Abstract: A method for operating a linear compressor includes establishing a set of predictors, and establishing a model for an estimated head clearance of the linear compressor with the set of predictors. Coefficients of the model for the estimated head clearance of the linear compressor may also be established. The model for the estimated head clearance of the linear compressor may be used to calculate an estimated head clearance during operation of the linear compressor.

Abstract: Systems and compression assemblies thereof are provided. In one example aspect, a system includes a cooling fluid circuit and a piston slidably received within a chamber of a casing. The casing defines an inlet passage and an outlet passage. The inlet passage receives a cooling fluid, e.g. oil or a refrigerant, from the cooling fluid circuit. The cooling fluid flows into the inlet passage and downstream into an inlet groove defined by the piston along its outer surface. The cooling fluid flows downstream to a cooling channel defined by a piston head of the piston and thereafter into an outlet groove defined by piston along its outer surface. The cooling fluid then flows into outlet passage of casing and is returned to cooling fluid circuit. The passage of cooling fluid through the passages, grooves, and channels removes heat from the casing and the piston.

Abstract: A linear compressor includes a piston with a piston head and a cylindrical side wall. An inner surface of the cylindrical side wall defines a ball seat. A coupling extends between a mover and a piston. The coupling includes a flex mount that extends between a first end portion and a second end portion. The flex mount is connected to the mover away from the first end portion of the flex mount. A ball nose is positioned at the first end portion of the flex mount. The ball nose contacts the piston at the ball seat of the piston. A spring urges the ball nose against the ball seat of the piston.

Abstract: Systems and compression assemblies thereof are provided. In one example aspect, a system includes a cooling fluid circuit and a piston slidably received within a chamber of a casing. The casing defines an inlet passage and an outlet passage. The inlet passage receives a cooling fluid, e.g. oil or a refrigerant, from the cooling fluid circuit. The cooling fluid flows into the inlet passage and downstream into an inlet groove defined by the piston along its outer surface. The cooling fluid flows downstream to a cooling channel defined by a piston head of the piston and thereafter into an outlet groove defined by piston along its outer surface. The cooling fluid then flows into outlet passage of casing and is returned to cooling fluid circuit. The passage of cooling fluid through the passages, grooves, and channels removes heat from the casing and the piston.

Abstract: A method for detecting head crashing in a linear compressor includes sampling a rolling average of a peak applied voltage and a desired peak current each time that a current controller adjusts the desired peak current. The method also includes calculating a linear regression for a predicted peak applied voltage as a function of the desired peak current, calculating the predicted peak voltage for the motor of the linear compressor with the linear regression and a current value for the desired peak current from the current controller, and establishing that a piston of the linear compressor is soft crashing when the predicted peak voltage is different than the current value for the rolling average of the peak applied voltage by more than a threshold value.

Abstract: A method for operating a linear compressor includes substituting a first observed velocity, a bounded integral of the first observed velocity, an estimated clearance, an estimated discharge pressure, and an estimated suction pressure into the mechanical dynamic model for the motor, calculating an observed acceleration for the piston with the mechanical dynamic model for the motor, calculating a second observed velocity for the piston by integrating the observed acceleration for the piston, calculating an observed position of the piston by integrating the second observed velocity for the piston, and updating an estimated clearance, an estimated discharge pressure, and an estimated suction pressure based upon an error between the first and second observed velocities and an error between the bounded integral of the first observed velocity and the observed position.

Abstract: A linear compressor and methods of operation, for example, to detect polarity for the linear compressor are provided herein. The method may include supplying an initial time varying voltage to the motor of the linear compressor at an assumed polarity; estimating a first acceleration of the motor of the linear compressor when the motor is at a bottom dead center position; estimating a second acceleration of the motor of the linear compressor when the motor is at a top dead center position; comparing the first acceleration to the second acceleration; and determining whether the assumed polarity is correct based on the comparison.

Abstract: A method for operating a linear compressor includes providing a dynamic model for a motor of the linear compressor, estimating values for each unknown constant of a plurality of unknown constants of the dynamic model for the motor and repeatedly updating the estimate for each unknown constant of the plurality of unknown constants of the dynamic model for the motor in order to reduce an error between a measured value for the electrical dynamic model and an estimated valve for the electrical dynamic model.

Abstract: A linear compressor includes a piston with a piston head and a cylindrical side wall. An inner surface of the cylindrical side wall defines a ball seat. A coupling extends between a mover and a piston. The coupling includes a flex mount that extends between a first end portion and a second end portion. The flex mount is connected to the mover away from the first end portion of the flex mount. A ball nose is positioned at the first end portion of the flex mount. The ball nose contacts the piston at the ball seat of the piston. A spring urges the ball nose against the ball seat of the piston.

