Gearbox Overload Clutch Spring Positioning

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Solution Overview

Problem

Existing transmission devices for hammer drills and chisel hammers lack a compact and cost-effective overload clutch design that efficiently manages torque transmission and provides additional installation space for switching between different transmission stages.

Innovation Solution

A transmission device with a spring element positioned ahead of the gear unit along the force flow direction, featuring a one-piece gear unit and force transmission element with a trapezoidal end profile, and a latching element arranged in a rotationally fixed manner, allowing for a structurally simple and space-saving overload clutch with multiple torque transmission areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the gear unit is arranged along the force flow direction on the output means in front of the spring element and locking element, then the transmission device achieves a compact and space-saving design, but the gear unit requires additional support structures and components

Engineering Contradiction:
Improvetransmission device sizeVSAvoidoverload clutch structure
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The gear unit is merged with the force transmission element into a one-piece structure. This integration eliminates the need for separate support structures and reduces the number of components, thereby achieving a compact design while simplifying the overall structure of the overload clutch.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The gear unit serves multiple functions: it transmits torque, provides structural support, and integrates with the force transmission element. This multi-functionality reduces the need for additional components and contributes to the compact design of the transmission device.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If the gear unit is arranged along the force flow direction on the output means in front of the locking element, then a structurally simple and component-saving overload clutch is achieved, but the gear unit requires direct support against the locking element

Engineering Contradiction:
Improveoverload clutch structureVSAvoidtorque transmission
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

The gear unit is directly coupled with the locking element through the force transmission element, merging their functions. This direct coupling simplifies the structure by eliminating intermediate components while maintaining effective torque transmission through the integrated force flow path.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If the gear unit has at least two torque transmission areas for transmitting different drive speeds, then additional installation space for switching between transmission stages is required, but the patent aims to save installation space

Engineering Contradiction:
Improvetorque transmission capabilityVSAvoidinstallation space
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The gear unit is designed with multiple torque transmission areas that can transmit different drive speeds, making it a multi-functional component. This eliminates the need for separate transmission stages and switching mechanisms, thereby saving installation space while maintaining adaptability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The gear unit is segmented into multiple torque transmission areas, each capable of transmitting different drive speeds. This segmentation allows the single gear unit to perform the function of multiple transmission stages without requiring additional space for switching mechanisms.

Inventive Principle:
Principle #1Segmentation

4Ease of manufacture

If the gear unit is formed as a sintered component, then production costs are reduced and post-processing is minimized, but the manufacturing precision may be limited

Engineering Contradiction:
Improveproduction costVSAvoidgear unit precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The gear unit is manufactured using a sintering process, which changes the manufacturing parameters to achieve cost-effective production. The sintering process allows for complex geometries to be produced directly without extensive post-processing, balancing manufacturing precision with cost efficiency.

Inventive Principle:
Principle #35Parameter changes

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 compact, cost-effective, and efficient torque transmission system that saves installation space, assembly effort, and costs while enabling switching between different torques, ensuring reliable operation by defining a maximum torque transferable to tools or objects.

Implementation Method 1

The overload clutch has a spring element, a gear unit and a latching element

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP2132453B1Gearbox device
Publication Date: 2011.11.02 ROBERT BOSCH GMBH
  • EP2132453B1 patent drawingFigure 1
  • EP2132453B1 patent drawingFigure 2
  • EP2132453B1 patent drawingFigure 3

AI summary

The invention relates to a gearbox device, in particular for a hammer drill or chisel, comprising a drive means (12) and an overload clutch (14), arranged on the drive means (12), comprising a spring element (16), a toothed gear unit (18) and a locking element (20). According to the invention, the spring element (16) is arranged along a force flow direction (22) of the drive means (12) on the drive means (12) before the toothed gear unit (18) and the locking element (20).