Interstage capacity control valve with separate drive and stabilization links

Abstract

A stabilizing link and a drive link of a compressor capacity control valve are physically and / or completely separated, for example, such that the respective links use separate and discrete attachment protrusions disposed on a drive ring and a restrictor ring of the capacity control valve. The discrete attachment protrusions are used to apply a lower stress on each attachment protrusion than links that share some attachment protrusions, including a pair of stabilizing links and drive links. A stabilizing link may be connected to the inter-stage housing. The link assembly allows the restrictor ring to be driven in an axial direction to open or close the compressor capacity control valve.

Description

Technical Field

[0001] This disclosure relates to an interstage capacity control valve for a centrifugal compressor, and more particularly to a capacity control valve that provides flow regulation or distribution and linkages between its components. Background Technology

[0002] When operating under full and partial load conditions, multistage compressors can use single or multiple rows of fixed or rotatable return vanes to guide and / or control interstage flow. Under partial load conditions, these return vanes may result in low-momentum regions or unfavorable pressure gradients in the return channel path that alter the intended side-flow injection rate, potentially leading to compressor instability, reduced system efficiency, and a narrower operating range. Summary of the Invention

[0003] This disclosure relates to an interstage capacity control valve for a centrifugal compressor, and more particularly to a capacity control valve that provides flow regulation or distribution and linkages between its components.

[0004] By attaching the two links to their respective drive rings and throttle rings at different locations using separate and discrete attachments instead of a common protrusion, the stress applied to the protrusions can be reduced. Furthermore, the assembly can be simplified. Because the stress applied to the attachment protrusions of the respective links is reduced, component costs can be lower, and durability can be increased by reducing tension in the link assembly. The torque required to move the throttle ring on the drive ring can be reduced, resulting in smoother operation of the capacity control valve.

[0005] In one embodiment, an assembly for a capacity control valve includes a drive ring and a throttling ring. The assembly also includes a plurality of drive links, each drive link including a first attachment protrusion on the drive ring, a second attachment protrusion on the throttling ring, and a link arm connected to each of the first and second attachment protrusions. The throttling ring includes a plurality of stabilizing link attachment protrusions and a plurality of stabilizing link arms, the plurality of stabilizing link attachment protrusions being decoupled from the second attachment protrusions of the plurality of drive links; each of the plurality of stabilizing link arms is attached to one of the stabilizing link attachment protrusions.

[0006] In one embodiment, the component further includes an interstage housing, wherein each of the plurality of stabilizing links is attached to the interstage housing.

[0007] In one embodiment, the first attachment protrusions of the plurality of drive links are evenly distributed along the circumference of the drive ring.

[0008] In one embodiment, the second attachment protrusions of the plurality of drive links are evenly distributed along the circumference of the throttle ring. In another embodiment, the attachment protrusions of the plurality of stabilizing links are evenly distributed along the circumference of the throttle ring, and the attachment protrusions of the plurality of stabilizing links are offset from the second attachment protrusions of the plurality of drive links.

[0009] In one embodiment, a compressor includes a first thruster, a second thruster, and a plurality of guide vanes formed in a channel located between the first and second thrusters. The channel is configured to guide interstage flow of fluid from the first thruster to the second thruster. The compressor also includes a side-flow injection port located between the first and second thrusters. The side-flow injection port is configured to receive side flow of fluid. The compressor further includes a throttling ring configured to move axially through the side-flow injection port between an extended position and a retracted position, wherein, in the extended position, the throttling ring blocks side flow of fluid through the side-flow injection port and partially blocks interstage flow of fluid through the channel; and in the retracted position, the throttling ring allows side flow of fluid through the side-flow injection port. The compressor also includes a drive ring. The throttling ring and the drive ring are connected by a plurality of drive links, each drive link including a first attachment protrusion on the drive ring, a second attachment protrusion on the throttling ring, and a link arm connected to each of the first and second attachment protrusions. The throttling ring also includes a plurality of stabilizer rod attachment protrusions separated from the second attachment protrusions of the plurality of drive links. The compressor also includes a plurality of stabilizer rod arms, and each of the plurality of stabilizer rod arms is attached to one of the stabilizer rod attachment protrusions.

[0010] In one embodiment, the compressor also includes an interstage housing, wherein each of the plurality of stabilizing link arms is attached to the interstage housing.

[0011] In one embodiment, the first attachment protrusions of the plurality of drive links are evenly distributed along the circumference of the drive ring.

[0012] In one embodiment, the second attachment protrusions of the plurality of drive links are evenly distributed along the circumference of the throttle ring. In another embodiment, the attachment protrusions of the plurality of stabilizing links are evenly distributed along the circumference of the throttle ring, and the attachment protrusions of the plurality of stabilizing links are offset from the second attachment protrusions of the plurality of drive links.

[0013] In one embodiment, the throttling ring includes teeth, and in the extended position, the teeth of the throttling ring are disposed in a channel and block the channel. In another embodiment, the teeth extend in the axial direction and include radially inwardly curved tips.

[0014] In one embodiment, the compressor further includes an actuator configured to rotate a drive ring such that a throttle ring is driven to travel in an axial direction.

[0015] In one embodiment, a method of assembling a compressor includes: providing a drive ring; and providing a throttling ring. The method further includes: attaching a plurality of first attachment protrusions to the drive ring; and attaching a plurality of second attachment protrusions to the throttling ring. The method further includes: attaching each of a plurality of connecting rod arms to a corresponding one of the plurality of first attachment protrusions and to a corresponding one of the plurality of second attachment protrusions; attaching a plurality of stabilizing link attachment protrusions to the throttling ring, the plurality of stabilizing link attachment protrusions being separate from the second attachment protrusions of the plurality of drive links; and attaching each of the plurality of stabilizing link arms to a corresponding one of the stabilizing link attachment protrusions.

[0016] In one embodiment, the method further includes providing an interstage housing and attaching each of a plurality of stabilizing links to the interstage housing. Attached Figure Description

[0017] Figure 1 A compressor according to an embodiment is shown.

[0018] Figure 2A Components for a capacity control system according to an embodiment are shown.

[0019] Figure 2B It shows Figure 2A Components used in capacity control systems.

[0020] Figure 3 Components for installing a capacity control system into a compressor, according to an embodiment, are shown.

[0021] Figure 4 A method for assembling a compressor according to an embodiment is shown.

[0022] Figure 5 An HVACR system including a compressor is shown according to an embodiment.

