Device and method for reducing forces in mechanisms
AssigneeBristol Compressors, Inc.
InventorsScott G. Hix, John R. Walters JR., David T. Monk, Tyrone S. Simerly
Life of this patent
Estimating the term…
Abstract
The reliability of a compressor may be improved by affixing an inertia-increasing member to the drive shaft of the compressor in order to reduce the forces imposed on a mechanical coupling between the drive shaft and a compression member when the rotation of the drive shaft is initiated. A method of selecting the size and configuration of the inertia-increasing member is also provided.
Claims25
A compressor for use in an HVAC system, the compressor comprising:
- a block defining at least one compression chamber;
- a drive shaft rotatably supported by the block;
- a compression member for compressing a fluid within the compression chamber, said compression member coupled to said drive shaft through a mechanical coupling;
- a motor coupled to the drive shaft for rotating the drive shaft;
- an inertia-increasing member added to the drive shaft that reduces the acceleration of the drive shaft as the motor initiates the rotation of the drive shaft in one or more directions and adds to the service life of the mechanical coupling;
- and
- a housing containing the block, the drive shaft, the compression member, the motor, and the inertia-increasing member,
- wherein the forces imposed on the mechanical coupling are minimized when the motor initiates rotation of the drive shaft.
A modulating compressor for use in an HVAC system, the modulating compressor comprising:
- a block defining at least one cylinder;
- a reversible drive shaft rotatably supported by the block;
- a piston, coupled to the reversible drive shaft through a mechanical coupling, for compressing a fluid within the cylinder;
- a motor coupled to the reversible drive shaft for rotating the drive shaft;
- an inertia-increasing member added to the reversible drive shaft that reduces the acceleration of the reversible drive shaft as the motor initiates the rotation of the drive shaft in one or more directions and adds to the service life of the mechanical coupling;
- and
- a housing containing the block, the reversible drive shaft, the piston, the motor, and the inertia-increasing member,
- wherein the capacity of the modulating compressor is changed upon reversal of the direction of rotation of the reversible drive shaft.
A reciprocating drive system comprising:
- a reversible drive shaft;
- a motor coupled to the reversible drive shaft for rotating the reversible drive shaft;
- a reciprocating member, coupled to the reversible drive shaft through a mechanical coupling, for providing a reciprocating linear displacement;
- a cam member coupled to the reversible drive shaft;
- an eccentric member coupling the cam member to the reciprocating member;
- and
- an inertia-increasing member added to the reversible drive shaft that reduces the acceleration of the reversible drive shaft as the motor initiates the rotation of the drive shaft in one or more directions and adds to the service life of the mechanical coupling,
- wherein the cam member and eccentric member are configured to alter the reciprocating linear displacement of the reciprocating member upon reversal of the direction of rotation of the reversible drive shaft.
A method for reducing an impact force between components in a cylinder disengagement-type compressor comprising a block defining at least one cylinder, a reversible drive shaft rotatably supported by the block, a piston, coupled to the reversible drive shaft through a mechanical coupling, for compressing a fluid within the cylinder, a motor coupled to the reversible drive shaft for rotating the reversible drive shaft, a housing containing the block, the reversible drive shaft, the piston, and the motor, wherein the capacity of the cylinder disengagement-type compressor is changed upon reversal of the direction of rotation of the reversible drive shaft, the method comprising:
- increasing the inertia of the reversible drive shaft by adding an inertia-increasing member to the reversible drive shaft;
- and
- selecting a mass and shape of the inertia-increasing member that reduces the acceleration of the reversible drive shaft upon start-up and reversal of the direction of rotation of the reversible drive shaft and adds to the service life of the mechanical coupling, while not degrading the service life of other components of the compressor below the extended service life of the mechanical coupling.
A method for selecting the mass of an inertia-increasing member for reducing an impact force between components in a cylinder disengagement-type compressor comprising a block defining at least one cylinder, a reversible drive shaft rotatably supported by the block, a piston, coupled to the reversible drive shaft through a mechanical coupling, for compressing a fluid within the cylinder, a motor coupled to the reversible drive shaft for rotating the reversible drive shaft, a housing substantially containing the cylinder disengagement-type compressor and fixed to the block via at least one compressor mount, wherein the capacity of the cylinder disengagement-type compressor is changed upon reversal of the direction of rotation of the reversible drive shaft, the method comprising:
- (a) selecting a prototype inertia-increasing member having a mass and a configuration that provides clearance between the inertia-increasing member and the housing;
- (b) placing the prototype inertia-increasing member on the reversible drive shaft;
- (c) operating the compressor in a manner which repeatedly reverses the direction of rotation of the reversible drive shaft to determine the relative wear of the drive shaft and the compressor mounts;
- and
- (d) optimizing the size and shape of the inertia-increasing member so that the use of the inertia-increasing member will provide a compressor with an extended service life.
Dependencies are inferred from the claim text.