Closed compressor and refrigeration device
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Solution Overview
Problem
Existing closed compressors require high accuracy in manufacturing and assembly to maintain coaxiality and clearance between components, leading to increased costs and reduced efficiency due to potential crankshaft twisting and uneven clearances.
Innovation Solution
A closed compressor design with a separate auxiliary bearing coaxial to the main bearing, allowing for accurate fixing of the stator and rotor with even clearance, reducing the need for precise component processing and assembly, and using an outer-rotor motor configuration to enhance motor efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If high accuracy manufacturing and assembly are performed to maintain coaxiality and clearance, then motor efficiency is improved, but manufacturing costs increase
Solution Approach 1:
The invention divides the bearing support system into two independent parts: main bearing supported by the closed vessel and auxiliary bearing supported by the stator fixing member. This segmentation allows each bearing to be positioned and adjusted independently, enabling accurate coaxiality and clearance control without requiring extremely high manufacturing precision across all components, thus reducing manufacturing costs while maintaining motor efficiency
Solution Approach 2:
The stator fixing member acts as an intermediary element that connects the stator to the compression element and provides the auxiliary bearing support. This intermediary structure enables precise positioning of the stator and auxiliary bearing relative to the main bearing, allowing for accurate rotor-stator clearance control without requiring the entire assembly to be manufactured with high precision, thereby reducing manufacturing costs while maintaining efficiency
2Loss of energy
If clearance between rotor and stator is narrowed to improve motor efficiency, then motor efficiency increases, but risk of contact and reliability decreases
Solution Approach 1:
By separating the bearing support functions into main bearing (vessel-supported) and auxiliary bearing (stator fixing member-supported), the system can precisely control and maintain even clearance between rotor and stator. This independent positioning capability allows narrowing the clearance for high efficiency while ensuring uniform distribution that prevents localized contact, thus maintaining reliability
Solution Approach 2:
The invention changes the clearance parameter from a fixed value determined by single-point contact to a controllable even clearance distributed around the rotor-stator interface. The auxiliary bearing positioned coaxially with the main bearing enables this uniform clearance distribution, allowing the system to operate with narrower clearances for higher efficiency while preventing contact through even load distribution, thereby maintaining reliability
3Reliability
If coaxiality between main bearing and auxiliary bearing is maintained with high accuracy, then crankshaft twisting is prevented, but manufacturing and assembly complexity increases
Solution Approach 1:
The invention segments the bearing support system so that the main bearing is supported by the closed vessel and the auxiliary bearing is supported by the stator fixing member. This segmentation allows each bearing to be independently positioned and adjusted, simplifying the assembly process while ensuring accurate coaxiality. The independent support structures eliminate the need for complex multi-point positioning, reducing assembly complexity while preventing crankshaft twisting
Solution Approach 2:
The stator fixing member serves multiple functions: it fixes the stator to the compression element, supports the auxiliary bearing, and provides the positioning reference for achieving coaxiality with the main bearing. This multi-functionality reduces the number of separate components and simplifies the overall structure, making it easier to manufacture and assemble while maintaining accurate coaxiality to prevent crankshaft twisting
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 design reduces crankshaft twisting, narrows the clearance between rotor and stator, achieving high motor efficiency and reliability at lower costs, while maintaining coaxiality between bearings, thus improving overall compressor performance.
Implementation Method 1
an outer-rotor type motor having a rotor fixed to the crankshaft on a main shaft side and a stator disposed on an inner side of the rotor
Data Source
Figure 1
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AI summary
A stator (129) of an outer-rotor type motor is fixed to a stator fixing member (130), and the stator fixing member (130) is fixed to a member (cylinder block (111)) of a compression element, which has a main bearing (119). Further, an auxiliary bearing (133) is configured to be separate from the stator fixing member (130) and is fixed to the stator fixing member (130). In this manner, it is possible to fix the stator fixing member (130) to the member of the compression element in a state in which an even clearance is formed between an inner circumference (128a) of a rotor (128) and an outer circumference (129a) of the stator (129), and it is possible to fix the auxiliary bearing (133) to the stator fixing member (130) in a state in which the auxiliary bearing is reliably coaxial to the main bearing (119). Therefore, it is possible to narrow the clearance between the inner circumference (128a) of the rotor (128) and the outer circumference (129a) of the stator (129) such that it is possible to achieve high efficiency of the motor.