US3150503A

US3150503A - Refrigerating apparatus

Info

Publication number: US3150503A
Application number: US330181A
Authority: US
Inventors: John H Heidorn
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1963-12-12
Filing date: 1963-12-12
Publication date: 1964-09-29
Anticipated expiration: 1981-09-29

Description

Sept. 29, 1964 J. H. HEIDORN REFRIGERATINGAPPARATUS Filed Dec. 12, 1963 N %R 'Y T0 E MD N I R V5 0 WH 0T H T a A M 1 0 Wm M m United States l ate'nt O 3,150,503 REFRIGERATING APPARATUS John H. Heidorn, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed Dec. 12, 1963, Ser. No. 330,181 Claims. (Cl. 62-324) This invention pertains to refrigerating apparatus and more particularly to means for initiating and accomplishing reverse cycle operation of a refrigerating system.

Reversed refrigeration cycling can be used for heating a room or melting frost from an evaporator. It is especially effective for melting frost from an evaporator because it applies the heat internally within the frost coating. The use of reversed cycling has been retarded by the cost of the control system and doubts as to the reliability of the reversing mechanisms.

It is an object of this invention to provide an improved, inexpensive and simplified control system for reversing a refrigerating system.

'It is another object of this invention to provide a reversing control which can be readily controlled by a fluid motor.

It is another object of this invention to combine a reversing control for a refrigerating system with a fluid motor which will also operate a switch to control the fan or air circulation.

These and other objects are attained in the form shown in the drawings in which a slide member has a leaking piston at its opposite ends fitting within a cylinder. The slide membercarrie's a spring pressed slide valve member which alternately connects the compressor suction connection witheither the condenser or the evaporator. The discharge connection of the compressor connects to the interior of the cylinder and the gas flows around either end of the slide valve member, depending upon its position, to either the evaporator or the condenser. The slide member is positioned by the differential of pressure on its opposite ends controlled by a double throw valve member providing a connection alternately between the opposite ends of the cylinder and the suction conduit. A fluid motor responsive to the temperature adjacent the outlet of the evaporator when it reaches a predetermined low temperature operates the double throw pilot valve to defrost position to cause the pressure differential on one of the slide member pistons to move the slide valve into position to connect the suction conduit with the condenser. The compressor discharge is then effectively connected to the evaporator to defrost the evaporator. A plungertype switch is also controlled to de-energize both the condenser and evaporator fans during this period. Normal control of the system is by a thermostatic switch responsive to either compartment or room air or evaporator temperature. When the evaporator reaches a sutficiently high temperature to assure defrosting, the fluid motor is expanded to move the double throw pilot valve to the normal position. The differential in pressures on the one piston of the slide member causes it to move to the normal position at the opposite end and return the refrigerating system to normal refrigeration.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

1 FIGURE 1 is a diagrammatic view of a reversed cycle refrigerating system embodying a reversing control illustrating one form of my invention.

FIGURE 2 is a fragmentary sectional view taken along the line 22 of FIGURE 3 illustrating the pilot valve.

3,150,503 Patented Sept. 29, 1964 FIGURE 3 is a sectional view taken substantially along the line 33 in FIGURE 1. 1

FIGURE 4 is a fragmentary transverse sectional view taken along the line 4-4 of FIGURE 3 and FIGURE 5 is a sectional view taken along the line 5--5 of FIGURES 2 and 3.

Referring now more particularly to FIGURE 1, there is shown a reversing cycle refrigerating system including a sealed motor compressor unit and two heat transfer units 22 and 24. Normally the unit 22 will operate as the condenser, and the unit 24 will operate as the evaporator. However when the cycle is reversed, the unit 22 becomes the evaporator and the unit 24 will become the condenser. This system may be used for cooling a household refrigerator or for air conditioning, such as cooling a room or a house. The unit 22 is shown as being enclosed within an enclosure 26 which may be the machinery compartment of a household refrigerator or an air conditioner. A fan 28 driven by an electric motor 30 circulates air into heat transfer relation with the heat transfer unit 22. If it is used for household refrigerator, the

room air will be circulated in heat transfer with the unit 22 while if it is used for air conditioning, outside air will be circulated in heat transfer with the unit 22. If desired water may be used as the cooling medium and the electric motor 30 may be used to operate a water pump to circulate water in heat transfer with the unit 22.

