Abstract: In the operation of a compressor system in a subsea station for transporting a well stream, separated well stream gas is supplied to a compressor (12, 13) which is arranged with its motor (8) in a common drive atmosphere within a pressure shell (21). As the drive atmosphere there is used a suitable, continually supplied dry extraneous gas, which is supplied to the well stream. There may be used a suitable dry extraneous gas which is stored in liquid form in an insulated container. There is also described a compressor system wherein there may be used as the drive atmosphere a continuously supplied, suitable dry extraneous gas.

Abstract: A gas turbine engine includes a casing cooling system which operates in one of two conditions, the first being operational at engine cruise, where all of the cooling air is initially directed onto a specific region of the casing; under full power conditions, some of the cooling air is directed onto the specific casing region and the reminder directed onto the reminder of the casing; the cooling system operates to optimize turbine blade/casing radial clearances.

Abstract: A flow directing device is provided for a fluid filled seal chamber for a centrifugal fluid pump, wherein the pump includes a seal chamber housing, a rotary shaft extending through the housing, an impeller mounted on one end of the shaft, and a rotary seal mounted about the shaft. The rotary shaft and housing define the seal chamber opening toward the impeller. A plurality of angled vanes radially depend about a circumferential portion of the seal chamber to direct the flow of fluid in the seal chamber along the rotary shaft to remove suspended solids from the rotary seal when the vanes extend in one direction, and to remove vapor bubbles from adjacent the rotary seal when the vanes extend in another direction and are coupled with a bulkhead flange.

Abstract: A cooling system for a generator is provided with a primary coolant loop containing a primary coolant for cooling the generator, and a secondary coolant loop provided with a secondary coolant medium for cooling the primary coolant loop in a heat exchanger. The secondary coolant is cooled in radiators formed in the wall of the chamber. The cooling system also has a transmission and a turbine, and is positioned in a chamber and is surrounded by running water.

Abstract: A stator seal assembly for a gas turbine engine of a type having a high pressure compressor section and a high pressure turbine section, the stator seal having a seal segment extending between a stator vane support structure and disk seal teeth, the stator seal segment having an arm for forming a cavity, a retaining segment attached to the seal segment and the arm for sealing the cavity to form a dead air space, a control ring located in the cavity having a coefficient of thermal expansion lower than a coefficient of thermal expansion for the seal segment, and a honeycomb pad located between the arm and the seal teeth, whereby thermal expansion clearance between the stator vane and the rotor disk is minimized.

Abstract: A seal support assembly for a gas turbine engine includes a stator seal support having an annular seal backing extending axially away therefrom and having an integral retention flange at one end thereof. The retention flange includes a retention groove. An annular seal block is supported radially inwardly of the seal backing for cooperating with rotor seal teeth to define a fluid seal. A control ring is disposed radially outwardly of the seal backing and is supported thereby, with the control ring having a plurality of circumferentially spaced apart retention tabs cooperating with the retention flange for axially retaining the control ring on the seal backing. An annular heat shield is fixedly joined at one end to the seal support, and includes a plurality of circumferentially spaced apart retention tabs cooperating with the retention flange for axially retaining the heat shield to the seal backing while permitting unrestrained differential radial movement therebetween.

Abstract: An axial flow gas turbine is provided with a shroud ring which is defined by two axially adjacent heat pipes. The radially inner face of the shroud ring has a plurality of axially extending cooling air passages located adjacent to it. Cooling air, which in operation is directed through the passages serves to provide cooling of the shroud ring and the substantial elimination of any radial heat flux in the shroud ring.

Abstract: A generally cylindrical thermal shield for a heat exchanger in a centrifugal pump which includes a fixed inner diameter vertical wall that forms an annular clearance coaxially around the pump impeller shaft, an outer vertical wall that has a diameter greater than the diameter of the inner vertical wall, and a bottom section that extends upwardly between the inner and outer diameter vertical walls such that the bottom section meets the outer wall at an obtuse angle and meets the inner wall at an acute angle. Such a construction prevents any part of the outer wall from being located opposite the journal return holes of the impeller chamber and minimizes or eliminates erosive wear that may otherwise occur from the flow of fluid from the return holes against the bearing journal.

