Force Transmission Arrangement for Thermal Expansion Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The miniaturization of electronic circuits increases the demand for accurate component placement and viscous medium application, but powerful linear motors generate excess heat, causing thermal expansions and deformations that compromise positioning accuracy in circuit board manufacturing.
Innovation Solution
A positioning system with a force transmission arrangement that provides a semi-rigid engagement between the moving motor member and the positioning unit, allowing for direct linear force transmission while compensating for thermal deformations by being resilient in directions other than the linear motion direction, ensuring accurate and fast positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If more powerful linear motors are provided closer to the work head to increase positioning accuracy and speed, then positioning accuracy and manufacturing speed are improved, but thermal expansion and deformation increase which deteriorates positioning accuracy
Solution Approach 1:
The force transmission arrangement is divided into multiple segments or zones with different rigidity characteristics. The engagement structure includes rigid portions for force transmission and resilient portions for thermal compensation, allowing different parts of the same component to serve different functions simultaneously.
Solution Approach 2:
The engagement between the force transmission arrangement and the positioning unit is designed to be rigid in the direction parallel to the axis for force transmission, but resilient in directions other than the axis to accommodate thermal expansion. This local differentiation of mechanical properties allows simultaneous achievement of force transmission efficiency and thermal compensation.
2Measurement precision
If more powerful linear motors are provided closer to the work head to reduce motion transmission influence, then positioning accuracy is improved, but heat generation increases causing thermal deformation
Solution Approach 1:
The force transmission arrangement is designed to utilize the thermal expansion of the motor as a beneficial effect. The resilient engagement allows the motor to expand thermally while maintaining rigid force transmission in the axial direction, converting the harmful thermal effect into a manageable mechanical accommodation.
Solution Approach 2:
The force transmission arrangement acts as an intermediary between the linear motor and the positioning unit. It mediates the thermal expansion forces by providing a resilient engagement that absorbs thermal deformations while transmitting linear forces efficiently, protecting the positioning unit from direct thermal effects.
3Force
If a rigid engagement is used for instantaneous force transmission, then linear force transmission is improved, but thermal expansion forces create stress and deformation
Solution Approach 1:
The mechanical properties of the engagement are changed based on direction. The engagement exhibits rigid characteristics (high stiffness) in the direction parallel to the axis for force transmission, but resilient characteristics (low stiffness) in directions perpendicular to the axis for thermal compensation. This anisotropic mechanical behavior resolves the contradiction between force transmission and stress reduction.
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 solution maintains high operational accuracy and speed by reducing or eliminating the detrimental effects of thermal expansions on the positioning unit, ensuring precise linear motion and reducing stress-related errors.
Implementation Method 1
The engagement is rigid in a direction parallel to said axis for instantaneous transmission of a linear force
Implementation Method 2
forces arising from thermal expansion of the motor is reduced or eliminated
Implementation Method 3
The engagement is resilient in directions other than said direction parallel to said axis
Implementation Method 4
electric current flows back and forth through the electric circuit coils surrounding the cores, thereby generating heat which may result in thermal expansion of the moving motor member
Data Source
Figure 1
Figure 2
Figure 3
AI summary
This invention relates to a positioning system for positioning a positioning unit along a longitudinal axis. The positioning system comprises a linear guide arrangement for enabling a linearly guided motion parallel to said axis, wherein the positioning unit is operatively connected to said guide arrangement. Furthermore, the positioning system comprises a motor, wherein the motor comprises a moving motor member operatively connected to said linear guide arrangement and an elongated stationary motor member extending parallel to said axis. The moving motor member is adapted to move along the stationary motor member for providing motion parallel to said axis. Moreover, the positioning system further comprises a force transmission arrangement which operatively connects said moving motor member to the positioning unit. The force transmission arrangement is arranged to provide an engagement between said positioning unit and said moving motor. The engagement is rigid in a direction parallel to said axis for instantaneous transmission of a linear force, and is resilient in directions other than said direction parallel to said axis, whereby transmission to the positioning unit of forces arising from thermal expansion of the motor is reduced or eliminated.