The unit 24 may be used to cool the air within a household refrigerator or it may be used to cool the air in a room or a house if used for air conditioning. It is enclosed within an enclosure 32. The air in the enclosure is circulated in heat transfer relation with the heat transfer unit 24 by a fan 34 driven by an electric motor 36. The sealed motor compressor unit 20 is provided with a discharge conduit 38 connecting with the inlet 40 of a reversing valve 42. The sealed motor compressor 20 also has a suction conduit 44 connecting with the outlet 46 of the reversing valve 42. This connection is shown diagrammatically in FIGURE 1 by the use of a dot and dash line.

The reversing valve 42 is also provided with a connection 48 connecting through the conduit 50 with the one end of the heat transfer unit 22 which will be the inlet end when the unit 22 operates as a condenser. The reversing valve 42 is also provided with a connection 52 connecting with a conduit 54 to the top of the heat transfer unit 24. This connection serves as the outlet of the heat transfer unit 24 when it operates as an evaporator. The opposite end 56 of the heat transfer unit 22 is connected through the flow control valve or restricter 58 and the conduit 60 with the other end of the heat transfer unit 24. When the unit 22 acts as a condenser, the liquefied refrigerant flows through the outlet 56 and the valve 58 and expands and flows through the conduit 60 into the unit 24. When the reversing valve 42 is reversed, the refrigerant flows in the opposite direction to heat the unit 24 and cool the unit 22.

I According to my invention, the flow of refrigerant within the reversing valve 42 is controlled by a slide valve 62 in the form of a D-type valve which may be made of nylon. This D-type valve has its periphery sealed to the Walls of the cylinder 64 and within the periphery contains the cavity 66 for providing a connection between the suction connection 46 and either the

connections

48 and 52 connecting with either the heat transfer units 22 or 24. This arrangement also provides a connection between the discharge connection 40 and either of the

connections

52 or 48 by the flow of refrigerant around the D-type shaped valve 62.

The D-shaped valve 62 is provided with notches 68 at its opposite ends which fit slidably on the cages 70 provided at the opposite ends of the metal frame 72. A bowed wire spring '74 fits into a groove extending axially in the D-shaped valve member 62 and at its ends extends through apertures in each of the cages 71 so as to apply a spring force upon the D-shaped valve 62 so as to hold the D-shaped valve member 62 against the walls of the cylinder 64 to provide a satisfactory seal. The frame 72 has connected to it, on the outside of each of the cages 70, a sintered iron piston 76 provided with a bleed hole 78. This connection is made by a spring holding arrangement which includes a conically shaped valve provided at each end having a valve stem 82 passing through each of the pistons and each of the cages and provided within each of the cages a compression type coil spring 84 which holds the piston resiliently in engagement with the adjacent cage 70. A retainer 86 retains the spring of the stem. This arrangement prevents misalignment of the pistons 76,

At the left end of the cylinder 64 there is provided a cylinder head 88 provided with a central passage 91 having a valve seat cooperating the conical valve 80. This passage connects with an end chamber 92 provided between the head 88 and the threaded cap 94. This end chamber 92 is connected by a passage 96 extending through the walls of the cylinder 64 to a passage 98 in a valve head 121 provided in the head at the opposite end of the cylinder 64. The passage 98 connectswith a valve chamber 123 in the head 121. The head 121 is also provided with a coaxial passage and seat 125 cooperating with the adjacent conical valve 80 on the slide frame 72 and connecting through a passage 127 with a valve chamber 129. The valve chamber 129 contains a valve 131 adapted tocooperate with a valve passage and valve seat 133 connecting with a central passage 135. The valve 131 is connected through an integral connection 137 with an oppositely oriented valve 139 located in the valve chamber 123 and cooperating with the valve seat and valve passage 149 connecting the valve chamber 123 with the central passage 135. The two

valve members

131 and 139 are therefore integrally connected by the connection 137 so as to operate as a double throw valve member in which they alternately make sealing engagements with their

respective valve seats

133 and 149. These valves are also provided with conical closing springs 151 and 153 at their opposite ends. The passage connects with an end chamber 155 which in turn connects through a passage 157 with the suction conduit 46.

The connection 137 is notched at its center point as illustrated in FIGURES 2 and 3 to receive the forked end of a valve operating lever 159 pivotally mounted upon and sealed to a diaphragm 161 sealed to the walls of the cylinder 64 by the cap 163. The diaphragm 161 also forms a sealing wall for the chamber 155. The outer end of the lever 159 extends through a central aperture in the cap nut 163 and is pivotally linked to the lower end of an operating rod 165. This operating rod 165 extends through an aperture in the toggle extension arm 167 and has on opposite sides thereof a set of adjustable contact nuts 169 for operating the rod 165. The extension arm 167 is a part of the toggle blade 171 pivoted at one end to the U-spring 173 and pivoted at its other end to the follower 175 of the power element diaphragm 177. The cooperating toggle link 179 is provided between the follower 175 and the other end 181 of the U-spring 173. The toggle operation is adjusted not only by the nuts 169, but also by the adjusting screw 183 which threads through a bracket fastened to the walls of the cylinder 64 and presses against the end 181 of the U-spring 173 to apply a column loading to the toggle links 171 and 179 to create a satisfactory toggle snap action mechanism. The diaphragm 177 is sealed within the cup member 185 to form a fluid motor mounted on the walls of the cylinder 64. This cup member has its interior connected through a capillary tube 187 with the thermostat bulb 189 preferably mounted at the top of the heat transfer unit 24 which serves as the outlet when this unit operates as an evaporator.