Abstract: The runner for pumping hot reactor liquids includes a runner body which is connected with a shaft portion which transmits a driving torque. An annular insert is disposed between a bearing sleeve projecting from the runner body and the drive shaft portion to define an annular flow path in order to guide an auxiliary flow which, in the case of an injection operation, leads cool reactor liquid to the runner in one direction of flow and, in the case of a leakage operation, leads hot reactor liquid for cooling away from the runner in an opposite direction of flow. A closed cavity is formed between the runner body and the drive shaft portion in a transition zone between the two components so as to reduce the cross-sectional area for the transfer of heat between the runner body and the drive shaft portion. The cavity is formed by a blind bore which has a diameter greater than 30% of the outer diameter of the shaft portion.

Abstract: A multiple piece seal and method for reducing the leakage of air through a narrow gap separating a higher pressure section from a lower pressure in a gas turbine engine. The seal is comprised of a first sealing member having a thickness sufficiently small so that the first sealing member will deform into sealing contact across the gap when subjected to a pressure differential, and a second sealing member having a thickness sufficiently large so as to prevent both sealing members from buckling when inserted the gap.

Abstract: An apparatus is provided to thermally control a section of engine casing by flowing heat transfer fluid within an axially disposed set of circular flowpaths within a section of engine casing or flange such as a thermal control ring. Flowpaths are preferably arranged in alternating counterflowing directions in the ring such that there is substantially no circumferential gradient in the mass flowrate weighted average temperature of the heat transfer fluid supplied by any two adjacent counterflowing fluid flowpaths. Each flowpath may have two or more circuits having inlets and outlets for flowing the heat transfer fluid.

Abstract: A cylindrical support portion is provided on a wafer pump case to surround a rotary shaft, and a cylindrically formed power transmitting rotary wheel surrounding the support portion is integrally coupled to an outer end of the rotary shaft which protrudes outwardly from the support portion. A bearing means is interposed between an inner surface of the power transmitting rotary wheel and an outer surface of the support portion. A plurality of sealing members disposed concentrically with the bearing means are interposed between the rotary shaft and an inner surface of the cylindrical support portion at a location axially outwardly spaced from the mechanical seal, and a grease is filled between the sealing members. The water pump structure not only improves the sealing property of the sealing members by providing the sealing members at a location in which the deflection of the rotary shaft is smallest, but also increases the retaining property for the grease between the plurality of sealing members.

Abstract: Apparatus and method for making an immersed fuel transfer pump free of possible sources of ignition for fuel-vapor mixtures when the pump is run dry. The bearings and face seals are cooled by hydraulic oil used to power the pump, preferably through connecting the case leakage port on a conventional multiple piston type hydraulic motor to the pump as a supply and ducting the leakage through the bearings and near the seals on its way to the reservoir. An auxiliary pump built into the centrifugal pump shaft increases flow over these critical parts via a closed loop. Leakage past the dynamic face seals is led overboard through a flame-quenching passage.

Abstract: A pump assembly includes a shaft driven rotary impeller operating in a housing and adapted for pumping a stream of material-carrying liquid through a pump chamber in the housing, with an annular seal assembly operative about a portion of the impeller shaft where the shaft extends through a wall of the housing. An annular seal chamber about the annular seal is adapted for receiving impeller driven seal lubricating and cooling liquid from the stream. A vane arrangement causing a sweeping flow of the liquid moves through the seal chamber with flushing effect.

Abstract: A vacuum pump of the present invention comprises a housing including a suction port and an exhaust port, a stator fixed in the housing, a rotor rotatably supported in the housing, and a cooling jacket provided adjacent to the stator. Gas suctioned from the suction port and having a pressure substantially equal to or close to the atmospheric pressure is exhausted from the exhaust port. A cooling fluid having a thermal conductivity less than that of water, for example, of 0.08 to 0.25 Kcal/m.h..degree.C. flows through the cooling jacket. When the gas contains aluminum chloride, the cooling fluid flows into the cooling jacket in such a manner that the temperature inside a gas conduit is maintained to be higher than the sublimation temperature of aluminum chloride. Lubrication oil may be supplied as the cooling fluid to the cooling jacket from the same supply line as lubrication oil supplied to oil lubricating bearings provided below a pump mechanism unit.

