JP2009524776A - Pump flow restriction device - Google Patents

Abstract

A split ring is inserted into the annulus between the shaft and the housing to limit the flow of fluid along the shaft. When both ends of the split ring are separated from each other, the effective diameter of the split ring is enlarged, and a gap (clearance) allowing fluid flow is maintained between the inner diameter surface of the split ring and the shaft. When the ends are released and close to each other, the split ring clogs the annular gap and restricts flow flow. It is also contemplated to insert an axially movable sleeve into the annulus between the shaft and housing to limit fluid flow along the shaft. A fluid flow rate in the annular portion between the movable sleeve and the shaft can be suppressed by a feature or interval such as a labyrinth structure that forms a pressure difference along the other end of the sleeve.
[Selection figure] None

Description

  In summary, the present invention relates to rotary pumps such as chemical processing pumps or refrigerant pumps of nuclear reactors (fusion reactors) and components such as flow restriction devices used in rotary pumps.

  In a pressurized water nuclear power plant, a reactor refrigerant device is used to generate heat by transferring heat generated from a core to a steam generator. The turbine generator is driven using the steam generated from the steam generator. The reactor refrigerant apparatus includes a plurality of cooling pipe circuits to be separated, and each cooling pipe circuit connected to the core includes a steam generator and a rotary refrigerant pump. There are also other sites where a process fluid containment facility may be required, such as a chemical process rotary pump.

As a rotary pump used for a reactor refrigerant pump, a chemical processing pump, or the like, a centrifugal pump designed to convey a large volume of processing fluid (for example, a reactor refrigerant) at high temperature and high pressure is usually used. This centrifugal pump usually includes a hydraulic pressure drive unit, a shaft sealing unit, and a motor unit. An impeller attached to the end of the pump shaft (shaft) and operated in the pump casing to convey the processing fluid is usually provided in the hydraulic pressure drive. A motor provided in the motor unit is connected to the pump shaft to drive the pump. In the shaft sealing portion provided between the hydraulic drive unit and the motor unit, a plurality of series-type sealing assemblies are usually installed coaxially with the pump shaft and near the upper end of the pump shaft. Series seal assemblies are typically designed to minimize the amount of process fluid leakage along the pump shaft during normal operating conditions. At least representative examples of pump shaft sealing assemblies known in the field of reactor refrigerant pumps include the following patent document 1 in the name of McLamb, the following patent document 2 in the name of Singleton, the following patent document 3 in the name of Villacer, and the following patents in the name of Andrew and others. It is disclosed in Document 4 and the following Patent Document 5 in the name of Bose.
U.S. Pat. No. 3,522,948 U.S. Pat. No. 3,529,838 U.S. Pat. No. 3,632,117 U.S. Pat. No. 3,720,222 U.S. Pat. No. 4,275,891 US Pat. No. 5,171,024

  The sealing assembly of the pump shaft must normally maintain a high pressure in the device without causing excessive leakage. The in-line type sealing device of the sealing assembly has a function of decreasing the pressure stepwise, for example. The actual pump seal assembly acts as a leak control seal that controls leakage to a minimum amount at each stage during operation, while an excessive amount of processing fluid (eg, reactor refrigerant) from the main fluid device to each leak hole Has the effect of preventing leakage. Pump seal assemblies are used in many situations where excessive leakage sealing is required. For example, the reactor coolant pump pump seal assembly may fail due to the uncontrolled high temperature of the reactor coolant, resulting in excessive leakage flow resulting in the core being exposed to the reactor coolant and being damaged. There are things to do.

  The above-mentioned Patent Document 6 (in the name of Janoko) discloses a shutdown type sealing device that prevents and suppresses excessive fluid leakage along the pump shaft, whether it is a reactor refrigerant pump or other pump such as a chemical processing pump. It is necessary to provide a device that is more effective in preventing fluid leakage.

  This document contemplates a comprehensive split ring (split ring or discontinuous ring) device disposed around a shaft and operating in response to fluid leakage in accordance with at least one embodiment of the present invention. In the first state in which both ends of the split ring device are separated from each other, a fluid flow path is formed between both separated ends, and a gap (clearance) is formed with respect to the shaft that moves normally. In the second state where the distance between both ends of the split ring device is narrow, the fluid flow path is closed or restricted. A pressure load can be used to hold the split ring device in a second state that is in the close or closed position between the ends of the split ring device. In a preferred variant embodiment, after the fusible spacer is placed in the gap between the ends of the split ring, the spacer is melted at a predetermined temperature to reduce or close the gap in the split ring device. Can do.

  In at least one other embodiment of the present invention, a sliding sleeve is provided around the shaft. For example, in the longitudinal axis of the shaft in a position where the flow rate is restricted or interrupted around the shaft in response to a pressure drop due to a high fluid flow rate or fluid flow velocity, phase change or choke flow (flow in a reduced cross-sectional flow path) The sleeve can be slid in parallel.

  In at least one other embodiment of the present invention, the split ring-sliding sleeve device can be integrally provided in a single pump structure.

  In summary, according to at least one presently preferred embodiment of the present invention, the pump structure generally contemplated herein includes a shaft member, a support structure through which the shaft member is inserted, and a support structure. A flow restriction device for restricting a flow rate along the shaft member, the flow restriction device being disposed in at least one annular space formed between the shaft member and the support structure, wherein the flow restriction device is disposed on the shaft. A discontinuous ring member (split ring) disposed around the member, the discontinuous ring member having two ends, the discontinuous ring member having first ends spaced apart from each other by a first distance; 1 and a second state in which both ends are separated from each other by a second interval that is narrower than the first interval, and in the first state, formed between the shaft member and the support structure. At least One of the fluid flow path through which fluid passes into the annular space is formed, the cross-section of the fluid channel is greater than the cross-section of the fluid flow path in the second state.

