EP1428978A1 - Rotary fluid machine - Google Patents
Rotary fluid machine Download PDFInfo
- Publication number
- EP1428978A1 EP1428978A1 EP02772880A EP02772880A EP1428978A1 EP 1428978 A1 EP1428978 A1 EP 1428978A1 EP 02772880 A EP02772880 A EP 02772880A EP 02772880 A EP02772880 A EP 02772880A EP 1428978 A1 EP1428978 A1 EP 1428978A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- rotor
- vane
- water
- steam
- chamber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C27/00—Sealing arrangements in rotary-piston pumps specially adapted for elastic fluids
- F04C27/001—Radial sealings for working fluid
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
- F01B13/00—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion
- F01B13/04—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion with more than one cylinder
- F01B13/06—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion with more than one cylinder in star arrangement
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
- F01B13/00—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion
- F01B13/04—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion with more than one cylinder
- F01B13/06—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion with more than one cylinder in star arrangement
- F01B13/061—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion with more than one cylinder in star arrangement the connection of the pistons with the actuated or actuating element being at the outer ends of the cylinders
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
- F01B13/00—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion
- F01B13/04—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion with more than one cylinder
- F01B13/06—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion with more than one cylinder in star arrangement
- F01B13/068—Reciprocating-piston machines or engines with rotating cylinders in order to obtain the reciprocating-piston motion with more than one cylinder in star arrangement the connection of the pistons with an actuated or actuating element being at the inner ends of the cylinders
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
- F01C1/00—Rotary-piston machines or engines
- F01C1/30—Rotary-piston machines or engines having the characteristics covered by two or more groups F01C1/02, F01C1/08, F01C1/22, F01C1/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members
- F01C1/34—Rotary-piston machines or engines having the characteristics covered by two or more groups F01C1/02, F01C1/08, F01C1/22, F01C1/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F01C1/08 or F01C1/22 and relative reciprocation between the co-operating members
- F01C1/344—Rotary-piston machines or engines having the characteristics covered by two or more groups F01C1/02, F01C1/08, F01C1/22, F01C1/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F01C1/08 or F01C1/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member
- F01C1/3446—Rotary-piston machines or engines having the characteristics covered by two or more groups F01C1/02, F01C1/08, F01C1/22, F01C1/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F01C1/08 or F01C1/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member the inner and outer member being in contact along more than one line or surface
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
- F01C19/00—Sealing arrangements in rotary-piston machines or engines
- F01C19/02—Radially-movable sealings for working fluids
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
- F01C21/00—Component parts, details or accessories not provided for in groups F01C1/00 - F01C20/00
- F01C21/04—Lubrication
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
- F01C21/00—Component parts, details or accessories not provided for in groups F01C1/00 - F01C20/00
- F01C21/08—Rotary pistons
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
- F01C21/00—Component parts, details or accessories not provided for in groups F01C1/00 - F01C20/00
- F01C21/08—Rotary pistons
- F01C21/0809—Construction of vanes or vane holders
- F01C21/0818—Vane tracking; control therefor
- F01C21/0827—Vane tracking; control therefor by mechanical means
- F01C21/0836—Vane tracking; control therefor by mechanical means comprising guiding means, e.g. cams, rollers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
- F01C21/00—Component parts, details or accessories not provided for in groups F01C1/00 - F01C20/00
- F01C21/08—Rotary pistons
- F01C21/0809—Construction of vanes or vane holders
- F01C21/0818—Vane tracking; control therefor
- F01C21/0854—Vane tracking; control therefor by fluid means
- F01C21/0872—Vane tracking; control therefor by fluid means the fluid being other than the working fluid
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
- F01C21/00—Component parts, details or accessories not provided for in groups F01C1/00 - F01C20/00
- F01C21/08—Rotary pistons
- F01C21/0809—Construction of vanes or vane holders
- F01C21/0881—Construction of vanes or vane holders the vanes consisting of two or more parts
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
- F04C18/30—Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members
- F04C18/34—Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members
- F04C18/344—Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member
- F04C18/3446—Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member the inner and outer member being in contact along more than one line or surface
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B53/00—Internal-combustion aspects of rotary-piston or oscillating-piston engines
Definitions
- the present invention relates to a rotary fluid machine for interconverting the pressure energy of a gas-phase working medium and the rotational energy of a rotor.
- a rotary fluid machine disclosed in Japanese Patent Application Laid-open No. 2000-320543 is equipped with a vane piston unit in which a vane and a piston are combined; the piston, which is slidably fitted in a cylinder provided radially in a rotor, interconverts the pressure energy of a gas-phase working medium and the rotational energy of the rotor via a power conversion device comprising an annular channel and a roller, and the vane, which is radially and slidably supported in the rotor, interconverts the pressure energy of the gas-phase working medium and the rotational energy of the rotor.
