Abstract: A compressor (22) has a housing assembly (50) with a suction port (24) and a discharge port (26). A shaft (70) is mounted for rotation about an axis (500) and an impeller (44) is mounted to the shaft to be driven in at least a first condition so as to draw fluid in through the suction port and discharge the fluid from the discharge port. A mag netic bearing system (66, 67, 68) supports the shaft. A controller (84) is coupled to a sensor (80, 82) and configured to detect at least one of surge and pre-surge rotating stall and, responsive to said detection, take action to prevent or counter surge.
Abstract: In various embodiments, a lubricating shaft assembly may comprise a shaft, a front seal, a front seat, an inner race, a spacer, a lubricating fitting and a nut. The front seat may define a first portion of a fluid conduit. The front seat may be part of a first load path. The inner race may define a second portion of the fluid conduit. The inner race may be installed about the shaft. The inner race may be part of the first load path. The spacer may define an internal diameter of a third portion of the fluid conduit. The lubricating fitting may be installed about at least a portion of the spacer. The lubricating fitting may define an outer diameter of the third portion of the fluid conduit. The lubricating fitting may be outside the first load path.
Abstract: A rocket engine turbopump with a main rotor shaft supporting a liquid oxygen impeller on a forward end and a turbine on an aft end, and with a multiple stage liquid hydrogen impeller in-between. Two hydrostatic bearings support the main rotor shaft such that the liquid oxygen impeller and the turbine are both overhung. A balancing piston is used to balance the main rotor shaft in an axial direction. This structure allows for the main rotor shaft to be of such a large diameter that the turbopump is capable of operating at around 70,000 rpm that can produce a liquid hydrogen outlet pressure of around 4,000 psia in a turbopump having a diameter of less than 10 inches.
Abstract: An inter-propellant thrust seal for a rocket engine with purge fluid introduced into purge chambers to prevent mixing of reactive fluids located outside of bearings, and where one of the purge chambers is formed by an axial thrust piston on the rotor shaft so that the purge fluid in that chamber will also produce axial thrust on the rotor shaft.
Abstract: A device and method for axially displacing at least one turbine rotor relative to at least one corresponding turbine stator in a multistage axial turbine is disclosed. The turbine shaft is provided with a split design and has a first axially displaceable shaft half, which is connected via a turbine disc to the turbine rotor and via a torque coupling to the second shaft half. By axially displacing the turbine rotor relative to the turbine stator and by controlling this axial displacement, the operation of the turbine is held in its possible optimum of efficiency.
Abstract: A steam turbine power plant that includes a first steam turbine, the steam turbine power plant including: a thrust piston operably connected to the first steam turbine via a shaft; and means for applying a supply of pressurized steam against the thrust piston such that the thrust piston applies a desired thrust force to the shaft. The desired thrust force may comprise a thrust force that partially balances a thrust force the first steam turbine applies to the shaft during operation.
December 31, 2009
Date of Patent:
April 23, 2013
General Electric Company
Kristan B. Sears, Michael J. Bowman, John R. Powers
Abstract: A control valve is provided that includes a valve body, a valve element, a first radial seal, and a second radial seal. The valve body forms an inlet, an outlet, and a fluid flow passage therebetween. The valve element is disposed at least partially within the valve body, and is movable between at least a closed position and an open position. When the valve element is in the closed position, fluid is restricted from flowing through the fluid flow passage. When the valve element is in the open position, the fluid is allowed to flow through the fluid flow passage. The first radial seal is disposed against the valve body at a first distance from a centerline of the control valve. The second radial seal is disposed against the valve body at a second distance from the centerline, the second distance being greater than the first distance.
Abstract: An apparatus for adjusting a thrust load on a rotor assembly of a gas turbine engine includes an impeller rear cavity defined between a rear face of an impeller of the rotor assembly and a stationary wall spaced axially apart from the rear surface of the impeller. A pressurized air flow with a tangential velocity is introduced into the impeller rear cavity at a tip of the impeller to pressurize the cavity. Means are provided in the cavity for directly interfering with the tangential velocity of the pressurized air flow to affect an average static pressure of the pressurized air flow within the cavity in order to adjust the thrust load on the rotor assembly caused by the average static pressure in the cavity.
