 30 of internal radius R1, and a cylindrical second part 34 which has a radially inner surface 36 of radius R2>R1 and into which an end 38 of a generally cylindrical adapter member 14 is fitted and secured. The other end 40 of the adapter member is attached to a hub 16 and thereby provides a cantilever support of the rim on the hub. The end 40 may be secured to the hub by clamping members 50 as shown, or may alternatively be formed into a radial flange received on the hub studs 52 and secured by nuts 54. <IMAGE>

Description

SPECIFICATION Vehicle rim and hub assembly The present invention relates to a rim and hub assembly for a vehicle. More particuiarly, this invention relates to a new and improved structure for attachment of a single piece rim to the hub of a vehicle so as to provide improved means for transmittal of forces between the rim assembly and the hub and to allow balanced flexing of each of the side members of the rim which contain the bead seating surfaces thereon. This invention is adaptable for large rims such as earth mover and truck tire rims including those having a bead diameter greater than 25 inches.

Currently in the industry, large earthmover rims are almost exclusively of the multipiece variety consisting of the main body of the rim and usually three or four pieces in the flange areas of the rim.

Simplicity of design is a desirable feature which may be provided by single piece rims in some applications. Single piece rims have a reduced number of parts and do not require special hot rolled sections for their manufacture. These rims require what is commonly referred to as a drop center; i.e., the axially central portion of the rim is disposed radially inward of the axially outer bead-engaging surfaces on the sides of the rim to provide a radially extending space between the side members to permit assembly of the tire on the rim.

For the purposes of this specification and the claims, "axiaily" refers to a direction generally parallel to the axis of rotation of the rim. The term "radiaily' refers to a direction generally perpendicularto the axis of rotation of the rim. The axis of rotation of the rim is the axis about which the rim rotates during normal use. The midcircumferential plane is a plane perpendicular to the axis of rotation of the rim which divides the rim into two halves. A radial plane is one which contains the axis of rotation of the rim.

A common practice for mounting automobile rims to the hub is to provide a disc disposed perpendiculay to the axis of rotation of the rim and to provide bolt holes in the disc to be engaged by studs projecting from the hub for attachment thereof to the hub. A method used with heavier vehicles such as earthmovers involves the use of an annular member called an adapter member which may be attached at one end to a portion of the rim. The other end of this adapter member may be attached to the hub of the vehicle by clamping means.

If this adapter member is attached to one of the side members of the rim and not to the other, then that side member is not free to flex in the same manner as the other side member. This attachment may result in undesirable stress concentrations in that member as well as a rise in the stress level at the other side member.

Design requirements may necessitate the positioning of the rim with respect to the hub such that the clearance between the hub and the central portion of the rim is less than the thickness of the adapter member. In this situation, the adapter member may have to be attached to the rim at a side member which is not desirable for the reasons set forth.

The present invention, in at least some aspects, provides a solution to this problem by providing a rim assembly wherein the central portion of the rim has a recessed surface radially inward thereof to provide load-transmitting engagement with the adapter member and the adapter member is not otherwise attached to the rim. Because of this cantilever attachment of the adapter member to the rim, the full load carried by the hub is transmitted to the rim at the central portion whereby balanced flexing of the side members may result.

In the drawings: Figure lisa sectional view taken in a radial plane of a rim and hub assembly made in accordance with this invention; Figure 2 is a fragmentary elevation taken along line 2-2 in Figure 1; and Figure 3 is a sectional view similar to that of Figure 1 showing an alternative embodiment of a rim and hub assembly made in accordance with this invention.

A rim assembly is shown in the drawings and is generally referred to by the numeral 10. This assembly 10 comprises an annular rim 12 with an annular adapter member 14 attached thereto. The adapter member 14 is connected to a cylindrical hub 16 whereby the load ofthevehicle being carried bythe hub is transmitted through the adapter member to the rim.

The rim 12 provides bead-seating surfaces 18 for the beads of a tire mounted thereon. As shown in Figure 1, the rim 12 may be a single piece of formed metal such as steel or it may be made of several pieces of metal welded together in an integrally formed single piece. However, this invention is not limited to single piece rims and the rim may have removable flanges and other removable pieces in the bead-seating and flange areas. In addition, rim assemblies may be made in accordance with this invention to provide dual wheel mountings as well as single wheel mountings for hubs.

