JPH05240536A - Refrigerant compressor - Google Patents

Abstract

PURPOSE: To prevent oil loss, contamination of oil and damages to an apparatus by employing self-lubrication (oil-less) in a refrigerant compressor. CONSTITUTION: A refrigerant compressor comprises a cylinder wall 102, a cylinder head 104 surrounding one end of the cylinder wall 102 and defining an inlet port 106 and an exhaust port 108, and a valve means for controlling refrigerant flow passing through the inlet port 106 and the exhaust port 108. A piston 110 is slidably received in the cylinder wall 102, and a gap between the piston 110 and the cylinder wall 102 is sealed by a self-lubricating annular bidirectional seal 112. The piston 110 is reciprocated within the cylinder wall 102, so as to effect vacuum suction and high pressure exhaustion. With this constitution, oil loss, contamination of oil and damages to the compressor itself related to these are avoided.

Description

Detailed Description of the Invention

This application is a continuation-in-part of US patent application Ser. No. 07 / 551,936 dated July 12, 1990.

[0002]

FIELD OF THE INVENTION The present invention relates to the field of cooling systems.

[0003]

BACKGROUND OF THE INVENTION Global attention to the seriousness of the environmental impact of chlorofluorocarbon refrigerant emissions into the atmosphere has now led to global agreement to regulate the production and use of chlorofluorocarbons. ..
As a result of the above adjustments, the cost of chlorofluorocarbon refrigerants is expected to rise dramatically.

Therefore, attention has been paid to the recovery of the refrigerant.
A chlorofluorocarbon refrigerant recovery device is disclosed in US Pat. No. 4,766,733, also assigned to the assignee of the present invention, the disclosure of which is incorporated herein by reference.

When outdoor service is required for a cooling installation, a refrigerant recovery system may be provided, for example, to allow service personnel to carry the system from his car to the rooftop air conditioner without undue time and effort. It should be easily portable.

The known portable CFC recovery unit is
It includes a conventional refrigerant compressor that transfers refrigerant from a device such as a cooling unit to a receiver such as a pressure vessel. The use of conventional refrigerant compressors in portable CFC recovery units has several drawbacks.

The portability of a particular portable CFC recovery unit depends largely on the weight of the unit. A normal 1/2 HP refrigerant compressor weighs about 40
Pounds make up a significant portion of the total weight of a typical recovery unit, which is about 70 to about 100 pounds.

The problems associated with the use of conventional refrigerant compressors in portable CFC recovery units have been recognized by the industry and are described, for example, in J. Wheeler, “Th
ePerfect HCFC Recovery Ma
chine, " Contracting Busin
ess , October 1990, p. 7 and P
eter Powell, “'Don't Wait”
To Buy Recyclers' MFRS T
ell HVAC Contractors, " Th
e Air Conditioning, Heati
ng and Refrigeration News,
See October 7, 1991.

Further, conventional refrigerant compressors are designed to operate in a closed loop in which lubricating oil is mixed with the refrigerant and continuously circulates within the system. The open loop refrigerant recovery system does not return the lubricating oil to the compressor, which may result in insufficient lubrication and premature wear of the compressor. This problem is compounded by the fact that a vacuum must be realized in the unit from which the refrigerant has been recovered. However, the lubricating oil present in the refrigerant recovered in the closed loop system can contain contaminants such as hydrochloric acid and / or hydrofluoric acid that can damage the compressor.

[0010]

SUMMARY OF THE INVENTION The present invention is a device for recovering a compressible refrigerant from a cooling system and delivering the recovered refrigerant to a refrigerant receiver, which makes the refrigerant recovery unit lightweight, that is, It is an object of the present invention to provide a device which weighs about 30 pounds and is free from the disadvantages caused by lubricating oil.

[0011]

[Means for Solving the Problems] To achieve the above object,
The present invention provides a lightweight, or about 10 pound, refrigerant compression device. The compressor includes a tubular cylinder wall, a cylinder head that surrounds one end of the cylinder wall and defines an intake port and an exhaust port, and valve means that controls the flow through the intake port and the exhaust port. A piston is slidably received in the cylinder wall, and the piston is provided with a self-lubricating annular bidirectional sealing means for sealing between the piston and the cylinder wall. The compression device of the present invention further includes means for reciprocating the piston within the cylinder wall to provide an intake stroke and an exhaust stroke. The compression device of the present invention, due to its self-lubricating feature, avoids the problems of oil loss, oil contamination, and the associated damage to the device itself, and does not require an oil separator. The feature that a bi-directional seal is used allows the compressor of the present invention to completely remove spent refrigerant from the cooling system by implementing a vacuum intake stroke.