Abstract: A first centrifugal impeller and a second centrifugal impeller are arranged in such an orientation that back sides of the first centrifugal impeller and the second centrifugal impeller face to each other. Bearings are cylindrical roller bearings and a thrust bearing. The cylindrical roller bearings are arranged at two axially spaced supporting positions respectively, and support a radial load applied to the rotating shaft. The thrust bearing supports a thrust load applied to the rotating shaft.
December 4, 2006
Date of Patent:
April 6, 2010
Ishikawajima-Harima Heavy Industries, Co., Ltd.
Abstract: An axial thrust balancing system for a centrifugal compressor, having improved safety characteristics, the centrifugal compressor comprising a rotor having impellers adjacent to each other and connected by a shaft, the rotor rotating in a stator, the centrifugal compressor additionally including a balancing piston, a balancing line being provided between an intake of a first compression stage and an area downstream of the balancing piston; this system comprises an intake mechanical gas seal around the shaft upstream of the first compression stage and an outlet mechanical gas seal downstream of the balancing piston, the balancing line being closable by blocking elements.
Abstract: A helical screw rotor machine is provided which has at least one trunnion having an axial thrust surface located in a chamber filled with pressure medium and actuated axially by the pressure medium. A casing is closely fitted around the trunnion. The casing has an outer end which is connected to a bottom wall that includes a hole in its center, and the casing is rotatably and slidably mounted on the trunnion and is movable between a first axial position in which the bottom wall is spaced from an end wall of the chamber and a second axial position in which the bottom wall is in abutment with said end wall. A supply channel is connected to an opening in the end wall of the chamber opposite the hole in the bottom wall of the casing for controlled delivery of the pressure medium into the casing.
Abstract: A turbo-compressor having a housing and at least one rotor shaft pivotably supported in the housing, with a free shaft end and with a rotor connected with the other end of the rotor shaft. The free end of the rotor shaft facing away from the rotor projects into a pressure chamber connected with the housing, and is acted upon by a pressurized fluid whose force of pressure compensates for the force of the axial thrust acting on the rotor. Thus, the starting friction of the compressor is lower and drive motors of lower output target can be utilized.
Abstract: A thrust compensation apparatus for high-speed rotating machinery includes an electromagnetic thrust bearing having a thrust rotor and a thrust stator, a first chamber filled with a pressurized medium on one side of the bearing, and a second chamber on the other side of the bearing. The pressure differential across the bearing augments the electromagnetic force between the rotor and stator in order to counteract the axial thrust load of the high-speed rotating machinery.
August 27, 1999
Date of Patent:
April 9, 2002
Allison Advanced Development Company, Rolls-Royce Corporation
Robert Anthony Ress, Jr., Mark Stephen Henry
Abstract: A turboexpander associated with a rotary compressor by means of a rotor shaft connecting the two. A bearing housing includes magnetic radial and thrust bearings which control the placement and dynamics of the shaft within the housing. A control passageway extends from the inlet of the compressor to the gas cavity behind the compressor rotor. This passage is controlled by a valve and in turn by the magnetic bearing controller to augment the operation of the active magnetic thrust bearings.
Abstract: A thrust control system for use with a turbocompressor having gas bearings. More specifically, the system concerns an arrangement of gas bearings for use in a turbocompressor or other device where a large temperature difference between the turbine and the compressor housing could cause unacceptable performance of the turbocompressor thrust bearings if located in proximity of the turbine and compressor wheels. This danger is obviated in the system by relocating the gas thrust bearings so as to minimize the axial distance between them. This configuration affords the additional advantage that gasses of different composition may be separately used as a seal gas in cases where the process gas in the turbine and compressor are incompatible.
Abstract: A low friction bearing comprises a first element having a first surface. A second element having a second surface is rotatable about a centerline relative to the first element. A flow passage extends radially outward between the first surface and the second surface. The first surface and the second surface are separated by a fluid flow. The two surfaces are complementary and positioned in close proximity. The bearing finds a preferred application in a fluid cooled turbine to create a high temperature, high efficiency turbine.
Abstract: An integrated bearing system with journal and thrust bearings is incorporated in a single unit centrally pinned to the bearing housing and having integral thrust surface and journal surface lubrication grooves in combination with turbine and compressor wheel thrust surfaces. The bearing employs a first aperture substantially equidistant from the ends to engage the locating pin to prevent rotation of the bearing within the bearing case bore, while allowing the bearing to be free to symmetrically wobble within the bearing case bore.
July 9, 1998
Date of Patent:
January 25, 2000
Allied Signal Inc.