The rim 12 has a generally cylindrical central portion 20 positioned centrally of the midcircumferential plane 21 of the rim. As shown in Figure 1, the midcircumferential plane 21 is perpendicular to the axis of rotation 23 of the rim 12. Extending outwardly from the axially outer ends of the central portion 20 in the radial direction, as well as in the axial direction, are a pair of side members 22 and 24 which provide the surfaces 18 for the seating of beads 25 of a tire thereon. The rim 12 of this invention may be used with any size tire; however, there are advantages in using the rim with a large tire such as an earthmover or truck tire having a bead diameter D, as shown in Figure 1, of more than 40 inches (102 cm). Axially outward of each of the bead-seating surfaces 18 is an annular flange 26.The resultant positioning of the annular central portion 20 radially inward of the bead-seating surfaces 18 provides a space between the side members 22 and 24 for disposition of one tire bead while the other bead is being positioned over a flange 26 during mounting of the tire on the rim 12. Accordingly, the diameter of the central portion 20 should normally be small enough to allow a tire to be mounted on the rim 12. The rim 12 need not necessarily be of the configuration shown, the particular shape of the rim being more dependent on design considerations as found in the rim art.

The side members 22 and 24 each has a radially inner surface 28. The annular central portion 20 has a first cylindrical portion 30 disposed coaxialiy of the axis of the rim 12 with a radially inner first cylindrical or main surface 32, and a second cylindrical portion 34 which extends coaxially from one end of the first cylindrical portion with a radially inner second cylindrical surface. The second cylindrical surface or recessed surface 36 has a radius R2 greater than radius R1 of the surface 32. The radially inner surface 28 of the side member 22 is contiguous with the recessed surface 36 and the radially inner surface 28 of the side member 24 is contiguous with the main surface 32.

The adapter member 14 has a first end portion 38, the radially outer cylindrical surface 39 of which is coaxially engaged with and fixed to the recessed surface 36 of the central rim portion 20, preferably over the full width S of the recessed surface, for attachment of the adapter member as a cantilever member to the rim 12. Adapter member 14 also has a second end portion 40 which extends axially beyond the second cylindrical surface 36 of the central portion 20 for attachment to the hub 16 whereby the full load carried by the hub is transmitted to the rim at the central portion.Radially outer surface 39 of the first end portion 38 has a radius R4 which is preferably slightly larger than the radius R2 of the recessed surface 36 so as to permit a press fit between the adapter member 14 and the recessed surface, thereby providing for load-transmitting engagement of the adapter member with the central portion 20. The rim 12 is free of any support of or by the adapter member 14 other than at the central portion 20.

The recessed surface 36 has a sufficient width S in the axial direction to provide adequate surface contact between the adapter member 14 and the central rim portion 20 for cantilever support of the adapter member, but should not extend so far that the drop center depth is unduly reduced. Forties having a bead diameter greater than 25 inches, the width S is preferably at least one inch (2.54 cm) or about 25 percent of the overall width Win the axial direction of the central rim portion 20.

The central rim portion 20 is disposed radially outward of the hub 16. Both the radius R1 of the main surface 32 of the central portion 20 and radius R3 ofthe hub 16 are based primarily upon design considerations. In the environment of one aspect of this invention, the radius R1 of the main surface 32 of the central portion 20 is greater than the radius R3 of the hub 16 by an amount less than thickness 42 of the first end portion 38 of the adapter member 14.

The thickness 42 of the first end portion 38 of the adapter member 14 is defined as the distance between a radially outer surface 39 and a radially inner surface 44 of the first end portion.

In order to provide a supporting connection with operating clearance between the hub 16 and the central portion 20 of the rim 12, the radius R2 of the recessed surface 36 of the central portion 20 is greater than the radius R3 of the hub 16 by an amount which is greater than the thickness 42 of the first end portion 38 of the adapter member 14.

Preferably, the radially inner surface 44 of the first end portion 38 of the adapter member 14 has a radius R5 which is substantially equal to radius R1 ofthe main surface 32 of the central rim portion 20. The first end portion 38 is preferably press fitted into the recessed surface 36 and then welded as shown by welds 46 to the central portion 20 to prevent movement in the axial direction of the adapter member 14 relative to the central portion. Also, as shown in Figure 1,the surfaces 32 and 36 preferably do not have any sharp corners which would provide points of stress concentration for cracks to develop in the welds 46.

As shown in Figures 1 and 2, the second end portion 40 of the adapter member 14 has an annular flange 48 for engagement with the hub 16. Clamps 50 spaced circumferentially urge the flange 48 against the hub 16 and are fastened to the hub by suitable fasteners such as studs 52 attached to the hub and nuts 54 threaded on the studs to provide, at least in part, means for mounting the adapter member 14 as a cantilever member on the hub 16.