In a preferred example, the cylinder wall is made of hardened steel and the inside surface of the cylinder wall is finished by honing to a finished surface of about 2 μm to about 16 μm.

Preferably, the piston is made of aluminum or aluminum alloy.

In a preferred example, the reciprocating means includes an electric motor, a crank arm operatively associated with the electric motor, and a connecting rod operably associated with the crank arm and the piston. The crank arm is attached to the input shaft, and the electric motor and the crank arm are operatively associated with each other by a speed reducing means coupling the electric motor and the input shaft.

In a particularly preferred example, the electric motor is about 8,0.
Including an open frame high speed AC / DC Class A electric motor having an operating speed of 00 rpm to about 25,000 rpm, the reduction means providing a reduction of about 4: 1 to about 6: 1;
The operating speed of the input shaft and crank arm is about 20,
From 00 rpm to about 4,000 rpm. Compared to a conventional compressor motor, the compressor motor of the present invention is much lighter, but operates at a relatively high speed. The use of a lightweight high speed electric motor reduces the speed reducing means of the compressor of the present invention to the speed of the input shaft so that the piston-cylinder assembly of the compressor of the present invention operates within the range in which a self-lubricating piston seal can be used. It becomes possible by making it.

In a particularly preferred example, the piston is laterally displaced relative to the crank arm on the compression side such that the extended central axis of the piston is laterally displaced from the center of rotation of the crank arm. Displacement of the piston laterally with respect to the center of rotation of the crank arm dramatically reduces wear on the piston seal, thereby increasing the life of the compressor of the present invention having such an arrangement.

The bidirectional seals used in the compressor of the present invention, of whatever type, are exposed to various refrigerants and associated contaminants under high pressure, ie about 400 ps.
Relatively high speed under pressure of ig, that is, about 2,000-
Allows operation at 4,000 rpm.

In a preferred example, the piston comprises a first annular groove and a pair of end annular grooves. One end groove is located on each side of the first annular groove and is spaced apart from the first annular groove. A ring-shaped seal is arranged in the first annular groove, and a rubber elastic means for pushing the ring-shaped seal toward the cylinder wall is arranged between the piston and the ring-shaped seal in the first groove. .. A guide ring is arranged in each end annular groove to maintain the piston in a parallel orientation to the cylinder wall.

In a particularly preferred embodiment, the annular seal comprises a carbon-loaded PTFE matrix composite, the guide ring comprises a graphite-loaded PTFE matrix composite, and the rubber elastic means comprises a chlorosulfonated elastomer, a polychloroprene elastomer, a perfluorinated elastomer or Includes EPDM elastomer ring.

In another preferred embodiment, the piston is provided with a pair of annular grooves, the sealing means being disposed in one of said annular grooves and sealing between the piston and the cylinder wall to provide a vacuum suction stroke. And a second annular one-way seal that is disposed in the other annular groove and that seals between the piston and the cylinder wall to achieve a high-pressure exhaust stroke. Including.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The refrigerant recovery unit shown in FIG. 1 enables recovering a compressible refrigerant from a cooling system 2 and delivering the recovered refrigerant to a refrigerant receiver 6. The cooling system 2 has a port 4 and the refrigerant receiver 6 has a first port 8 and a second port 10.

The illustrated unit includes an identification chamber 12. The identification chamber 12 has an intake port 14, a liquid intake port 15, a liquid discharge port 16 and a gas discharge port 18. A fluid flow passes through a conduit 20 that connects the port 4 of the cooling system and the intake port 14 of the identification chamber 12. The valve 22 allows control of the flow through the conduit 20 and the filter dryer 24 is the cooling system 2.
It allows the removal of moisture and particulate contaminants from the refrigerant taken from the. A conduit 26 is provided to direct the liquid phase refrigerant from the discharge port 16 of the identification chamber 12 to the first port 8 of the receiver 6. The conduit 26 is the conduit 2
6, a solenoid valve 28 for controlling the flow through the valve 6 and an actuator 30 for opening and closing the solenoid valve 28 are provided.