[0023] Figures 6A to 6D Compressors according to embodiments are shown respectively. Detailed Implementation

[0024] This disclosure relates to an interstage capacity control valve for a centrifugal compressor, and more particularly to a capacity control valve that provides flow regulation or distribution and linkages between its components.

[0025] Interstage capacity control valves are discussed in U.S. Patent Nos. 11,391,289, 11,536,277, 11,661,949, and 11,859,621, the entire contents of which are incorporated herein by reference.

[0026] Figure 1A compressor according to an embodiment is shown. The compressor 100 is a multi-stage centrifugal compressor. The compressor 100 is configured to compress a suitable working fluid, such as any suitable refrigerant. The compressor 100 includes a first stage S1, a second stage S2, and an interstage throttling valve 102 connecting the first stage S1 to the second stage S2. The first stage S1 includes a first-stage propeller 104A, and the second stage S2 includes a second-stage propeller 104B, which rotate to compress the fluid in their respective stages S1, S2. Although the interstage throttling valve 102 is discussed as being located between the first stage S1 and the second stage S2 in the compressor 100, it should be understood that the interstage throttling valve 102 can be located between any two consecutive stages in a compressor having more than two stages, such as between the second and third stages, between the third and fourth stages, etc.

[0027] The compressor 100 also includes a drive shaft 106, a rotor 108, and a stator 110. Thrusters 104A and 104B are respectively fixed to the drive shaft 106. For example, a first-stage thruster 104A is fixed to an end of the drive shaft 106, while a second-stage thruster 104B is fixed closer to the middle of the shaft 106. The rotor 108 is attached to the drive shaft 106 and rotated by the stator 110, causing the drive shaft 106 and the thrusters 104A and 104B to rotate. The rotor 108 and the stator 110 form an electric motor for the compressor 100. The electric motor (e.g., the stator 110 and rotor 108) operates according to generally known principles. In another embodiment, the drive shaft 106 may be connected to and rotated by an external electric motor, internal combustion engine (e.g., a diesel engine or a gasoline engine), etc. It should be understood that in this embodiment, the rotor 108 and stator 110 will not be present within the compressor housing 112 of the compressor 100. The drive shaft 106 extends through the first stage S1, the second stage S2, and the interstage throttle valve 102, as shown. Figure 1 As shown. It should be understood that, unless otherwise stated, the terms “axial,” “radial,” and “circumferential” as used herein are generally relative to the axis of the compressor 100 (e.g., the axis of the drive shaft 106).

[0028] The working fluid flows through the flow path F1 of the compressor 100 in... Figure 1 The flow path F1 extends from the suction port 114 of compressor 100 to the discharge port 116 of compressor 100, as indicated by a dashed arrow. The working fluid enters compressor 100 through suction port 114, is compressed by first propeller 104A in first stage S1, flows through interstage throttle valve 102 to second stage S2, is further compressed by second-stage propeller 104B in second stage S2, and is then discharged from compressor 100 through discharge port 116. The first-stage propeller 104A in first stage S1 is configured to draw the working fluid from the inlet pressure (e.g., pressure P).I The working fluid is compressed to a first pressure P1, and the second-stage thruster 104B in the second stage S2 is configured to further compress the working fluid to a second pressure P2, which is greater than the first pressure P1. Side flow of the intermediate-pressure working fluid can flow into (depending on the position of the throttle ring 128) the flow path F1 between the first-stage thruster 104A and the second-stage thruster 104B. The pressure of the working fluid flowing into the inlet 120 of the second-stage thruster 104B can be different from the first pressure P1 (e.g., it can be a pressure between the intermediate working fluid pressure and the first pressure P1).

[0029] In flow path F1, an interstage throttle valve 102 is disposed between the first-stage thruster 104A of the first stage S1 and the second-stage thruster 104B of the second stage S2. The interstage throttle valve 102 is disposed between the outlet 118 of the first thruster S1 and the inlet 120 of the second thruster 104B. A drive shaft 106 extends through the interstage throttle valve 102. The interstage throttle valve 102 fluidly connects the outlet 118 of the first-stage thruster 104A to the inlet 120 of the second-stage thruster 104B. The interstage throttle valve 102 guides the working fluid discharged from the first stage S1 (e.g., compressed working fluid under a first pressure P1) to the second-stage thruster 104B of the second stage S2. For example, the interstage throttle valve 102 radially guides the compressed working fluid (after radially outward discharge from the first-stage thruster 104A) radially inward to the inlet 120 of the second-stage thruster 104B. Interstage throttle valve 102 also directs intermediate-pressure working fluid to the second-stage thruster 104B. For example, interstage throttle valve 102 directs intermediate-pressure working fluid into the compressed working fluid flow from the first-stage thruster 104A to the second-stage thruster 104B, and then radially inwards directs the mixture of intermediate-pressure working fluid and compressed working fluid to the inlet 120 of the second-stage thruster 104B. The intermediate working fluid can mix with the compressed working fluid from the first-stage thruster 104A within channel 122.

[0030] The interstage throttle valve 102 is adjustable to control the flow rate of the compressed working fluid flowing from the first stage S1 to the second stage S2, and to control the flow rate of the intermediate working fluid entering the second stage S2 (e.g., the flow rate of the intermediate working fluid entering the compressor 100). The interstage throttle valve 102 includes an actuator 124 for operating the interstage throttle valve 102. The actuator 124 is operable / actuated to regulate the flow rate of the compressed working fluid flowing through the interstage throttle valve 102. For example, the compressor 100's controller (not shown) and / or HVACR controller can be configured to control the capacity of the compressor 100 by controlling the position / actuation of the actuator 124.

[0031] The interstage throttle valve 102 includes a guide vane 126 with guide vanes 132 and a channel 122 formed by the guide vanes 132. The channel 122 is radially inwardly spiraled. Working fluid flows through the interstage throttle valve 102 by flowing through the channel 122. The channel 122 guides the working fluid discharged from the first stage S1 radially inward to the inlet 120 of the second stage propeller 104B. The interstage throttle valve 102 includes a throttle ring 128 configured to be actuated to adjust the size of the channel 122 (e.g., the cross-sectional area of ​​the channel 122).