- Such a rotary fluid machine comprises an elliptical rotor chamber formed in a casing and a circular rotor rotatably housed within the rotor chamber, and by setting the diameter of the rotor substantially equal to the minor axis of the rotor chamber, the clearance between the rotor and the rotor chamber becomes a minimum at positions at opposite ends of the minor axis.
- An intake port and an exhaust port are provided on either side, circumferentially, of these minimum clearance positions, and leakage of a gas-phase working medium from a high pressure vane chamber, with which the intake port communicates, into a low pressure vane chamber, with which the exhaust port communicates, is prevented by making a seal at the extremity of the vane abut against the inner peripheral face of the rotor chamber.
- it is difficult to completely prevent the leakage of the gas-phase working medium using only the seal at the extremity of the vane and there is the problem that the gas-phase working medium leaks between vane chambers having different pressures, thus degrading the performance of the rotary fluid machine.
- the present invention has been achieved under the above-mentioned circumstances, and an object thereof is to prevent leakage of a gas-phase working medium from an intake port to an exhaust port via a clearance between a rotor and a rotor chamber of a rotary fluid machine.
- a rotary fluid machine that includes a rotor chamber formed in a casing, a rotor rotatably housed within the rotor chamber, a plurality of vane channels formed radially in the rotor, a plurality of vanes slidably supported in the respective vane channels, vane chambers defined by the rotor, the casing, and the vanes, and an intake port and an exhaust port for supplying and discharging a gas-phase working medium to and from the vane chambers, characterized in that gas-phase working medium leakage preventing means is provided on at least one of the outer peripheral face of the rotor and the inner peripheral face of the rotor chamber in a region in which there is a large difference in pressure between adjacent vane chambers that are in between the trailing edge of the exhaust port and the leading edge of the intake port.
- the gas-phase working medium leakage preventing means is provided on at least one of the outer peripheral face of the rotor and the inner peripheral face of the rotor chamber in a region in which there is a large difference in pressure between adjacent vane chambers that are in between the trailing edge of the exhaust port and the leading edge of the intake port, it is possible to prevent the gas-phase working medium from leaking from the intake port, which is at high pressure, to the exhaust port, which is at low pressure, thereby improving the performance of the rotary fluid machine.
- the leakage preventing means is formed from a labyrinth, a problem such as seal wear, which occurs when the leakage preventing means is formed from a seal, can be avoided.
- Labyrinths 43g of embodiments correspond to the leakage preventing means of the present invention
- steam and water of the embodiments correspond to the gas-phase working medium and the liquid-phase working medium respectively of the present invention.
- FIG. 1 to FIG. 18 illustrate a first embodiment of the present invention
- FIG. 1 is a schematic view of a waste heat recovery system of an internal combustion engine
- FIG. 2 is a longitudinal sectional view of an expander, corresponding a sectional view along line 2-2 of FIG. 4
- FIG. 3 is an enlarged sectional view around the axis of FIG. 2
- FIG. 4 is a sectional view along line 4-4 of FIG. 2
- FIG. 5 is a sectional view along line 5-5 of FIG. 2
- FIG. 6 is a sectional view along line 6-6 of FIG. 2
- FIG. 7 is a sectional view along line 7-7 of FIG. 5
- FIG. 8 is a sectional view along line 8-8 of FIG. 5;
- FIG. 1 is a schematic view of a waste heat recovery system of an internal combustion engine
- FIG. 2 is a longitudinal sectional view of an expander, corresponding a sectional view along line 2-2 of FIG. 4
- FIG. 3 is an enlarged sectional view around
- FIG. 9 is a sectional view along line 9-9 of FIG. 8;
- FIG. 10 is a sectional view along line 10-10 of FIG. 3;
- FIG. 11 is an exploded perspective view of a rotor;
- FIG. 12 is an exploded perspective view of a lubricating water distribution section of the rotor;
- FIG. 13 is a schematic view showing cross-sectional shapes of a rotor chamber and the rotor;
- FIG. 14A is a view showing the shape of an annular channel of a casing (embodiment);
- FIG. 14B is a view showing the shape of an annular channel of a casing (conventional example);
- FIG. 15A is a view showing the shape of the inner peripheral face of a rotor chamber and the intake and exhaust timing (embodiment);
- FIG. 15B is a view showing the shape of the inner peripheral face of a rotor chamber and the intake and exhaust timing (conventional example);
- FIG. 16 to FIG. 18 are views for explaining the operation of labyrinths.
