A-ARM FRAME WITH BEARING FOR HAULING DEVICES
An A-arm frame 10 for a vehicle has two arms 12, 14 that converge at an apex 16. Each arm has a mounting end opposite the apex for mounting to the housing for an axle of the vehicle. A pivot joint at the apex connects the A-arm frame to the vehicle frame. The pivot joint includes a case-hardened spherical plain bearing 22 that includes an inner ring 26 and an outer ring 28. The inner ring 26 may have a lubrication aperture therethrough, but the outer ring 28 has no lubrication aperture therethrough. The outer ring 28 may have a multi-fracture configuration and, therefore, a greater wrap-around of the inner ring 26 than it otherwise would have.
1 . An A-arm frame for joining an axle housing to a vehicle frame, the A-arm frame comprising two arms that converge at an apex, each of the arms having a mounting end opposite from the apex for mounting to the axle housing, the A-arm frame further having a pivot joint at the apex for connecting the A-arm frame to the vehicle frame, the pivot joint comprising a spherical plain bearing that comprises an inner ring and an outer ring; wherein the spherical plain bearing is a case-hardened bearing.
2 . The A-arm frame of claim 1 , wherein the inner ring and the outer ring that each have a surface hardness of at least about Rockwell C56 and a core hardness of not more than about Rockwell C49.
3 . The A-arm frame of claim 2 , having an effective case of about 0.5 millimeters to about 1.6 millimeters from the surfaces of the inner ring and the outer ring.
4 . The A-arm frame of claim 1 , wherein the inner ring and the outer ring that each have a surface hardness of about Rockwell C56 to about Rockwell C59 and a core hardness of about Rockwell C30 to about Rockwell C49.
5 . The A-arm frame of claim 4 , having an effective case of about 0.5 millimeters to about 1.6 millimeters from the surfaces of the inner ring and the outer ring.
6 . The A-arm frame of claim 1 , wherein the inner ring has a convex bearing surface that conforms to a spherical diameter of about 134 mm and a shaft bearing surface having a diameter of about 100 mm, and the outer ring has an outside diameter of about 150 mm; and
wherein the inner ring and the outer ring that each have a surface hardness of at least about Rockwell C56 and an effective case of about 0.5 millimeters to about 1.6 millimeters from the surfaces of the inner ring and the outer ring.
7 . The A-arm frame of claim 6 , wherein the inner ring and the outer ring that each have a core hardness of not more than about Rockwell C49.
8 . The A-arm frame of claim 1 , wherein the outer ring has no lubrication aperture therethrough.
9 . The A-arm frame of claim 1 , wherein the outer ring has a multi-fracture configuration.
10 . The A-arm frame of claim 1 , wherein the outer ring has a double fracture configuration.
11 . The A-arm frame of claim 1 , wherein the pivot joint comprises a linking pin in the inner ring, the linking pin having a lubrication supply conduit.
12 . The A-arm frame of claim 11 , wherein the inner ring includes a lubrication groove and the lubrication supply conduit permits a lubricant to pass from the linking pin to a linkage load zone between the linking pin and the inner ring.
13 . The A-arm frame of claim 12 , wherein the inner ring includes an aperture extending radially therethrough, the aperture permitting lubricant to pass from the linkage load zone to a bearing load zone between the inner ring and the outer ring.
14 . In a vehicle comprising a vehicle frame, an axle having an axle housing and an A-arm frame joining the axle housing to the vehicle frame, the A-arm frame comprising two arms that converge at an apex, each of the arms having a mounting end opposite from the apex for mounting to the housing for an axle of the vehicle, the A-arm frame further having a pivot joint at the apex for connecting the A-arm frame to the vehicle frame, the pivot joint comprising a spherical plain bearing, and the spherical plain bearing comprising an inner ring and an outer ring; the improvement comprising that the spherical plain bearing is a case-hardened bearing.
15 . The vehicle of claim 14 , wherein the inner ring and the outer ring that each have a surface hardness of at least about Rockwell C56 and a core hardness of not more than about Rockwell C49.
16 . The vehicle of claim 15 , having an effective case of about 0.5 millimeters to about 1.6 millimeters from the surfaces of the inner ring and the outer ring
17 . The vehicle of claim 14 , wherein the inner ring and the outer ring that each have a surface hardness of about Rockwell C56 to about Rockwell C59 and a core hardness of about Rockwell C30 to about Rockwell C49.
18 . The vehicle of claim 17 , having an effective case of about 0.5 millimeters to about 1.6 millimeters from the surfaces of the inner ring and the outer ring
19 . The vehicle of claim 14 , wherein the inner ring has a convex bearing surface that conforms to a spherical diameter of about 134 mm and a shaft bearing surface having a diameter of about 100 mm, and the outer ring has an outside diameter of about 150 mm; and
wherein the inner ring and the outer ring that each have a surface hardness of at least about Rockwell C56 and an effective case of about 1.1 millimeters to about 1.6 millimeters from the surfaces of the inner ring and the outer ring.
20 . The vehicle of claim 19 , wherein the inner ring and the outer ring that each have a core hardness of not more than about Rockwell C49.
21 . The vehicle of claim 14 , wherein the outer ring has no lubrication aperture therethrough.
22 . The vehicle of claim 14 , wherein the outer ring has a multi-fracture configuration.
23 . The vehicle of claim 14 , wherein the outer ring has a double fracture configuration.
24 . The vehicle of claim 14 , wherein the pivot joint comprises a linking pin in the inner ring, the linking pin having a lubrication supply conduit.
25 . The vehicle of claim 24 , wherein the inner ring includes a lubrication groove and the lubrication supply conduit permits a lubricant to pass from the linking pin to a linkage load zone between the linking pin and the inner ring.
26 . The vehicle of claim 14 , wherein the inner ring includes an aperture extending radially therethrough, the aperture permitting lubricant to pass from the linkage load zone to a bearing load zone between the inner ring and the outer ring.