Cluster Block Positioning in Motor-Driven Compressor Shrink Fit
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Solution Overview
Problem
In conventional motor-driven compressors, the cluster block engaged with the stator core can move and incline during assembly by shrink fit, leading to thermal deformation and improper connection with the conductor, limiting positional and orientational adjustment.
Innovation Solution
An assembly jig with projections that fit into recesses of the cluster block restricts its movement relative to the stator core, ensuring proper alignment and preventing contact with the heated motor housing during assembly, thereby maintaining the cluster block's position and orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the cluster block is allowed to move and incline relative to the stator core during assembly, then it is easier to connect between the cluster block and the conductor, but the cluster block may come into contact with the heated motor housing causing thermal deformation
Solution Approach 1:
The patent introduces a positioning projection on the stator core that fits into a positioning groove on the cluster block as an intermediary mechanism. This mediator structure guides and constrains the cluster block during assembly, allowing easy connection while preventing unwanted movement and thermal deformation.
Solution Approach 2:
The positioning projection and groove are pre-formed on the stator core and cluster block respectively, establishing the correct position and orientation before the actual assembly process. This preliminary positioning action ensures that when the cluster block is inserted, it automatically assumes the correct position without requiring manual adjustment, thus preventing contact with the heated motor housing.
2Manufacturing precision
If the cluster block is tightly fixed to the stator core, then thermal deformation is prevented, but adjustment of position or orientation becomes difficult
Solution Approach 1:
The positioning projection and groove are pre-formed structures that automatically establish the correct position and orientation of the cluster block relative to the stator core during assembly. This preliminary positioning action occurs before final tightening, allowing for easy adjustment during the assembly process while ensuring precise final positioning.
Solution Approach 2:
The positioning projection acts as an intermediary element that facilitates the connection between the cluster block and stator core. It provides both guidance for easy positioning and constraint for tight fixation, resolving the contradiction between ease of adjustment and positioning accuracy.
3Ease of manufacture
If the motor housing is heated for shrink fit assembly, then the stator core can be inserted easily, but the cluster block may be thermally deformed if it contacts the housing
Solution Approach 1:
The positioning projection and groove structure serves as an intermediary mechanism that physically separates the cluster block from the heated motor housing during assembly. By constraining the cluster block's position and orientation, this intermediary structure prevents direct contact with the hot housing surface, eliminating thermal deformation while maintaining ease of assembly through the shrink fit process.
Solution Approach 2:
The positioning features are pre-formed to establish the correct spatial relationship between the cluster block and stator core before heating occurs. This preliminary positioning ensures that during the heating and insertion process, the cluster block remains properly positioned and does not contact the heated motor housing, preventing thermal deformation while allowing easy assembly.
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 prevents thermal deformation of the cluster block, ensures accurate connection between the cluster block and conductor, and facilitates easier assembly by maintaining the cluster block's position and orientation during the shrink fit process.
Implementation Method 1
the motor housing is radially expanded by heating so that the inner diameter of the housing becomes larger than the outer diameter of the stator core
Implementation Method 2
As the motor housing is cooled, the motor housing is shrunk radially inward and the inner peripheral surface of the motor housing is pressed against the outer peripheral surface of the stator core
Data Source
Figure 1A~1B
Figure 2
Figure 3A~4
AI summary
A motor-driven compressor (10) includes an electric motor (19) having a stator core (26), a compression mechanism (18) driven by the electric motor (19), a motor housing (12) accommodating the electric motor (19) , and a cluster block (61) engaged with the stator core (26) in the motor housing (19) . The stator core (26) of the electric motor (19) and the motor housing (12) are assembled by shrink fit. The cluster block (61) accommodates a connecting terminal (31) for electrical connection between a conductor (54) connected to a motor drive circuit (52) and a lead wire (30) drawn from the electric motor (19). The cluster block (61) has a terminal hole (65) for receiving the connecting terminal (31) and has an opening (66, 67) that is provided separately from the terminal hole (65). A mehod for manufacturing the motor-driven compressor (10) applyng heating and cooling of the motor housing is also disclosed.