Abstract: A two-axis solar tracker is capable of withstanding extreme weather conditions. The solar tracker includes a solar array, a frame, a base, a pivot frame, and a first and second actuator. The solar array is mounted to the frame and captures sunlight. The base is pivotally connected to the frame and defines a pivot axis for elevational movement of the solar array. The pivot frame is also pivotally connected to the frame and defines a pivot axis for azimuthal movement of the solar array. The first actuator controls elevational movement of the solar array and the second actuator controls azimuthal movement of the solar array. The solar tracker is pivotable between a raised position and a stowed position.

Abstract: An improvement to the oil supply grooves in connecting rods for compressors increases surface area in an upper bearing half. The upper bearing half transmits a force from a driveshaft to the connecting rod. The lower half of the connecting rod includes an oil supply groove that extends over the majority of a circumferential extent of a bearing surface in the lower half that contacts an eccentric. On the other hand, the inner surface of the upper half does not include any large oil supply groove such that the surface area between the upper half and the eccentric is maximized.

Abstract: A method of detecting and diagnosing operating conditions for a heat pump water heating system includes the steps of monitoring system operating conditions and comparing actual operating conditions to predicted operating conditions. The predicted operating conditions are based on expected pressures and temperatures given current system inputs. A difference between the actual and expected values for refrigerant pressures and temperature outside a desired range provides indication of a fault in the system. The system controller initiates a prompt to alert of the need for maintenance and direct to potential causes.

Abstract: A transcritical vapor compression system includes a compressor assembly that includes an oil separator for separating oil from refrigerant. The oil separator is disposed between a motor and a compression chamber in a sub-critical portion of the vapor compression system. Oil emitted from the drive assembly attached to the motor is substantially removed from the refrigerant before entering the compression chamber of the compressor.

Abstract: A method of detecting and diagnosing operating conditions for a heat pump water heating system includes the steps of monitoring system operating conditions and comparing actual operating conditions to predicted operating conditions. The predicted operating conditions are based on expected pressures and temperatures given current system inputs. A difference between the actual and expected values for refrigerant pressures and temperature outside a desired range provides indication of a fault in the system. The system controller initiates a prompt to alert of the need for maintenance and direct to potential causes.

Abstract: A compressor includes a motor having a rotor for driving a shaft, to drive compressor pistons. A lubricant supply system supplies lubrication to the moving elements within the compressor and motor. A suction fluid to be compressed passes over the motor on its way to the compression chambers. The oil is returned from a bearing mounting an end of the shaft intermediate the motor rotor and the compressor pistons. The bearing mount ensures that the lubricant is returned away from the motor rotor, to reduce the amount of oil that is entrained in the fluid to be compressed.

Abstract: A reciprocating compressor is provided with a discharge valve having an area inward of a valve seat which is greater than the area of the discharge port. The valve seat also has a distinct shape compared to the valve port in preferred embodiments. The increased area within the valve seat results in an increased force tending to open the valve from a compressed fluid. On the other hand, since the valve port remains relatively small, the flow losses are not significantly increased.