FIGURE 1 shows the system in the condition at the end of the defrosting cycle with the temperature of the heat transfer unit 24 having risen sufficiently to cause the diaphragm 177 to be moved upwardly to trip the toggle blades 171 and 179 to their upper position. The toggle blade 171 has a second extension arm 191 which depresses the plunger of the switch 193 to close the circuit to the fan motors 3t) and 36 to resume operation of the

fans

28 and 34. For this purpose the supply conductor 195.comnects through the conductor 197 and the switch 193 to the conductor 199 connecting with the

branch conductors

226 and 222 connecting respectively with the

fan motors

36 and 30. These fan motors 36 and 30have the

second conductors

224 and 226 connecting with the conductor 228 which connects through the thermostatic switch 239 with the second supply conductor 232. The thermostatic switch 230 is provided with a fluid operating motor 234. connected by a capillary tube with the thermostat bulb 236 located in the air stream of'the heat transfer unit 24. The fluid motor 234 is provided with a snap action mechanism formed of toggle blades similar to the toggle blades 171 and 179 which are associated with the fluid motor formed by the cup member 185 and the diaphragm 177. The conductors 228 and also connect with the sealed motor compressor unit 20 so that it will operate whenever the switch 230 is closed by reason of a high temperature of the bulb 236.

The fluid motor formed by the cup member 185 and the diaphragm 177 has moved the rod '165 downwardly to pivot the lever 159 in the clockwise direction to close the valve 139 upon its seat 137 and to move the valve 131 to the open position. This causes suction to be applied from the suction connection 46 through the passage 157, the chamber 155, the passage 135, the valve passage 133, past the open valve 131 through the valve chamber 129, the

passage

127 and 125 to the right end of the cylinder 64. This will apply a pressure differential upon the piston 76 which will then have discharge pressure applied to its left side from the discharge inlet 40 and the suction pressure applied to its right side so as tocause the frame 72 to be moved to the right carrying the D.-shaped valve 62 with it until the cavity in the valve 62 bridges the suction inlet 46 with the evaporator connection 52. The bleed orifice 78 in the piston 76 at the opposite endprevents the occurrence of a vacuum at the opposite end. The conical valve 80 at the end of this movement enters and closes the passage 125 to stop the flow of gas to the suction connection 46 after this movement is accomplished. The discharge connection 40 is then effectively connected to the connection 48 connecting through the conduit 50 with the inlet of the heat transfer unit 22 which then operates as a normal condenser.

The system continues to operate in this condition until the temperature of the switch 230 is satisfiedto cause the opening of this switch. Should the evaporator 24 at any time become coated with frost to an objectionable amount, the insulating effect of the frost on the evaporator 24 when the switch 230 is closed will cause the temperature adjacent the bulb 189 to become abnormally low. This will cause the fluid motor formed by the cup member 185 and the diaphragm 177 to move the diaphragm 177 downwardly to pull the toggle blades 171 and 179 downwardly with a snap action to lift the arms 167 and 191. The lifting of the arm 191 will release the plunger of the switch 193 causing it to open and deenergize the

fan motors

30 and 36. The rod 165 will also be lifted to move the lever 159 in the counterclockwise direction to move both

valves

131 and 139 downwardly thereby moving the valve 131 into engagement with the seat 133 and to move the valve 139 to open position. This connects the left end of the cylinder 64 through the passage 90, the chamber 92, the

passages

96 and 98, the chamber 123, the valve passage 149, the

chambers

135 and 155 with the passage 157 connecting with the suction connection 46. This will apply a pressure differential tothe left piston 76 since discharge pressure will be applied on its right face from the discharge connection 40 and suction pressure will be applied to its left face through the open valve 139 as previously descri ed. This pressure diflerential on the left piston 76 will cause the frame 72 and the slide valve 62 to move again to the left to the position shown in FIGURE 3 to start another defrosting cycle which will continue until the bulb 189 reaches a predetermined high temperature and again moves a fluid motor formed by the diaphragm 185 and 177 back to the position shown in FIGURE 1. The switch 23th will be closed during this operation by reason of the higher temperature prevailing in the vicinity of the bulb 238.

