Pump Rotor Housing Thermal Expansion Clearance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pump systems face challenges in achieving optimal torque and volumetric efficiency across varying temperatures, which affects the size and cost of motive input devices and overall performance, particularly in applications like vehicles where weight and fuel economy are concerns.
Innovation Solution
The use of materials with specific thermal expansion characteristics for the housing and rotor, such as steel and aluminum, to vary the face clearance of the pump system, minimizing torque requirements at low temperatures and maximizing volumetric efficiency at high temperatures by tailoring the thermal expansion coefficients to manage clearance over a wide temperature range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the face clearance is reduced to improve volumetric efficiency, then volumetric efficiency increases, but torque requirements increase at low temperatures
Solution Approach 1:
The patent applies thermal expansion by selecting materials with different coefficients of thermal expansion for the rotor and housing. The rotor material has a higher coefficient than the housing material, causing the rotor to expand more than the housing when temperature increases. This differential expansion automatically adjusts the face clearance: at low temperatures, the clearance is larger reducing torque requirements; at high temperatures, the clearance is smaller improving volumetric efficiency. This resolves the contradiction by using thermal effects to dynamically optimize both parameters.
2Force
If the face clearance is increased to reduce torque requirements, then torque requirements decrease, but volumetric efficiency decreases
Solution Approach 1:
The patent uses differential thermal expansion to resolve this contradiction. By choosing materials where the rotor has a higher coefficient of thermal expansion than the housing, the system automatically reduces face clearance at high temperatures (improving volumetric efficiency) and maintains larger clearance at low temperatures (reducing torque requirements). The thermal expansion effect provides automatic adjustment without requiring external control mechanisms.
3Weight of moving object
If the pump size is reduced to minimize weight, then weight decreases, but performance requirements cannot be met across all temperatures
Solution Approach 1:
The patent applies thermal expansion to enable smaller pump design. The differential expansion between rotor and housing materials provides automatic clearance adjustment across temperature ranges, allowing the pump to maintain reliable performance without requiring oversized components. The thermal effects compensate for clearance variations that would otherwise require larger dimensional tolerances or larger overall pump size, thus reducing weight while maintaining performance consistency.
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 approach results in minimized torque requirements at cold temperatures and maximized volumetric efficiency at hot temperatures, enabling the use of smaller motors and pumps while maintaining performance, thus reducing energy input and consumption.
Implementation Method 1
The housing is made of a material selected to have a thermal expansion characteristic and the rotor is made of a second material selected to have another thermal expansion characteristic. The thermal expansion characteristics deliver the target performance characteristics of the pump system.
Data Source
AI summary
Systems and methods are provided for pumps that deliver optimized torque characteristics and volumetric efficiency. A system includes a housing defining a surface and a rotor defining a face. A face clearance is defined between the face and the surface. The face clearance is variable in magnitude and determinative of target performance characteristics of the pump system. The housing is made of a material selected to have a thermal expansion characteristic and the rotor is made of a second material selected to have another thermal expansion characteristic. The thermal expansion characteristics deliver the target performance characteristics of the pump system.