[0032] Throttling ring 128 includes protrusions 130. Protrusions 130 may be toothed structures (e.g., teeth). Teeth 130 extend toward guide vane 126. Throttling ring 128 is configured to be actuated relative to channel 122 in an axial direction (e.g., in the positive axial direction D1 and in the negative axial direction D2). Axial movement of throttling ring 128 changes the length of teeth 130 disposed in channel 122 to adjust the cross-sectional area of ​​channel 122. For example, when throttling ring 128 is actuated toward channel 122 (e.g., in the positive axial direction D1), teeth 130 extend further into channel 122 and reduce the cross-sectional area of ​​channel 122. As each tooth 130 is further disposed into its corresponding channel 122, the tooth 130 partially obstructs more of channel 122 and reduces the cross-sectional area of ​​channel 122 (e.g., reduces the cross-sectional area of ​​the opening in each channel 122). The reduced cross-sectional area of ​​channel 122 decreases the flow rate of the working fluid through channel 122 and interstage throttle valve 102. When throttle ring 128 is actuated away from channel 122 (e.g., in the negative axial direction D2), teeth 130 extend less into channel 122, and the cross-sectional area of ​​channel 122 increases, which increases the flow rate of the working fluid through interstage throttle valve 102. For example, in an embodiment, throttle ring 128 may have a retracted position; in this retracted position, teeth 130 are fully positioned outside channel 122.

[0033] Figure 2A Components for a capacity control system according to an embodiment are shown. Figure 2A As shown, the capacity control system assembly 200 includes a drive ring 202 and a throttling ring 204. The drive ring 202 includes a first attachment protrusion 206, and the throttling ring 204 includes a second attachment protrusion 208. Link arms 210 are respectively connected to one of the first attachment protrusions 206 and one of the second attachment protrusions 208. The throttling ring 204 also includes a stabilizing link attachment protrusion 212. Stabilizing link arms 214 are respectively attached to one of the stabilizing link attachment protrusions 212.

[0034] The capacity control system assembly 200 is configured to control the position of the capacity control system in order to control interstage flow and / or the interstage flow that introduces side flow into the compressor between its stages. The capacity control system assembly 200 can be used to position the throttle ring 204 appropriately to control the side flow and / or the compressor (such as those described above) Figure 1 The interstage flow of the working fluid in the compressor 100 shown is deflected.

[0035] The drive ring 202 is a ring configured to be rotated, such that rotation of the drive ring 202 can drive the translational movement of the throttle ring 204. The drive ring 202 can be connected to a rotary interface 216, which is configured to allow rotational force to be applied to the drive ring 202, for example, through an actuator and any suitable mechanical connection (such as a lever, bushing, gear, etc.).

[0036] Throttling ring 204 is configured to interact with the side-flow injection port and interstage flow in the compressor to influence the interstage flow and / or control the flow through the side-flow injection port. Throttling ring 204 may be configured to be axially movable to extend into or retract from the side-flow injection port to control the flow through the throttling ring 204 and / or deflect the interstage flow. Throttling ring 204 may include a protrusion 218, which in some examples may be configured as a toothed structure. Teeth 218 extend from the end of the throttling ring 204. Teeth 218 may be configured to prevent the derotator blades from being positioned in the interstage flow path of the compressor, even when the throttling ring 204 is extended.

[0037] like Figure 2A and Figure 2B As shown, the drive ring 202 may have the same or approximately the same circumference as the throttle ring 204 (e.g., depending on manufacturing tolerances, design tolerances, etc.). In one embodiment, the difference in circumference between the drive ring 202 and the throttle ring 204 is less than or approximately 10%. In another embodiment, the difference in circumference between the drive ring 202 and the throttle ring 204 may be less than 5% or approximately 5%.

[0038] First attachment protrusions 206 are disposed on the drive ring 202. Each of the first attachment protrusions 208 is a protrusion configured to abut a corresponding one of the connecting arms 210. In an embodiment, each first attachment protrusion 206 is configured to abut only one of the corresponding connecting arms 210. The first attachment protrusions 206 may be radially distributed around the drive ring 202. In an embodiment, the first attachment protrusions are uniformly radially distributed around the drive ring 202. As used herein, "uniformly radially distributed" means that the angle between adjacent attachment protrusions is the same, for example, an angle of 120 degrees or approximately 120 degrees between each of three attachment protrusions, an angle of 90 degrees or approximately 90 degrees between each of four attachment protrusions, etc. In an embodiment, each of the first attachment protrusions 206 connects the drive ring 202 to only one of the connecting arms 210. In one embodiment, the first attachment protrusion 206 is attached to the drive ring 202, for example, as a bolt attached to the drive ring 202. The attachment of the first attachment protrusion 206 can be achieved through any suitable adhesive, weld, mechanical fastener (such as a threaded connection or other mechanical fastener). In another embodiment, the first attachment protrusion 206 can be a protrusion integrally formed with the drive ring 202.

[0039] Second attachment protrusions 208 are disposed on the throttle ring 204. Each of the second attachment protrusions 208 is configured to abut a corresponding one of the connecting rod arms 210. In an embodiment, each of the second attachment protrusions 208 is configured to abut only one of the corresponding connecting rod arms 210. In an embodiment, at the end of the corresponding connecting rod arm 210, at a position opposite to the end of the corresponding connecting rod arm that abuts with one of the first attachment protrusions 206, the second attachment protrusion 208 may abut against the connecting rod arm 210. The second attachment protrusions 208 may be radially distributed around the throttle ring 204. In an embodiment, the second attachment protrusions may be uniformly radially distributed around the throttle ring 204. In an embodiment, each of the second attachment protrusions 208 connects only one of the connecting rod arms 210 to the throttle ring 204. In an embodiment, the second attachment protrusions 208 are attached to the throttle ring, for example, each is a bolt attached to the throttle ring 204. The attachment of the second attachment protrusion 208 can be achieved by any suitable adhesive, weld, mechanical connection (such as a threaded connection or other mechanical connection). In an embodiment, the second attachment protrusion 208 can be a protrusion integrally formed with the throttle ring 204.

[0040] Linkage arm 210 is an arm that is respectively connected to one of the first attachment protrusions 206 and to one of the second attachment protrusions 208. Aside from the corresponding drive ring 202 or throttle ring 204 connected to the corresponding first attachment protrusion 206 and the corresponding second attachment protrusion 208, linkage arm 210 may be the only component. Linkage arms 210 may each have a fixed length, which is selected to convert rotation of linkage arm 210 into translational motion to be transmitted to the throttle ring 204.