The refrigerant recovery unit also includes a compressor 32, a condenser 34 and a back pressure regulator 36 that condenses the vapor phase refrigerant to provide a low pressure flow of substantially liquid phase fluid to conduit 26. The vapor phase refrigerant is discharged from the discharge port 18 of the identification chamber 12.
To compressor 32 in conduit 38. Conduit 38 includes a solenoid valve 40 that controls the flow through conduit 38. An actuator 42 is installed to open and close the solenoid valve 40. Through conduit 44, fluid flows from compressor 32 to condenser 34. Condensing device 3
A fan 46 that causes an air flow to remove heat is installed between the No. 4 and the back pressure regulator 36. The fluid passing through the back pressure regulator 36 is introduced into the conduit 26 via the conduit 50.

Is the compressor 32 a normal refrigerant compressor?
Alternatively, it may be the refrigerant compression device of the present invention. 2 and 3
The compression device 32 'of the present invention shown in FIG.
2 includes a piston-cylinder-cylinder head assembly 101. The tubular cylinder wall 102 can be made of steel, stainless steel, or the like. Preferably, the cylinder wall 1
02 consists of hardened steel. Most preferably, the cylinder wall 1
02 consists of A2 steel hardened to Rockwell C60-65. The inner surface of the cylinder wall 102 is preferably a very smooth finished surface, eg, 2-16 μm, with a honing finish to reduce wear and leakage of the piston seal (described in detail below). One end of the tubular cylinder wall 102 is attached to the cylinder head 10
4 is surrounded. The cylinder head 104 has an intake port 106 and an exhaust port 108, and is equipped with intake and exhaust valves (not shown) that control the flow through these ports 106 and 108. A piston 110 is slidably received in the tubular cylinder wall 102. Preferably, the housing of the compression device 32 ', the piston 110 and the cylinder head 104 are all made of aluminum or a light metal alloy.

An annular seal 112 around the piston 110
Is installed. The ring-shaped seal 112 is a self-lubricating ring-shaped bidirectional seal, and is composed of a piston 110 and a tubular cylinder wall 102.
The space between and is sealed so that a high pressure exhaust stroke and a vacuum intake stroke are performed in the apparatus of the present invention. Piston 110
The central axis of the piston 110 is the tubular cylinder wall 102.
A piston ring 113 is installed in order to maintain the position in line with the central axis of the. Piston rod 114
Causes piston 110 to reciprocate within tubular cylinder wall 102. The piston rod 114 is rotatably mounted on the wrist pin 116. The wrist pin 116 is fixed to the end of the crank arm 118. The crank arm 118 is rotated via the shaft 120.
Gears 122 and 124 move shaft 120 to electric motor 128.
Of the output shaft 126.

Preferably, the electric motor 128 is an open frame AC / DC Class A electric motor having an operating speed of about 8,000 to about 25,000 rpm. Gears 122 and 124
Indicates that the operating speed range of the shaft 120 is about 2,000-
4,000 rpm, or about 4: 1 to about 6: 1 deceleration over the operating speed range of the electric motor 128.

Significantly, the piston-cylinder assembly of the compressor of the present invention has a speed of 2,000-4.
When operated at 000 rpm, friction between the piston seal and the cylinder wall causes high temperatures, for example 300-500 ° F., and accelerated wear of the seal material, which can shorten the life of the seal. Particularly high demands are placed on the self-lubricating two-way seals of the inventive compression device. Each of the example piston seals detailed below has a long life, such as at least 500 hours of functioning in a high speed, high pressure, high temperature, and chemically unfavorable environment in the compressor of the present invention.

FIG. 4 schematically shows a first example of the piston-cylinder assembly of the compressor of the present invention. In this piston-cylinder assembly 144, the cylinder 14
6 is a rotation center 1 of the crank arm 148 when the central axis line 145 of the cylinder 146 and the piston 150 is extended.
The orientation is such that it passes through 49. A circle drawn by the rotation of the crank arm 148 is shown by a dotted line in FIG. Piston 150 is slidably received in cylinder 146 and is coupled to crank arm 148 via wrist pin 152, connecting rod 154 and crank pin 156. The illustrated piston-cylinder assembly 144 is in the middle of a compression stroke. The compression stroke, that is, the upward movement of the piston 150, progresses as the crank arm 148 further rotates in the direction indicated by the arrow, and the end of the crank arm 148 reaches the top dead center so that the central axis of the crank arm 148 and the piston 150 move. When the center axis of 150 coincides, the process ends. The force acting on the piston 150 during the compression stroke can be divided into two components, an upward compressing force F1 and a lateral force F2 acting in a direction perpendicular to the acting direction of the compressing force F1.