  In addition, according to at least one presently preferred embodiment of the present invention, the structure of the pump comprehensively contemplated herein includes a shaft member, a support structure through which the shaft member is inserted, and a shaft of the support structure. A flow restriction device for restricting a flow rate along the member, wherein the flow restriction device is disposed in at least one annular space formed between the shaft member and the support structure, and the flow restriction device is disposed on the shaft member. A sleeve member disposed around the sleeve member, the sleeve member being movable substantially parallel to the longitudinal axis of the shaft member between a first position and a second position, wherein the sleeve member and the shaft member are supported in the first position; A fluid flow path is formed in at least one annular space formed between the structure and the cross section of the fluid flow path that is larger than the cross section of the fluid flow path in the second state.

  Further, according to at least one presently preferred embodiment of the present invention, a rotary pump as generally contemplated herein includes a motor, a shaft member extending from the motor, and an impeller attached to the free end of the shaft member. And a housing that surrounds a main portion of the shaft member, the housing including a sealed housing that contacts at least a portion of the shaft member, and a flow restriction device that restricts fluid flow along the shaft relative to the sealed housing, The sealed housing has at least one sealing member that restricts fluid flow along the shaft member, the motor rotates the shaft member to drive the impeller, and the flow restriction device is between the shaft member and the sealed housing. The flow restrictor is disposed in at least one annular space formed on the shaft member. The discontinuous ring member has two ends, and the discontinuous ring member has a first state in which both ends are separated from each other by a first interval, and a second state that is narrower than the first interval. In the first state, in which the fluid flow path is formed in at least one annular space formed between the shaft member and the sealed housing. The cross section of the fluid flow path is larger than the cross section of the fluid flow path in the second state.

  Also, according to at least one presently preferred embodiment of the present invention, a rotary pump as generally contemplated herein includes a motor, a shaft member extending from the motor, and an impeller attached to the free end of the shaft member. And a housing that surrounds a major portion of the shaft member, the housing surrounding at least a portion of the shaft member and having at least one sealing member that restricts flow along the shaft member; and A motor for rotating the shaft member to drive the impeller, and the flow restrictor is at least one formed between the shaft member and the sealed housing. The flow restriction device arranged in one annular space has a sleeve member arranged around the shaft member, and the sleeve The material can move between the first position and the second position substantially parallel to the longitudinal axis of the shaft member, and in the first position, at least one ring formed between the shaft member and the sealed housing. A fluid flow path is formed in the space, and the cross section of the fluid flow path is larger than the cross section of the fluid flow path in the second state.

  The novel features considered as the characteristics of the present invention will be described below. However, the invention itself, structure and method of operation, together with further objects and advantages, will be better understood from the following description of specific embodiments in connection with the accompanying drawings.

  The following detailed description with reference to the accompanying drawings will provide a better understanding of the present invention and the presently preferred embodiments. As shown in FIG. 1, the pump 10 typically includes a main pump housing 12. In the illustrated embodiment, the main pump housing 12 forms the main part of the outer housing of the pump 10, but includes an inner sealed housing 12a protruding radially inward from the main pump housing 12 and having a smaller diameter than the main pump housing 12. It can be provided in the main pump housing 12. The impeller housing 14 that houses the impeller 16 is also fixed to the pump shaft 18 in the main pump housing 12 with bolts. Pump 10 represents a variety of rotary pumps including conventional centrifugal pumps, reactor refrigerant pumps and chemical processing pumps (eg, pumps commonly used in the chemical processing industry). For example, the pump 10 can be arranged in all directions suitable for the intended application, such as a substantially horizontal direction (in the case of a reactor refrigerant pump) or a substantially vertical direction.

  The pump 10 includes a pump shaft 18 extending centrally with respect to the main pump housing 12, and the pump shaft 18 is rotatably mounted in a sealed structure within the inner sealed housing 12a. One end of the pump shaft 18 is connected to the impeller 16 (for example, by a cap 20 shown in the figure), and the other end of the pump shaft 18 is drivingly connected to the electric motor 22. When the motor 22 rotates the pump shaft 18, the impeller 16 pressurizes the reactor refrigerant and supplies the reactor refrigerant to a general reactor refrigerant device. At the same time, this pressurized refrigerant applies a lift hydraulic pressure load to the pump shaft 18.

  While maintaining the high pressure boundary formed between the high pressure pump region formed in the cavity of the impeller 16 extending to the right side of FIG. 1 and the peripheral region 24 of the internal sealed housing 12a, within the inner sealed housing 12a. In order to freely rotate the pump shaft 18, it is preferable to provide a sealing assembly with a mechanical contact surface sealing structure. The general structure and function of a conventional sealing assembly can be fully understood from the above-mentioned Patent Document 6 in the name of Janoko. While at least one presently preferred embodiment of the present invention broadly contemplates a split ring 26 that provides the function of restricting fluid flow between the pump shaft 18 and the inner seal housing 12a under given conditions, This point can be better understood from the following description.

  It is preferable to divide or cut the ring 26 along a cut surface at one point along the circumference of the ring 26 and to perform non-planar edge processing on the cut edge as described later. It is preferable that no intervening structure is provided between the pair of free ends of the split ring 26 or that a considerable reaction force is generated in the direction in which the free ends come into contact with each other when in the relaxed state or the free state. In this way, when a pair of free ends of the split ring 26 are separated so that a gap is generated between the free ends and the gap is further expanded, the split ring 26 can be deformed with elasticity and the effective diameter of the split ring 26 can be increased. Is more preferable. (Thus, conversely, it is possible to reduce the effective diameter of the ring by reducing the clearance of the split ring 26 to a position where both ends are in contact with each other.) The split ring 26 according to at least one embodiment of the present invention includes: There is an advantage that both ends can be separated in the first state (initial state), and the second “approaching” state is obtained by the elastic characteristics of the split ring 26 itself, regardless of whether other auxiliary approaching force is used. It can be understood from the following explanation that both ends can be brought close to each other. To better understand the operation of the split ring 26 shown in FIG. 1, reference is made to FIG. 2 showing an enlarged view of the split ring 26 and the surrounding member of the pump 10.