[0041] The stabilizer link attachment protrusions 212 are a plurality of discrete protrusions provided on the throttle ring 204. The stabilizer link attachment protrusions 212 can be separated from and are different from the second attachment protrusion 208. For example, the stabilizer link attachment protrusions are completely and / or physically separated from and different from the second attachment protrusion 208. Each stabilizer link attachment protrusion 212 is configured to engage with a corresponding one of the stabilizer link arms 214. In an embodiment, each of the stabilizer link attachment protrusions 212 is configured to engage only with a corresponding one of the stabilizer link arms 214. In an embodiment, the stabilizer link attachment protrusions 212 are attached to the throttle ring 204, for example, each being a bolt attached to the throttle ring 204. The attachment of the stabilizer link attachment protrusions 212 can be achieved through any suitable adhesive, weld, mechanical connection (such as a threaded connection or other mechanical connection, etc.). In an embodiment, the stabilizing link attachment protrusion 212 may be a protrusion integrally formed with the throttle ring 204.

[0042] At one of the corresponding stabilizer attachment protrusions 212, stabilizer arm 214 is connected to throttle ring 204. Stabilizer arm 214 may also be attached to a fixed point (such as a fixed point on the housing of the compressor including capacity control assembly 200) such that when drive ring 202 is rotated, stabilizer arm 214 and its connecting member will rotationally constrain and facilitate translational movement of throttle ring 204.

[0043] Figure 2B It shows Figure 2A Components used in capacity control systems. Figure 2BIn this configuration, the drive ring 202 has been rotated, for example, by operating the rotary interface 216, causing the assembly 200 to move to the retracted position. Specifically, the rotation of the drive ring 202 moves the position of the first attachment protrusion 206 relative to the corresponding second attachment protrusion 208, causing the linkage arm 210 to rotate and pull the throttle ring 204 toward the drive ring 202, thereby placing the capacity control system 200 in the retracted state. The stabilizing linkage arm 214, connected to the stabilizing linkage attachment protrusion 212, can constrain the rotation of the throttle ring 204 to facilitate the relative movement of the first attachment protrusion 206 and the linkage arm 210 to achieve the retraction of the throttle ring 204.

[0044] Figure 3 Components for mounting a capacity control system into a compressor according to an embodiment are shown. The compressor 300 includes a capacity control system 200 (as described above and in...) Figure 2A and Figure 2B (As shown in the diagram) and interstage housing 302. Figure 3 As shown, the stabilizing link arm 214 is connected to a fixed point 304 provided on the interstage housing 302 and to a corresponding stabilizing link attachment protrusion 212. By connecting to the fixed point 304 provided on the interstage housing 302, the stabilizing link arm 214 can constrain the rotation of the throttle ring 204. The throttle ring 204 can be translated and driven by the rotation of the drive ring 202 relative to the throttle ring 204 and by the movement of the link arm 210 around their respective connections at the corresponding first attachment protrusion 206 and second attachment protrusion 208.

[0045] Figure 4 A method for assembling a compressor according to an embodiment is illustrated. Method 400 includes: 402—providing a drive ring, 404—providing a throttling ring, 406—providing a plurality of first attachment protrusions on the drive ring, and 408—providing a plurality of second attachment protrusions on the throttling ring. Method 400 further includes: 410—attaching each of a plurality of connecting rod arms to a corresponding one of the plurality of first attachment protrusions and to a corresponding one of the plurality of second attachment protrusions. Method 400 further includes: 412—providing a plurality of stabilizing link attachment protrusions on the throttling ring, and 414—attaching each of the plurality of stabilizing link arms to a corresponding one of the stabilizing link attachment protrusions. Optionally, method 400 may also include: 416—providing a compressor housing (such as... Figure 3 (as shown in the interstage housing), and 418—attaching each of the multiple stabilizer arms to the compressor housing.

[0046] Method 400 may be a step in the assembly of a compressor and / or its components. The compressor assembled according to method 400 may be a compressor with a capacity control system, and the components assembled according to method 400 may be a capacity control system for the compressor or part of a capacity control system. The compressor obtained by method 400 or using the components assembled according to method 400 may be a multistage centrifugal compressor. In embodiments, method 400 may be used as described above and as... Figure 1 The assembly of the compressor 100 shown. In an embodiment, method 400 can be used to assemble the capacity control system 200 (as described above and as...) Figure 2A and Figure 2B And as Figure 3 Assemble the components shown. It should be understood that the steps of method 400 can be performed in any suitable order, and some steps can be combined if possible, such as providing attachment protrusions at 406 and / or 408 while attaching the linkage arm at 410, etc.

[0047] A drive ring is provided at 402. This drive ring can be, for example, drive ring 202 (as described above and as...). Figure 2A and Figure 2B (As shown). A throttling ring is provided at 404. This throttling ring can be, for example, throttling ring 204 (as described above and as shown). Figure 2A and Figure 2B (As shown).

[0048] Method 400 may include providing a plurality of first attachment protrusions on the drive ring at 406. The first attachment protrusions may be first attachment protrusion 206 (as described above and as...) Figure 2A and Figure 2B (As shown). The first attachment protrusion can be positioned on the drive ring at 406 by attaching the first attachment protrusion to the drive ring, for example by any suitable connection between the first attachment protrusion and the drive ring (such as mechanical connection, welding, adhesive, a combination thereof, etc.). Non-limiting examples of mechanical connections may include threaded connections, press-fit, engagement of any suitable engagement feature, etc.

[0049] Method 400 may include providing a plurality of second attachment protrusions to the throttling ring at 408. The second attachment protrusions may be as described above and Figure 2A and Figure 2B The second attachment protrusion 208 is shown in the figure. The second attachment protrusion can be positioned on the drive ring at 408 by attaching it to the drive ring, for example, by any suitable connection (such as mechanical connection, welding, adhesive, a combination thereof, etc.) between the second attachment protrusion and the throttle ring. Non-limiting examples of mechanical connections may include threaded connections, press-fit, engagement of any suitable engagement feature, etc.

[0050] At position 410, each of the plurality of linkage arms is attached to a corresponding one of the plurality of first attachment protrusions, and also to a corresponding one of the plurality of second attachment protrusions. The linkage arm can be as described above and as... Figure 2A and Figure 2B The link arm 210 is shown. In an embodiment, attachment at 410 can be performed during attachment of the corresponding attachment protrusions at 406 and 408, for example, by guiding bolts, which serve as the corresponding attachment protrusions, through the corresponding holes in the link arm. Each of the plurality of link arms can be attached to only one of the first attachment protrusions and to only one of the second attachment protrusions. In an embodiment, after attachment at 410, each attachment protrusion can be attached only to the corresponding portion of the corresponding link arm.