Assembly 1 of FIG. 4 of the compression device of the invention.
In the example including the piston-cylinder assembly corresponding to 44, the wear pattern of the seal (detailed later) of the piston 110 corresponds to the direction of the lateral force F2, i.e., the seal is the piston lateral to which the lateral force F2 acts. Was found to wear relatively rapidly at.

FIG. 5 shows a preferred example of the piston-cylinder assembly of the compression device of the present invention. This piston
In the cylinder assembly 158, the center axis 159 of the cylinder 160 and the piston 164 is the crank arm 162.
Is laterally displaced from the rotation center 161 of the. Preferably, the central axis 159 of the cylinder 160 is displaced from the center of rotation 161 of the crank arm 162 by a distance equal to about 1/2 the radius (D) of the circle drawn by the rotation of the crank arm 162. Piston 164 is cylinder 1
Wrist pin 1 slidably received in 60 and
66, the connecting rod 168 and the crank pin 170, and is connected with the crank arm 162.

The piston-cylinder assembly 158 shown in FIG. 5 is in the middle of the compression stroke. The compression stroke continues, similar to that described above with respect to FIG. 4, until the crank arm 162 further rotates and the crank pin 170 located at the end of the crank arm 162 reaches the top dead center of the crank arm 162. Unlike the case of the example in FIG. 4, the top dead center of the crank arm 162 is not on the center axis of the cylinder 160, and the crank pin 170 is in the middle of moving from the position shown in FIG. 5 to the top dead center of the crank arm 162. Cross the central axis of 160.

The force acting on the piston 164 can be divided into two components, an upward compressing force F3 and a lateral force F4 acting in a direction perpendicular to the acting direction of the compressing force F3.
The inventor of the present invention has found that the preferred example shown in FIG. 5 remains the same except for the above-mentioned factors: the compressive force F3 is less than F1, i.e. about 3% less, while the lateral force F4 is less than F2. Remarkably, that is, about 50% smaller, -Since the lateral force F4 is smaller, the lateral force acting on the piston seal is correspondingly smaller, and the piston 16
The fast wear pattern associated with lateral force observed with the seal installed at No. 4 should be effectively avoided;
6 and the crankpin 170 are less loaded, resulting in longer bearing life, a reduction of approximately 8% of the power input required by the crank arm 162 during the compression stroke, and a smaller lateral force F4. Piston 164
The friction between the cylinder and the cylinder 160 is remarkable, that is, about 400
It has been evaluated that it has a reduction in%, as an advantage over the example of FIG.

The combination of the various advantages described above should significantly extend the life of the compression system including the piston-cylinder assembly shown in FIG.

FIG. 6 shows an example of a self-lubricating annular bidirectional seal of a compression device 32 'according to the present invention. The piston 110 has an annular groove 130 around its circumference. An annular seal 112 is located in the groove 130. Preferably, the ring seal 112 comprises graphite or a carbon-loaded fluoropolymer, ie, polytetrafluoroethylene, for example.
Chemical resistant elastomer ring 132 is piston ring 1
12 is pushed towards the cylinder wall 102 to achieve a bidirectional seal. Preferably, the elastomer ring 132 comprises chlorosulfonated polyethylene elastomer, polychloroprene elastomer, perfluorinated elastomer or ethylene-propylene-diene (EPDM) elastomer.

FIG. 7 is a schematic partial cross-sectional view of a seal 172 which is another example of a self-lubricating annular bidirectional seal of a compression device 32 'according to the present invention. In this figure, the cylinder wall 174
Also shown is piston 176. The piston 176 is
It has three annular grooves 178, 180 and 182 spaced apart from each other. An annular seal 184 is disposed in the central groove 180, and the annular seal 184 is a groove 1
A cylinder wall 174 is formed by an elastomer ring 186 located within the seal 80 between the seal 184 and the piston 176.
Have been pushed to. End groove 17 located at both ends
8 and 182, a piston 176 is installed in the piston 17
Guide rings 188 and 190 are respectively arranged to keep the central axis of 6 aligned with the central axis of the cylinder wall 174.

Annular seal 184 and guide ring 188
And 190 preferably consist of graphite or carbon-loaded fluoropolymer matrix composites. Most preferably, the ring seal 184 comprises a carbon-loaded polytetrafluoroethylene matrix material known as TURCITE ™ 109. A suitable seal is
For example, W. S. Shamban Company,
Available from Fort Wayne, Indiana. Guide rings 188 and 190 are TURCIT
Most preferably it consists of a graphite-loaded polytetrafluoroethylene matrix material known as E ™ 51. A suitable wear ring is, for example, W. S.
It is available for purchase from the Shamban Company.

