Variable Pitch Punch Apparatus for Stator Core Hole Patterns
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hole-punching processes for materials like steel are time-consuming and complex, especially when forming irregular patterns, due to the need for precise measurement and adjustment of hole spacing and material position.
Innovation Solution
A variable pitch punch apparatus with a rotary punch head and die head system that allows for selective speed differences between the punch head and material through varying the rotary speed and feed rate, using a punch shaft with non-contacting peripheral portions and low friction coatings or bearings to achieve relative motion and control hole spacing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional stamping roller assembly with fixed pitch is used, then manufacturing precision is maintained, but productivity is reduced due to repeated stopping and positioning
Solution Approach 1:
The punch shaft is designed with variable radius peripheral portions that dynamically change the spacing between punch members during rotation. This allows the apparatus to transition from fixed pitch to variable pitch operation, enabling continuous punching without stopping and repositioning, thereby significantly improving productivity while managing device complexity through a geometrically variable rather than mechanically complex solution.
Solution Approach 2:
The invention changes the geometric parameter of the punch shaft from a constant radius to a variable radius along the peripheral portions. This parameter change allows the distance between adjacent punch members to vary during rotation, enabling different hole spacings to be produced by a single rotating apparatus, thus improving productivity without requiring multiple fixed-pitch apparatuses.
2Manufacturing precision
If material feed is stopped for each hole punching, then manufacturing precision is ensured, but loss of time increases
Solution Approach 1:
The variable pitch punch shaft enables continuous punching action by varying the pitch during rotation. The material can feed continuously while the punch shaft rotates, with the variable radius peripheral portions automatically adjusting the effective pitch between punches. This eliminates the need to stop and reposition the material for each hole, maintaining manufacturing precision through controlled variable spacing while dramatically reducing the time lost to repeated stopping and starting.
3Adaptability or versatility
If fixed pitch punch members are used, then device complexity is minimized, but adaptability is reduced for irregular patterns
Solution Approach 1:
The punch shaft incorporates local quality variation through peripheral portions with different radii at different locations. Each peripheral portion can have a specific radius that determines the spacing for that particular punch member. This allows different sections of the punch shaft to have different effective pitches, enabling the creation of irregular patterns and diverse hole spacings with a single apparatus, thereby improving adaptability without requiring multiple specialized fixed-pitch devices.
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
Enables efficient and flexible hole punching with variable spacing, reducing the complexity and time required for producing regular or irregular patterns in materials, such as laminated steel stator cores for axial-flux machines.
Implementation Method 1
The punch shaft may further comprise a coating of at least one low friction material. At least one peripheral portion of the punch shaft preferably comprises at least one rotating bearing element arranged to contact the material. The presence of a coating of at least one low friction material and/or rotating bearing element(s) on the peripheral portion(s) of the punch shaft which are arranged to come into contact with the material enables relative motion, for example slipping motion, to be provided between the punch head, in particular the punch shaft, and the material to be punched.
Data Source
Figure 1
Figure 2
AI summary
A variable pitch punch apparatus (1) for punching holes in material. The apparatus comprises a rotary punch head (2) comprising at least one punch member (4a-c) to punch at least one hole in a material at least one desired location. The apparatus (1) further comprises a die head (6) comprising at least one die (7) corresponding to said punch member (4a-c). The apparatus (1) further comprises an actuator for providing a selective relative speed difference between the material and the rotary punch head (2).