GB2198482A

GB2198482A - Piston drive transmission structure in a rotary compressor

Info

Publication number: GB2198482A
Application number: GB08629828A
Authority: GB
Inventors: Ruling Chen
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-12-13
Filing date: 1986-12-13
Publication date: 1988-06-15
Also published as: GB8629828D0

Abstract

An electric motor driven shaft 23 directly actuates a rotary drive disc 24 with an integrally moulded crank pin 25 which actuates a piston disc 26 with a motion of eccentrically rotary stroke. A plurality of bearing rollers 28 on the outer peripheral surface of the piston disc 26 actuate a surrounding piston element 22 with a synchronous motion of eccentrically rotary stroke rolling on a cylinder wall 29, so as to decrease the frictional resistance at the cylinder wall 29 during suction and compression, save horse-power and enhance efficiency. <IMAGE>

Description

"PISTON DRIVE TRANSMISSION STRUCTURE IN A ROTARY COMPRESSOR" The invention relates to the piston drive transmission structure in a rotary compressor.

The piston structure and the manner of the intake and compression of a conventional rotary compressor are shown in Fig. 1 of the accompanying drawings. An air sealing member 3 is capable of reciprocatory displacement up and down in a groove 2 at the top of a cylinder 1 and projects into the cylinder 1. The interior of the cylinder 1 is divided by the sealing member 3 into a suction side 5, connected to and communicating with an intake port 4, and a compression side 7 connected to and communicating with an exhaust port 6. A compression spring 8 is mounted in the groove 2 in which the sealing member 3 is disposed so as to press against the top end surface of the sealing member 3, the bottom end surface of which closely contacts the outer peripheral surface of a disc piston 9.A motor-driven shaft 10 directly actuates the disc piston 9 which rotates along the cylinder wall 11, so that (when the compressor is a refrigerant compressor, for example) the refrigerant in the refrigeration cycle is suctioned into the cylinder 1 through the intake port 4, flows to the compression side 7 from the suction side 5 in the cylinder 1 to be compressed, flows out of the exhaust port 6 of the cylinder 1, and then flows back to the refrigeration cycle through an exhaust pipe to establish the refrigeration cycle. This known compressor in operation has the following drawbacks which render it impossible to enhance its efficiency: 1. The driving of the piston of a conventional rotary compressor consists in the motor-driven shaft 10 directly actuating the metallic disc piston 9 which rotates eccentrically along the cylinder wall 11.In the course of a compression stroke, the frictional force derived from the cylinder wall 11 and the action of the air sealing member 3 on the outer peripheral surface of the disc piston 9 is extremely large, and the disc piston 9 has to overcome the frictional resistance to allow the rotation of the disc piston 9, so the required horse-power is correspondingly increased. For example, with a power input of 1 HP, the maximum oil pressure bearable by a 1 ton air conditioner is only 450 psi, so it is impossible to achieve the purpose of saving power.

2. Since the frictional force of a conventional rotary compressor in operation is larger, the noise derived from its running is also larger and it tends to be noisy.

In view of the poor design of the piston drive transmission structure of a conventional rotary compressor, which cannot achieve the purpose of saving power during operation, the present inventor who has engaged in the manufacture of various compressors for a number of years, continuously and positively proceeded with experiment, research and innovation as a result of which he acquired a variety of results and experience, and eventually developed a new construction of power-saving rotary compressor which can substantially eliminate the aforesaid drawbacks of the conventional construction so as to achieve the purpose of saving power.

The present invention, which relates to an improved piston drive transmission structure in a rotary compressor, particularly relates to a novel compressor which is designed to decrease the frictional resistance on the cylinder wall in the course of running so as to achieve the purpose of saving power and enhancing efficiency.

The invention will now be further described with reference to the accompanying drawings which illustrate, by way of example, an embodiment of the invention. In the drawings: Fig. 1 is a diagrammatic sectional view of a conventional compressor; Fig. 2 is a diagrammatic longitudinal sectional view showing the relationship of the piston and cylinder of an embodiment of the invention; Fig. 3 is a lateral sectional view of the embodiment of Fig. 2; and Fig. 4 is a similar view showing the piston at a different position in its cycle of operation.

