Abstract:
A method and apparatus for minimizing the amplitude of mechanical vibrations of a mechanical apparatus including a linear, freely reciprocating, prime mover coupled to and driving a reciprocating mass of a driven machine in reciprocation at a driving frequency. The coupled prime mover and driven machine have a spring applying a force upon the reciprocating mass to form a resonant main system having a main system resonant frequency of reciprocation. A driving frequency range over which the driven machine operates at an acceptable efficiency of operation is determined and stored. A parameter of the operation of the mechanical apparatus, such as the amplitude of vibrations or an operating temperature, is sensed and the prime mover is driven in response to the sensed parameter at a driving frequency that is offset from the main system resonant frequency of reciprocation, is within the driving frequency range of acceptable efficiency of operation and reduces or minimizes the amplitude of mechanical vibration of the mechanical apparatus under existing operating conditions.
Abstract:
The present invention discloses a linear compressor which can rapidly overcome load and improve compression efficiency, by synchronizing an operation frequency of a linear motor (10) with a natural frequency of a movable member (6) varied b y the load and varying a stroke of the movable member (6) according to the load. The linear compressor includes a fixed member (4) having a compression space (9) inside, a movable member (6) linearly reciprocated in the fixed member (4) in the axial direction, for compressing refrigerants sucked into the compression space (9), one or more springs (8a, 8b) installed to elasticaily support the movable member (6) in the motion direction of the movable member (6), spring constants of which being varied by load, and a linear motor (10) installed to be connected to the movable member (6), for linearly reciprocating the movable member (6) in the axial direction, and varying a stroke of the movable member (6) according to a predetermined refrigeration force, so that the movable member (6) can be linearly reciprocated to reach a top dead center.
Abstract:
The present invention discloses a linear compressor which can rapidly overcome load and improve compression efficiency, by synchronizing an operation frequency of a linear motor with a natural frequency of a movable member varied by the load and varying a stroke of the movable member according to the load. The linear compressor includes a fixed member having a compression space inside, a movable member linearly reciprocated in the fixed member in the axial direction, for compressing refrigerants sucked into the compression space, one or more springs installed to elastically support the movable member in the motion direction of the movable member, spring constants of which being varied by load, and a linear motor installed to be connected to the movable member, for linearly reciprocating the movable member in the axial direction, and varying a stroke of the movable member according to a predetermined refrigeration force, so that the movable member can be linearly reciprocated to reach a top dead center.
Abstract:
The present invention discloses a linear compressor in which a piston (6) is driven by a linear motor (10) and linearly reciprocated inside a cylinder (4) to suck, compress and discharge refrigerants. The linear compressor synchronizes an operation frequency of the linear motor (10) with a natural frequency of the piston (6), considering that an elastic force of a mechanical spring (8a, 8b) and a gas spring which elastically support the piston (6) in the motion direction is varied by load. Even if the load is varied, the linear motor is operated in the resonance state, to maximize efficiency. The linear compressor varies a stroke of the piston (6) according to the load, thereby actively handling and rapidly overcoming the load and reducing power consumption.
Abstract:
A negative pressure wound therapy device includes at least one piezoelectric pump and a control circuit. The control circuit is configured to generate a first control signal to control operation of the at least one piezoelectric pump, the control signal having a first root mean square (RMS) voltage, transmit the first control signal to the at least one piezoelectric pump, identify at least one of a change of state of the at least one piezoelectric pump or an expiration of a duration of time associated with operation of the at least one piezoelectric pump, responsive to identifying the at least one of the change of state or the expiration of the duration of time, generate a second control signal having a second RMS voltage less than the first RMS voltage, and transmit the second control signal to the at least one piezoelectric pump.
Abstract:
A control for an electric motor is utilized to avoid operation in or near the resonance frequencies for the electric motor and its associated system components. The resonance frequencies can be identified experimentally at the design stage, or during operation of a component and electric motor. During start-up, shutdown or frequency adjustment, the control drives the speed through the resonance frequency zones more rapidly, and also avoids operation in or near those resonance frequencies during steady state operation. In disclosed embodiments, the electric motors are associated with fans, pumps and compressors in a refrigerant system.
Abstract:
A method and apparatus for minimizing the amplitude of mechanical vibrations of a mechanical apparatus including a linear, freely reciprocating, prime mover coupled to and driving a reciprocating mass of a driven machine in reciprocation at a driving frequency. The coupled prime mover and driven machine have a spring applying a force upon the reciprocating mass to form a resonant main system having a main system resonant frequency of reciprocation. A driving frequency range over which the driven machine operates at an acceptable efficiency of operation is determined and stored. A parameter of the operation of the mechanical apparatus, such as the amplitude of vibrations or an operating temperature, is sensed and the prime mover is driven in response to the sensed parameter at a driving frequency that is offset from the main system resonant frequency of reciprocation, is within the driving frequency range of acceptable efficiency of operation and reduces or minimizes the amplitude of mechanical vibration of the mechanical apparatus under existing operating conditions.