The TURCITE ™ 109 material has a tensile strength of 3,000 psi and an elongation at break of 200% (both measured according to ASTM D 1457-81A), a specific gravity of 2.10 and a Shore D of 60 to 65.
With hardness. The TURCITE ™ 51 material has a tensile strength of 1,800 psi and an elongation at break of 100% (both measured according to ASTM D 1457-81A), a specific gravity of 2.06 and a Shore D hardness of 63.

The elastomer ring 186 is preferably C
It consists of an elastomer that is FC resistant, oil resistant, and also resistant to contaminants such as HF and HCl, and has excellent temperature resistance, ie, stable at temperatures of 300-400 ° F. Suitable materials include perfluorinated elastomers, chlorosulfonated polyethylene elastomers, polychloroprene elastomers and ethylene-propylene-diene elastomers. Most preferably, elastomer ring 1
86 comprises an elastomer known as TUREL ™ EGA. Suitable elastomer rings are described, for example, in W.
S. It can be purchased from Shamban. It should be noted that the choice of elastomer may limit the application of the compression device of the present invention, since no single selected elastomer may have the highest resistance to any CFC. is there.

FIG. 8 is a schematic cross-sectional view of yet another example of various applications of the self-lubricating annular bidirectional seal of the compression device 32 'according to the present invention. In this example, a piston body 110 'and a piston cap 111 tightly coupled to the piston body 110' are slidably received in the tubular cylinder wall 102, and two annular grooves 134 are provided.
And 139 are provided on the outer circumference of the piston body 110 '. A pair of chemical resistant one-way seals 136 and 140 are disposed in the grooves 134 and 139, respectively. In the preferred example shown, the seals 136 and 140 are "U".
Cup "type seals, each having an annular groove. Coil springs 138 and 141 disposed within the annular grooves of seals 136 and 140, respectively, are seals 136 and 140.
Are pushed radially outward, ie towards the tubular cylinder wall 102. The piston body 110 'is surrounded by a pair of guide rings 142 and 143 which maintain the piston body 110' in a position where its central axis coincides with the central axis of the cylinder wall 102.

Both seals 136 and 140 are preferably made of fluoropolymer. More preferably, both one-way seals 136 and 140 are made of glass-loaded fluoropolymer matrix composite material. Most preferably,
U-cup seals 136 and 140 are made of a material known as TURCITE ™ 404. TURCIT
E (TM) 404 material has a tensile strength of about 3,500.
psi (according to ASTM D638), elongation at break approx. 2
30% (according to ASTM D638), Shore D hardness about 55 (according to ASTM D2240), and specific gravity 2.1.
8 (according to ASTM D792) and molybdenum-doped polytetrafluoroethylene.

Both springs 138 and 141 are preferably made of stainless steel. Most preferably, the spring 13
Both 8 and 141 are made of 302 stainless steel.

A suitable U-cup seal-spring assembly is described, for example, in American Variseal, B.
Commercially available from roomfield, Colorado.

Guide rings 142 and 143 are preferably composed of a graphite-loaded polytetrafluoroethylene matrix material. Most preferably, the guide ring 1
42 and 143 are the TURCITE (trademark) mentioned above.
It consists of 51 materials.

FIG. 9 shows a modification of the compression device according to the present invention. The compressor 32 "includes an electric motor 128 ', a rotatably mounted output shaft 126, a rotatably mounted input shaft 120', a crank arm 118 ', a piston rod 114', and a piston.
2 except that pulleys 194 and 196 and belt 198 are used in place of gears 122 and 124 as a means of transmitting power from shaft 126 'to shaft 120', including cylinder-cylinder head assembly 101 '. Similar to device 32 '. Belt driven compressors are more cost effective than gear driven devices and require more frequent maintenance than gear driven devices, while repairs are easier and cheaper. The belt driven device is also less noisy and less vibrating than the gear driven device of FIG.

Returning to FIG. 1, valve 28 is normally closed and valve 40 is normally open. The identification chamber 12 is
A float sensor 52 is included to detect the level of liquid phase refrigerant in the chamber 12. The sensor 52 responds to the level of liquid phase refrigerant in the identification chamber 12 and emits a control signal when the identification chamber 12 is filled with liquid phase refrigerant. The actuators 30 and 42 respond to this control signal. In response to the control signal, the actuator 42 closes the valve 40 to prevent liquid from flowing from the identification chamber 12 to the compressor 32, while the actuator 30 opens the valve 28 to eject liquid from the identification chamber 12. And allows access to the receptor 6 through the conduit 26.