Abstract: A discharge valve assembly includes an outer shell. An inner sleeve is positioned within the outer shell. A side wall of the inner sleeve is spaced from a side wall of the outer shell along a radial direction. A distal end of the side wall of the inner sleeve is spaced from an end wall of the outer shell by a gap along an axial direction. The inner sleeve divides an interior volume of the outer shell into a first muffler cavity and a second muffler cavity. A related compressor is also provided.

Abstract: A linear compressor and methods of operation, for example, to detect polarity for the linear compressor are provided herein. The method may include supplying an initial time varying voltage to the motor of the linear compressor at an assumed polarity; estimating a first acceleration of the motor of the linear compressor when the motor is at a bottom dead center position; estimating a second acceleration of the motor of the linear compressor when the motor is at a top dead center position; comparing the first acceleration to the second acceleration; and determining whether the assumed polarity is correct based on the comparison.

Abstract: A linear compressor and methods of operation, for example, to control extension of the linear compressor, are provided herein. A method may include supplying a time varying voltage to a motor of the linear compressor, determining an uneven fatigue condition at the linear compressor, and applying a limiting force at the motor in a negative axial direction in response to the determining step.

Abstract: A compressor includes a discharge conduit that extends between a discharge valve and a hermetic shell within the hermetic shell. A sealing connection assembly includes a housing mounted to one of the discharge valve and the hermetic shell. An inner surface of the housing has a tapered portion that contracts to a sealing edge. An end portion of the discharge conduit is positioned within the passage of the housing such that an outer surface of the discharge conduit is positioned on and contacts the inner surface of the housing at the sealing edge.

Abstract: A sealed system for an appliance includes a compressor having a shell and lubrication oil disposed with the shell. A condenser in fluid communication with the compressor such that compressed refrigerant from the compressor flows to the condenser during operation of the compressor. The sealed system also includes a heat exchanger for cooling the lubrication oil during operation of the compressor.

Abstract: A method for detecting head crashing in a linear compressor includes sampling a rolling average of a peak applied voltage and a desired peak current each time that a current controller adjusts the desired peak current. The method also includes calculating a linear regression for a predicted peak applied voltage as a function of the desired peak current, calculating the predicted peak voltage for the motor of the linear compressor with the linear regression and a current value for the desired peak current from the current controller, and establishing that a piston of the linear compressor is soft crashing when the predicted peak voltage is different than the current value for the rolling average of the peak applied voltage by more than a threshold value.

Abstract: A method for operating a linear compressor includes substituting a first observed velocity, a bounded integral of the first observed velocity, an estimated clearance, an estimated discharge pressure, and an estimated suction pressure into the mechanical dynamic model for the motor, calculating an observed acceleration for the piston with the mechanical dynamic model for the motor, calculating a second observed velocity for the piston by integrating the observed acceleration for the piston, calculating an observed position of the piston by integrating the second observed velocity for the piston, and updating an estimated clearance, an estimated discharge pressure, and an estimated suction pressure based upon an error between the first and second observed velocities and an error between the bounded integral of the first observed velocity and the observed position.

Abstract: A method for operating a linear compressor is provided. The method includes estimating an acceleration of the motor of the linear compressor using at least a robust integral of the sign of the error feedback. A position of the motor of the linear compressor when the motor of the linear compressor is at the bottom dead center point is also determined based at least in part on a measured current to the motor of the linear compressor and an estimated acceleration of the motor. The position of the motor of the linear compressor when the motor of the linear compressor is at a top dead center point is calculated based at least in part on the position of the motor of the linear compressor when the motor of the linear compressor is at the bottom dead center point and a stroke length of the motor of the linear compressor.

Abstract: A method for operating a linear compressor includes providing a current controller, a resonance controller and a clearance controller. The current controller, the resonance controller and the clearance controller are configured for regulating operating parameters of a motor of the linear compressor. By managing priority between the current controller, the resonance controller and the clearance controller, the method may assist with efficiently operating the linear compressor while also maintaining stability.

Abstract: A compressor includes a discharge conduit that extends between a discharge valve and a hermetic shell within the hermetic shell. A sealing connection assembly includes a housing mounted to one of the discharge valve and the hermetic shell. An inner surface of the housing has a tapered portion that contracts to a sealing edge. An end portion of the discharge conduit is positioned within the passage of the housing such that an outer surface of the discharge conduit is positioned on and contacts the inner surface of the housing at the sealing edge.

Abstract: A linear compressor includes an inner back iron positioned in a driving coil. A flex mount is positioned within the inner back iron and is coupled to the inner back iron. A coupling extends between the flex mount and a piston, and a compliant bellows is coupled to the flex mount and the piston.