Linear Actuator Assembly with External Bearing and Brake
Solution Overview
Problem
Existing test machines face challenges in accurately and efficiently positioning and moving an armature within a stator housing due to magnetic interactions, leading to misalignment and potential wear, and require effective heat dissipation and braking mechanisms to maintain precision and control during testing.
Innovation Solution
An electric linear displacement motor with a stator assembly, armature, bearing, and brake assembly, where the armature is supported by end portions that engage bearings outside the magnetic field, and a cooling system with fins and fans to manage heat, along with an anti-rotation mechanism to prevent unwanted movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the armature is positioned within the magnetic field of the stator, then the motor can generate linear motion through magnetic interaction, but magnetic interference causes misalignment and wear of the armature
Solution Approach 1:
The motor is divided into two distinct zones: a magnetic field generation zone with stator coils and magnets for power generation, and a separate bearing support zone where bearings are positioned outside the magnetic field to support the armature without magnetic interference. This segmentation allows the armature to be supported in a non-magnetic environment while still enabling magnetic interaction for motion generation in the active zone.
Solution Approach 2:
Bearings are introduced as intermediary components that are strategically positioned outside the magnetic field boundary. These bearings act as mediators between the armature and the external environment, providing mechanical support and reducing wear without being subjected to magnetic forces that would cause misalignment and degradation.
2Measurement precision
If conventional braking mechanisms are used to control armature movement, then positioning control is improved, but the moving mass of the armature increases reducing responsiveness
Solution Approach 1:
The brake assembly is extracted from the armature structure and positioned as a separate stationary component. The braking force is applied through a stationary brake pad that contacts the moving armature, allowing the armature to maintain minimal mass while still achieving effective positioning control through the external braking mechanism.
Solution Approach 2:
Instead of attaching the brake to the moving armature (which would increase its mass), the brake is inverted to be a stationary component that applies force to the moving armature. This reverses the traditional approach where the braking mechanism moves with the load, thereby reducing the moving mass while maintaining positioning control.
3Ease of operation
If the brake assembly is attached to the armature, then braking control is achieved, but the moving mass increases affecting system responsiveness
Solution Approach 1:
The brake assembly is extracted from the moving armature and repositioned as a stationary component mounted to the stator housing. This extraction removes the brake mass from the moving components while maintaining the ability to apply braking force to the armature during operation, thereby preserving control capability without sacrificing responsiveness.
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 enables precise, efficient, and controlled linear movement of the armature, reduces wear, and maintains testing accuracy by minimizing magnetic interference and heat generation, while ensuring stability and responsiveness.
Implementation Method 1
a plurality of coils within the stator housing. An armature is positioned within the stator and having a first end and a second end and wherein the armature includes a plurality of magnets along a length of the armature and moves along a longitudinal axis
Implementation Method 2
A bearing assembly is attached to the first end of the stator housing. The bearing assembly comprises a bearing housing configured to be attached to the first end of the stator housing and a bearing positioned within the bearing housing and wherein the first end portion of the armature engages and is carried by the bearing
Implementation Method 3
A brake assembly is coupled to the first end of the armature and the bearing housing. The brake assembly comprises a moving portion coupled to the armature and a non-moving portion coupled to the bearing housing
Implementation Method 4
a cooling system with fins and fans to manage heat
Data Source
AI summary
An electric linear displacement motor for use in a testing apparatus includes a stator assembly having a stator housing and a plurality of coils within the stator housing. An armature is positioned within the stator housing and includes a plurality of magnets along a length of the armature. A bearing assembly is attached to the first end of the stator housing and includes a bearing housing containing a bearing. A first end portion of the armature engages and is carried by the bearing. A brake assembly is coupled to the first end of the armature and the bearing housing. The brake assembly includes a moving portion coupled to the armature and a non-moving portion coupled to the bearing housing wherein the moving portion has less mass than the non-moving portion and therefore reduces the moving mass of the armature.