Maintenance free extended life cam follower for a necker machine

Abstract

A cam follower for a ram of a metal can necker machine is provided. The cam follower has an outer ring and an inner ring coaxially disposed in the outer ring. A plurality of rolling elements is disposed in an annular cavity between the outer ring and the inner ring. The plurality of rolling elements is disposed between a first seal and a second seal. A shaft is received in a bore in the inner ring and is fixed relative thereto about the shaft axis. The outer ring is received in a tire. The tire has a thickness and a crown radius. The composition of the tire includes a metallic material, a plastic material, a non-metallic material, and combinations thereof.

What is claimed is: 
     
         1 . A cam follower, the cam follower comprising:
 an outer ring having an outer ring bearing surface and an exterior surface;   an inner ring coaxially disposed in the outer ring and having an inner ring bearing surface, the inner ring having a bore extending therethrough;   a plurality of rolling elements disposed in an annular cavity between the outer ring bearing surface and the inner ring bearing surface, the plurality of rolling elements being in rolling engagement with the outer ring bearing surface and the inner ring bearing surface such that the outer ring is rotatable relative to the inner ring about a shaft axis A, the plurality of rolling elements having a pitch radius PR defined by a distance between the shaft axis A and a rolling element axis C;   a shaft received in the bore in the inner ring, the shaft being fixed relative thereto about the shaft axis A, the shaft having a first groove formed therein, extending radially inward and extending circumferentially therearound;   the plurality of rolling elements being disposed between a first seal and a second seal, the second seal and the first seal sealing a lubricant therebetween;   the inner ring being axially retained by a first clip disposed at a depth D 1  in the first groove;   the outer ring being received in a tire, the tire having a thickness T 1  and a crown radius R, the crown radius having an apex R′, wherein the inner ring and the outer ring are axially centered with respect to the apex R′, the composition of the tire comprising at least one of a metallic material, a plastic material, and a non-metallic material, and the tire having a second groove formed therein, extending radially outward and extending circumferentially therearound; and   the outer ring being axially retained by a second clip disposed at the depth D 1  in the second groove.   
     
     
         2 . The cam follower of  claim 1 , wherein a ratio of the depth D 1  to the tire thickness T 1  is between 0.17 and 0.19. 
     
     
         3 . The cam follower of  claim 1 , wherein a ratio of the tire thickness T 1  to the pitch radius PR is between 0.18 and 0.19. 
     
     
         4 . The cam follower of  claim 1 , a first distance R 1  is defined between an exterior surface of the outer ring and the longitudinal axis A of the shaft and a second distance R 2  is defined between the longitudinal axis A of the shaft and an interior surface of the tire, wherein a ratio of the first distance R 1  to the second distance R 2  is between 1.000 and 1.015. 
     
     
         5 . The cam follower of  claim 1 , wherein the plurality of rolling elements is a plurality of spherical balls. 
     
     
         6 . The cam follower of  claim 1 , wherein the cam follower has a duty cycle, a bearing load capacity being selected based on the duty cycle. 
     
     
         7 . The cam follower of  claim 1 , wherein the shaft includes a hollow portion. 
     
     
         8 . A cam follower comprising:
 a shaft extending from a first axial end to a second axial end, the shaft having a first groove proximate to the first axial end, a shoulder formed in the shaft between the first groove and the second axial end, and a first clip radially engaging the first groove;   a tire defining an interior area, the tire having a flange extending radially inward from one axial end of the tire proximate the first axial end of the shaft and a second groove extending radially outward at an opposite axial end of the tire; and   a first ball bearing and a second ball bearing, the first ball bearing having a first plurality of spherical balls disposed between a first inner ring and a first outer ring, the second ball bearing having a second plurality of spherical balls disposed between a second inner ring and a second outer ring, the first outer ring and the second outer ring extending at least partially into the interior area of the tire, the first inner ring axially abuts the second inner ring and the first clip, the second inner ring axially abuts the shoulder and the first inner ring, the first outer ring axially abuts the second outer ring and the flange, and the second outer ring axially abuts the first outer ring and a second clip engaging the second groove;   wherein the first clip axially retains the first inner ring and the second inner ring on the shaft between the first clip and the shoulder.   
     
     
         9 . The cam follower of  claim 8 , further comprising a first seal extending radially between the first inner ring and the first outer ring, a second seal extending between the first inner ring and the first outer ring, a third seal extending between the second inner ring and the second outer ring, and a fourth seal extending between the second inner ring and the second outer ring proximate to the first clip;
 wherein the second seal and the first seal sealing a first lubricant therebetween and the third seal and the fourth seal sealing a second lubricant therebetween.   
     
     
         10 . The cam follower of  claim 9 , wherein the first clip is disposed at the depth D 1  in a first groove and a second clip is disposed at the depth D 1  in a second groove;
 the first tire having a thickness T 1  and a crown radius R, the crown radius having an apex R′, wherein the first inner ring and the second inner ring, are axially centered with respect to the apex R′, the composition of the tire including at least one of a metallic material, a plastic material, and a non-metallic material, and combinations thereof. 
 
