Abstract: The present disclosure provides a sleeve for a hydraulic hammer. The sleeve includes an elongated body. The elongated body defines an outer surface, an inner surface, and a plurality of axial conduits to transmit hydraulic fluid. The elongated body further defines a plurality of radial holes extending from the plurality of axial conduits to the inner surface of the elongated body. The elongated body also defines a plurality of circumferential grooves on the inner surface. Each of the plurality of circumferential grooves is located along a longitudinal axis of the sleeve. The elongated body also defines at least one micro channel extending radially to form a fluid connection between each of the plurality of axial conduits and each of the plurality of circumferential grooves to transmit the hydraulic fluid for lubrication on the inner surface of the elongated body.

Abstract: A hydraulic hammer assembly is disclosed. The hydraulic hammer assembly includes a piston and an accumulator membrane disposed external and coaxial to the piston The hydraulic hammer assembly includes a sleeve disposed coaxially between the piston and the accumulator membrane. The sleeve defines a first set of holes in an outer surface thereof to receive hydraulic fluid. The sleeve defines a second set of holes in an inner surface thereof and located distant from the first set of holes along a longitudinal axis of the sleeve. The sleeve defines a plurality of passages within a wall, and extending along the longitudinal axis. Each of the plurality of passages includes a porous medium to increase surface area of each of the plurality of passages. The increased surface area of each of the plurality of passages increases a rate of dissipation of heat from the wall of the sleeve.