Abstract: In a single-shaft axial-flow gas turbine, the shaft part lying between turbine and compressor is a drum (12) which is surrounded by a drum cover (13). The annular passage (18) formed between drum and drum cover assumes the function of conducting all the rotor cooling air, tapped on the hub side behind the last moving row of the compressor, to the front end (16) of the turbine and after this to its rotor-side cooling passages. The cooling air is deflected inside the annular passage in a spin cascade (25) and accelerated to the highest possible tangential velocity. With this measure, the axial thrust of the gas turbine can be reduced on the one hand and the hitherto conventional recooler for the cooling air can be dispensed with on the other hand.

Abstract: An engine compressor comprising an internal combustion engine with a drive shaft; a compressor with a head and a cylinder; and a device for ventilating the head and cylinder, and having: an impeller fitted on to the drive shaft; a housing mounted between the casings of the engine and the compressor, and defining an internal chamber housing the impeller; an inlet formed in a central position of the housing and through which ambient air is drawn; and an outlet formed in the top portion of the housing and through which air is fed to the head and the cylinder.

Abstract: A cover plate for a cooling fan motor includes a heat shield portion spaced from the motor and a deflector portion extending beyond the motor. The deflector portion redirects axial discharge airflow across the motor to provide cooling, thereby improving the life of the motor bearings and the operating efficiency of the motor.

Abstract: Discloses a torque converter device with a light stator and turbine. The torque converter device comprises a converter cover, a turbine hub, a washer provided between the cover and the hub, and an oil flow passage provided between the washer and the turbine hub to lighten the stator.

Abstract: A clearance control assembly in a gas turbine engine includes several stages of cylindrical turbine shroud rings and a one-piece continuous cylindrical housing surrounding the shroud rings in radially outward spaced relation. Each shroud ring is composed of at least a pair of semi-cylindrical segments mounted to the housing. The shroud ring segments are radially positioned by thermal expansion and contraction of the housing in response to temperature-controlled air flow between the housing and shroud segments. Coupling elements joins together opposite edge portions of adjacent shroud ring segments to permit axial movement of the shroud segments toward and away from one another. Lands which protrude outwardly from the housing interior and shroud ring segment exteriors are located between the housing and shroud segments for defining several spiral channels for air flow about the interior of the housing and exterior of the shroud segments.

Abstract: A shroud support includes an annular casing and an annular hanger spaced radially inwardly therefrom. The hanger includes a circumferentially extending flow duct therein and a base for radially supporting a shroud positionable radially over a plurality of circumferentially spaced turbine blades. The hanger is cooled by channeling a cooling fluid circumferentially inside the hanger flow duct for providing more uniform circumferential blade tip clearance and for better matching the thermal movement between the shroud and blade tips.

Abstract: An air channeling assembly includes an outer casing having a series of spaced apart air ports spaced radially outwardly from an inner casing to define a plenum therebetween. A series of baffles are disposed in the plenum and spaced radially inwardly from the outer casing. Each of the baffles includes an intermediate opening joined in flow communication with a respective one of the air ports, and first and second ends extending circumferentially oppositely away from the intermediate opening. The baffle provides a flow shield between the inner and outer casing around each of the air ports and channels air through the intermediate opening and respective air ports.

Abstract: A coupling for feeding a heat-exchange fluid between a stationary supply and a rotating body comprises a tubular rotor shaft fixed to the rotating body and rotatable about and centered on an axis and a nonrotatable housing fixed stationarily adjacent and surrounding the body. This housing is provided with an inlet connected to the supply and is formed with a passage permitting fluid communication between the supply and the body through the shaft. At least one roller bearing rotationally supports the shaft in the housing and outer and inner seals axially flanking the bearing define an annular substantially closed chamber containing the bearing and each seal between the housing and the shaft. The inner seal has an inner side exposed to the fluid and the outer seal has an outer side exposed to the surrounding atmosphere. A coolant is circulated through the chamber.

Abstract: A cooling system for centrifugal pump bearings and seals for use with a centrifugal pump having a housing containing a pumping chamber and a rotating impeller within the pumping chamber, a passage being formed in the housing, the passage receiving fluid from the pumping chamber and directing the fluid thereby providing cooling fluid flow, and an arcuate groove formed in the housing in fluid communication with the passage, a first end of the groove being adjacent the passage, a second end of the groove being distal of said passage, the groove having a depth which varies from the first end to the second end, the depth at the first end being greater than the depth at the second end.

