Lubricant-impregnated bushing for impact tool
AssigneeMilwaukee Electric Tool Corporation
InventorsPeter Malak, Michael R. Sande, Ryan Allen Dedrickson, Guang Hu, Fan Bin Zeng, Wei Chao Xu, Qiao Cai
Life of this patent
Estimating the term…
Abstract
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.
Claims20
A power tool comprising:
- a housing including a motor housing portion and a front casing coupled to the motor housing portion;
- an electric motor positioned within the motor housing portion;
- a drive assembly including 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, the bushing rotatably supporting the output shaft,
- wherein the bushing is impregnated with lubricant such that the bushing is self-lubricating, and
- wherein the bushing has an impregnation ratio between about 5% and about 25%.
An impact tool comprising:
- a housing including a motor housing portion and a front casing coupled to the motor housing portion;
- an electric motor positioned within the motor housing portion;
- a drive assembly including
- an anvil,
- a shaft configured to receive torque from the electric motor, and
- a hammer configured to impart consecutive rotational impacts upon the anvil;
- and
- a lubricant-impregnated bushing disposed within the front casing, the bushing rotatably supporting the anvil,
- wherein the bushing gradually releases lubricant over time during ordinary operation of the impact tool.
A method of manufacturing a power tool, the method comprising:
- forming a bushing from powdered metal by compacting and sintering the powdered metal;
- inserting the bushing into a mold cavity;
- molding a gear case of the power tool in the mold cavity around the bushing;
- and
- immersing the gear case in lubricant such that the lubricant is wicked into the bushing to impregnate the bushing with the lubricant.
Dependencies are inferred from the claim text.