Controlled stroke electrodynamic oscillating motor compressor
AssigneeMechanical Technology Incorporated
InventorHarlan Vernon White
Life of this patent
Estimating the term…
Abstract
A compressor of the free-piston resonant type driven by an electrodynamic oscillating motor incorporates means to control the stroke to allow for stable operation over a wide range of operating conditions. The spring-mass system of the compressor which is forced into vibration by the electrodynamic oscillating motor is arranged to have a selectively variable natural resonant frequency generally centered on the power line frequency. Variable area port means responsive to any overstroking are operative to vary the natural frequency of the spring-mass system by varying the stiffness of a gas spring means thereof so as to oppose overstroking and also provide for a maximum stroke limit.
Claims24
In an apparatus wherein a movable mass is arranged with gas spring means to form an oscillating system with an oscillating driving means, the combination with such apparatus comprising:
- means responsive to the amplitude of oscillation of said oscillating system for varying the natural frequency of said oscillating system by varying the stiffness of said gas spring means, said means including port means operative to communicate said gas spring means with a source of fluid at higher pressure whenever the amplitude of oscillation exceeds a predetermined normal operating level, said port means being so selected, arranged and shaped that the area thereof which is disposed in communication with said source of fluid at higher pressure increases non-slidably with increase in oscillation amplitude beyond said predetermined normal operating level.
In an apparatus wherein a movable mass is arranged with gas spring means to form an oscillating system with an oscillating driving means, the combination with such apparatus comprising:
- a. piston means coupled to and adapted to be driven by said oscillating driving means;
- and
- b. means responsive to the position of said piston means for controlling the amplitude of oscillation of said oscillating system, said means including first port means carried by said piston means and being operative to communicate said gas spring means with a source of gas at higher pressure whenever said piston means exceeds a predetermined normal operating stroke position so tha fluid flows from said source into said gas spring means increasing the pressure therein and the stiffness thereof, said port means being so selected, arranged and shaped that the area thereof which is disposed in communication with said source of fluid at higher pressure increases non-linearly with increase in oscillation amplitude beyond said predetermined normal operating position.
In a compressor wherein piston means coupled to and adapted to be driven within a selectively valved working cylinder by an electrodynamic oscillating motor substantially in synchronism with an A-C power source and oppositely disposed enclosed volumes of gas acting as resilient means coact with said piston means and with said motor to form a mechanical resonant system having a natural frequency approximately equal to the frequency of said A-C power source and including means responsive to the position of said piston for controlling the force output of said motor to provide stable operation over varying compressor load conditions by varying the natural frequency of said resonant system and which means includes first port means communicating said enclosed volumes of gas with each other at an intermediate stroke position of said piston to equalize the gas pressures in said enclosed volumes during operation and second port means communicating one of said enclosed volumes of gas with a source of gas at higher pressure whenever said piston exceeds a predetermined normal operating stroke position so that gas flows from said source into said enclosed volume increasing the gas pressure therein and effecting an increase in the stiffness of the resilient means and thereby increasing the resonant frequency of said mechanical resonant system, the combination with said compressor of:
- said second port means shaped to effect an non-linear increase in gas flow from said source of fluid at higher pressure to said enclosed volume of gas as a function of increase in piston travel beyond said predetermined normal operating stroke position.
Dependencies are inferred from the claim text.