In-line incremetally adjustable electronic expansion valve

• US 5,417,083 A
• Filed: 09/01/1994
• Issued: 05/23/1995
• Est. Priority Date: 09/24/1993
• Status: Expired due to Fees

• Current Assignee: American Standard Companies Incorporated (Ideal Standard International Topco SCA)
• Original Assignee: American Standard Companies Incorporated (Ideal Standard International Topco SCA)
• Inventors: Eber, David H.
• Primary Examiner(s): Wayner, William E.
• Application Number:
  US08/300,093
• Time in Patent Office: 264 Days
• Field of Search: 251/129.12, 251/129.11, 251/285, 251/208, 251/266, 62/528, 236/78 C, 236/75
• US Class Current: 62/528
• CPC Class Codes: F16K 3/085 the axis of supply passage and the axis of discharge passage being coaxial and parallel to the axis of rotation of the plates
• CPC Class Codes: F16K 31/041 for rotating valves F16K31/055 takes precedence
• CPC Class Codes: F25B 41/35 by rotary motors, e.g. by stepping motors
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

A variable flow rate expansion valve designed for in-line installation in a fluid conveying conduit such as between the high pressure condenser and lower pressure evaporator of a refrigeration system includes an integrally defined restrictor disc and a closure disc for controlling the flow of fluid through the valve. The restrictor disc has a first set of flow apertures and the closure disc a second set of flow apertures. The closure disc is rotatably coupled to the restrictor device in a plane parallel to the plane of the restrictor disc and perpendicular to refrigerant flow. A stepper motor is coupled to the closure disc through a linear actuator. Movement of the linear actuator causes the closure disc to rotate relative to the restrictor disc such that the flow apertures of the closure disc are selectively brought into and out of registry with the apertures of the restrictor disc.

Claims

1. A refrigerant expansion valve comprising:

a motor, said motor being a bi-directional motor having a drive shaft;

a housing said housing defining at least one aperture;

a rotating member having a peripheral edge exposed to refrigerant flow through said valve, said rotating member disposed in a plane generally perpendicular to the direction of flow through said valve and defining at least one aperture, the degree to which said aperture of said rotating member is in registry with said aperture of said housing being determinative of the amount of refrigerant flow through said valve; and

an actuator, said actuator being operably coupled to said rotatable shaft member of said motor and to said rotating member, the rotation of said motor shaft causing linear motion of said actuator in said valve and said linear motion of said actuator causing rotary motion in rotating member.

2. The expansion valve according to claim 1 wherein each of said at least one aperture in said rotating member and each of said at least one aperture in said housing are of the same size and shape so that when at least one aperture in said rotating member and said at least one aperture in said housing are in registry the peripheral edges thereof are coincidental with respect to the flow of refrigerant through said valve.

3. The expansion valve according to claim 1 further comprising means for limiting the axial movement of said actuator.

4. The expansion valve according to claim 3 wherein said means for limiting the axial movement of said actuator limits the movement of said actuator such that the actuator is not permitted to move to an extent which puts said at least one aperture in said rotating member and said at least one aperture in said housing in full registry, thereby limiting the amount of flow through said valve to an amount which is less than the amount of flow which would occur if said at least one aperture in said fixed member were in full registry with said at least one aperture in said rotating member.

5. The expansion valve according to claim 4 wherein said valve housing defines a bore in which said actuator moves, said means for limiting the movement of said actuator comprising a member having a predetermined length, said member projecting into the path of movement of said linear actuator in said bore.

6. The expansion valve according to claim 1 wherein the peripheral edge of said rotating member is radially outermore than the outermost edge of any of said at least one aperture in said housing and wherein said rotating member is upstream of the portion of said housing which defines said at least one aperture with respect to the direction of refrigerant flow through said valve, said rotating member being spaced from said housing so that a leakage path between said rotating member and said housing is maintained even when said at least one aperture of said housing is out of registry with said at least one aperture of said rotating member.

7. The expansion valve according to claim 1 wherein the shape of said at least one aperture in said rotary member and said housing is such that the rate of flow through said valve varies non-linearly as the degree of registry of said apertures changes.

8. The expansion valve according to claim 1 wherein the shape of said at least one aperture of said housing and said rotating member is such that the rate of flow through said valve varies linearly as the degree of registry of said apertures changes.

9. The expansion valve according to claim 1 wherein said shaft of said motor has a threaded portion and wherein said rotating member is spaced from said housing so that a leakage path between said rotating member and said housing is maintained even when said at least one aperture of said housing is out of registry with said at least one aperture of said rotating member.

10. The expansion valve according to claim 9 further comprising a bellows, said bellows being attached to said actuator for expansion and contraction in accordance with the direction of linear movement of said actuator, said threaded portion of said shaft being in threadable engagement with said actuator and disposed interior of said bellows means.

11. The expansion valve according to claim 10 wherein said rotatable shaft of said motor has a threaded portion and a threaded insert disposed in said actuator, said threaded portion of said shaft being in threadable engagement with said insert.

12. The expansion valve according to claim 9 further comprising means for limiting the axial movement of said actuator.

13. The expansion valve according to claim 12 wherein said means for limiting the movement of said actuator limits the movement of said actuator such that the actuator is not permitted to move to an extent which puts said at least one aperture of said rotating member and said at least one aperture of said housing in full registry, thereby limiting the amount of flow through said valve to an amount which is less than the amount which would occur if said at least one aperture of said housing were in full registry with said at least one aperture of said rotating member.