Abstract: A stator assembly 46 for an axial flow rotary machine 10 is disclosed. Various construction details which increase the efficiency of the machine are developed. In one embodiment, the machine includes a circumferentially continuous structural outer case and a circumferentially continuous inner case which is a pressure vessel for the working medium flow path.

Abstract: The rotor of a canned motor for a centrifugal pump is cooled by a heat-exchanger installed in the rotor chamber and receives liquid from the plenum chamber of the pump or from another source. Liquid entering the rotor chamber can leak therefrom by way of a flow-restricting outlet (at 10). The outlet permits gases to escape from the rotor chamber when the motor is started, but limits the leakage of liquid from the rotor chamber. Leaking liquid is admitted into the suction chamber of the pump.

Abstract: A pump for high temperature liquid includes a duct interconnecting the suction inlet space, and the annular clearance space between the shaft and the pressure housing at a point immediately adjacent to the seal around the shaft. During hot stand-by uniform thermosyphon circulation of liquid occurs from the suction inlet space through the annular clearance space and back to the suction inlet via the duct, which helps prevent thermal stresses being set up in the shaft.

Abstract: A secondary oil system for a gas turbine engine includes a reservoir in a bearing sump of the engine and a mist tube extending across the top of the reservoir and connected at one end to a compressed air source and at the other end to a nozzle in a bearing sump. A shut-off valve responsive to primary system oil pressure normally blocks the mist tube but unblocks the latter when primary system pressure is low. The compressed air pressurizes the reservoir when the shut-off valve is open and forces oil through a pick-up tube to another orifice in the mist tube located at a venturi passage. Oil issuing into the mist tube mixes with high velocity air in the venturi passage to form a mist which is conducted by the mist tube to the nozzle from which it is directed at a rotor shaft bearing. The orifice at the venturi passage is at a lower elevation than the pressurizing orifice relative to the bottom of the reservoir and defines the normally filled oil level in the reservoir.

Abstract: The invention concerns an active clearance control for controlling clearance between a turbine and a casing in a gas turbine aircraft engine.The invention calculates the instantaneous clearance between a turbine casing and a turbine rotor, based on temperature. Two temperatures are involved. First, a steady state temperature (SSTemp) is computed for the rotor and the casing. SSTemp is a predicted, future temperature, which will be attained when the engine reaches steady state operation. Each SSTemp is computed based on presently occurring engine operating conditions, such as selected temperatures, pressures, and rotational speeds.Changes which occur in the SSTemp's indicate the second temperatures, which are the instantaneous temperatures of the casing and rotor. These changes in SSTemp are caused by changes in the present operating conditions, which occur during engine acceleration and deceleration.

Abstract: A control system 30 for measuring the clearance "x" between the tip 26 of a blade 24 and wall 28 in a turbine engine8. A series of probes 32, 32' and 32.sup.N located in the wall 28 each have a reference orifice 52 and a sensing orifice 54. Fluid from a source flows through the reference orifices 52 into the turbine engine. This fluid flow is substantially unrestricted and as a result a fluid pressure P.sub.2 is established in a reference chamber 44. Fluid flow from the sensing orifice 54 is restricted by the relationship of the tip 26 of each blade 24 and as a result fluid pressure P.sub.2 ' is created in chamber 48. A multiplexer 62 sequentially provides transducer 92 and 94 with fluid pressure P.sub.2 from the reference chamber 44 and P.sub.2 ' from sensing chamber 48. The transducers 92 and 94 convert the pneumatic signals into electrical signals which are supplied to a computer 116.

Abstract: A method and apparatus for controlling a temperature of a turbine casing and a turbine rotor in a gas turbine, which method and apparatus enables a maintaining of an optimum gap at a tip end of the rotor blades of the gas turbine over an entire operating range by independently controlling the amounts of heat energy supplied to a space of the turbine casing and the turbine rotor.

Abstract: The invention relates to a multi-stage lateral channel compressor, wherein the housings of the individual compressor stages consisting of individual housing shells are arranged axially, one behind the other, and are mechanically interconnected, wherein, in addition, a common driving shaft is provided for the impellers of the individual compressor stages, and a coolant is provided in the interspace which exists between the housings of the individual compressor stages. An intensive cooling is thereby achieved, in that the interspace is sealed both from the outside and also against the driving shaft, an inlet and an outlet orifice are each assigned to the interspace and a liquid coolant, which flows through the interspace, is supplied and evacuated by way of these orifices.