[0051] At position 412, multiple stabilizer bar attachment protrusions are provided on the throttle ring. The stabilizer bar attachment protrusions can be as described above and... Figure 2A and 2B The stabilizer link attachment protrusion 212 is shown. The stabilizer link attachment protrusion may be physically and / or completely separate from, and distinct from, the second attachment protrusion disposed on the throttle ring at 408. Providing the second attachment protrusion to the throttle ring at 412 may include attaching the attachment protrusion to the throttle ring, for example, by any suitable connection (e.g., mechanical connection, welding, adhesive, a combination thereof, etc.) between the stabilizer link attachment protrusion and the throttle ring. Non-limiting examples of mechanical connections may include threaded connections, press-fit, engagement of any suitable engagement feature, etc.

[0052] At 414, each of the plurality of stabilizer arms is attached to a corresponding stabilizer attachment protrusion in the stabilizer attachment protrusion. The stabilizer arm may be a second attachment arm 214 (as described above and as...) Figure 2A and Figure 2B (As shown). Each of the stabilizer arms can be a unique element provided at 412, attached to each corresponding stabilizer arm. In an embodiment, the attachment at 414 can be performed at 412 during the attachment of the corresponding stabilizer attachment protrusion, for example by guiding a bolt, which serves as the corresponding stabilizer attachment protrusion, through the corresponding hole in the stabilizer arm. The attachment of the stabilizer arm formed at 414 can physically separate and distinguish from any connection between the arm and the first and second attachment protrusions.

[0053] Optionally, method 400 may also include providing a compressor housing (such as having) at 416. Figure 3The compressor housing shown is the housing of the interstage housing. For example, the compressor housing may be part of the compressor housing 112 (as described above and as shown in the diagram). Figure 1 (as shown), or part of the interstage housing 302 (as described above and as shown) Figure 3 (As shown). The compressor housing may include features or fixing locations for attaching the stabilizer arm (such as threaded openings for receiving bolts, or any suitable mechanical features for mating with the stabilizer arm).

[0054] At 418, each of the multiple stabilizer arms can be attached to the compressor housing. This attachment can be achieved through any suitable connection (such as a mechanical connection) between the stabilizer arm and the compressor housing. Non-limiting examples of a mechanical connection may include the use of mechanical fasteners (such as bolts, engagement of any suitable engagement feature, etc.).

[0055] Figure 5 An HVACR system including a compressor is shown according to an embodiment. The HVACR system 500 includes a compressor 502, a condenser 504, an expander 506, and an evaporator 508.

[0056] The HVACR system 500 is a system configured to provide heating and / or cooling using a compressed cycle of a working fluid. The working fluid can be any suitable fluid, such as a refrigerant or a blend thereof. Figure 5 In the embodiment shown, the HVACR system 500 is configured to provide cooling in a cooler system; however, it should be understood that an HVACR system including a compressor according to the embodiment may also be arranged as a heat pump, a reversible system, or any other suitable system that provides heating and / or cooling through a compression cycle of a working fluid.

[0057] Compressor 502 is a compressor according to any embodiment described herein. Compressor 502 may be a multi-stage centrifugal compressor including a capacity control system, for example... Figure 1 The compressor 100 shown and described above. Compressor 502 can be configured to receive side flow as at least part of its capacity control characteristics. Compressor 502 may include a capacity control system, such as those described above. Figure 2A , Figure 2B and Figure 3 The capacity control system 200 is shown in the figure.

[0058] Condenser 504 receives the working fluid compressed by compressor 502. Condenser 504 is a heat exchanger configured to allow the working fluid received from compressor 502 to dissipate heat in order to condense the working fluid. The heat can be dissipated to, for example, the ambient environment, the heated process fluid, the heated load, or any other suitable radiator used to dissipate the heat from the working fluid at condenser 504.

[0059] Expander 506 is configured to receive working fluid from condenser 504 and expand the received working fluid. Expander 506 can be any suitable expander, such as one or more expansion valves, one or more expansion orifices, one or more expansion orifice plates, combinations thereof, etc. In embodiments, expander 506 can be a controllable expander, such as an electronic expansion valve.

[0060] Evaporator 508 is configured to receive working fluid from expander 506 and exchange heat, such that the working fluid receives heat (e.g., heat from the process fluid or the conditioned space to be cooled, heat from the surrounding environment, etc.) to evaporate the working fluid. Non-limiting examples of evaporator 508 may include an evaporator, coil, etc., of a cooler, the evaporator being configured to cool the process fluid, and the coil being used to cool the air to be distributed to the conditioned space. Working fluid exiting evaporator 508 may return to the suction inlet of compressor 502, and the working fluid may continue to circulate within HVACR system 500.

[0061] Figures 6A to 6D A compressor 600 according to an embodiment is shown. The compressor 600 includes a first-stage thruster 604. The first-stage thruster 604 is driven by a shaft 606. The shaft 606 is rotated by, for example, a prime mover (such as a motor, electric motor, etc.). The first-stage thruster 604 is configured to draw in working fluid through one or more inlet guide vanes 602 and discharge the working fluid toward a diffuser 608 when rotating.

[0062] The diffuser 608 receives fluid discharged from the first-stage thruster 604 and directs the fluid flow toward the return bend 610. The return bend 610 changes the direction of fluid flow, causing the fluid to travel toward the second-stage thruster 618 through the de-rotor blades 612.

[0063] One or more derotator blades 612 extend from the bend 610 toward the second-stage propeller 618. The derotator blade 612 is shaped to straighten the flow of fluid as it flows toward the second-stage propeller 618. The derotator blade 612 may include a notch configured to receive at least a portion of a capacity control valve 616.

[0064] Sideflow injection port 614 is a port configured to allow sideflow to be introduced into the interstage flow of fluid via compressor 600. Sideflow injection port 614 includes a front end 624 facing bend 610 and a rear end 626 facing second-stage propeller 618. Sideflow injection port 614 connects sideflow passage 628 to interstage flow. Sideflow passage 628 can receive sideflow of fluid from within a fluid circuit (e.g., including compressor 600). The source of the sideflow received by sideflow passage 628 can be one or more of a condenser, economizer, intercooler, heat exchanger, or other suitable fluid source located at an intermediate pressure between the suction and discharge pressures of compressor 600. Sideflow injection port 614 can be annular around the inlet of second-stage propeller 618. Sideflow injection port 614 can be located between bend 610 and second-stage propeller 618.

[0065] A capacity control valve 616 is a valve configured to regulate flow through a side-flow injection port 614. The capacity control valve 616 is configured to extend axially through the side-flow injection port 614, for example, such that the capacity control valve 616 extends substantially perpendicular to the flow direction of interstage flow from the derotator blade 612 toward the second-stage propeller 618. The capacity control valve 616 is configured to block flow through the side-flow injection port 614 in a closed position, for example, by including a portion having a thickness corresponding to the width of the side-flow injection port 614 from the front end 624 to the rear end 626. In one embodiment, the capacity control valve 616 is controlled together with the inlet guide vane 602. In another embodiment, the capacity control valve 616 is controlled independently of the inlet guide vane 602.

