US 5,865,604 AGranted

Displacement controlling structure for clutchless variable displacement compressor

AssigneeKabushiki Kaisha Toyoda Jidoshokki Seisakusho

InventorsMasahiro Kawaguchi, Masanori Sonobe, Ken Suitou, Tomohiko Yokono

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Abstract

A variable displacement compressor which has a suction chamber, a discharge chamber, and a crank chamber. The displacement of the compressor is controlled by supplying refrigerant to the crank chamber from the discharge chamber via a pressurizing passage and releasing the gas into the suction chamber via a pressure releasing passage. An increase in the pressure in the crank chamber decreases the displacement, and a decrease in the pressure in the crank chamber increases the displacement. A displacement controlling structure of the compressor includes an electromagnetic valve which alters the size of an area of the pressurizing passage. A computer controls the electromagnetic valve in accordance with commands to alter the displacement. The computer enlarges the opened area of the pressurizing passage by controlling the electromagnetic valve in response to commands to reduce the displacement.

Claims43

Dependent claims

A variable displacement compressor comprising:

a suction chamber;
a discharge chamber;
a pressure control chamber;
a supply passage interconnecting said discharge chamber with said pressure control chamber;
a pressure release passage interconnecting said pressure control chamber with said suction chamber;
inlet means for coupling a refrigerating circuit outlet to said suction chamber for supplying a gaseous refrigerant from said refrigerating circuit to said suction chamber;
means for drawing gaseous refrigerant from said suction chamber, subjecting it to compression, and discharging compressed gaseous refrigerant to said discharge chamber;
the displacement of said compressor being controlled by supplying said gaseous refrigerant through said supply passage from said discharge chamber to said pressure control chamber and delivering said refrigerant through said pressure release passage from said pressure control chamber to said suction chamber, said displacement decreasing when the pressure in said pressure control chamber increases, and said displacement increasing when the pressure in said pressure control chamber decreases;
a valve having a valve seat, a valve body, and means including a solenoid coupled to said valve body for moving said valve body continuously relative to said valve seat for changing the flow rate of said gaseous refrigerant through at least one of said supply and pressure release passages as a function of the energization of said solenoid between a first position for establishing maximum displacement of said compressor and a second position for establishing minimum displacement of said compressor;
and a controller coupled thereto for controlling said solenoid;
said controller and said valve being constructed for positioning said valve body at said first and second positions and at all positions in-between, whereby said suction pressure within said suction chamber can be adjusted over a predetermined range by said controller.

8 more elements

A variable displacement compressor having a suction chamber, a discharge chamber and a pressure control chamber, the displacement of a refrigerant from the compressor being controlled by supplying said refrigerant via a supply passage from said discharge chamber to said pressure control chamber and delivering said refrigerant via a pressure release passage from said pressure control chamber to said suction chamber, wherein said displacement decreases when the pressure in said pressure control chamber increases and said displacement increases when the pressure in said pressure control chamber decreases, said compressor further comprising:

a casing having said discharge chamber and said suction chamber;
a crank chamber defined in said casing, said crank chamber serving as said pressure control chamber;
a plurality of cylinder bores formed in said casing, each cylinder bore being connected to said discharge chamber and said suction chamber;
a plurality of pistons accommodated each in a different one of said cylinder bores;
a rotary shaft rotatably supported by said casing;
and
a swash plate supported on said rotary shaft for integral rotation with and inclining motion with respect to said rotary shaft, wherein said pistons draw said refrigerant into said cylinder bores from said suction chamber, compress said refrigerant and then discharge said refrigerant to said discharge chamber, and wherein the inclined angle of said swash plate is varied according to the pressure in said crank chamber and the displacement is altered according to the resulting inclined angle of said swash plate;
said supply passage connecting said discharge chamber to said crank chamber;
an electromagnetic valve disposed for changing the opening of said supply passage over a continuous range between two end positions;
a computer for controlling said electromagnetic valve in response to instructions to increase and instructions to decrease the displacement, said computer controlling said electromagnetic valve to enlarge the opening of said supply passage in response to instructions to decrease the displacement.

7 more elements

A variable displacement compressor having a suction chamber, a discharge chamber and a pressure control chamber, the displacement of a refrigerant from the compressor being controlled by supplying said refrigerant via a supply passage from said discharge chamber to said pressure control chamber and delivering said refrigerant via a pressure release passage from said pressure control chamber to said suction chamber, wherein said displacement decreases when the pressure in said pressure control chamber increases and wherein said displacement increases when the pressure in said pressure control chamber decreases, said compressor further comprising:

changing means for changing the opening of said pressure release passage in a continuous manner between two end positions;
and
control means for controlling said changing means in response to instructions to increase and instructions to decrease the displacement, said control means controlling said changing means to reduce the opening of said pressure release passage in response to instructions to decrease the displacement.

A clutchless variable displacement compressor to be driven directly by a power source, said compressor comprising:

a casing having a discharge chamber and a suction chamber;
a crank chamber defined in said casing;
a plurality of cylinder bores formed in said casing, each cylinder bore being connected to said discharge chamber and said suction chamber;
a plurality of pistons each accommodated in a different one of said cylinder bores;
a rotary shaft rotatably supported by said casing;
a swash plate supported on said rotary shaft for integral rotation with and inclining motion with respect to said rotary shaft, wherein said pistons draw a refrigerant into said cylinder bores from said suction chamber, compress said refrigerant and then discharge said refrigerant to said discharge chamber, and wherein the inclined angle of said swash plate is varied according to the pressure in said crank chamber and the displacement is altered according to the resulting inclined angle of said swash plate;
a control passage connecting said crank chamber to at least one of said discharge chamber and said suction chamber;
changing means for changing the opening of said control passage, wherein the changed opening results in altering the pressure difference between the pressure in said crank chamber and the pressure in said cylinder bores, both pressures acting on said pistons, said pressure difference determining the inclined angle of said swash plate to change the stroke of each piston, thereby changing the displacement of the compressor, wherein said changing means includes:
a valve body for changing the opening of said supply passage;
a pressure sensing member responsive to a suction pressure for transmitting variation of said suction pressure to said valve body;
and
a solenoid for biasing said valve body when energized;
and
control means for controlling the amount of current supplied to said solenoid in a continuous manner between two end values in response to instructions to change the displacement, wherein said control means controls the amount of the current supplied to said solenoid such that the displacement is changed to a minimum level in response to minimum displacement instructions, and wherein said control means controls the value of the current supplied to said solenoid to change the suction pressure in response to a cooling demand.

11 more elements

Dependencies are inferred from the claim text.