Thus through thi relatively simple arrangement I have provided an automatic defrosting control for reversing the refrigerations cycle to defrost the evaporator. cycle will be automatically terminated by the same mechanism used for initiating the defrost cycle. By using a fluid motor to operate a pilot valve I eliminate the use of magnetic or other electrically operated valves which are commonly used to control the reversing valve. This makes the system less expensive and more reliable. The use of the fluid motor to open the switch 193 further simplifies the controls.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. Refrigerating apparatus including first and second heat transfer means each having inlet and outlet connections, one of said inlet connections being connected to one of said outlet connections, circulating means for circulating a heat transfer medium in heat transfer relation with one of said heat transfer means, a compressor having inlet and outlet connections, a reversing valve connected to the outlet and inlet connections of said heat transfer means and said compressor operable to reverse the connections between said compressor and said heat transfer means, fluid pressure means for operating said reversing valve, a pilot valve means for controlling said fluid pressure means to operate said reversing valve, and a fluid motor having means for operating said pilot valve means and for controlling said circulating means.

2. Refrigerating apparatus including first and second heat transfer means each having inlet and outlet connections, one of said inlet connections being connected to one of said outlet connections, circulating means for circulating a heat transfer medium in heat transfer relation with one of said heat transfer means, a compressor having inlet and outlet connections, a reversing valve connected to the outlet and inlet connections of said heat transfer means and said compressor operable to reverse the connections between said compressor and said heat transfer means, fluid pressure means for operating said reversing valve, a double throw pilot valve means for controlling said fluid pressure means to operate said reversing valve means to and from reversing position, electrical operating means for said circulating means, a switch for controlling said electrical operating means, a fluid motor, and snap acting means operatively connecting said fluid motor with said pilot valve means and said switch.

3. Refrigerating apparatus including first and second heat transfer means each having inlet and outlet connections, one of said inlet connections being connected to one of said outlet connections, a compressor having inlet This and outlet connections, means forming a cylindrical chamber having its interior connected to said compressor inlet and outlet connec ions andto the remaining inlet and outlet connections of said heat transfer means, a slide means within said chamber having alternate positions for alternately connecting said compressor inlet and outlet connections with said remaining inlet and outlet connections of said heat transfer means, said means forming a cylindrical chamber including a valve means at one end of said chamber having fluid connections with one end of said chamber and with said compressor inlet connection, a fluid motor, and snap acting means operatively connecting said fluid motor and said valve means for controlling the positioning of said slide means.

4. Refrigerating apparatus including first and second heat transfer means each having inlet and outlet connections, one of said inlet connections being connected to one of said outlet connections, a compressor having inlet and outlet connections, means forming a cylindrical chamber having its interior connected to said compressor inlet and outlet connections and to the remaining inlet and outlet connections of said heat transfer means, a slide means within said chamber having alternate positions for alternately connecting said compressor inlet and outlet connections with said remaining inlet and outlet connections of said heat transfer means, said means forming a cylindrical chamber including a valve means at one end of said chamber having fluid connections with the opposite ends of said chamber and with said compressor inlet con nection for alternately connecting either end of said chamber with said compressor inlet connection, a fluid motor, and snap acting means operatively connecting said fluid motor and said valve means for controlling the positioning of said slide means.

5. Refrigerating apparatus including first and second heat transfer means each having inlet and outlet connections, one of said inlet connections being connected to one of said outlet connections, a compressor having inlet and outlet connections, means forming a cylindrical chamber having its interior connected to said compressor inlet and outlet connections and to the remaining inlet and outlet connections of said heat transfer means, a slide means within said chamber having alternate positions for alternately connecting said compressor inlet and outlet connections with said remaining inlet and outlet connections of said heat transfer means, said means forming a cylindrical chamber including a valve means at one end of said chamber having fluid connections with the opposite ends of said chamber and with said compressor inlet connection for alternately connecting either end of said chamber with said compressor inlet connection, electrically operated means for circulating a heat transfer medium in heat transfer relation with one of said heat transfer means, a switch for controlling said electrically operated means, a fluid motor, and snap acting means operatively connecting said fluid motor to said switch and said valve means.

References Cited in the file of this patent UNITED STATES PATENTS 2,714,394 Moran Aug. 2, 1955 2,765,628 Anthony Oct. 9, 1956 2,875,780 Martin Mar. 3, 1959 2,976,701 Greenawalt Mar. 28, 1961 2,991,631 Ray July 11, 1961