Pump-Motor Common Shaft Design for Friction Reduction
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Solution Overview
Problem
Conventional pump-motor units have high development and manufacturing costs due to multiple bearing arrangements, leading to increased frictional losses and the need for a larger motor capacity to achieve a given pump capacity.
Innovation Solution
A pump-motor unit design featuring a common shaft for both the pump and electric motor, reducing the number of shafts and bearings, which allows for a cost-effective and efficient configuration by eliminating the need for a coupling and minimizing friction losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple bearing arrangements and a coupling are used to connect the motor shaft to the pump shaft, then the pump-motor unit achieves reliable operation, but the development and manufacturing costs increase
Solution Approach 1:
The patent merges the motor shaft and pump shaft into a single common shaft that extends through both the motor and pump assemblies. This eliminates the need for separate shafts, couplings, and multiple bearing arrangements, thereby reducing component count and manufacturing complexity while maintaining reliable operation through a simplified, integrated design
2Reliability
If multiple bearing arrangements are used to support separate shafts, then the pump-motor unit operates reliably, but frictional losses increase
Solution Approach 1:
The patent combines multiple bearing arrangements into a single integrated bearing system that supports the common shaft at multiple locations. This reduces the total number of bearings from four or more to two, thereby minimizing aggregate frictional losses while maintaining reliable shaft support and operation
3Adaptability or versatility
If two separate shafts with multiple bearings are used, then the pump and motor can be independently designed, but the motor capacity must be increased to compensate for frictional losses
Solution Approach 1:
The patent integrates the shaft system into a single common shaft that serves both the motor and pump, eliminating redundant bearing arrangements and reducing frictional losses. This allows the motor to be sized more efficiently for the actual pump load requirements rather than compensating for excessive friction, thereby optimizing power usage while maintaining design flexibility
4Ease of manufacture
If a coupling is used to connect the motor shaft to the pump shaft, then the components can be manufactured separately, but the device complexity and manufacturing costs increase
Solution Approach 1:
The patent eliminates the coupling by integrating the shaft system into a single continuous common shaft that passes through both the motor and pump assemblies. The motor and pump can still be manufactured as separate components and assembled together, but the coupling and associated alignment mechanisms are eliminated, reducing device complexity and assembly requirements
Data Source
AI summary
A pump-motor combination includes a motor (30) and a pump (20). The pump has a first rotor (21) and a first housing 300). The motor is an electric motor (30) having a second rotor (31), a stator (33) and a second housing (32). The first (pump) rotor (21) is at least partially coupled, and the second (motor) rotor (31) is completely coupled, to a common rotating shaft (40) in order to enable transmission of rotation of the second (motor) rotor (31) to the first (pump) rotor (21). The pump-motor combination can be installed with the gearbox (G) or transmission of a motor vehicle, to assure supply of lubricant (360) when a primary lubricant pump (350) has not been operating, for example, upon start-up. Use of the common shaft (40) minimizes frictional losses during operation and reduces the cost of manufacture, since fewer bearings are needed.