- FIG. 19 to FIG. 21 are views for explaining the operation of labyrinths of a second embodiment of the present invention.
- a first embodiment of the present invention is explained below with reference to FIG. 1 to FIG. 18.
- a waste heat recovery system 2 for an internal combustion engine 1 includes an evaporator 3 that generates high temperature, high pressure steam by vaporizing a high pressure liquid (e.g. water) using as a heat source the waste heat (e.g. exhaust gas) of the internal combustion engine 1, an expander 4 that generates an output by expansion of the steam, a condenser 5 that liquefies steam having decreased temperature and pressure as a result of conversion of pressure energy into mechanical energy in the expander 4, and a supply pump 6 that pressurizes the liquid (e.g. water) from the condenser 5 and resupplies it to the evaporator 3.
- a high pressure liquid e.g. water
- a condenser 5 that liquefies steam having decreased temperature and pressure as a result of conversion of pressure energy into mechanical energy in the expander 4
- a supply pump 6 that pressurizes the liquid (e.g. water) from the condenser 5 and resupplies it to the evaporator 3.
- a casing 11 of the expander 4 is formed from first and second casing halves 12 and 13, which are made of metal.
- the first and second casing halves 12 and 13 are formed from main body portions 12a and 13a, which in cooperation form a rotor chamber 14, and circular flanges 12b and 13b, which are joined integrally to the outer peripheries of the main body portions 12a and 13a, and the two circular flanges 12b and 13b are joined together via a metal gasket 15.
- the outer face of the first casing half 12 is covered with a transit chamber outer wall 16 having a deep bowl shape, and a circular flange 16a, which is joined integrally to the outer periphery of the transit chamber outer wall 16, is superimposed on the left face of the circular flange 12b of the first casing half 12.
- the outer face of the second casing half 13 is covered with an exhaust chamber outer wall 17 for housing a magnet coupling (not illustrated) for transmitting the output of the expander 4 to the outside, and a circular flange 17a, which is joined integrally to the outer periphery of the exhaust chamber outer wall 17, is superimposed on the right face of the circular flange 13b of the second casing half 13.
- a transit chamber 19 is defined between the transit chamber outer wall 16 and the first casing half 12
- an exhaust chamber 20 is defined between the exhaust chamber outer wall 17 and the second casing half 13.
- the exhaust chamber outer wall 17 is provided with an outlet (not illustrated) for guiding the decreased temperature, decreased pressure steam that has finished work in the expander 4 to the condenser 5.
- the main body portions 12a and 13a of the two casing halves 12 and 13 have hollow bearing tubes 12c and 13c projecting outward in the lateral direction, and a rotating shaft 21 having a hollow portion 21 a is rotatably supported by these hollow bearing tubes 12c and 13c via a pair of bearing members 22 and 23.
- the axis L of the rotating shaft 21 thus passes through the intersection of the major axis and the minor axis of the rotor chamber 14, which has a substantially elliptical shape.
- a seal block 25 is housed within a lubricating water supply member 24 screwed onto the right-hand end of the second casing half 13, and secured by a nut 26.
- a small diameter portion 21b at the right-hand end of the rotating shaft 21 is supported within the seal block 25, a pair of seals 27 are disposed between the seal block 25 and the small diameter portion 21b, a pair of seals 28 are disposed between the seal block 25 and the lubricating water supply member 24, and a seal 29 is disposed between the lubricating water supply member 24 and the second casing half 13.
- a filter 30 is fitted in a recess formed in the outer periphery of the hollow bearing tube 13c of the second casing half 13, and is prevented from falling out by means of a filter cap 31 screwed into the second casing half 13.
- a pair of seals 32 and 33 are provided between the filter cap 31 and the second casing half 13.
- a circular rotor 41 is rotatably housed within the rotor chamber 14, which has a pseudo-elliptical shape.
- the rotor 41 is fitted onto and joined integrally to the outer periphery of the rotating shaft 21, and the axis of the rotor 41 and the axis of the rotor chamber 14 coincide with the axis L of the rotating shaft 21.
- the shape of the rotor chamber 14 viewed in the axis L direction is pseudo-elliptical, and is similar to a rhombus with its four apexes rounded, the shape having a major axis DL and a minor axis DS.
- the shape of the rotor 41 viewed in the axis L direction is a perfect circle having a diameter DR that is slightly smaller than the minor axis DS of the rotor chamber 14.