In order to enable the Examiner more clearly to understand the features and functions of the invention, they are hereinafter described in detail in conjunction with the accompanying drawings.

As shown in Figs. 2 and 3, the invention also has an air sealing member 16 capable of reciprocatory displacement up and down in a groove 15 at the top of a cylinder 14. The vane-like member 16 projects into the cylinder 14, the interior of which is divided by the sealing member 16 into a suction side 18 connected to and communicating with an intake port 17, and a compression side 20 connected to and communicating with an exhaust port 19. The groove 15 containing the sealing member 16 is closed at its upper end and can be connected to a source of compressed air at a coupling 21 (the exhaust port 19 may be connected to the pressure coupling 21), so that the air pressure urges the bottom end surface of the sealing member 16 into close contact with the outer peripheral surface of the disc piston 22 continuously.Since the disc piston 22 is made of abrasion and acid resistant, non-metallic material, neither a high frictional resistance nor any air leakage between the sealing member 16 and the disc piston 22 will occur.

So far as the operation of the embodiment is concerned, an electric motor output shaft 23 directly actuates a rotary crank disc 24 whereon an integrally moulded eccentric crank pin 25 actuates a piston disc 26 with a motion having an eccentrically rotary stroke. A plurality of bearing rollers 28 disposed respectively in corresponding arcuate grooves 27 on the outer peripheral surface of the piston disc 26 actuate the ring-like disc piston 22 with a synchronous planetary motion of eccentrically rotary stroke along the cylinder wall 29 so as to achieve the purpose of suction and compression.In the course of such compression, the disc piston 22 running on the cylinder wall 29 is actuated through the rollers 28 seated on the outer peripheral surface of the piston disc 26, so the frictional resistance between the disc piston 22 and the cylinder wall 29 will not be very large, and the disc piston 22 will have a rolling movement and will not have to cope with the force to cause the rotation of itself, so the horse-power required to drive the compressor is correspondingly decreased. For example, under a power input of 1/8HP, the maximum oil pressure bearable by a 1 ton air conditioner is 675 psi. In comparison with the conventionally driven piston under the same oil pressure and tonnage, the present invention can save about HP.

In view of the above, the primary object of the invention is to offer an improved piston drive transmission structure in a rotary compressor which can achieve the purpose of materially reducing the driving horse-power during compressor operation.

The secondary object of the invention is to make use of the structure of itself to decrease frictional noise during operation.

In summary, it is undeniable that the invention provides a practicable structural design since it is characterized by the foregoing advantages which can achieve the purpose of saving horse-power, decreasing frictional noise and enhancing practicability.

Claims

CLAIMS:

1. An improved piston drive transmission structure in a rotary compressor which is characterized by the following features: it is composed of a rotary drive disc, an eccentric crank pin, two piston discs and a plurality of bearing rollers, wherein the rotary drive disc and crank pin are integrally moulded and can be directly coupled to an electric motor output shaft; and on the other side the eccentric crank pin is pivotally connected to an inner one of said piston discs whereon a plurality of arcuate grooves are provided on its outer peripheral surface to receive the rollers on which the other piston disc is disposed concentrically surrounding the inner piston disc, so that the rotation of the electric motor output shaft actuates the inner piston disc with a motion having an eccentrically rotary stroke; and meantime, the rolling of the bearing rollers can actuate the outer piston disc running on the cylinder wall with a synchronous motion of eccentrically rotary stroke so as to decrease the frictional resistance and save horse-power during the operation of piston suction and compression.

2. An improved piston drive transmission in a rotary compressor as claimed in claim 1, wherein the individual members are made of an alloy of chromium and vanadium except that the outer piston disc supported on the bearing rollers is made of an abrasion and acid resistant, non-metallic material, so that the frictional resistance and noise during operation of the compressor can be decreased and the piston per se will be much more durable and practicable.

3. A piston drive transmission in a rotary compressor, substantially as herein particularly described with reference to Figs. 2 to 4 of the accompanying drawings.