14. A refrigerant expansion valve comprising:

a motor, said motor being a bi-directional motor having a rotatable drive shaft;

a housing, said housing defining a plurality of apertures in said valve;

a plate mounted for rotary motion within said valve, said plate defining a plurality of apertures; and

an actuator, said actuator disposed in said valve for linear movement in a plane generally coincident with the plane of said plate and being operably coupled to both said rotatable drive shaft of said motor and to said plate, rotation of said motor drive shaft causing said actuator to move linearly within said valve in a plane generally coincident with the plane of said plate, said linear movement of said drive shaft causing rotary motion of said plate, the degree of registry of said apertures in said plate with respect to said apertures in said valve being determinative of the amount of refrigerant flow through said valve; and

means for isolating said drive shaft of said motor from refrigerant flowing through said valve.

15. The expansion valve according to claim 14 wherein said plate is spaced apart from said housing and wherein said plate and said housing are disposed in a plane generally perpendicular to the flow of refrigerant through said valve.

16. The expansion valve according to claim 15 wherein said apertures defined in said plate and the apertures in said housing are of the same size and shape so that when said apertures are in registry, the peripheral edges thereof are coincident with respect to the direction of flow of refrigerant through said valve.

17. The expansion valve according to claim 14 further comprising means for limiting the axial movement of said actuator.

18. The expansion valve according to claim 17 wherein said means for limiting the axial movement of said actuator limits the movement of said actuator such that the actuator is not permitted to move said apertures of said plate into full registry with said apertures of said housing, thereby limiting the amount of flow through said valve to an amount which is less than the amount of flow which would occur if said apertures were in full registry.

19. The expansion valve according to claim 18 wherein said valve housing defines a bore in which said actuator moves, said means for limiting the movement of said actuator comprising a member of a predetermined length, said member projecting into the path of movement of said linear actuator.

20. The expansion valve according to claim 14 wherein the peripheral edge of said rotating plate is radially outermore than the outermost edge of any of said plurality of apertures defined by said means for defining a plurality of apertures in said valve.

21. The expansion valve according to claim 20 wherein the shape of said apertures in said plate and the shape of said apertures in said housing is such that the rate of flow of refrigerant through said valve varies non-linearly as the degree of registry of said apertures changes.

22. The expansion valve according to claim 20 wherein the shape of said apertures of said plate and the shape of said apertures defined in said housing is such that the rate of flow through said valve varies linearly as the degree of registry of said apertures changes.

23. The expansion valve according to claim 14 further comprising means for limiting the axial movement of said actuator, said means for limiting the movement of said actuator being such that the actuator is not permitted to move to an extent which puts said apertures in said plate in full registry with said apertures defined in said housing, thereby limiting the amount of flow through said valve to an amount which is less than that which would occur if said apertures in said plate and said apertures in said means for defining a plurality of apertures in said valve were in full registry.

24. A refrigeration system comprising:

a compressor;

a condenser connected for flow to said compressor;

an evaporator connected for flow to said compressor; and

refrigerant metering means, disposed in flow communication with said condenser and said evaporator, said metering means including a motor, a rotating member defining a plurality of apertures, a fixed member defining a plurality of apertures and an actuator operably coupling said motor and said rotating member, said actuator first translating rotary motion of said motor to linear motion and then translating said linear motion to rotary motion of said plate, the degree to which said apertures in said rotating member are in registry with said apertures in said fixed member being determinative of the amount of refrigerant flow through said valve, said refrigerant metering means including means for limiting the movement of said actuator such that the actuator is prevented from rotating said rotating member to an extent which puts said apertures of said rotating member in full registry with said apertures of said fixed member thereby limiting the amount of refrigerant flow through said metering means to an amount which is less than the amount which would occur if said apertures of said fixed and rotating members were in full registry.

25. The refrigeration system according to claim 24, wherein the shape of said apertures in said fixed member and in said rotary member of said metering means are such that the rate of refrigerant flow through said metering means varies non-linearly as the degree of registry of said apertures changes.

26. The refrigeration system according to claim 24, wherein the shape of said apertures in said rotating and said fixed members of said metering means is such that the rate of refrigerant flow through said metering means varies linearly as the degree of registry of said apertures changes.

27. The refrigeration system according to claim 24, wherein said motor of said metering means has a threaded rotatable shaft, said shaft of said motor being in threadable engagement with said actuator.

28. The refrigeration system according to claim 24 further comprising bellows means disposed in said metering means, said bellows means being attached to said actuator for expansion and contraction in accordance with the direction of movement of said actuator, said motor drive shaft being disposed interior of said bellows means.

29. The refrigeration system according to claim 28 wherein said rotating member is spaced apart from said fixed member so that a leakage path between said rotating member and said fixed member is maintained even when said apertures of said rotating member and said apertures of said fixed member are out of registry, said rotating member, said fixed member and said actuator being disposed in a plane generally perpendicular to the flow of refrigerant through said valve, movement of said actuator and said rotating member in said valve likewise being in a plane perpendicular to the direction of refrigerant flow through said metering means.