A spray dust compression system and method includes a nozzle holder for affixing a spray nozzle to a percussive tool. The nozzle holder includes an arcuate wall having a first surface engageable with the percussive tool, and a second surface opposing the first surface. A protruding body protrudes radially outwardly from the second surface relative to a longitudinal axis of the arcuate wall and a concave recess is formed in the protruding body and receives the spray nozzle. The concave recess is angled inwardly toward the longitudinal axis of the arcuate wall.

A power tool has a motor, a rotary shaft and a housing. The rotary shaft has a first end portion on a first direction side and a second end portion on a second direction side in an axial direction of the rotary shaft. The housing is configured to store a lubricant on the first direction side of the first end portion of the rotary shaft. The rotary shaft has a first hole and a second hole. The first hole extends in the axial direction and that has a first opening in the first end portion of the rotary shaft. The second hole extends in a direction crossing an axis of the rotary shaft, that communicates with the first hole. The second hole has a second opening in an outer peripheral surface of the rotary shaft. A spiral part is provided within the first hole.

A tool bushing of a breaking hammer, a tool bushing arrangement, a breaking hammer and a method of mounting a tool bushing of a breaking hammer are disclosed. The tool bushing is a sleeve-like piece having a multi-shouldered outer surface with three or more successive cylindrical portions. The cylindrical portions have different diameters that match with corresponding surfaces of a bushing housing when the tool bushing is mounted. Diameters of the bushing and the bushing housing are dimensioned so that friction forces are generated when the bushing is assembled.

A hammer drill is provided including a housing, a motor mounted within the housing, and a hammer mechanism. The hammer mechanism includes a crank plate or a wobble plate driven by the motor, a con rod coupled to the crank plate or the wobble plate, a piston reciprocatingly driven by the con rod along a longitudinal axis, a ram and a beat piece. At least one of the wobble plate or the con rod is made of sintered steel.

A tool includes a housing, a drive assembly including an output shaft extending from the housing such that a tool element for performing work on a workpiece is attachable to the output shaft, and a bushing disposed within the housing. The bushing rotatably supports the output shaft. The bushing is impregnated with lubricant such that the bushing is self-lubricating, and the bushing has an impregnation ratio between about 5% and about 25%.

A lubrication system for a hydraulic hammer includes a body defining a recess in fluid communication with a lubricant inlet and a lubricant outlet. A sleeve, located co-axially within the recess, defines a stepped tubular cavity having first and second portions. The sleeve also defines inlet and outlet ports extending from an outer surface to an inner surface of the sleeve. A piston, located partly within the recess and the first portion of the stepped tubular cavity respectively, has a tubular cavity co-axial with the stepped tubular cavity. A spool is located partly within the tubular cavity and the second portion of the stepped tubular cavity respectively. The spool co-operates with the inlet and outlet ports of the sleeve for reciprocally moving the piston in relation to the body so that lubricant from the lubricant inlet is delivered by the piston to the lubricant outlet via the recess.

A piston for a hammer drill is a flat piston made from sintered steel. The piston can be impregnated with a lubricant.

A power tool includes a housing having a motor housing portion and a front casing coupled to the motor housing portion. The power tool also includes an electric motor positioned within the motor housing portion, a drive assembly having an output shaft to which a tool element for performing work on a workpiece is attachable, and a powdered metal bushing disposed within the front casing that rotatably supports the output shaft.

A power tool has a motor, a rotary shaft and a housing. The rotary shaft has a first end portion on a first direction side and a second end portion on a second direction side in an axial direction of the rotary shaft. The housing is configured to store a lubricant on the first direction side of the first end portion of the rotary shaft. The rotary shaft has a first hole and a second hole. The first hole extends in the axial direction and that has a first opening in the first end portion of the rotary shaft. The second hole extends in a direction crossing an axis of the rotary shaft, that communicates with the first hole. The second hole has a second opening in an outer peripheral surface of the rotary shaft. A spiral part is provided within the first hole.

A main shaft of a power tool is sequentially divided into an impact section, a penetrative section and an output section, wherein the impact section is formed with an impact portion and has a curved recess defined therein, and the penetrative section is adapted to extend through a front portion of the power tool. The main shaft has a linear tunnel defined therein and extending therethrough. The linear tunnel has two opposite ends respectively defined as an inlet and an outlet, wherein the inlet is situated in the output section and the outlet is adapted to correspond to an impact block of an impact device of the power tool. An axis of the linear tunnel is formed an included angle with an axis of the main shaft.