Scott Grover Aguilar, David George Elpern, Peter John Hebben, Lloyd Bill Jensen, Steven Walter Coleman, Sunhil Nandan Sahay, Douglas Alan Milliken, Raymond Leo Lopez, Werner Wick
Abstract: In order to accommodate a labyrinth seal whose diameter is too large to form a gas passage using conventional techniques, the labyrinth seal is made in two parts. A first part is an inner ring whose outer diameter is sufficiently small so as to permit the forming of a passage therein with conventional techniques. The second part is an outer ring which can then be fastened to the inner ring so as to then extend, in combination, to the radial extent necessary to complete the sealing engagement with an adjacent element. The outer and inner rings are preferably interconnected by way of an interference fit.
Abstract: A system for controlling thrust forces on a thrust bearing in a rotating structure of a gas turbine engine at designated operating points including a device for providing thrust load compensation to the thrust bearing, a control for operating the thrust load compensation device, and a sensor for detecting rotational cage speed of the thrust bearing. The sensor provides a signal to the control when the rotational cage speed of the thrust bearing drops below a specified ratio of the rotational speed for the rotating structure, the signal being indicative of an incipient skid condition for the thrust bearing. The control then causes the thrust load compensation device to provide an additional predetermined load on the thrust bearing when it receives the signal from the sensor so that a resultant load thereon is within a specified load range which extends the life of the thrust bearing.
Abstract: A pressurized bearing assembly for turbomachines like gas turbine engines wherein pressurized oil is used to apply an axial force to the outer bearing race of a ball bearing assembly. The force is transmitted through the race to the ball bearings and to the inner race of the bearing assembly, and is further transmitted, via the engine shaft, to the bearings of another, axially spaced apart bearing assembly. The force moves the balls in both assemblies into line-on-line running contact with their respective bearing races, and minimizes vibration in the assemblies.
Abstract: A condensing turbine includes a live-steam inlet, an exhaust-steam outlet and at least two seals for sealing off a turbine casing in the region of a turbine shaft carrying a turbine rotor. At least one of the seals is disposed on the live-steam side and one of the seals is disposed on the exhaust-steam side. The overall construction is substantially simplified by constructing at least one respective seal as a gas-lubricated mechanical surface seal on both the live-steam side and the exhaust-steam side. The outermost mechanical surface seals in each case on the live-steam side and the exhaust-steam side seal off separate seal spaces which are acted upon through a balancing line by an identical vacuum lying below the outer atmospheric pressure. These mechanical surface seals are constructed and fitted in such a way that a flow which is necessary for gas lubrication can occur through the mechanical surface seals from the outer atmosphere into the interior of the casing.
Abstract: In a turbo machine, for example, a turbo compressor, the rotor shaft extends through and is sealed relative a housing via dry gas seals in which a seal clearance is achieved between a rotating, sealing body and a non-rotating sliding body in which the inner side of the dry gas seal is charged with a barrier gas, with the leakage of the dry gas seal being dammed via a back-up plate and the dynamic pressure is monitored via a pressure inspection device, wherein due to increasing dynamic pressure an alarm is given off or the turbo machine is automatically shutdown without delay so that the exit of gas, particularly of toxic or explosive gas from the inner area of the housing of the turbo machine is avoided, wherein, via the use of multiple seals the leakage pressure of one of the inner dry gas seals can initiate a warning or alarm signal and via the leakage pressure of the outer dry gas seal, the turbo machine can be shut down.
Abstract: In a turbo machine with magnetic bearings on both sides and dry gas seals for the rotor, the axial thrust acting upon the rotor and generated by the pressure difference between the pressure side and the suction side is compensated for in that a dry gas seal provided on the suction side and the end of the shaft are acted upon by a certain pressure, which generates a compensating axial thrust, so that the resultant axial thrust becomes as slight as possible. Advantageously, this pressure is regulated via the bearing gap of an axial magnetic bearing of the rotor such that the bearing gas assumes a predetermined value.
Abstract: A thrust control system for fluid handling rotary machines, such as turbo expanders equipped with a magnetic thrust bearing, includes a magnetic thrust control circuit for providing a thrust signal which is a measure of the magnitude and direction of the thrust force on the thrust bearing. The rotor and stator of the machine have generally axially opposed thrust areas separated by a thrust cavity. Valves are connected between the thrust cavity and high and low pressure fluid sources. A controller, responsive to the thrust signal, controls the valves to selectively conduct fluid between the cavity and the high and low pressure sources to increase or decrease the fluid pressure in the cavity to minimize variations of the thrust force from a preset value which could be zero, for example.