[0066] The capacity control valve 616 includes a front side 630 and a rear side 632, the front side 630 facing the bend 610 and the rear side 632 facing the inlet into the second-stage propeller 618. The front side 630 includes a curved surface 634 extending toward the tip 636 of the capacity control valve 616. The curved surface 634 can change the distance between the capacity control valve 616 and the front end 624 of the side-flow injection port 614 as the capacity control valve 616 extends or retracts axially.

[0067] The tail side 632 includes one or more passages 638 configured to allow sideflow from the sideflow passage 628 to pass through the sideflow injection port 614 and be introduced into interstage flow on the tail side 632 of the capacity control valve 616. In an embodiment, the passage 638 includes one or more channels having openings on the tail side 632 of the capacity control valve 616. In an embodiment, the passage 638 is a cut, fan-shaped portion, etc., formed in the tail side 632 such that at some locations on the capacity control valve 616, a gap exists between the tail side 632 and the tail end 626 of the sideflow injection port 614.

[0068] In the fully open position of the capacity control valve 616, sideflow flows from the sideflow channel 628 through the sideflow injection port 614, and this flow is between the front end 624 of the sideflow injection port 614 and the front side 630 of the capacity control valve 616. The tip 636 of the capacity control valve 616 is located within the sideflow injection port 614 or retracted into the sideflow channel 628, and the capacity control valve 616 substantially does not affect the interstage flow from the bend 610 to the second-stage propeller 618. Optionally, in Figure 6A In the fully open position shown, the inlet guide vane 602 can be in the open position, where it provides little or no resistance to the fluid flowing into the first-stage propeller 604. For example, when the compressor 600 operates at or near full capacity, it can be used... Figure 6A The fully open position shown. Figure 2A and Figure 2B In the embodiment shown, when in Figure 6A When shown in the fully open position, some or all of the side flow through the side flow injection port 614 can pass through the front side 630 of the capacity control valve 616.

[0069] The second-stage thruster 618 is used to achieve the second stage of compression. The second-stage thruster 618 draws in a combination of interstage and side-flow flows and discharges the fluid toward the volute turbine 620. The second-stage thruster 618 can be rotated by a shaft 606, which also rotates the first-stage thruster 604. The fluid at the volute turbine 620 can then be discharged from the compressor 600 at the discharge cone 622.

[0070] In this embodiment, the sideflow provided through the sideflow injection port 614 can be received from an economizer. The economizer may be a flash tank economizer, in which flash gas or bypass gas rises and can be directed to the sideflow passage 628. Gas from the economizer, directed to the sideflow passage 628, can reduce or eliminate the presence of gas in the liquid delivered to the evaporator of the HVACR system, including the compressor 600. This, in turn, can improve energy absorption at the evaporator by providing more saturated liquid working fluid without further subcooling. During a full-load cycle corresponding to the fully open position of the capacity control valve 616, the pressure at the sideflow injection port 614 can allow entrained vapor to be substantially removed from the working fluid in the economizer.

[0071] Figure 6B This shows what happens when the capacity control valve 616 is in the high flow position. Figure 6A The compressor shown is a cross-sectional view. Figure 6B The high flow rate position shown can be used for partial load conditions, where the load is relatively close to the full load of compressor 600. Figure 6B At the high flow position shown, the capacity control valve 616 extends such that its tip 636 protrudes into the interstage flow path from the bend 610 to the second propeller 618, thereby partially blocking the interstage flow path. Figure 6B In the high-flow position of the embodiment shown, a first gap exists between the front end 624 of the side-flow injection port and the front side 630 of the capacity control valve 616, and a second gap exists in the passage 638 between the rear side 632 of the capacity control valve 616 and the rear end 626 of the side-flow injection port 614. Each of the first and second gaps allows some of the side-flow to merge into the interstage flow. Because the portion passing through the second gap is introduced on the rear side 632 of the capacity control valve 616, the portion passing through the second gap experiences a smaller pressure exerted by the interstage flow. Optionally, in Figure 6B At the high flow rate position shown, the inlet guide vane 602 can be in a high flow rate position, wherein, with Figure 6A Compared to the fully open position shown, the inlet guide vane 602 provides increased drag on the flow entering the first-stage thruster 604, but compared to the positions shown separately... Figure 6C and Figure 6D The low flow position or the off position shown provides less resistance. Figure 6B At the high flow rate position shown, the flow through the side flow injection port 614 can include both the flow on the front side 630 of the capacity control valve and the flow through the rear side 632 of the capacity control valve.

[0072] Figure 6C This shows what happens when the capacity control valve 616 is in the low flow position. Figure 6AThe compressor shown is a cross-sectional view. Figure 6C The low flow position shown can be used under partial load conditions where the load is less than 600 rpm of the compressor at full load, and under load conditions where the capacity control valve is in the high flow position (such as in...). Figure 6B (As shown). In Figure 6C As shown in the low flow position, the capacity control valve 616 extends further into the interstage flow from the bend 610 to the second propeller 618. Therefore, with Figure 6B Compared to the high flow rate position shown, the capacity control valve 616 provides even greater resistance to interstage flow. Figure 6C In the low-flow position of the embodiment shown, a first gap exists between the front end 624 of the side-flow injection port and the front side 630 of the capacity control valve 616, and a second gap exists at the passage 638 between the rear side 632 of the capacity control valve 616 and the rear end 626 of the side-flow injection port 614. Figure 6B Compared to the first and second gaps at the high flow rate locations shown, in Figure 6C At low flow rates, the second gap is relatively larger than the first gap, and a larger proportion of the sideflow flows through the second gap to merge into the interstage flow, relative to the amount of sideflow flowing through the first gap. Optionally, in Figure 6C As shown in the low flow position, the inlet guide vane 602 can be in a low flow position, wherein, with Figure 6B Compared to the high-flow-rate location shown, the inlet guide vane 602 provides increased drag on the flow entering the first-stage thruster 604, but compared to... Figure 6D The closed position shown provides less resistance. Figure 6C In the low-flow position shown, the flow through the side-flow injection port 614 can pass primarily or entirely through the tail side 632 of the capacity control valve. The shapes of the front side 630 and the passage 638 can be selected individually or both to control the relative flow introduced into either the front side 630 or the tail side 632 of the capacity control valve 616, and to control how these relative quantities change as the capacity control valve 616 moves from the fully open position to the closed position, such as... Figures 6A to 6D As shown.