  Although the end of the split ring 26 can be cut along a simple cutting plane parallel to the central (vertical) axis forming the split ring 26, other “end face processing” can of course be performed. As known in the field of piston rings (and other rings), diagonal or diagonal cutting planes can be provided on the split ring 26 to form opposing free ends or even more complex end treatments It is. For example, the end portion of the notch portion type may be formed at a place where the protruding portion provided at one end is fitted into a groove or notch portion provided at the other end. In general, various ends can be formed to reduce joint leakage at the ends while adapting to shaft or split ring circumferential deformation due to manufacturing tolerances, thermal expansion or loading . (In a particularly preferred embodiment of the present invention, the split ring 26 is formed as described above by using the oblique interface or diagonal interface provided at both ends of the split ring 26 to protect the split ring from leakage. For example, in response to minute displacements due to thermal expansion, the ends of the split ring 26 can be slid relative to each other.)

  As shown in FIG. 2, the split ring 26 is housed in a cavity between the pump shaft 18 and the inner sealed housing 12a. Alternatively, the split ring 26 in both an initial state and an approached state may be accommodated in the cavity between the part formed integrally with the pump shaft 18 and the inner sealing housing 12a. It is particularly preferable to form the cavity in a size that can be easily accommodated. In this way, in the first state, that is, the split ring 26 in the initial state, the gap between both end portions of the split ring 26 is maintained so that the split ring 26 contacts only the inner sealing housing 12a. This allows normal relative movement between the inner sealed housing 12a and the pump shaft 18. When permitting the approach of both ends of the split ring 26 (as will be described later), the split ring 26 is reduced in diameter around the pump shaft 18, and the inner diameter surface of the split ring 26 and the outer diameter surface of the pump shaft 18 It is also preferable to design the split ring 26 so as to narrow the annular gap between the two.

  Since the gap between the ends of the split ring 26 is usually forcedly formed, it is possible to hold both ends of the split ring 26 apart and hold them in the first state, i.e., the initial state, using a suitable holder. preferable. When exposed to a fluid in a particular state, such as temperature, fluid chemistry, or other state, it dissolves (soluble) in response to the fluid and changes state or substantially deforms or disappears (see below for FIG. 3B) The holding device is preferably formed by a spacer made of a material. When the spacer is exposed to a fluid in a specific state, both ends of the split ring 26 are released from the spacer, and the diameter of the split ring 26 can be reduced around the shaft 18. In this way, the spacer can be automatically activated. For example, the spacer can be formed from an alloy or thermoplastic polymer having a melting point that is within the desired operating range (the chemical compatibility of the spacer material with the surrounding fluid is of course important).

  Alternatively, a machine that initially holds the split ring 26 in the first state (initial state) and then reduces the diameter of the split ring 26 around the pump shaft 18 to deform it into the second state (closed state). An actuator or mechanical actuator may be provided. A mechanical actuator of the type that automatically responds to fluid state changes can be used to mechanically release the end of the split ring 26 and reduce the diameter of the split ring 26 around the pump shaft 18 ( As described below with respect to FIGS. 4A and 4B).

  A number of springs 28a are arranged in an annular cavity surrounding the split ring 26 and parallel to the central axis of the pump 10, and are directed towards the motor 22 and away from the impeller 16 (i.e. possible flow directions or pumps). The dividing ring 26 can be biased by a number of springs 28a in the direction from the high pressure side inside the housing to the low pressure side outside the pump. Disposing another spring 28b radially with respect to the central axis of the pump 10 and actuating an “actuator” (eg, meltable or mechanically) to release the spaced apart ends of the split ring 26; Due to the elasticity of another spring 28b that assists the normal elastic characteristics of the split ring 26, the diameter reduction of the split ring 26 can be promoted in the direction in which both ends of the split ring 26 are close to each other or in the diameter reduction direction.

  Each of the two different cross-sectional shapes of the contemplated split ring 126 are shown in FIGS. 3A-4D. 3A-3D show a first split ring 126 having a cross-sectional shape that approximates a right triangle. As shown, the split ring 126 can be disposed within a cavity formed by the shaft 118 and the housing 112a. An urging spring 128a that urges the split ring 126 or urges away from the impeller and in a direction toward the motor may be provided above FIGS. 3A and 3C. 3A and 3B clearly show the split ring 126 in the first position (initial position) where both ends of the split ring 126 are separated from each other, while FIGS. 3C and 3D show that both ends of the split ring 126 are tight. The split ring 126 is shown in a second position (closed position) in contact with. The dotted line in FIG. 3B, indicated at 129, indicates the expected position of the fusible or consumable spacer.

  3A and 3C, the two sides of the triangle forming a right angle in the cross-sectional shape of the right triangle are aligned parallel to the axial direction and the radial direction of the shaft 118, so that the split ring 126 is substantially parallel to the surface of the shaft 118. It is preferable to form an inner diameter surface. An inclined conical surface is formed by the hypotenuse of a right triangle forming the cross section of the split ring 126, and the inclined conical surface of the split ring 126 is formed on a similar inclined conical surface formed integrally with the housing 112a (or an accessory of the housing 112a). Can be contacted.

