US 12,325,116 B1
Greaseless hydraulic hammer
Cody Moore, Robinson, TX (US); Curtis A. Henning, Dunlap, IL (US); and John Kevin Clemons, Wamego, KS (US)
Assigned to Caterpillar Inc., Peoria, IL (US)
Filed by Caterpillar Inc., Peoria, IL (US)
Filed on May 8, 2024, as Appl. No. 18/657,919.
Int. Cl. B25D 17/08 (2006.01); B25D 17/02 (2006.01); E02F 3/96 (2006.01)
CPC B25D 17/08 (2013.01) [B25D 17/02 (2013.01); B25D 2250/111 (2013.01); B25D 2250/125 (2013.01); E02F 3/966 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A hydraulic hammer comprising:
a housing defining a chamber extending along a longitudinal axis configured to receive a tool;
a plurality of splines disposed on an inner surface of the chamber, the plurality of splines extending parallel to the longitudinal axis, each of the plurality of splines having a contact surface configured to slidably guide the tool when disposed within the chamber;
a treated layer applied to the contact surface of each of the plurality of splines, the treated layer configured to withstand approximately between 100 MPa to 320 MPa of pressure applied during an operation of the hydraulic hammer without galling; and
wherein an interface is defined between the contact surface of each of the plurality of splines and a surface of the tool and is configured to facilitate sliding engagement between the contact surface of each of the plurality of splines and the surface of the tool without lubricant during the operation of the hydraulic hammer.