A bypass conduit 56 is provided to allow fluid to flow from the condenser 34 directly to the intake port 8 of the receiver 6. Bypass conduit 56
Is a solenoid valve 58 that controls the flow through the conduit 56.
It is equipped with. An actuator 60 is installed to open and close the solenoid valve 58. The valve 58 is normally closed. The pressure sensor 62 included in the identification chamber 12 responds to the pressure in the identification chamber 12 and issues a control signal when the pressure in the identification chamber 12 falls below a predetermined value. Actuator 60 responds to this control signal to open valve 58.

The refrigerant recovery unit shown in FIG. 1 includes a safety chamber 64. Safety chamber 64 has intake port 6
6, a gas discharge port 68, and a liquid discharge port 70. A conduit 72 is provided to allow fluid to flow from port 10 of receiver 6 to intake port 66 of safety chamber 64. Conduit 72
A solenoid valve 74 is provided to control the flow through the conduit 72. An actuator 76 is installed to open and close the solenoid valve 74. The conduit 78 allows fluid to flow from the gas outlet port 68 of the safety chamber 64 to the conduit 38 and further to the compressor 32. Conduit 8
The zero has a solenoid valve 82 that controls the flow through the conduit 80. An actuator 84 is installed to open and close the solenoid valve 82.

An intake tube 86 extends through the port 10 of the receiver 6 and its open end 88 extends into the receiver 6.

When the liquid refrigerant level in the receiver 6 is below the open end 88 of the intake tube 86, the gas refrigerant flows through conduit 72, safety chamber 64 and conduit 78 to the compressor 32. Flowing.

The liquid level rises as the refrigerant fills the receiver 6 and finally ends 88 of the intake tube 86.
Reach. If more liquid is introduced into the receiver 6 after the liquid level in the receiver 6 reaches the level of the open end 88 of the intake tube 86, the liquid-phase refrigerant is forced out of the conduit 72 and into the intake port. From 66 into the safety chamber 64. Sensor 90 installed inside the safety chamber 64
Responds to the liquid level in the safety chamber 64. When liquid refrigerant enters the safety chamber 64, the sensor 90 emits a control signal. In response to this control signal, actuators 30, 42 and 76 close valves 28, 40 and 74, respectively, and switch 33 shuts off power to compressor 32.

The refrigerant recovery unit shown in FIG. 1 has two functional modes, one for recovering the refrigerant from the cooling system (recovery mode) and the other for supplying the refrigerant obtained from the receiver to the cooling system (supply mode). Can be used.

In the recovery mode, the compressor 32 and the condenser fan 46 are turned on. The compressor 32 reduces the pressure in the receiver 6 and compresses the incoming vapor phase refrigerant stream 38. The refrigerant that vaporizes and flows out from the receiver 6 is the conduit 72,
Guided by intake port 66, safety chamber 64, discharge port 68 and conduit 78, it joins the incoming gas stream 38. The temperature of the liquid-phase refrigerant remaining in the receiver 6 decreases due to vaporization of the refrigerant flowing out of the receiver 6. This refrigerant recovery unit maintains a differential pressure that moves the refrigerant from the cooling system 2 to the receiver 6 until substantially all of the refrigerant has been removed from the cooling system 2.

In the supply mode, the compressor 32 is turned on, the fan 46 is turned off, the back pressure regulator 36 is closed, and the valve 58 is opened. The refrigerant in the receiver 6 is vaporized and flows out, and is compressed in the compressor 32 to become a high-pressure and high-temperature refrigerant flow. The high-pressure, high-temperature refrigerant stream is introduced into the receiver 6 via the conduit 56 to increase the pressure inside the receiver 6, so that the refrigerant is extruded from the receiver 6 and flows in the conduit (not shown), It reaches the cooling system 2 which is supplied with refrigerant.

The identification chamber 12 is provided with a compressor 32, as the liquid-phase refrigerant moves from the cooling unit 2 to the refrigerant receiver 6.
The time it takes to bypass the condenser 34 and the back pressure regulator 36 and thereby withdraw the refrigerant from the cooling system 2 has been determined using the apparatus disclosed in US Pat. No. 4,766,733. This makes it possible to significantly reduce the time required in some cases.