Abstract: A secondary oil system for a gas turbine engine includes a dual phase blocking member in a passage between an oil reservoir and a secondary orifice adjacent a bearing of the engine. The blocking member has a first phase at temperatures below a threshold temperature of the bearing in which the blocking member prevents secondary oil flow and a second phase at temperatures above the threshold temperature in which the blocking member permits secondary oil flow. Normally, primary oil flow maintains the bearing at an operating temperature below the threshold temperature so that secondary oil flow is normally blocked. After primary oil flow stops, the bearing temperature increases to the threshold temperature and the blocking member transitions to its second phase to initiate secondary lubrication.

Abstract: A vacuum pump with a heating portion for preventing adhesion of reaction products on a discharge side thereof.

Abstract: A bearing cap (16) is sealingly inserted between a front bearing bush (3) and a fluid-tight sleeve (17). Between a front portion (10) of a rotor shaft (5) and the front bearing bush, two overlying lubricating grooves (11, 12) are disposed. On a rear portion (13) of the shaft, a baffle plate (20) having vanes is mounted, an annular gap (21) existing between the shaft and the inside diameter of the vanes. Between the rear portion of the shaft and a rear bearing bush (4), lubricating grooves (14, 15) are formed continuously. The rotor chamber is quickly vented, no contamination thereof taking place. Lubrication and heat evacuation from the rotor chamber are ensured.

Abstract: A centrifugal pump of the "sealless" type including a casing containing a pumping chamber, inlet and outlet, and an impeller mounted on a shaft supported by an independent bearing system. The impeller shaft is driven by a motor located outside of the casing through a set of magnets located on the opposite sides of the wall of the casing and magnetically interconnected together with the motor driving the magnets located on the outside of the casing and with magnets located on the inside of the casing being connected to and driving the pump impeller. The bearing system includes a lubricating system which in some cases will use the pumped fluid as a lubricant and coolant.

Abstract: A nose cowl or spinner is provided for a fixed, non-rotatable central hub of a turbojet engine having assembly means that facilitate the attachment and detachment of the nose cowl to the central hub, and provides a readily visible indication of whether or not the nose cowl has been properly assembled to the hub. The nose cowl has a smooth outer surface to provide undisturbed air flow into the turbojet engine compressor and defines means to circulate heated air to prevent icing of the external surface. An inner cowl member is attached to a bearing cover of the central hub in a non-rotatable manner, an outer cowl member is axially locked to the central hub so as to be concentrally arranged about the inner cowl member, and a locking device is used to lock the inner and outer cowl members together to prevent inadvertent rotation of the outer cowl member.

Abstract: A gas turbine jet propulsion unit of multi-shaft-double-flow construction in which a front compressor or fan supplies compressed air into a secondary channel arranged coaxially to the propulsion unit axis and formed between outer and inner wall structures, from which a secondary air component is taken and blown out against the turbine housing structures for purposes of turbine component cooling; the secondary air channel extends essentially over the entire propulsion unit length or at least up to the area near the turbine housing structure while the secondary air component is taken off from the secondary flow by way of openings in the inner wall structure which are arranged in direct proximity of the respective turbine housing structure.

Abstract: A device for cooling the salient-type rotor of electrical machines in which interpolar bodies are placed between and parallel to the salient poles of a rotor creating narrow channels between the salient poles and the interpolar bodies, to effectively cool the salient poles by the cooling air blowing radially through the channels between the interpolar body and the salient poles, and the interpolar bodies having circumferentially extending top surface close to the internal surface of stator creating a circumferential channel between the interpolar body and the internal surface of stator, bridging the gap between the salient poles to reduce turbulences and energy losses created by the rotation of the rotor.

Abstract: A coolable stator assembly is positioned outwardly of an array of rotor blades in a high by pass turbofan gas turbine engine as disclosed. The stator assembly includes case tied air seals positioned by rails and a shield which extends circumferentially about the rails and the rail connector section extending between the rails. Various constructions details for improving the control of clearances and circumferential temperature gradients in the rails are developed. In one particular embodiment, cooling air tubes are employed with the shield.

