Deformable Crankpin Recess for Scroll Compressor Bearing
Solution Overview
Problem
Conventional scroll compressors experience tilting or wobbling movements of the orbiting scroll due to uneven forces, leading to edge loading on the drive shaft bearings and reduced integrity of the orbiting scroll bearing, which increases manufacturing costs and reduces bearing lifetime.
Innovation Solution
A scroll compressor design featuring a crankpin with a recess and a deformable circumferential wall along its outer surface, which reduces contact pressure between the orbiting scroll bearing and the crankpin during tilting or wobbling movements, thereby increasing the bearing's lifetime without complex drive shaft bearings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional rigid crankpin structure is used, then manufacturing cost is reduced, but edge loading occurs on the orbiting scroll bearing reducing its lifetime
Solution Approach 1:
The crankpin incorporates a deformable circumferential wall that can dynamically adapt its shape during operation. When the orbiting scroll applies contact pressure during tilting or wobbling movements, the circumferential wall deforms radially inward, allowing the crankpin to flex and accommodate the bearing loads without transmitting edge loading to the bearing, thus extending bearing lifetime without complex additional components.
Solution Approach 2:
The invention changes the physical parameter of the crankpin structure by introducing a recess that creates a deformable circumferential wall. This structural modification allows the crankpin to change its effective stiffness and deformation characteristics under load, enabling it to absorb and distribute bearing contact pressures more evenly, thereby protecting the bearing from edge loading while maintaining structural simplicity.
2Reliability
If deformable circumferential wall is added to crankpin, then contact pressure on bearing is reduced, but manufacturing complexity increases
Solution Approach 1:
The crankpin is segmented by introducing a recess that creates a distinct deformable circumferential wall portion. This segmentation allows the crankpin to function as both a rigid structural component and a flexible bearing protection mechanism. The recess can be manufactured using standard machining operations, dividing the crankpin into functional zones without requiring complex manufacturing processes.
3Reliability
If orbiting scroll bearing is designed to withstand edge loading, then bearing lifetime is improved, but device complexity and cost increase
Solution Approach 1:
The invention converts the harmful edge loading effect into a beneficial mechanism by allowing the crankpin itself to deform and absorb the bearing loads. Instead of designing the bearing to withstand edge loading, the deformable circumferential wall of the crankpin flexes under load, transforming the potentially damaging edge loading into a controlled deformation of the crankpin that protects the bearing from excessive stresses.
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 deformable circumferential wall on the crankpin effectively reduces contact pressure between the orbiting scroll bearing and the crankpin, enhancing the bearing's lifetime and maintaining the integrity of the orbiting scroll bearing while simplifying the compressor structure and reducing manufacturing costs.
Implementation Method 1
the circumferential wall being deformable in a radial direction, with respect to the crankpin axis of the crankpin, during operation of the scroll compressor, and particularly when the orbiting scroll performs tilting or wobbling movements and applies a contact pressure on the circumferential wall
Data Source
AI summary
The scroll compressor comprises a fixed scroll having a fixed end plate and a fixed spiral wrap extending from the fixed end plate; an orbiting scroll (9) having an orbiting end plate and an orbiting spiral wrap extending from the orbiting end plate, the fixed spiral wrap and the orbiting spiral wrap meshing with each other to form compression chambers; a vertical drive shaft (19) having a crankpin (21) at an upper end portion of the vertical drive shaft (19), the crankpin (21) including an outer circumferential surface (23) cooperating with an orbiting scroll bearing (24). The crankpin (21) includes a recess (25) formed in an axial end face (26) of the crankpin (21), the recess (25) and an upper portion (27) of the outer circumferential surface (23) defining therebetween a circumferential wall (28) extending along at least a part of the circumference of the crankpin (21), the circumferential wall (28) being deformable in a radial direction during operation of the scroll compressor.