  In the embodiment shown in FIGS. 3A to 3D, the flow rate is restricted by pressing the split ring 126 against the conical surface formed in the housing 112a, and the conical surface of the housing 112a is brought into contact with the pressure difference generated by the flow rate restriction. The direction of the seating surface (inclined surface) of the housing 112a and the split ring 126 is determined so that a hydrostatic load is applied to the split ring 126. Due to the axial load applied to the conical interface between the split ring 126 and the housing 112a, a radial reaction force component is generated on the split ring 126, and this reaction force component is split radially inside the shaft 118. Pressing the ring 126 reduces or closes the annular gap formed between the inner diameter surface of the split ring 126 and the shaft 118, thereby reducing or closing the annular gap between the ends of the split ring 126. .

  It is preferable to press and hold the split ring 126, which is held open between both ends using a mechanical actuator or spacer, against the conical seating surface of the housing 112a by a spring or other suitable device. Any movement of the split ring 126 is restricted until a mechanical actuator or spacer releases both ends of the split ring 126 to allow the diameter of the split ring 126 to be reduced. When the diameter of the conical surface of the split ring 126 is effectively changed and the split ring 126 contracts, the split ring 126 moves in the axial direction toward the conical seating surface of the housing 112a and splits with the housing 112a. The contact state between the conical interfaces of the ring 126 can be maintained. The split ring 126 continues to be pressed against the conical seating surface of the housing 112a by a spring or another elastic biasing device. If the contact state is continuously maintained between the conical interface between the housing 112a and the split ring 126, the flow rate between the split ring 126 and the housing 112a is limited.

  Of course, the triangular cross-sectional shape of the split ring 126 is just one possible embodiment. For example, the split ring 126 provides a flat or spherical surface in contact with the housing 112a on the split ring 126 instead of a triangular inclined conical surface so that the inner circular shaft member is misaligned or radially aligned with the outer housing member. Other desired advantages, such as automatically correcting misalignment, may be produced. 4A-4D, on the other hand, show a split ring 126 with a generally rectangular cross section. Essentially similar to FIGS. 3A-3D, FIGS. 4A and 4B and FIGS. 4C and 4D show the split ring 126 in a first position (initial position) and a second position (closed position), respectively. . 4A to 4D, parts that are essentially the same as the parts shown in FIGS. 3A to 3D are indicated by reference numerals that add 100 to the respective reference numerals in FIGS. 3A to 3D.

  In the embodiment shown in FIGS. 4A-4D, the annular cavity that accommodates the split ring 226 formed by a cross-section that is essentially rectilinear is the split ring 226 (the top of the split ring 226) and the housing 212a. A substantially flat interface (or an interface perpendicular to the common central longitudinal axis of the shaft 218 and the housing 212a).

  4A and 4B show a mechanical actuator 231 that is an alternative to the fusible / consumable spacer 129 shown in FIG. 3B. The machine actuator 231 has a function similar to the fusible / consumable spacer 129 and has the effect of promoting the closing of the split ring 226 in response to a given condition. As described above, the mechanical actuator 231 can be realized by any of a wide variety of devices. For example, both ends of the split ring 226 are kept in a separated state by a spring-biased contraction type plunger, and both ends of the split ring 226 are released in response to a change in temperature of the surrounding fluid or other factors. Both end portions of the split ring 226 can be close and closed by a unique action. The plunger can be actuated by an electric device (eg, a solenoid or motor) of the mechanical actuator 231 that responds to an external electrical signal transmitted when a predetermined condition is met. Alternatively, the plunger device may be provided with different hydrostatic regions that are fluidly connected within different portions or cavities of the pump, and the plunger may be contracted when the pump is in a particular pressure condition.

  When the spring-biased plunger itself comprises a fusible / consumable member or pacer that melts or physically deforms in response to temperature, the plunger is contracted so that the ends of the split ring 226 A combined type device that is brought close together is also conceivable. In this hybrid device, the fusible / consumable material actually provided away from the processing fluid (eg, in the cavity in which the plunger spring is mounted) can only react to temperature.

  The fusible / consumable spacer 129 shown in FIG. 3B and the mechanical actuator 231 shown in FIGS. 4A and 4B are essentially interchangeable and can be used in essentially any split ring device. It will be clearly understood that it is not necessary to associate the spacer 129 and the mechanical actuator 231 only with a particular split ring device and the structure and shape shown in the drawings.

  In all embodiments that can be envisaged, the inner diameter surface of the split ring and the outer diameter of the shaft when the inner diameter surface of the split ring that is released at both ends and contracts around the shaft contacts or is close to the surface of the shaft. Preferably, the split ring is sized so that the annular gap between the faces can be closed or reduced very little. As a result, there is an effect that the flow rate of the fluid flowing through the annular portion between the housing surrounding the shaft and the shaft is entirely limited.

  The split ring creates a differential pressure along the contact surface between the split ring and the shaft and the contact surface between the split ring and the housing due to the restricted flow rate in the second state (contracted state or constricted state). In addition, it will be further understood that the position of the pressure drop can be controlled by precisely controlling the position of the contact surface. A plurality of the contact surfaces and a pressure drop caused by the contact surfaces form a hydrostatic pressure region in which various pressures act, a force acting on the split ring to seat the split ring on the housing, and a split ring A force that can be used to increase the force to reduce the diameter on the shaft is generated by the hydrostatic pressure region, and the deformation of the split ring can be preferentially controlled.

  The split ring may be provided with a deformable element that firmly seats the contact surface between the contact surfaces of the split ring and the inner member and the outer member and / or the contact surfaces between both ends of the gap along the outer periphery of the split ring. Good.

