Planetary Impact Tool Housing for Lightweight Gear Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rotary power tools, such as hydraulic torque wrenches, are bulky and heavy due to their metal construction, making them difficult to manufacture and handle. Additionally, they lack compactness and protection for internal components.
Innovation Solution
The development of a rotary power tool with a compact design that utilizes a resin case for the speed reducing gear part and incorporates a cover for protection. This design includes a motor, pinion, planet gears, internal gear, and an output part, with a bearing held by the internal gear retaining part, and a damper held by the cover for shock absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the outer casing part is formed of metal, then strength and durability are improved, but weight increases and ease of handling deteriorates
Solution Approach 1:
The patent changes the material parameter of the outer casing part from metal to resin, fundamentally altering the weight and strength characteristics. This material substitution directly addresses the contradiction by reducing weight while maintaining sufficient strength through appropriate resin selection and structural design.
Solution Approach 2:
The patent employs composite material construction by integrating the resin outer casing part with internal metal components (such as the planetary gear mechanism and motor housing). This allows the exterior to be lightweight resin while critical internal structures retain metal strength, resolving the weight-strength tradeoff.
2Strength
If the outer casing part is formed of metal, then strength is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent changes the material parameter from metal to resin, which fundamentally improves manufacturability. Resin components can be formed through injection molding into complex shapes in a single process, eliminating the need for metal forming, machining, and assembly operations, thereby significantly simplifying manufacturing while maintaining strength.
Solution Approach 2:
The patent replaces mechanical metal forming and assembly processes with resin molding processes. The outer casing part can be molded as a single integrated component or pre-assembled unit, eliminating multiple machining and fastening operations required for metal construction, thus improving ease of manufacture.
3Volume of moving object
If the small diameter part of the cylinder overlaps the bearing in the circumferential direction, then compactness is improved, but protection of internal components deteriorates
Solution Approach 1:
The patent uses the resin outer casing part as a protective shell that encompasses and protects internal components including the bearing and planetary gear mechanism. The resin material provides shock absorption and protection while allowing the compact overlapping arrangement of components, thus maintaining both compactness and component protection.
Solution Approach 2:
The resin outer casing part serves as a protective cushioning structure that absorbs external shocks before they reach internal components. This beforehand protection allows the bearing and other sensitive components to be positioned in compact overlapping arrangements without compromising their protection from external impacts.
Data Source
AI summary
A rotary power tool, such as an oil pulse driver, includes: a motor, a pinion rotated by the motor, planet gears that mesh with the pinion, an internal gear that meshes with the planet gears and a shaft that is rotationally driven by the planet gears and disposed frontward of the planet gears. The internal gear comprises an internal gear part and an internal gear retaining part for holding the internal gear part. An oil unit bearing is disposed frontward of the internal gear part, and the oil unit bearing is held at a front part of the internal gear retaining part.