Composite Gear Structure for High-Torque Lightweight Drill Hammers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing compound gears for electropneumatic rotary hammers face challenges in achieving high stability with low weight, as they are exposed to varying torque levels during operation, which is not effectively addressed by prior technologies.
Innovation Solution
The compound gear features a tooth body made of steel along a first circular arc and a base body made of a lighter material, such as plastic, with the tooth body being securely integrated into the base body, and a balancing weight is used to compensate for imbalances, allowing for a high-stability, low-weight design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the circumferential toothing is reinforced with a heavy material to handle high torque loads, then the strength and durability are improved, but the overall weight of the compound gear increases
Solution Approach 1:
The patent applies local quality by using a steel tooth body only in the specific region where high torque loads occur (first circular arc), while the base body and other regions use lighter plastic material. This localized reinforcement provides necessary strength exactly where needed without unnecessarily increasing overall weight.
Solution Approach 2:
The compound gear combines two different materials - steel for the tooth body and plastic for the base body - to achieve optimal performance. The steel provides high strength for torque transmission, while the plastic reduces overall weight and provides good damping characteristics.
2Reliability
If the tooth body is made of steel to withstand high torque, then the durability is improved, but the manufacturing complexity increases
Solution Approach 1:
The gear is segmented into two distinct components: a steel tooth body and a plastic base body. This segmentation allows each part to be manufactured using the most suitable process for its material and function, then assembled together, simplifying the overall manufacturing approach compared to making an entirely steel gear.
Solution Approach 2:
The patent merges two separately manufactured components (steel tooth body and plastic base body) into a single functional compound gear assembly. The tooth body is inserted into the base body with proper positioning features, creating a durable integrated structure that combines the advantages of both materials.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration results in a compound gear that maintains high stability while minimizing weight, effectively managing torque variations and enhancing the performance of electropneumatic rotary hammers.
Implementation Method 1
the compound gear has a balancing weight (9) to compensate for an imbalance caused by the tooth body (5)
Implementation Method 2
In the radial direction, the tooth body can be held in the base body by frictional engagement, e.g., by press-fitting
Data Source
Figure 1A)~1C)
Figure 2A)~2B)
AI summary
The invention relates to a composite gear for an electropneumatic hammer drill, the composite gear having a main body, which consists of a first material, and having a peripheral toothing, the peripheral toothing being formed, along a first circular arc, by a tooth body of the composite gear and, along the remaining second circular arc, by the main body itself, the tooth body consisting of a second material which is different from the first material.