[0073] In this embodiment, the sideflow passage 628 can receive sideflow from the economizer. Providing a passage 638 in the capacity control valve 616 allows the valve to control not only the introduced flow rate, but also the specific point at which the sideflow is introduced into the sideflow injection port 614, and the pressure at that point. Controlling the location of the point where the sideflow is introduced provides control over the relationship between the core flow and the sideflow in the compressor. Controlling the point of introduction can improve economizer efficiency under different load conditions. When the compressor 600 operates under partial load, it can be used... Figure 6C The low flow position is shown. When the compressor 600 operates under partial load, the static pressure at the side-flow injection port 614, particularly between the front end 624 of the side-flow injection port 614 and the front side 630 of the capacity control valve 616, can be relatively increased. Apart from piping losses and the fixed orifice pressure drop of the system, the pressure within the economizer is a function of the static pressure at the injection position in the compressor 600. Therefore, the increased pressure at the side-flow injection port 614 may lead to increased pressure at the economizer, thereby reducing the effectiveness of removing flash gas or bypass gas from the fluid containing that gas. By placing the passage 638 on the opposite side of the capacity control valve 616 facing the front side 630 of the interstage flow within the compressor 600, the passage 638 experiences a reduced pressure compared to the pressure on the front side 630, or with... Figure 6C In the illustrated embodiment, the passage 638 experiences a reduced pressure compared to the static pressure at the side-flow injection port 614. As described above, the reduced pressure at such an injection point can correspondingly lower the pressure within the economizer, thereby improving the release of flash gas or bypass gas from the liquid in the economizer and improving the removal of flash gas and bypass gas from the flow of working fluid delivered to the evaporator. This improves heat transfer at the evaporator and can also reduce recompression losses in systems including compressor 600 (which has a capacity control valve 616 including passage 638).

[0074] Figure 6D This shows the situation when the capacity control valve 616 is in the closed position. Figure 6A The image shows a cross-sectional view of the compressor. When the compressor 600 is under partial load conditions (at or near minimum load) for the compressor, it can be used... Figure 6DThe closed position is shown in the diagram. In the closed position, the capacity control valve 616 partially or completely blocks the side flow injection port 614 from the front end 624 to the rear end 626. It should be understood that some leakage may occur even when the capacity control valve 616 is in the closed position due to manufacturing tolerances, etc. In an embodiment, the capacity control valve 616 may be sized such that the capacity control valve 616 does not contact the side flow injection port 614 and allows some fluid to pass through the gap between the side flow injection port 614 and the capacity control valve 616. Any features of the capacity control valve 616 (such as passage 638) configured to allow side flow to be introduced at the rear end 632 of the capacity control valve 616 may be configured such that they do not allow this flow when the capacity control valve 616 is in the closed position. For example, as Figure 6D As shown, in this embodiment, the fan-shaped portion on the tail side 632 forming the passage 638 is sized and positioned such that when the capacity control valve 616 extends to the closed position, the tail side 632 contacts the tail end 626 of the side flow injection port 614. The extension of the capacity control valve 616 through the compressor 600 to the interstage flow is maximized, thereby reducing the orifice size through which the interstage flow flows from the turnaround section 610 toward the second-stage propeller 618. Therefore, this position imparts the maximum additional velocity to the interstage flow while preventing the side flow from merging into the interstage flow. Optionally, the inlet guide vane 602 can be rotated to further block the flow to the first-stage propeller 604 of the compressor 600, for example, by positioning the inlet guide vane 602 in a minimum flow position.

[0075] aspect:

[0076] It should be understood that any one of aspects 1 to 5 can be combined with any one of aspects 6 to 13 or any one of aspects 14 to 15.

[0077] Aspect 1. An assembly for a capacity control valve, the assembly comprising:

[0078] Drive ring;

[0079] Throttling ring;

[0080] Multiple drive links, each drive link including: a first attachment protrusion on the drive ring, a second attachment protrusion on the throttle ring, and a link arm, the link arm being connected to each of the first attachment protrusion and the second attachment protrusion.

[0081] The throttling ring includes:

[0082] Multiple stabilizing link attachment protrusions, wherein the multiple stabilizing link attachment protrusions are separated from the second attachment protrusions of the multiple drive links; and

[0083] Multiple stabilizing links, each of which is attached to one of the stabilizing link attachment protrusions.

[0084] Aspect 2. The component according to aspect 1 further includes an interstage housing, wherein each of the plurality of stabilizing links is attached to the interstage housing.

[0085] Aspect 3. The assembly according to any one of Aspects 1 to 2, wherein the first attachment protrusions of the plurality of drive links are uniformly distributed along the circumference of the drive ring.

[0086] Aspect 4. The assembly according to any one of Aspects 1 to 3, wherein the second attachment protrusions of the plurality of drive links are uniformly distributed along the circumference of the throttle ring.

[0087] Aspect 5. The assembly according to aspect 4, wherein the plurality of stabilizing link attachment protrusions are uniformly distributed along the circumference of the throttle ring, and the plurality of stabilizing links are offset from the second attachment protrusions of the plurality of drive links.

[0088] Aspect 6. A compressor, comprising:

[0089] First thruster;

[0090] Second thruster;

[0091] Multiple guide vanes form a channel between the first thruster and the second thruster, the channel being configured to guide interstage flow of fluid from the first thruster to the second thruster;

[0092] A side-flow injection port, located between the first and second thrusters, configured to receive a sideflow of fluid; and

[0093] A throttling ring configured to move axially between an extended position and a retracted position through the side-flow injection port, wherein, in the extended position, the throttling ring blocks the side-flow of fluid through the side-flow injection port and partially blocks the interstage flow of fluid through the channel; and in the retracted position, the throttling ring allows the side-flow of fluid through the side-flow injection port; and

[0094] Drive ring,

[0095] The throttling ring and the drive ring are connected by a plurality of drive links, each drive link including: a first attachment protrusion on the drive ring, a second attachment protrusion on the throttling ring, and a link arm, the link arm being connected to each of the first attachment protrusion and the second attachment protrusion.

[0096] The throttling ring includes:

[0097] Multiple stabilizing link attachment protrusions, wherein the multiple stabilizing link attachment protrusions are separated from the second attachment protrusions of the multiple drive links; and

[0098] Multiple stabilizing links, each of which is attached to one of the stabilizing link attachment protrusions.

