Internal Gear Grinding Machine Dressing Mechanism

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Solution Overview

Problem

Conventional internal gear grinding machines face challenges in simplifying the dressing operation of barrel-shaped threaded grinding wheels, leading to increased machine size and risk of tool damage during abnormal situations like power outages.

Innovation Solution

An internal gear grinding machine with a disk-shaped dresser that is rotatable and equipped with a direct-drive motor and a braking mechanism, allowing for precise dressing and maintaining the dresser position, even during power shutdowns, to prevent damage and reduce machine size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a conventional dressing device is provided in an internal gear grinding machine, then the threaded grinding wheel can be dressed, but the dressing operation becomes complex and the machine size increases

Engineering Contradiction:
Improvedressing operation simplicityVSAvoiddressing device complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

Instead of moving the dresser to follow the threaded grinding wheel during dressing (conventional approach), the invention inverts the approach by making the threaded grinding wheel rotate on its own axis while the dresser remains stationary. This inversion simplifies the dressing device structure and operation while maintaining effective dressing capability.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The threaded grinding wheel serves dual functions: it performs grinding during normal operation and rotates on its own axis during dressing to present different thread faces to the stationary dresser. This multi-functionality eliminates the need for complex dressing device movements.

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

2Ease of manufacture

If the threaded grinding wheel and dresser mesh during dressing, then dressing can be performed, but tool damage may occur during abnormal situations like power outages

Engineering Contradiction:
Improvedressing capabilityVSAvoidtool damage prevention
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The threaded grinding wheel is rotated on its own axis before dressing begins, and this rotation is maintained throughout the dressing process. This preliminary and continuous rotation ensures that the wheel is not stationary during dressing, preventing damage if power is lost during the operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The threaded grinding wheel dresses itself by rotating on its own axis, presenting different thread faces to the stationary dresser. This self-service mechanism eliminates the need for complex coordinated movements between the wheel and dresser, reducing the risk of damage during abnormal conditions.

Inventive Principle:
Principle #25Self-service

3Volume of stationary object

If the machine size is reduced by simplifying the dressing device, then space is saved, but the dresser must maintain precise position during rotation

Engineering Contradiction:
Improvemachine sizeVSAvoiddresser position precision
Core Design Contradiction:
Volume of stationary objectVSManufacturing precision

Solution Approach 1:

The invention inverts the conventional approach by making the threaded grinding wheel rotate instead of moving the dresser. This allows the dresser to remain stationary with simple positioning requirements, significantly reducing machine size while maintaining dressing precision through the rotation of the grinding wheel itself.

Inventive Principle:
Principle #13The other way round (Inversion)

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

The solution simplifies the dressing operation, reduces machine size, and prevents tool damage during abnormal conditions by ensuring the dresser remains in a stable position, enhancing operational safety and efficiency.

Implementation Method 1

braking means for applying a braking force to the dresser turning means, and maintaining the dresser at a turned position

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2377648B1Internal gear grinding machine
Publication Date: 2018.10.24 MITSUBISHI HEAVY IND MACHINE TOOL CO LTD
  • EP2377648B1 patent drawingFigure 1
  • EP2377648B1 patent drawingFigure 2
  • EP2377648B1 patent drawingFigure 3

AI summary

An object is to provide an internal gear grinding machine which makes it possible to achieve space savings and reduce the size of a machine, as well as to prevent the tools from being damaged even when an abnormal situation such as a blackout occurs, by simplifying dressing operation. To achieve the object, an internal gear grinding machine for use in grinding a workpiece (W) by synchronously rotating the workpiece (W) and a barrel-shaped threaded grinding wheel (17) in mesh with each other includes a dressing device (20) for dressing the threaded tool (17) by meshing the threaded grinding wheel (17) with a disk dresser (56). At the time of dressing, the threaded grinding wheel (17) and the disc dresser (56) are operated in accordance with the helix angle and barrel shape of the threaded grinding wheel (17), and the brake mechanism (58) applies a braking force to a dresser turn drive motor (53) to enable the disc dresser (56) to be maintained at a turned position thereof.