US 7,320,240 B2
Oil grooves formed in a race
Jack E. Pederson, Saline, Mich. (US)
Assigned to GKN Sinter Metals, Auburn, Mich. (US)
Filed on Sep. 13, 2005, as Appl. No. 11/225,696.
Claims priority of provisional application 60/609502, filed on Sep. 13, 2004.
Prior Publication US 2006/0162416 A1, Jul. 27, 2006
Int. Cl. B21J 13/02 (2006.01)
U.S. Cl. 72—355.6  [72/355.2; 72/416; 72/471] 24 Claims
OG exemplary drawing
 
1. A method for forming an oil groove in a face surface of a race, including the steps of:
a) providing the race preform comprising an outer diametral surface and opposing first and second faces extending radially inwardly from the outer diametral surface;
b) providing a die assembly comprising:
a die including a circumferential sidewall and an inwardly extending, arcuate lower chamfer tool formed on a lower portion of said die for forming a chamfer between an outer diametral surface and a lower face of the race preform, the lower chamfer tool including gaps in its circumference such that the lower chamfer tool is discontinuous;
a lower punch including oil groove tools extending upwardly thereon for forming oil grooves in the second face of the race and teeth extending radially outwardly and insertable into the gaps in the lower chamfer tool; and
an upper punch disposed opposite said lower punch.
c) disposing the race preform in said die assembly between said upper punch and said lower punch; and
d) forging the race preform in the die between the punches such that oil grooves are formed in the second face of the race.