Stamping Press Drive Unit Drag Crank Torque Mechanism

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Solution Overview

Problem

Existing direct drive units for automatic stamping machines require large, expensive, and energy-inefficient electric motors to achieve high torque, limiting their compactness and maintenance accessibility.

Innovation Solution

A drive unit with a drag crank mechanism arranged between the rotor and output shaft, allowing for a more compact motor design and adjustable torque through varying drag crank geometry, using a segment motor or servomotor with a rotatable rotor and stator, and an eccentric connecting rod for efficient power transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a direct drive with large diameter rotor is used to generate high torque, then the torque requirement is met, but the motor size and cost increase significantly

Engineering Contradiction:
ImprovetorqueVSAvoidmotor diameter
Core Design Contradiction:
ForceVSVolume of moving object

Solution Approach 1:

A drag crank mechanism is introduced as an intermediary between the rotor and the output shaft. The drag crank converts the rotational motion of the rotor into the required motion profile for the output shaft, allowing the rotor to operate at lower torque requirements while achieving the same output torque through mechanical leverage.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the motion parameters by introducing a drag crank that transforms the direct rotational output into a controlled reciprocating or oscillating motion. This parameter transformation allows the motor to operate in a more efficient torque-speed range, reducing the required motor diameter for the same effective output.

Inventive Principle:
Principle #35Parameter changes

2Force

If a direct drive with large diameter rotor is used to generate high torque, then the torque requirement is met, but the energy efficiency decreases

Engineering Contradiction:
ImprovetorqueVSAvoidelectrical connected load
Core Design Contradiction:
ForceVSUse of energy by moving object

Solution Approach 1:

The drag crank acts as a mechanical multiplier that allows the motor to deliver the same effective torque with lower electrical power consumption. By transforming the motion through the drag crank mechanism, the system achieves better matching between motor output characteristics and load requirements, improving overall energy efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The drag crank mechanism changes the torque-speed characteristics of the drive system, allowing the motor to operate in a more efficient region of its performance curve. The mechanical transformation enables the motor to deliver required torque with reduced electrical connected load.

Inventive Principle:
Principle #35Parameter changes

3Force

If a direct drive with large diameter rotor is used to generate high torque, then the torque requirement is met, but the motor becomes less compact and harder to maintain

Engineering Contradiction:
ImprovetorqueVSAvoidmaintenance accessibility
Core Design Contradiction:
ForceVSEase of repair

Solution Approach 1:

The drag crank mechanism serves as a compact intermediary that enables torque multiplication without requiring a large motor diameter. This intermediate mechanism allows the motor to be positioned and sized more favorably for maintenance access, while still achieving the required output torque through the mechanical advantage provided by the drag crank.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 a more compact, cost-effective, and energy-efficient motor with adjustable torque capabilities, facilitating easier maintenance and adaptable torque profiles without the need for additional gears.

Implementation Method 1

an electric motor (17) with a stator (4) and a rotor (6), which are arranged concentrically to one another, the stator (4) being non-rotatably connected to the press head piece (16) and by means of which the rotor (6) can be rotated

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentEP2497632B1Drive unit for a automatic stamping machine or a press
Publication Date: 2018.09.19 ANDRITZ TECH & ASSET MANAGEMENT GMBH
  • EP2497632B1 patent drawingFigure 1~2
  • EP2497632B1 patent drawingFigure 3

AI summary

The subject matter of this invention is a drive unit for a stamping press or a press for moving a ram, comprising at least one electric motor (17) having a stator (4) and a rotor (6) arranged concentrically to each other, wherein the stator (4) is rotationally fixed to the press frame (1) and an output shaft (8) for moving the ram can be driven by the rotor (6). According to the invention, a pull-crank (5) is arranged between the rotor (6) and the output shaft (8).