A conventional refrigerant receiver is equipped with a safety valve which prevents the internal pressure in the receiver from exceeding the rated pressure of the container. The safety valve opens under a predetermined maximum pressure that is less than the maximum rated pressure of the receiver. The amount of refrigerant introduced into the receiver must be controlled in order to avoid creating internal pressure in the receiver that causes the safety valve to open. The amount of refrigerant introduced into the normal refrigerant container,
It is controlled by the weight of the refrigerant. When recovering refrigerant from an outdoor cooling system, the weighing device is a cumbersome presence as an auxiliary facility to carry. Safety chamber 6 of FIG.
4 allows control of the amount of refrigerant introduced into the receiver,
At that time, it is not necessary to add any equipment to the illustrated refrigerant recovery unit.

[0056]

The features of the compressor according to the invention lead to some particularly favorable advantages in connection with the recovery of the refrigerant.

Conventional refrigerant compressors are typically bulky devices with thick cast iron cylinder walls, ie, typically about 40 lbs, awkward devices. The compression device of the present invention is lightweight, i.e. weighs only about 10 lbs and is easy to carry, thus providing a lightweight, i.e. only about 30 lbs, easily portable refrigerant recovery unit.

Generally, the materials of construction of conventional refrigerant compressors are not resistant to impurities such as acids present in the spent refrigerant. The compressor of the present invention is configured to transfer contaminated refrigerant.

Conventional refrigerant compressors operate in a closed loop refrigeration system in which lubricating oil moves around the loop to continuously lubricate the compressor. Recovery of spent refrigerant is essentially an open loop process. Each time the spent refrigerant travels from the refrigeration system, through the compressor, and into the receiver, the compressor is flushed with lubricating oil. The refrigerant compression device of the present invention is self-lubricating, that is, oilless, and therefore does not require an oil separator and therefore does not increase the weight thereof, and also causes oil loss, oil pollution, and compression related thereto. Avoids equipment damage.

A conventional refrigerant compressor includes a one-way seal,
The vacuum suction stroke cannot be realized. The seal installed on the piston of the refrigerant compression device of the present invention is a bidirectional type, and therefore, the refrigerant compression device of the present invention makes the refrigerant intake pressure smaller than the atmospheric pressure to completely remove the used refrigerant from the cooling system. Can be used to enable

While the preferred embodiments of the invention have been illustrated and described herein, various modifications and substitutions to these embodiments are possible without departing from the spirit and scope of the invention. Therefore, the contents of this specification should be understood as illustrative of the present invention and not limiting.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing a refrigerant recovery unit.

FIG. 2 is a schematic top view of the refrigerant compression device of the present invention.

FIG. 3 is a partial cross-sectional view of the refrigerant compression device of the present invention.

FIG. 4 is a schematic explanatory view showing a part of an example of a piston-cylinder assembly of a refrigerant compression device according to the present invention.

FIG. 5 is a schematic explanatory view showing a part of a modified example of the piston-cylinder assembly of the refrigerant compression device according to the present invention.

FIG. 6 is a partial cross-sectional view of an example of sealing means of the refrigerant compression device of the present invention.

FIG. 7 is a partial cross-sectional view of a second example of the sealing means of the refrigerant compression device of the present invention.

FIG. 8 is a partial cross-sectional view of a third example of the sealing means of the refrigerant compression device of the present invention.

FIG. 9 is a schematic explanatory view showing a modified example of the refrigerant compression device of the present invention.

[Explanation of symbols]

 102 Cylinder Wall 104 Cylinder Head 106 Intake Port 108 Exhaust Port 110 Piston 112 Annular Seal 114 Piston Rod 118 Crank Arm 120 Shaft 130 Annular Groove 132 Elastomer Ring

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Charles Kay Huh Owner United States, Masachi Yousets 01106, Longmeadow, Gracie Gutter Road 68

Claims (27)