Abstract: A labyrinth seal positioned between a turbine rotor and inner platforms of vanes of a turbine assembly controls the leakage flow of fluid from a chamber to the flowpath through the turbine assembly. The labyrinth seal is divided into two parts by a second chamber positioned between two adjacent fins of the labyrinth seal. The chamber is located at a predetermined position in the seal such that a predetermined pressure, sufficient to supply fluid to cool a stage of turbine rotor blades in the turbine assembly, is selected. The second chamber is interconnected to the turbine blades by passages, and a chamber. The pressure of fluid in the second chamber is less than that which would normally exist in the second chamber, because fluid is being supplied from the second chamber to the second stage of turbine rotor blades. The flow of fluid from the second chamber, through the second part of the labyrinth seal, to the flowpath through the turbine is therefore reduced.
Abstract: The axial forces imposed on a rotor of a fluid machine such as a compressor is controlled by modulating the pressure supplied to a piston and cylinder device acting between the rotor shaft and housing. A parameter indicative of axial force on the rotor during operation is monitored and changes in the magnitude and direction of the axial forces countered by varying the pressure in the cylinder. The net axial forces imposed on the shaft may thus be controlled in a predetermined range.
Abstract: Thrust compensating apparatus for providing a thrust force to compensate for the thrust forces applied to the shaft of single stage overhung turbo machines by the fluid pressure in the cavity of the turbo machine is disclosed and includes a thrust compensating member attached to the shaft of the turbo machine and having a first surface subjected to the fluid pressure in the cavity, an annular seal, an annulus cavity formed by a second surface of the thrust compensating member and the annular seal and venting apparatus for controlling the fluid pressure in the annulus cavity resulting in a compensating thrust force being applied to the thrust compensating member as a result of the differential in pressure across the first and second surfaces of the thrust compensating member.
Abstract: A gas compressor, particularly of the kind for boosting pressure in gas transmission and petro chemical process, has an impeller mounted on an impeller shaft of the overhung type mounted on front and rear bearings and having at least one impeller mounted between the front bearing and a front end of the shaft. Annular seals are provided co-axial with the shaft which separate an inner space communicating with the shaft front end from the suction end gas space which lies outside the seals. The seals include an outer seal and an inner dry gas seal. Pressurized process gas is supplied between these seals at a pressure higher than suction pressure and is vented from the inner gas space at a pressure well below suction pressure to limit gas pressure forces on the front end of the shaft.
Abstract: A labyrinth seal is provided to isolate the transmission from a balance piston of a centrifugal compressor, the labyrinth seal being pressurized with refrigerant vapor from the motor chamber, which vapor is at a pressure slightly above that in the transmission, to thereby minimize the efficiency losses that would otherwise occur from leakage of the vapor into the transmission and to the compressor suction.
Abstract: A gas compressor, particularly of the kind for boosting pressure in gas transmission lines, has an impeller mounted on a shaft located between two bearings with the gas space surrounding the impeller being separated from the bearings by dry gas seals, including a least primary dry gas seals. The primary dry gas seal adjacent the discharge end of the compressor is of larger diameter than the corresponding seal at the inlet end of the compressor so that pressurized gas acting on the respective rotary parts of the dry gas seals urges the shaft towards the discharge end of the compressor and thus counteracts dynamic forces on the impeller.
Abstract: A steam piston balance means for a turbine engine comprises, in one form, a pressure chamber and means for supplying steam to the chamber to apply a force to walls of the chamber. The chamber is defined, in part, by an inner surface portion of a member connected and rotating with a portion of a thrust bearing whereby pressure force applied on the inner surface in turn applies a tractor force on the thrust bearing.
Abstract: A compressor includes a rotor which is subject on the inlet side to high pressure process fluid whereas the other end of the rotor is subject to atmospheric pressure. This creates a force unbalance in the axial direction for which thrust bearings are designed under dynamic operating conditions. At start-up and shutdown, periods of low speed operation, force unbalance is particularly acute since the normal impeller high speed reactive forces are not present. This invention utilizes available high pressure seal fluid during periods of low speed operation to provide a closed operating chamber which will provide a static reactive force opposing the process fluid force. Under normal operating conditions, lubricating oil is then sent to the thrust bearing as the high pressure seal fluid is relieved.