  As shown in FIGS. 5-8B, a sliding sleeve device 330 that restricts fluid flow through the annulus between the shaft 318 and the housing 312a will be described below, but the invention is not limited to the illustrated example. Absent. FIG. 5 shows a partial cross-sectional view of a pump 310 that uses a sliding sleeve device 330. (To reiterate, pump 310 represents a wide variety of rotary pumps including common centrifugal pumps, reactor refrigerant pumps, and chemical processing pumps.) FIG. 6 is slid toward the motor (ie, motor). FIG. 6 is basically an enlarged view of FIG. 5 showing the sliding sleeve in position). The various pump components shown in FIGS. 5 and 6 are similar to the pump components shown in FIGS. 1 and 2, with reference numerals adding 300 to the corresponding reference numerals. To further explain, in order to better understand and recognize the sliding sleeve device, both FIGS. 5 and 6 are given the same reference numerals.

  A cylindrical sleeve 330 having a specific cross-sectional shape is preferably disposed around the shaft 318 so as to be movable essentially parallel to the longitudinal axis of the shaft 318 between the shaft 318 and the housing 312a. It is preferable to maintain a slight annular gap (clearance) between the inner diameter surface of the cylindrical sleeve 330 and the shaft 318 without contacting the surface of the shaft 318. It is preferable that the outer surface of the cylindrical sleeve 330 is fitted into the housing 312a by gap fitting (free fitting) so that the cylindrical sleeve 330 can be moved in the direction of the central axis thereof.

  A sliding fit and relative movement is still possible, while at the same time an elastic sealing member (eg O-ring) 332 that seals the joint of the two parts by compression or contact between the cylindrical sleeve 330 and the housing 312a. The gap fit can be sealed and sealed. A suitable alternative device such as a piston ring that minimizes leakage along the sliding fit can of course be used.

  An attached ring having a diameter larger than that of the shaft 318, that is, a fixed sleeve 334 is attached to the shaft 318, and one end or end surface of the cylindrical sleeve 330 is connected to the fixed sleeve 334, and the cylindrical sleeve 330 is connected to one side in the axial direction. When moving, it is preferable that one end or end surface of the cylindrical sleeve 330 can be brought close to the end surface of the fixed sleeve 334 on the shaft 318. Since the multiple movements between the shaft 318 and the housing 312a are usually extensive, the end surface of the cylindrical sleeve 330 maintains a sufficient clearance (clearance) with respect to the end surface of the fixed sleeve 334 secured to the shaft 318. The cylindrical sleeve 330 is held at a position suitable for the above. In certain situations when stopping or reducing the normal relative movement of the tubular sleeve 330 relative to the fixed sleeve 334 and when it is necessary to limit the flow rate between the shaft 318 and the housing 312a to a desired amount, the fixed sleeve 334 The cylindrical sleeve 330 can be moved over the shaft 318 toward and the opposing ends of the cylindrical sleeve 330 and the stationary sleeve 334 can be brought into contact with each other to limit any flow rate between the shaft 318 and the housing 312a. it can.

  In order to optimize the restricted flow rate when the opposite ends of the cylindrical sleeve 330 and the fixed sleeve 334 contact each other, the special shape of the contact surface between the fixed sleeve 334 fixed to the shaft 318 and the cylindrical sleeve 330 is changed. Also good. Movable by appropriately selecting the cross-sectional shape of the movable cylindrical sleeve 330, the position and size of the cylindrical sleeve 330 slidingly fitted in the housing 312a, and the position and size of the contact surface between the cylindrical sleeve 330 and the fixed sleeve 334 Optimize the hydrostatic pressure of the fluid so that the contact between the end faces of the sleeve 330 and the end face of the fixed sleeve 334 fixed to the shaft 318 is maintained due to the balance of the hydrostatic pressure. Can do.

  When the flow rate (leakage) is restricted, the surface of the cylindrical sleeve 330 and the shaft 318 are fixed by the starting force of the hydrostatic pressure that moves the cylindrical sleeve 330 in the axial direction toward the fixed sleeve 334 fixed to the shaft 318. Has the advantage of reducing or closing the gap with the surface of the fixed sleeve 334 and promoting the initial contact between the surfaces, changing the pressure acting on the cylindrical sleeve 330 to change the cylinder in the direction of fluid flow This can be achieved by designing the cylindrical sleeve 330 to take advantage of the specific state change of the fluid that moves the sleeve 330.

  The fluid flowing along the annulus formed between the inner diameter surface of the cylindrical sleeve 330 and the shaft 318 flows due to frictional force and fluid viscosity at the fluid interface, as explained in the basic law of hydrodynamics. Creates resistance. Due to this flow resistance, a pressure difference is generated between the inlet side and the outlet side of the annular portion. This pressure difference acting on the hydrostatic pressure region of the cylindrical sleeve 330 formed as a region between the inner diameter surface of the annular cylindrical sleeve 330 and the outer diameter surface to be slidably fitted is directed toward the flow direction. This creates a force imbalance that increases the applied force. When the flow rate through the annulus is a normal low volume flow rate, the pressure difference across the annulus is small and usually only insufficient force is generated to overcome the volume and friction forces acting on the cylindrical sleeve 330. Therefore, the cylindrical sleeve 330 is moved along the sliding fitting portion. However, when the volumetric flow rate of the annulus increases due to either an increase in the mass flow rate of the fluid or a change in the fluid level from liquid to gas, the pressure differential across the annulus increases, and the hydrostatic pressure causes the volume and friction forces to The cylindrical sleeve 330 moves in the flow (leakage) direction. Until the desired flow rate or desired state is reached, the tubular sleeve 330 is additionally pressed by a spring that produces a reaction force against the force generated by normal flow, or the tubular sleeve 330 is placed in the proper position by a suitable other device. By fixing the cylindrical sleeve 330, the cylindrical sleeve 330 may be further stabilized at a low volume flow rate without moving the cylindrical sleeve 330.