[Claims] 1. A device for compressing a vapor phase refrigerant, the tubular cylinder wall extending from a first end to a second end,
A cylinder head that surrounds the second end of the cylinder wall and defines an intake port and an exhaust port; valve means that controls the flow through the intake port and the exhaust port; and slidably received within the cylinder wall. A refrigerant including a piston, a self-lubricating bidirectional sealing means for sealing between the piston and the cylinder wall, and means for reciprocating the piston in the tubular cylinder wall to realize an intake stroke and an exhaust stroke. Compressor. 2. The apparatus according to claim 1, wherein a vacuum intake stroke and a high pressure exhaust stroke are performed. 3. The device according to claim 1, wherein the cylinder wall is made of stainless steel or heat-treated steel. 4. The inner surface of the cylinder wall is about 2 μm to about 1 μm.
The device according to claim 1, which has a finished surface of 6 μm. 5. A device according to claim 1, wherein the piston and the cylinder head are both made of aluminum. 6. The piston is provided with a first annular groove on its outer circumference, and the sealing means is disposed between the piston and the annular seal in the annular groove, the annular seal being disposed in the annular groove. 2. A device according to claim 1 including a rubber elastic means for pushing the annular seal towards the cylinder wall. 7. The device of claim 6, wherein the ring seal comprises a fluoropolymer. 8. The device of claim 7, wherein the ring seal comprises a carbon particle-loaded polytetrafluoroethylene matrix composite. 9. The rubber elastic means is an elastomer ring, the ring comprising chlorosulfonated polyethylene elastomer or polychloroprene elastomer, perfluorinated elastomer or ethylene-propylene-diene elastomer. Equipment. 10. A piston comprises a pair of end annular grooves, one on each side of the first annular groove and spaced apart from the groove, wherein the piston is in each of these end grooves. 7. An apparatus according to claim 6, wherein one of a pair of guide rings is arranged to maintain its central axis in a position coinciding with the central axis of the cylinder wall. 11. The device of claim 10, wherein the guide ring comprises a graphite-loaded polytetrafluoroethylene matrix composite material. 12. The piston comprises first and second annular grooves spaced apart from each other, and the sealing means seals between the piston and the cylinder wall disposed in the first annular groove. First annular one-way seal for realizing a vacuum suction stroke and a second annular seal disposed in the second annular groove for sealing between the piston and the cylinder wall to realize a high pressure exhaust stroke. The device of claim 1 including a one-way seal. 13. The device of claim 12, wherein each one-way seal includes a seal annulus having an annular groove and a metal coil spring disposed within the annular groove. 14. The device of claim 13, wherein the seal ring comprises a glass-loaded fluoropolymer matrix material and the metal coil spring comprises stainless steel. 15. The apparatus of claim 11 further including guide ring means for maintaining the piston in a position where its central axis coincides with the central axis of the cylinder wall. 16. The apparatus of claim 15 wherein the guide ring means comprises a graphite-loaded fluoropolymer matrix material. 17. The reciprocating means comprises an electric motor, a crank arm operatively associated with the electric motor, and a connecting rod operatively associated with the crank arm and the piston. apparatus. 18. A crank arm is attached to the input shaft, the electric motor includes an output shaft, and the electric motor and the crank arm are operatively associated with each other by a reduction means connecting the output shaft and the input shaft of the electric motor. 18. The device according to claim 17, characterized in that 19. The apparatus of claim 18, wherein the speed reducing means includes a drive gear mounted on the output shaft of the electric motor and a driven gear mounted on the input shaft. 20. The reduction means comprises an output pulley mounted on the output shaft of the electric motor, an input pulley mounted on the input shaft, and a belt connecting the input and output pulleys to each other. Claim 1
9. The device according to item 9. 21. The apparatus of claim 17, wherein the electric motor comprises an open frame high speed AC / DC Class A electric motor. 22. The apparatus of claim 17, wherein the operating speed of the output shaft of the electric motor is from about 8,000 rpm to about 25,000 rpm. 23. The apparatus of claim 22, wherein the speed reducing means provides a speed reduction of about 4: 1 to 6: 1. 24. The operating speed of the input shaft is about 2,000.
24. The device of claim 23, which is from 0 rpm to about 4,000 rpm. 25. The piston according to claim 17, wherein the piston is rotationally symmetric with respect to the central axis, the crank arm has a center of rotation, and extending the central axis of the piston passes through the center of rotation of the crank arm. apparatus. 26. The piston is rotationally symmetrical with respect to a central axis, the crank arm has a center of rotation, and the piston has a central axis of rotation of the piston with respect to a center of rotation of the crank arm. 18. The device of claim 17, wherein the device is laterally displaced toward the compression side such that it is laterally displaced from the center. 27. A crank arm is connected by a connecting rod and a crank pin, wherein the crank arm draws a circular actuation line having a radius equal to the distance between the center of rotation of the crank arm and the crank pin, and the piston is The center axis of the piston is transverse to the center of rotation of the crank arm, and is half the radius of the circular working line drawn by the crank arm.
27. The device according to claim 26, wherein the device is displaced so as to be displaced by a distance corresponding to.