Abstract: A plurality of openings are provided in a stationary wall of a gas turbine engine aft of the compressor discharge to admit compressor discharge air into a sealed cavity formed between the stationary wall and the rotor of the gas turbine engine. A valve, biased to an open position, is associated with each of the openings so that under low speed conditions some of the compressor discharge air is admitted to the cavity to provide supplementary axial force on the rotor in one direction to prevent crossover under such conditions. Under higher speed conditions the increase in compressor discharge pressure overcomes the force biasing the valve to its open position, thereby causing the valve to close and terminate flow of compressor discharge air to the cavity, terminating the aforementioned supplementary axial force on the rotor.
Abstract: A steam turbine having a chamber in the inlet end thereof adjacent the thrust balance piston and dummy ring formed so that the temperature is substantially reduced while the pressure is only slightly reduced to optimize the pressure temperature affect on the balance piston and rotor utilizing labyrinth seals and a static seal together with vent ports in fluid communication with the chamber and an area downstream of the first row of rotatable blades to provide a more efficient and reliable turbine.
Abstract: In a centrifugal pump containing a sealing shroud the pump impeller is mounted only radially for rotation on a stationary axle or shaft. The stationary axle or shaft is fixed in the suction connection by means of wing rib supports or ribs and possesses an equalizing channel which connects the pump chamber portion at the rear of the pump impeller with the suction connection. This pump chamber portion at the rear of the pump impeller is connected with the delivery or pressure connection, whereas the pump chamber portion at the front side of the pump impeller is also connected with the suction connection as well as with the delivery or pressure connection. Advantageously, throttling rings are provided for self-metering throughflow throttling, depending on the axial position of the pump impeller. Additionally, the throughflow can be regulated by a throttling screw which is provided for the equalizing channel.
Abstract: An overhung steam turbine is described which features a seal assembly and a bearing assembly to minimize axial shaft movement. The seal assembly forms a pressure barrier between a relatively low vacuum exhaust region and an exhaust cavity disposed at one end of the rotor shaft to minimize the pressure differential across the ends of the shaft and the resultant thrust force of the rotor shaft against the turbine casing. A bearing assembly is provided which includes a pair of journal bearings and a pair of oppositely disposed thrust bearings. In one embodiment one thrust bearing is connected by an adapter ring which is mounted to a horizontally split bearing casing. In another embodiment, the thrust bearing is carried by one of the journal bearings. The journal bearings are preferrably connected by horizontally split ring bearings to facilitate insertion and removal of the bearings without removing the overhung shaft.
April 13, 1983
Date of Patent:
December 10, 1985
Dresser Industries, Inc.
Alan H. Tuttle, James K. Leonard, Shireesh A. Agharkar, John Waggott
Abstract: This invention relates to an axial thrust balancing device for pumps which cancels an axial thrust caused by impellers by utilizing a discharge water pressure. In the device, there is provided a small axial gap between a low pressure sidewall of a balancing drum tightly fitted over a shaft of impellers and a flange-like end wall extending inwardly from a stationary wall along the low pressure sidewall of said balancing drum. On application of the device to a vertical pump, in particular, the balancing drum is prevented from being in contact with the end wall during suspension of operation.
Abstract: A method and apparatus for counteracting an axial thrust imparted to a shaft of a fluid turbine is disclosed. The apparatus includes first and second shaft thrust plates affixed to the shaft. A first, stationary axial thrust bearing engages the first shaft thrust plate. A second axial thrust bearing, having components which are axially movable, engages the second shaft thrust plate. The apparatus also includes a system of fluid lines for supplying pressurized fluid to bellows-like thrust chambers in the second axial thrust bearing. The source of the pressurized fluid is fluid compressed by a compressor mounted on the shaft.
Abstract: A gas turbine engine having variable geometry flow controllers therein for controlling mass flow in accordance with engine operation includes a rotor with a wide variation in thrust forces thereon during different phases of engine operation countered by a variable axial load integrating device having a rotating hydraulic thrust compensating piston mounted forwardly of the rotor in association with a rotor thrust bearing and further including means for generating a centrifugal head in accordance with engine speed by means of rotating oil trapped between the rotating piston and a nonrotating counter piston; depth of rotating oil is automatically regulated by an integral, flow regulator having flow area therethrough varied in accordance with axial position of a thrust bearing carriage that has the variable rotor thrust loading imposed thereon.