Directional control valve for switching the mode of operation in a heat transfer system

A directional control valve for switching the mode of operation in a heat transfer system which includes a compressor, for compressing a refrigerant with discharge and suction ports, first and second heat exchangers, and an expansion valve provided between the first and second heat exchangers, comprising:

• a cylindrical valve body with a high pressure port which is fluidly connected to the discharge port through a conduit, a low pressure port which is fluidly connected to the suction port though a conduit, first and second ports which are connected to the first and second heat exchangers respectively through conduits;
• a first valve element which is enclosed within the valve body, and rotational between first and second rotational positions about the axis of the valve body;
• means for rotating the first valve element between the first and second positions;
• the first valve element including means for fluidly connecting, at the first rotational position, the high pressure port to the second port, and connecting the low pressure port to the first port, and at the second rotational position, connecting the high pressure port to the first port, and connecting the low pressure port to the second port to switch the flow direction of the refrigerant
• first and second pressure chambers which are integrally formed with the first valve element;
• means for fluidly connecting the first and second pressure chambers to the high pressure port;
• means for selectively fluidly connecting one of the first and second chambers to the low pressure port;
• and
• the first valve element rotating from first rotational position to the second rotational position when the second pressure chamber is fluidly connected to the low pressure port due to the pressure difference between the first and second pressure chambers, and rotating from second rotational position to the first rotational position when the first pressure chamber is connected to the low pressure port due to the pressure difference between the first and second pressure chambers.