  7A-8B are schematic diagrams partially illustrating the sliding sleeve device. That is, FIG. 7A schematically shows a cross-sectional view of the first sliding sleeve device 430 deployed in a first position (initial position) around the shaft, and FIG. 7B is essentially the same view as FIG. 7A. However, the sliding sleeve device 430 is shown deployed in a second position (advanced position) (ie, a position closer to the pump motor). In contrast, FIG. 8A schematically shows a cross-sectional view of the second sliding sleeve device 530 deployed in a first position (initial position) around the shaft, and FIG. 8B is essentially identical to FIG. 8A. FIG. 5 shows a second sliding sleeve device 530 deployed in a second position (advanced position) (ie, a position closer to the pump motor).

  As illustrated, the function of increasing the flow resistance or the function of increasing the differential pressure along the annular portion can be imparted to the shape or surface of the inner diameter surface of the cylindrical sleeve 430. For example, a series of annular grooves (denoted by reference numeral 436) forming a labyrinth seal or pressure reducing device can be disposed along the entire or partial surface of the inner diameter surface of the cylindrical sleeve 430. For example, due to fluid mass flow, absolute pressure, fluid temperature and characteristics, liquid-to-vapor phase change or evaporation, flow resistance is created by the pressure reduction device anywhere along the length of the annulus. Can be made. When the choke flow occurs, a large pressure difference is generated between the inlet side and the outlet side of the sealing structure of the pressure reducing device, thereby generating a large force for moving the cylindrical sleeve 430.

  FIGS. 7A-8B each show an O-ring 432/532 similar to the O-ring indicated by 432 in FIGS.

  In yet another embodiment of the invention, as described in detail above, a given “split ring device” and a given “sliding sleeve device” can be combined into a single pump. In this way, one flow restriction device is arranged at one position around the shaft in the sealed housing, and the other flow restriction device is arranged at the other position around the shaft in the sealed housing. A plurality of relative positions can be selected for the purpose of maximizing the accompanying effects of each flow restrictor at the position.

  8A and 8B show that around the outer diameter surface of the shaft 518, a split ring 526 having substantially the above-described structure (and function) is mounted in a groove formed in the inner diameter surface of the cylindrical sleeve 530. A very useful and convenient variant of arranging the split ring 526 in one piece with the tubular sleeve 530 is shown. As described above, the split ring 526 arranged coaxially with the shaft 518 or the cylindrical sleeve 530 is split or cut in the radial direction at one place in the circumferential direction. In the sleeve 530 in the first position (initial position) shown in FIG. 8A, the split ring 526 is disposed in the first position (initial position) as described above (that is, in this case, both end portions of the split ring). Are separated from each other). On the other hand, in the cylindrical sleeve 530 at the second position (advanced position) shown in FIG. 8B, both end portions of the split ring 526 are close to each other, and the split ring 526 is further reduced in diameter around the shaft 518. The split ring 526 is moved from the first position shown in FIG. 8A to the second position shown in FIG. 8B so that both ends of the split ring 526 are released or approached. The split ring 526 can be opened or approached by the actuation of essentially any suitable device or mechanism that responds or the active operator. Thus, good results can be obtained with a “fusible” spacer / actuator.

  In the embodiment shown in FIGS. 8A and 8B, it should be understood that the split ring 526 can actually improve the operation of the sliding sleeve 530. In particular, when the split ring 526 is closed or reduced in diameter, the flow rate at the annular portion of the sliding sleeve 530 is limited, thereby creating a differential pressure along the sliding sleeve 530 and fixing the shaft (as described above). The sliding sleeve 530 can be moved toward the annular end surface of the sleeve 534.

  It should be understood that the salient features of the embodiments of the present invention allow for a wide variety of different applications and usage environments. An inner member and a second member are provided, the inner member is configured as a circular shaft that normally rotates or reciprocates with respect to the second member, and the second member is configured as a housing that surrounds the inner annular shaft member. In doing so, a "split ring device" and a "sliding sleeve device" can be incorporated essentially in any feasible environment where flow restriction through the annulus between two circular members is desired. (In practice, depending on the application, only relative movement between the two members is necessary for normal operation and only one of them can be moved in an absolute sense.) The inner circular member and the outer housing In combination, a device that can form a connecting surface between the inner circular member and the outer housing and a pressure interface with the fluid, and adjust the normal relative movement between the outer housing and the inner circular member, thereby allowing the outer housing to In yet another embodiment of the present invention, a more conceivable device is provided that restricts the flow of the annulus between the inner circular member and the outer housing when normal relative motion stops. Then, subsequent movement between the outer housing and the inner circular member can be further suppressed.

  Therefore, as described above, another flow restricting device can also be implemented by the split ring device, the sliding sleeve device, or a combination thereof. However, as described above, the shaft includes one shaft and the other housing. The present invention is essentially applicable to any device that produces relative movement with respect to at least the other housing.

  Although not analyzed further, the above description is sufficient to show the gist of the present invention and a plurality of embodiments that can be implemented by those skilled in the art. The present invention can be quickly applied to various applications without omitting the above features, and the general features or specific features of the present invention can be properly configured.

  In this specification, unless otherwise specified, where appropriate, replacement of similar configurations and / or methods disclosed herein with all of the above configurations and / or processes may be considered. .

  The entire contents of any and all patents, patent publications, papers, and other publications discussed or specified herein are hereby incorporated by reference, although not expressly stated herein. Is made a part of this specification.

