The hydraulic rotary-percussive hammer drill includes a fluid injection portion including a fluid feed-in inlet and an annular inner groove fluidly connected to the fluid feed-in inlet; a shank including a fluid injection conduit fluidly connected to the annular inner groove; front and rear main sealing gaskets disposed on either side of the annular inner groove and configured to cooperate with a first shank portion of the shank; a rear backup sealing gasket located at the rear of the rear main sealing gasket and configured to cooperate with a second shank portion of the shank; a leakage passage defined between the shank and the fluid injection portion; pressure drop generation means configured to generate pressure drops in the leakage passage when a leakage flow flows in the leakage passage.

A tool for a hydraulic hammer of a work machine is disclosed herein. The tool comprises a spline section and a tool section. The spline section includes a first spline sector including at least six spline grooves and a second spline sector including at least six spline grooves. The first spline sector and second spline sector are separated by a spacer. The tool section diameter is 3.2-4.8 times larger than the spline groove diameter and the tool section diameter is smaller than a spline section diameter.

An inner-flanged bushing for a hydraulic breaker is a tubular shape having an inner flange and is made of a steel containing at least 0.55% and less than 0.70% by mass of carbon, at least 0.15% and less than 0.35% by mass of silicon, at least 0.4% and less than 0.9% by mass of manganese, at least 0.4% and less than 1.3% by mass of chromium, and at least 0.10% and less than 0.55% by mass of molybdenum, with the balance being iron and unavoidable impurities. The bushing includes a base region having a hardness of at least 30 HRC and less than 45 HRC, and a quench hardened layer formed on an inner periphery side of the base region to include an inner peripheral surface of a region including the inner flange, the quench hardened layer having a hardness of at least 55 HRC and less than 63 HRC.

A hydraulic, pneumatic, gasoline, diesel, or electric tool may include a spindle that is adapted for rotational movement. A swing arm may be coupled to the spindle such that rotational motion of the spindle is transferred to the swing arm. The swing arm makes contact with a piston such that the rotational motion causes the piston to move along a linear path. The piston may interact with an energy storage medium when the swing arm moves the piston in the first direction, causing energy to be stored in the energy storage medium. As the swing arm continues to rotate, the swing arm may lose contact with the piston, thus allowing the energy storage medium to urge the piston in a second direction opposite the first direction to strike an anvil. The swing arm may be a multiple roller swing arm. The energy storage medium may be a compound spring assembly.

This percussion apparatus includes a striking piston mounted so as to be displaced inside a piston cylinder and arranged to strike a tool; and a guide bearing comprising a guide surface configured to guide the striking piston during the displacements of the striking piston in the piston cylinder. The guide bearing includes a centering device configured to center the striking piston in the piston cylinder, the centering device comprising centering chambers formed in the guide surface and distributed around the striking piston, each centering chamber being fluidly connected to a high pressure fluid supply circuit; and at least one discharge groove formed in the guide surface of the guide bearing and located proximate to at least one of the centering chambers, the at least one discharge groove being fluidly connected to a low pressure circuit.

A method of retaining a hammer tool in the front head of a powercell assembly of a hammer assembly includes biasing a hammer tool retaining pin such that a portion of the tool retaining pin extends into a tool receiving bore of the front head of the powercell assembly, holding a hammer tool in the tool receiving bore of the front head of the powercell assembly via the tool retaining pin, and releasing the hammer tool remotely from the hammer assembly.

A hydraulic hammer assembly is provided. The hydraulic hammer assembly includes a housing and a piston is arranged for reciprocating movement along a longitudinal axis within the housing. A head disposed along the longitudinal axis on an end of the housing and defines a chamber for holding a pressurized gas. The hydraulic hammer assembly further includes a locking mechanism to lock the head on the housing. The locking mechanism includes at least one first flange extending radially from the end of the housing and at least one second flange extending radially from the head, wherein the head is retained on the housing by blocking axial movement of the second flange against the first flange when in a locked position.

An impact tool includes a housing having a handle portion defining a first axis, a motor supported by the housing, and a rotary impact mechanism arranged on the first axis and configured to receive torque from the motor, the rotary impact mechanism configured to convert a continuous rotational input from the motor to consecutive rotational impacts upon a workpiece. The rotary impact mechanism includes a chamber containing a hydraulic fluid, an anvil positioned at least partially within the chamber, and a hammer for imparting the consecutive rotational impacts upon the anvil, the hydraulic fluid configured to attenuate a noise of the rotary impact mechanism that is created by the hammer impacting the anvil. An output member for receiving torque from the rotary impact mechanism is arranged on a second axis that is perpendicular to the first axis.

Provided is a hydraulic striking device in which a reverse operation circuit and a forward operation circuit can switch connection states to a high pressure circuit and a low pressure circuit by means of an operation switching valve. Further, the hydraulic striking device is configured to be selectable between a reverse operation mode or a forward operation mode by operating the operation switching valve. A high/low pressure switching portion is provided with a shortening portion for reducing the time required for high/low pressure switching operation in piston front and rear chambers in association with retraction of a valve to be shorter than the time required for high/low pressure switching operation in the piston front and rear chambers in association with advancement of the valve.

A lubrication system including a drive fluid chamber and a lubricant chamber. A first movable member is movable from a first position to a second position within the drive fluid chamber in response to drive fluid pressure acting on the first movable member. A second movable member is movable between a first position and a second position within the lubricant chamber and is operatively coupled to the first movable member. A biasing member is positioned to bias the first movable member toward the first position. A relief valve is associated with the first movable member and, when the relief valve in an open state, the drive fluid pressure acting on the first movable member is reduced such that the biasing member moves the first movable member to the first position within the drive fluid chamber.