Scroll pump with controlled axial thermal expansion
AssigneeVarian, Inc.
InventorsAnthony G. Liepert, Jeffrey C. Warren, Robert M. Curry, Jr.
Life of this patent
Estimating the term…
Abstract
Vacuum pumping apparatus includes a pump frame, a stationary scroll element secured to the pump frame, the stationary scroll element including a stationary scroll blade, an orbiting scroll element including an orbiting scroll blade intermeshed with the stationary scroll blade, a motor secured to the pump frame, and a crankshaft coupled between the motor and the orbiting scroll element for producing orbiting movement of the orbiting scroll blade relative to the stationary scroll blade when the motor is energized. The crankshaft includes a first component having a first coefficient of thermal expansion and a second component having a second coefficient of thermal expansion.
Claims18
Vacuum pumping apparatus comprising:
- a scroll set having an inlet and an outlet, said scroll set comprising a stationary scroll element including a stationary scroll blade and an orbiting scroll element including an orbiting scroll blade, wherein said stationary and orbiting scroll blades are intermeshed together defining one or more interblade pockets;
- a motor;
- and
- a crankshaft operatively coupled between the motor and the orbiting scroll element, which produces orbiting movement of said orbiting scroll blade relative to said stationary scroll blade when said motor is energized, said crankshaft comprising a first component of a first material rigidly joined to a second component of a second material, wherein the first component has a first coefficient of thermal expansion and the second component has a second coefficient of thermal expansion that is significantly different from the first coefficient of thermal expansion, and wherein the first and second components have relative axial lengths that provide controlled axial expansion and establish a small, non-contacting gap between the orbiting scroll element and the stationary scroll element during operation of the vacuum pumping apparatus.
Vacuum pumping apparatus comprising:
- a pump frame;
- a stationary scroll element secured to the pump frame, the stationary scroll element including a stationary scroll blade;
- an orbiting scroll element including an orbiting scroll blade intermeshed with said stationary scroll blade;
- a motor secured to the pump frame;
- and
- a crankshaft coupled between the motor and the orbiting scroll element producing orbiting movement of said orbiting scroll blade relative to said stationary scroll blade when said motor is energized, said crankshaft comprising a first component having a first coefficient of thermal expansion and a second component having a second coefficient of thermal expansion that is significantly different from the first coefficient of thermal expansion, and wherein the first and second components have relative axial lengths that provide controlled axial expansion and establish a small, non-contacting gap between the orbiting scroll element and the stationary scroll element during operation of the vacuum pumping apparatus.
A method for operating vacuum pumping apparatus of the type comprising a first scroll element and a second scroll element, comprising:
- producing orbiting motion of said second scroll element relative to said first scroll element with a motor and an eccentric crankshaft, said eccentric crankshaft comprising a first component of a first material having a first coefficient of thermal expansion rigidly joined to a second component of a second material having a second coefficient of thermal expansion that is significantly different from the first coefficient of thermal expansion, and wherein the first and second components have relative axial lengths that provide controlled axial expansion and establish a small, non-contacting gap between the orbiting scroll element and the stationary scroll element during operation of the vacuum pumping apparatus.
Dependencies are inferred from the claim text.