     
     
         11 . The cam follower of  claim 8 , wherein a ratio of the depth D 1  to the tire thickness T 1  is between 0.17 and 0.19. 
     
     
         12 . The cam follower of  claim 8 , wherein a ratio of tire thickness T 1  to the pitch radius PR of at least one of the bearings is between 0.18 and 0.19. 
     
     
         13 . The cam follower of  claim 8 , further comprising a distance R 1  defined between an exterior surface of the first outer ring to the shaft axis A and a distance R 2  defined between the shaft axis A and an interior surface of the tire; wherein the ratio of R 1  to R 2  is between 1.000 and 1.015. 
     
     
         14 . The cam follower of  claim 8 , wherein the shaft includes a hollow portion. 
     
     
         15 . A ram piston for a necker machine comprising a first cam follower of  claim 8  and a second cam follower of  claim 8 . 
     
     
         16 . The ram piston of  claim 15 , wherein the first cam follower has a first duty cycle, a bearing loading capacity being selected based on the first duty cycle. 
     
     
         17 . The ram piston of  claim 15 , wherein the second cam follower has a second duty cycle, a bearing loading capacity being selected based on the second duty cycle. 
     
     
         18 . A cam follower comprising:
 a shaft extending from a first axial shaft end to a second axial shaft end, the shaft having a first groove proximate to the first axial shaft end, a shoulder formed in the shaft between the first groove and the second axial shaft end, and a first clip radially engaged in the first groove;   a first cam follower segment comprising a first tire defining a first interior area and the first cam follower segment having a first ball bearing and a second ball bearing partially disposed in the first interior area;   a second cam follower segment comprising a second tire defining a second interior area, the second cam follower segment having a third ball bearing and a fourth ball bearing partially disposed in the second interior area, and   a spacer disposed on the shaft between the second ball bearing and the third ball bearing;   wherein the first cam follower segment and the a second cam follower segment are axially retained on the shaft by the first clip, the spacer and the shoulder.   
     
     
         19 . The cam follower of  claim 18 , wherein:
 (a) the first tire comprises:
 (i) a first flange extending radially inward from the first tire and located at a first axial tire end of the first tire; 
 (ii) a second groove extending radially outward into the first tire and located at a second axial tire end of the first tire; and 
 (iii) a second clip is engaged in the second groove; and 
   (b) the second tire comprises:
 (i) a second flange extending radially inward from the second tire and located at an third axial tire end of the second tire; 
 (ii) a third groove extending radially outward into the second tire and located at a fourth axial tire end of the second tire; and 
 (iii) a third clip engaged in the third groove. 
   
     
     
         20 . The cam follower of  claim 19 , wherein:
 the first ball bearing has a first inner ring disposed in a first outer ring and has a first plurality of spherical balls disposed between the first inner ring and the first outer ring;   the second ball bearing has a second inner ring disposed in a second outer ring and has a second plurality of spherical balls disposed between the second inner ring and the second outer ring;   the first inner ring axially abuts the second inner ring and the first clip, the first outer ring axially abuts the second outer ring and the first flange, and the second outer ring axially abuts the second clip;   the third ball bearing has a third inner ring disposed in a third outer ring and has a third plurality of spherical balls disposed between the third inner ring and the third outer ring;   the fourth ball bearing has a fourth inner ring disposed in a fourth outer ring and has a fourth plurality of spherical balls disposed between the fourth inner ring and the fourth outer ring;   the third inner ring axially abuts the fourth inner ring, and the fourth inner ring axially abuts the shoulder, the third outer ring axially abuts the second flange and the fourth outer ring, and the fourth outer ring axially abuts the third outer ring; and   the spacer abuts the second inner ring and the third inner ring.   
     
     
         21 . The cam follower of  claim 20 , wherein:
 the first plurality of spherical balls being disposed between a second seal and a first seal, the second seal and the first seal sealing a first lubricant therebetween;   the second plurality of spherical balls being disposed between a third seal and a fourth seal, the third seal and the fourth seal sealing a second lubricant therebetween;   the third plurality of spherical balls being disposed between a sixth seal and a fifth seal, the sixth seal and the fifth seal sealing a third lubricant therebetween; and   the fourth plurality of spherical balls being disposed between a seventh seal and an eighth seal, the seventh seal and the eighth seal sealing a fourth lubricant therebetween.   
     
     
         22 . The cam follower of  claim 20 , wherein the first seal is fixed to the first outer ring, the third seal is fixed to the second outer ring, the fifth seal is fixed to the third outer ring, and the seventh seal is fixed to the fourth outer ring. 
     
     
         23 . The cam follower of  claim 20 , wherein the second seal is fixed to the first outer ring, the fourth seal is fixed to the second outer ring, the sixth seal is fixed to the third outer ring, and eighth seal is fixed to the fourth outer ring. 
     
     
         24 . The cam follower of  claim 20 , wherein the first inner ring, the second inner ring, the spacer, the third inner ring, and the fourth inner ring define an axial stackup.