  It should be appreciated that the apparatus and method of the present invention can be configured and implemented to be adaptable to any situation at hand. It should be considered that the above embodiments are merely examples in all points and do not limit the present invention. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Partial sectional view of centrifugal pump using split ring device 1 is an enlarged cross-sectional view of the split ring and the surrounding member of the pump of FIG. Sectional view of a first split ring device deployed around a shaft in a first position Plan view of the split ring shown in FIG. 3A FIG. 3B is a cross-sectional view basically the same as FIG. 3A, but a cross-sectional view of the split ring device disposed at the second position. Plan view of split ring shown in FIG. 3C Sectional view of a second split ring device deployed around the shaft in a first position Plan view of the split ring shown in FIG. 4A FIG. 4B is a cross-sectional view basically the same as FIG. 4A, but a cross-sectional view of the split ring device disposed at the second position. Plan view of split ring shown in FIG. 4C Partial sectional view of centrifugal pump using sliding sleeve device FIG. 5 is an enlarged cross-sectional view of the sliding sleeve device and the surrounding member arranged at the operating position of the centrifugal pump shown in FIG. Sectional view of the first sliding sleeve device disposed around the shaft in the first position FIG. 7B is a cross-sectional view basically the same as FIG. 7A, but a cross-sectional view of the sliding sleeve device disposed in the second position. Sectional view of the second sliding sleeve device further comprising a split ring and disposed about the shaft in the first position FIG. 8B is a sectional view basically the same as FIG. 8A, but a sectional view of the sliding sleeve device arranged in the second position.

Explanation of symbols

  10 ・ ・ Pump, 12 ・ ・ Main pump housing, 12a ・ Inner sealed housing, 14 ・ ・ Impeller housing, 16 ・ ・ Impeller, 18 ・ ・ Pump shaft, 20 ・ ・ Cap, 22 ・ ・ Electric motor,

Claims (40)

