초록 ▼

A two stage reciprocating compressor and associated HVAC systems and methods are disclosed. The reciprocating compressor includes a crankshaft having an eccentric crankpin, a reversible motor for rotating the crankshaft in a forward and a reverse direction, and an eccentric, two position cam rotatab

A two stage reciprocating compressor and associated HVAC systems and methods are disclosed. The reciprocating compressor includes a crankshaft having an eccentric crankpin, a reversible motor for rotating the crankshaft in a forward and a reverse direction, and an eccentric, two position cam rotatably mounted over the crankpin. The crankshaft and cam combine to cause the piston to have a first stroke when the motor operates in the forward direction and a second stroke when the motor operates in the reverse direction. The cam and crankpin also include stabilization means to restrict the relative rotation of the cam about the crankpin. A lubrication system is provided to lubricate the engaging surfaces of the crankshaft and cam and between the cam and the bearing surface of the connecting rod. There is also provided a control for selectively operating the motor either in the forward direction at a first power load or in the reverse direction at a reduced second power load. A protector for the motor is also provided. In addition, the application of the reciprocating compressor to both air conditioning and heat pump systems is disclosed.

대표청구항 ▼

1. A heat pump system, comprising: a two-stage compressor having a piston disposed in a compression chamber, a crankshaft coupled with the piston, and a reversible motor for rotating the crankshaft in a forward direction to operate the compressor in a first stage at a first fixed load and a rever

1. A heat pump system, comprising: a two-stage compressor having a piston disposed in a compression chamber, a crankshaft coupled with the piston, and a reversible motor for rotating the crankshaft in a forward direction to operate the compressor in a first stage at a first fixed load and a reverse direction to operate the compressor in a second stage at a second fixed load; a condenser; an expansion device; an evaporator; means for operating the compressor, condenser, expansion device, and evaporator as a heat pump that can selectively provide air conditioning and heating, as required; and a control system for operating the system in a heating mode with the compressor running at the first stage or the second stage, based upon the heating requirements, and for operating the system in an air conditioning mode with the compressor running only at the first stage. 2. The system of claim 1 where said expansion device is a single orifice expansion valve. 3. The system of claim 1 wherein the compressor operates at 60% to 70% capacity for the air conditioning mode. 4. The system of claim 3 wherein the compressor is a reciprocating compressor. 5. The system of claim 4 wherein the compressor can operate only at one of two fixed power loads. 6. The system of claim 1 wherein the control system senses the outdoor temperature and in the heating modes operates the system in the first or second stage, based on the value of the sensed outside temperature. 7. A heat pump system, comprising: a two-stage compressor, wherein the compressor is a reciprocating compressor with two cylinders and their associated compressor chambers and pistons, the compressor designed to compress gas with only one cylinder when its motor rotates in a reverse direction and with two cylinders when its motor rotates in the forward direction; a condenser; an expansion device; an evaporator; means for operating the compressor, condenser, expansion device, and evaporator as a heat pump that can selectively provide air conditioning and heating, as required; and a control system for operating the system in a heating mode with the compressor running at the first stage or the second stage, based upon the heating requirements, and for operating the system in an air conditioning mode with the compressor running only at the first stage. 8. The system of claim 7 wherein the capacity of the evaporator and condensers are sized to match the cooling capacity associated with the capacity of the compressor operating at the first stage. 9. A method of cooling and heating a space with a heat pump in a cold climate environment, said method including the steps of: providing a heat pump system including a two stage compressor having a piston disposed in a compression chamber, a crankshaft coupled with the piston, and a reversible motor for rotating the crankshaft in a forward direction to operate the compressor in a first stage at a fixed first load and a reverse direction to operate the compressor in a second stage at a fixed second load, the heat pump system further including a condenser, an evaporator, and a single expansion device; sensing the outside temperature; operating the compressor only at the first stage when the system is operating in the cooling mode; running the compressor at the first stage in the heating mode whenever the outside temperature is above the preselected limit; and operating the compressor at the second stage in the heating mode whenever the temperature outside falls below a preselected limit. 10. The method of claim 9 wherein said expansion device is a single orifice expansion valve.