[0099] Aspect 7. The compressor according to aspect 6 further includes an interstage housing, wherein each of the plurality of stabilizing link arms is attached to the interstage housing.

[0100] Aspect 8. The compressor according to any one of Aspects 6 to 7, wherein the first attachment protrusions of the plurality of drive links are evenly distributed along the circumference of the drive ring.

[0101] Aspect 9. The compressor according to any one of Aspects 6 to 8, wherein the second attachment protrusions of the plurality of drive links are evenly distributed along the circumference of the throttling ring.

[0102] Aspect 10. The compressor according to aspect 9, wherein the plurality of stabilizing link attachment protrusions are evenly distributed along the circumference of the throttling ring, and the plurality of stabilizing links are offset from the second attachment protrusions of the plurality of drive links.

[0103] Aspect 11. The compressor according to any one of Aspects 6 to 10, wherein the throttling ring includes toothed protrusions; and in the extended position, the toothed protrusions of the throttling ring are disposed in the channel and block the channel.

[0104] Aspect 12. The compressor according to aspect 11, wherein the toothed protrusion extends in the axial direction and the toothed protrusion includes a tip that is radially curved inward.

[0105] Aspect 13. The compressor according to any one of Aspects 6 to 12 further includes an actuator configured to rotate the drive ring such that the throttling ring is driven to travel in the axial direction.

[0106] Aspect 14. A method of assembling a compressor, the method comprising:

[0107] Provide drive ring;

[0108] Provide a throttling loop;

[0109] Attach a plurality of first attachment protrusions to the drive ring;

[0110] Attach a plurality of second attachment protrusions to the throttling ring;

[0111] Each of the plurality of linkage arms is attached to a corresponding one of the plurality of first attachment protrusions and to a corresponding one of the plurality of second attachment protrusions;

[0112] A plurality of stabilizing link attachment protrusions are attached to the throttle ring, wherein the plurality of stabilizing link attachment protrusions are separate from the second attachment protrusions of the plurality of drive links; and

[0113] Each of the multiple stabilizer arms is attached to a corresponding stabilizer attachment protrusion.

[0114] Aspect 15. The method according to aspect 14 further includes providing an interstage housing and attaching each of the plurality of stabilizing links to the interstage housing.

[0115] The examples disclosed in this application are to be considered illustrative rather than limiting in all respects. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all modifications in the meaning and scope of equivalents of the claims are intended to be included therein.

Claims

1. An assembly for a capacity control valve, the assembly comprising: a drive ring; a throttle ring; a plurality of drive links, each drive link comprising: a first attachment tab on the drive ring, a second attachment tab on the throttle ring, and a link arm joined to each of the first and second attachment tabs, wherein the throttle ring comprises: a plurality of stabilizing link attachment tabs separate from the second attachment tabs of the plurality of drive links; and a plurality of stabilizing link arms, each of the plurality of stabilizing link arms attached to one of the stabilizing link attachment tabs.

2. The assembly of claim 1, further comprising an inter-stage housing, wherein each of the plurality of stabilizing link arms is attached to the inter-stage housing.

3. The assembly of claim 1, wherein the first attachment tabs of the plurality of drive links are evenly distributed along a circumference of the drive ring.

4. The assembly of claim 1, wherein the second attachment tabs of the plurality of drive links are evenly distributed along a circumference of the throttle ring.

5. The assembly of claim 4, wherein the plurality of stabilizing link attachment tabs are evenly distributed along a circumference of the throttle ring, the plurality of stabilizing link attachment tabs offset from the second attachment tabs of the plurality of drive links.

6. A compressor, comprising: a first impeller; a second impeller; a plurality of guide vanes forming a passage between the first impeller and the second impeller, the passage configured to direct an inter-stage flow of fluid from the first impeller to the second impeller; a side flow injection port between the first impeller and the second impeller, the side flow injection port configured to receive a side flow of fluid; and a throttle ring configured to move in an axial direction through the side flow injection port between an extended position and a retracted position, wherein, in the extended position, the throttle ring blocks the side flow of fluid through the side flow injection port and partially blocks the inter-stage flow of fluid through the passage; and, in the retracted position, the throttle ring allows the side flow of fluid to flow through the side flow injection port; and a drive ring, wherein the throttle ring and the drive ring are connected by a plurality of drive links, each drive link comprising: a first attachment tab on the drive ring, a second attachment tab on the throttle ring, and a link arm joined to each of the first and second attachment tabs, and the throttle ring comprises: a plurality of stabilizing link attachment tabs separate from the second attachment tabs of the plurality of drive links; and a plurality of stabilizing link arms, each of the plurality of stabilizing link arms attached to one of the stabilizing link attachment tabs.

7. The compressor of claim 6, further comprising an inter-stage housing, wherein each of the plurality of stabilizing link arms is attached to the inter-stage housing.

8. The compressor of claim 6, wherein the first attachment protrusions of the plurality of drive links are evenly distributed along a circumference of the drive ring.

9. The compressor of claim 6, wherein the second attachment protrusions of the plurality of drive links are evenly distributed along a circumference of the throttle ring.

10. The compressor of claim 9, wherein the plurality of stabilizer link attachment protrusions are evenly distributed along a circumference of the throttle ring, the plurality of stabilizer link attachment protrusions being offset from the second attachment protrusions of the plurality of drive links.

11. The compressor of claim 6, wherein the throttle ring includes a toothed protrusion; and in the extended position, the toothed protrusion of the throttle ring is disposed in the passage and obstructs the passage.

12. The compressor of claim 11, wherein the toothed protrusion extends in the axial direction and includes a radially inwardly curved tip.

13. The compressor of claim 6, further comprising an actuator configured to rotate the drive ring such that the throttle ring is driven to travel in the axial direction.

14. A method of assembling a compressor, the method comprising: providing a drive ring; providing a throttle ring; attaching a plurality of first attachment protrusions to the drive ring; attaching a plurality of second attachment protrusions to the throttle ring; attaching each of a plurality of link arms to a corresponding one of the plurality of first attachment protrusions and to a corresponding one of the plurality of second attachment protrusions; attaching a plurality of stabilizer link attachment protrusions to the throttle ring, the plurality of stabilizer link attachment protrusions being separate from the second attachment protrusions of the plurality of drive links; and attaching each of a plurality of stabilizer link arms to a corresponding one of the stabilizer link attachment protrusions.

15. The method of claim 14, further comprising providing an interstage housing and attaching each of the plurality of stabilizer link arms to the interstage housing. ​

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