Abstract: A seal assembly secured to the downstream end of a gas turbine engine combustor liner forms a gas path seal at the upstream facing platforms of turbine inlet guide vanes and also cools the vane platforms. The seal assembly includes an annular coolant compartment which feeds cooling air to a plurality of circumferentially spaced apart, axially extending open-ended channels formed between a conical portion of the downstream-most combustor liner and an annular baffle member disposed on the non-gas path side of the conical liner. The seal assembly is supported and axially located on a cylindrical surface which permits locating the seal assembly such that the downstream end of the conical liner is closely spaced from the turbine inlet guide vane platforms to reduce leakage from the gas path.

Abstract: A coolant system uses a first quantity of high temperature air at cruise power and a second larger quantity of cooler air at high power. Relatively high rotating clearances are achieved at high power and low clearance achieved at cruise power.

Abstract: The present invention includes an overhung turbine wheel which is provided with at least one ring of turbine blades and is connected with a shaft. In order to control the thermodynamically required circumferential speeds necessary to achieve maximum efficiency, the turbine wheel is designed as a closed disk which is narrow in the axial direction. The turbine wheel is integral with the turbine blades and furthermore is connected to the shaft through planar connecting surfaces having interfitting teeth. The turbine wheel has a relatively low mass, and the interfitting teeth allow a simple and optimal centering connection. Radial-flow turbines of this kind are standardized in model series, the turbine wheels and shafts in each case being provided with similar interfitting teeth to allow mutual combinations as desired.

Abstract: The hollow shaft of a high pressure compressor is provided in a conically tapering section downstream of the last rotor disc on its inner surface with a vane-like rib arrangement for conveying a stream of cooling air from the vicinity of the axis of the shaft into the outer peripheral regions of the last rotor disc. The stream then passes through corresponding circumferentially distributed axial holes in the rotor disc. In this way, better cooling of the last compressor stages which have been heated by the main stream of air in the compressor and a reduction in the stresses in the structural parts can be obtained.

Abstract: The conical section of the hollow shaft of a high pressure compressor behind the last rotor disc is surrounded by an annular protective shield. The shield serves to protect the hollow shaft and the last rotor disc from the main stream of hot compressed air leaving the compressor. Between the hollow shaft and the heat shield a stream of cooling air is furthermore conducted from the vicinity of the axis to the outer region of the last rotor disc. The stream of air then passes through corresponding circumferentially distributed axial holes in the last rotor disc.

Abstract: Apparatus for cooling and thermally isolating turbocompressor foil bearings. The bearing journal includes a hollow shaft through which gas is positively circulated to cool the shaft. A slinger at one end of the shaft develops a centrifugal pumping action during operation of the turbocompressor by virtue of a plurality of radially directed gas passages. Pressurized gas may be introduced from the compressor into the interior of the hollow shaft and, after traversing the shaft, returned to the compressor. The invention includes arrangements for protecting the bearing against combustion products which may leak past turbine wheel seals by removing such combustion products before they can reach the bearing.

Abstract: Hot water is uniformly accelerated in a nozzle having a tapered flow passage so that it can flow into a moving blade smoothly. The hot water is then expanded and accelerated within the flow passage of the moving blade which is not turned but widened toward its end and power is generated by its reaction, thereby ensuring a highly efficient total flow turbine.

Abstract: Stator blades and rotor blades are cooled by discharge air discharged from an air compressor coupled directly with gas turbine. A signal of the compressor discharge pressure and a signal of turbine exhaust gas temperature are obtained, and cooling air flow is controlled based on these signals.

Abstract: A blower serves for circulating larger gas volumes, in particular for high-power laser systems operating according to the gas-transportation principle. The blower comprises a radial compressor, having a compressor element extending into a connection duct to blow a gas from a first to a second gas duct. The radial compressor is driven by a vertical shaft which is provided with an axial and radial gas bearing within a gas-tight housing. A gas duct system is provided for supplying lubricating gas to both the axial and the radial gas bearings. The gas duct system is fed by both one of the axial gas bearings and by an external pressure-gas pump. Throttles and adjustable valves are provided at predetermined locations of the gas duct system to establish a predetermined profile of gas pressure in the duct system.

Abstract: In a centrifugal compressor of the type that has a head chamber in which various auxiliary passageways are provided that is mounted to a main chamber containing an impeller therein, an annular body is mounted to a free end of the head chamber via seal means, passageways which communicate with respective ones of the various auxiliary passageways are provided within the annular body, and external piping communicating with the respective passageways are fixedly secured to an outer circumferential portion of the annular body.