Such mounting means may alternatively be provided as shown in Figure 3. In this embodiment, a disc member 56 is integrally connected to a second end portion 58 and extends radially inward from the second end portion to engage a hub 60. Suitable fastening means such as studs 62 attached to the hub 60 and nuts 64 threaded on the studs secure the disc member 56 to the hub. The disc member 56 need not be provided by forming adapter member 66 as shown but may be welded or otherwise attached thereto.

Preferably, the disc member 56 and the adapter member 66 are integrally connected and forward from a single piece of metal. The radius of curvature R6 between the adapter member 66 and the disc member 56 may be such an amount as to require a first end portion 68 of the adapter member 66 to be spaced radially from the hub 60 a minimum amount for clearance. In the environment of this aspect of the invention, the hub 60 and first cylindrical or main surface 32a of the central rim portion 20a have predetermined radii R3 and R1, respectively, which are usually dependent on design considerations. In addition, design considerations may require a particular radius of curvature R6 for maximum strength.

These design considerations may result in the radius' R4 of radially outer surface 70 of the first end portion 68 of the adapter member 66 being greater than the radius R1 of the main surface 32a of the central rim portion 20a. In such a case, the adapter member 66 may still be attached to the rim 1 2a at the central portion 20a by providing recessed surface 36a having radius R2 approximately equal and preferably slightly smaller before assembly than radius R4 of the radially outer surface 70 of the first end portion 68.

Claims

1. A rim assembly rotatable about an axis for attachment to a vehicle hub, said rim assembly comprising a rim having a generally cylindrical central portion including a first cylindrical portion disposed coaxially about said axis and having a first radially inner cylindrical surface, said central portion further including a second cylindrical portion which extends coaxially from one end of said first cylindrical portion and which has a second radially inner surface with a radius greater than the radius of said first radially inner surface, said rim further having an annular side member extending outwardly in both the axial and radial directions of and from each axially outer end of said central portion and having a bead-engaging surface thereon, a generally cylindrical adapter member having a first cylindrical end portion, the radially outer surface of which is fixed to and coaxially engaged with said second cylindrical surface of said central portion, said adapter member having a second end portion which extends axially beyond said second cylindrical surface of said central portion, said rim being free of any support of or by said adapter member other than at said central portion, and means on said second end portion of said adapter member forming at least in part mounting means for cantileverly supporting said adapter member on the hub.

2. The rim assembly of claim 1 wherein the radially outer surface of said first cylindrical end portion is coaxially engaged with said second cylindrical surface of said central portion over the full width of said second cylindrical surface.

3. The rim assembly of claim 1 wherein said first cylindrical end portion of said adapter member has a radially inner surface which has a radius substantially equal to the radius of said first cylindrical surface of said central portion.

4. The rim assembly of claim 1 for use with a tire having a bead diameter greater than 25 inches.

5. The rim assembly of claim 4 wherein said second cylindrical surface of said central portion of said rim has a width in the axial direction of at least one inch.

6. The rim assembly of claim 1 wherein said second cylindrical surface of said central portion of said rim has a width in the axial direction equal to about 25 percent the width in the axial direction of said central portion.

7. The rim assembly of claim 1 wherein said central portion is disposed radially outward of the hub, said first cylindrical surface of said central portion having a radius which is greater than the radius of the hub by an amount less than the thickness of said first cylindrical end portion of said adapter member, and said second cylindrical surface of said central portion having a radius which is greater than the radius of the hub by an amount which is greater than the thickness of said first cylindrical end portion of said adapter member so that a supporting connection with operating clearance between the hub and the central portion of the rim is provided.

8. The rim assembly of claim 1 wherein said rim is a single piece rim.

9. The rim assembly of claim 1 wherein said mounting means includes a disc member extending generally radially inward from said second end portion of said adapter member to the hub, and fastening means for attachment of said disc member to the hub.

10. The rim assembly of claim 9 wherein the hub and said first cylindrical surface of said central portion of said rim have predetermined radii, said disc member and said adapter member being integrally connected and formed to define a radius of curvature of an amount such that said first end portion of said adapter member is spaced apart radially from the hub when said adapter member is attached to the hub a distance such that the radius of the radially outer surface of said first end portion of said adapter member is greater than the radius of said first cylindrical surface of said central portion.