In a structure including a shaft member and a support structure in which the shaft member extends,
A flow restricting device disposed in at least one annular space formed between the shaft member and the support structure and restricting a flow rate of fluid along the shaft member moving with respect to the support structure;
The flow restriction device has a discontinuous ring member disposed around the shaft member,
The discontinuous ring member has two ends,
The discontinuous ring member operates between a first state in which both ends are separated from each other by a first interval and a second state in which both ends are separated from each other by a second interval that is narrower than the first interval. And
In the first state, a fluid flow path is formed in at least one annular space formed between the shaft member and the support structure, and the cross section of the fluid flow path in the first state is the flow in the second state. A flow restrictor characterized by being larger than the cross section of the road.   The flow restriction device according to claim 1, wherein a sufficient interval is provided to displace the shaft member with respect to the support structure in both the first state and the second state of the discontinuous ring member.   2. The flow restriction according to claim 1, wherein in the second state, both ends of the discontinuous ring member are close to each other to restrict the flow of at least one annular space formed between the shaft member and the support structure. apparatus.   The flow restriction device according to claim 1, wherein the discontinuous ring member operated from the first state to the second state is in an elastically deformed state in the first state.   The flow restriction device according to claim 1, further comprising an operation promoting device that promotes the operation of the discontinuous ring member from the first state to the second state.   The flow restricting device according to claim 5, wherein the operation promoting device includes a spacer member disposed between both ends of the discontinuous ring member in the first state.   The flow restricting device according to claim 6, wherein the spacer member is substantially deformed or disappears according to at least one peripheral state, and brings the end of the discontinuous ring member close to the second state.   8. The flow restrictor of claim 7, wherein the at least one ambient condition includes at least one of a temperature change and a fluid chemistry change.   The flow restrictor according to claim 7, wherein the spacer member includes an alloy or a thermoplastic polymer.   The operation promoting device includes a mechanical actuator that holds both ends of the discontinuous ring member in the first state in a separated state and promotes the proximity of both ends of the discontinuous ring member toward the second state. Item 6. The flow restriction device according to Item 5. Further providing an annular cavity for accommodating the discontinuous ring member;
The flow restriction device of claim 1, wherein the annular cavity is large enough to accommodate a discontinuous ring member in both the first state and the second state.   The flow restrictor of claim 1, wherein the discontinuous ring member has a generally right-angled triangular cross-sectional shape.   The discontinuous ring member comprises a first side substantially parallel to the longitudinal axis of the shaft member and a second side substantially radial to the longitudinal axis of the shaft member. Flow restriction device. The discontinuous ring member includes a third side surface extending between the first side surface and the second side surface and substantially non-perpendicular and acute with respect to the longitudinal direction of the shaft member;
The flow restrictor of claim 13, wherein the annular cavity has a conical surface with which the third side of the discontinuous ring member contacts.   The flow restriction device according to claim 11, wherein the discontinuous ring member has a cross-sectional shape surrounded by a straight line.   The flow restrictor of claim 1, further comprising a biasing device that biases the discontinuous ring member in a predetermined direction substantially parallel to the longitudinal axis of the shaft member. In a structure including a shaft member and a support structure in which the shaft member extends,
A flow restricting device disposed in at least one annular space formed between the shaft member and the support structure and restricting a flow rate of fluid along the shaft member moving with respect to the support structure;
The flow restriction device includes a sleeve member disposed around the shaft member and movable between the first position and the second position substantially parallel to the longitudinal axis of the shaft member;
When the sleeve member is in the first position, a fluid flow path is formed in at least one annular space formed between the shaft member and the support structure, and the sleeve member is formed in the fluid flow path in the first position. The flow restricting device is characterized in that the cross section is larger than the cross section of the fluid flow path when the sleeve member is in the second position.   The flow restriction device according to claim 17, wherein the sleeve member has a generally cylindrical shape.   18. A flow restrictor according to claim 17, wherein the sleeve member normally maintains an annular spacing relative to the support structure in both the first position and the second position.   The flow restricting device according to claim 19, further comprising a sealing device for sealing an annular interval of the sleeve member with respect to the support structure.   21. A flow restriction device according to claim 20, wherein the sealing device comprises an O-ring. When the sleeve member is in the second position, the shaft member comprises a securing aid member that limits further movement of the sleeve member;
The fixed auxiliary member and the sleeve member integrally limit the flow rate of at least one annular space formed between the shaft member and the support structure when the sleeve member is in the second position. Flow restriction device.   The flow restricting device according to claim 22, wherein the fixing auxiliary member includes a cylindrical fixing sleeve that is fixed to the shaft member and expands an effective diameter of the shaft member.   The flow rate restriction device according to claim 17, wherein the sleeve member moves from the first position to the second position in response to a predetermined flow velocity state or flow rate state. The sleeve member further includes an inner deformation portion disposed adjacent to the shaft member,
18. The flow restriction device of claim 17, wherein the inner deformation portion increases the flow resistance while the sleeve member moves between the first position and the second position.   26. The flow restricting device according to claim 25, wherein the inner deformation portion includes an annular groove that forms a recess in at least one surface of the sleeve member so as to face the shaft member. A discontinuous ring member disposed around the shaft member;
The discontinuous ring member has two ends,
The discontinuous ring member operates between a first state in which both ends are separated from each other by a first interval and a second state in which both ends are separated from each other by a second interval that is narrower than the first interval. And
When the discontinuous ring member is in the first state, a fluid flow path is formed in at least one annular space formed between the shaft member and the support structure, and the fluid flow path in the first state of the discontinuous ring member The flow restriction device according to claim 17, wherein the cross section of is larger than the cross section of the fluid flow path in the second state. The sleeve member includes an inner surface facing the shaft member,
The sleeve member further comprises an annular cavity that forms a recess in the inner surface of the sleeve member;
28. The flow restriction device according to claim 27, wherein the discontinuous ring member is disposed in an annular cavity that forms a recess in the inner surface of the sleeve member. When the sleeve member is at least in the first position, the discontinuous ring member is in the first state;
29. The flow restriction device of claim 28, wherein the discontinuous ring member is in the second state when the sleeve member is at least in the second position. A motor,
A shaft member extending from the motor;
An impeller attached to the free end of the shaft member;
A housing surrounding the main part of the shaft member,
The housing has a sealed housing that surrounds at least a portion of the shaft member;
The sealed housing has at least one sealing element that restricts the flow of fluid along the shaft member;
The motor drives the impeller by rotating the shaft member,
A flow restriction device disposed in at least one annular space formed between the shaft member and the sealed housing and restricting a flow rate of fluid along the shaft moving relative to the sealed housing;
The flow restriction device has a discontinuous ring member disposed around the shaft member,
The discontinuous ring member has two ends,
The discontinuous ring member operates between a first state in which both ends are separated from each other by a first interval and a second state in which both ends are separated from each other by a second interval that is narrower than the first interval. And
When the discontinuous ring member is in the first state, a fluid flow path is formed in at least one annular space formed between the shaft member and the sealed housing, and the fluid flow path in the first state of the discontinuous ring member is formed. The rotary pump characterized in that the cross section is larger than the cross section of the fluid flow path in the second state.   30. The rotary pump of claim 29 having a chemical treatment pump.   31. The rotary pump according to claim 30, wherein the discontinuous ring member operated from the first state to the second state is in an elastically deformed state in the first state.   The rotary pump according to claim 30, further comprising an operation promoting device that operates the discontinuous ring member from the first state to the second state.   34. The rotary pump according to claim 33, wherein when the discontinuous ring member is in the first state, the operation promoting device includes a spacer member disposed between both ends of the discontinuous ring member.   The operation promoting device includes a mechanical actuator that holds both ends of the discontinuous ring member in the first state in a separated state and promotes the proximity of both ends of the discontinuous ring member toward the second state. Item 34. The rotary pump according to Item 33. A motor,
A shaft member extending from the motor;
An impeller attached to the free end of the shaft member;
A housing surrounding the main part of the shaft member,
The housing has a sealed housing that surrounds at least a portion of the shaft member;
The sealed housing has at least one sealing member that restricts the flow of fluid along the shaft member;
The motor drives the impeller by rotating the shaft member,
A flow restriction device disposed in at least one annular space formed between the shaft member and the sealed housing and restricting a flow rate of fluid along the shaft moving relative to the sealed housing;
The flow restriction device includes a sleeve member disposed around the shaft member and movable between the first position and the second position substantially parallel to the longitudinal axis of the shaft member;
When the sleeve member is in the first position, a fluid flow path is formed in at least one annular space formed between the shaft member and the sealed housing, and the cross section of the fluid flow path in the first position of the sleeve member is A rotary pump characterized by being larger than the cross section of the fluid flow path at position 2.   37. A rotary pump according to claim 36 having a chemical treatment pump.   37. The rotary pump of claim 36, wherein the sleeve member has a generally cylindrical shape. When the sleeve member is in the second position, the shaft member includes a fixing auxiliary member that suppresses further movement of the sleeve member;
The fixed auxiliary member and the sleeve member integrally limit the flow rate of at least one annular space formed between the shaft member and the sealed housing when the sleeve member is in the second position. Flow restriction device. A discontinuous ring member disposed around the shaft member;
The discontinuous ring member has two ends,
The discontinuous ring member operates between a first state in which both ends are separated from each other by a first interval and a second state in which both ends are separated from each other by a second interval that is narrower than the first interval. And
When the discontinuous ring member is in the first state, a fluid flow path is formed in at least one annular space formed between the shaft member and the sealed housing, and the fluid flow path in the first state of the discontinuous ring member is formed. 37. A flow restriction device according to claim 36, wherein the cross section is larger than the cross section of the fluid flow path in the second state.

Images