- the cross-sectional shapes of the rotor chamber 14 and the rotor 41 viewed in a direction orthogonal to the axis L are all racetrack-shaped. That is, the cross-sectional shape of the rotor chamber 14 is formed from a pair of flat faces 14a extending parallel to each other at a distance d , and arc-shaped faces 14b having a central angle of 180° that are smoothly connected to the outer peripheries of the flat faces 14a and, similarly, the cross-sectional shape of the rotor 41 is formed from a pair of flat faces 41a extending parallel to each other at the distance d , and arc-shaped faces 41b having a central angle of 180° that are smoothly connected to the outer peripheries of the flat faces 41a.
- the flat faces 14a of the rotor chamber 14 and the flat faces 41a of the rotor 41 are in contact with each other, and a pair of crescent-shaped spaces are formed between the inner peripheral face of the rotor chamber 14 and the outer peripheral face of the rotor 41 (see FIG. 4).
- the rotor 41 is formed from a rotor core 42 that is formed integrally with the outer periphery of the rotating shaft 21, and twelve rotor segments 43 that are fixed so as to cover the periphery of the rotor core 42 and form the outer shell of the rotor 41.
- Twelve ceramic (or carbon) cylinders 44 are mounted radially in the rotor core 42 at 30° intervals and fastened by means of clips 45 to prevent them falling out.
- a small diameter portion 44a is projectingly provided at the inner end of each of the cylinders 44, and a gap between the base end of the small diameter portion 44a and a sleeve 84 is sealed via a C seal 46.
- the extremity of the small diameter portion 44a is fitted into the outer peripheral face of the sleeve 84, which is hollow, and a cylinder bore 44b communicates with first and second steam passages S1 and S2 within the rotating shaft 21 via twelve third steam passages S3 running through the small diameter portion 44a and the rotating shaft 21.
- a ceramic piston 47 is slidably fitted within each of the cylinders 44. When the piston 47 moves to the radially innermost position, it retracts completely within the cylinder bore 44b, and when it moves to the radially outermost position, about half of the whole length projects outside the cylinder bore 44b.
- Each of the rotor segments 43 is a hollow wedge-shaped member having a central angle of 30°, and has two recesses 43a and 43b formed on the faces thereof that are opposite the pair of flat faces 14a of the rotor chamber 14, the recesses 43a and 43b extending in an arc shape with the axis L as the center, and lubricating water outlets 43c and 43d open in the middle of the recesses 43a and 43b. Furthermore, four lubricating water outlets 43e and 43f open on the end faces of the rotor segments 43, that is, the faces that are opposite vanes 48, which will be described later.
- a large number of labyrinths 43g are recessed in the arc-shaped face of each of the rotor segments 43 forming the arc-shaped face 41b of the rotor 41 so as to extend within a plane containing the axis L.
- the labyrinths 43g are channels having a U-shaped cross section and, for example, sixteen of the labyrinths 43g are provided on each of the rotor segments 43.
- the rotor 41 is assembled as follows.
- the twelve rotor segments 43 are fitted around the outer periphery of the rotor core 42, which is preassembled with the cylinders 44, the clips 45, and the C seals 46, and the vanes 48 are fitted in twelve vane channels 49 formed between adjacent rotor segments 43.
- shims having a predetermined thickness are disposed on opposite faces of the vanes 48.
- each of the rotor segments 43 and the vanes 48 are tightened inward in the radial direction toward the rotor core 42 by means of a jig so as to precisely position the rotor segments 43 relative to the rotor core 42, and each of the rotor segments 43 is then provisionally retained on the rotor core 42 by means of provisional retention bolts 50 (see FIG. 8).
- each of the rotor segments 43 and the rotor core 42 are co-machined so as to make two knock pin holes 51 run therethrough, and four knock pins 52 are press-fitted in the two knock pin holes 51 so as to join each of the rotor segments 43 to the rotor core 42.
- a through hole 53 running through the rotor segment 43 and the rotor core 42 is formed between the two knock pin holes 51, and recesses 54 are formed at opposite ends of the through hole 53.
- Two pipe members 55 and 56 are fitted within the through hole 53 via seals 57 to 60, and an orifice-forming plate 61 and a lubricating water distribution member 62 are fitted into each of the recesses 54 and secured by a nut 63.
- the orifice-forming plate 61 and the lubricating water distribution member 62 are prevented from rotating relative to the rotor segments 43 by two knock pins 64 running through knock pin holes 61a of the orifice-forming plate 61 and fitted into knock pin holes 62a of the lubricating water distribution member 62, and a gap between the lubricating water distribution member 62 and the nut 63 is sealed by an O ring 65.
- a small diameter portion 55a formed in an outer end portion of one of the pipe members 55 communicates with a sixth water passage W6 within the pipe member 55 via a through hole 55b, and the small diameter portion 55a also communicates with a radial distribution channel 62b formed on one side face of the lubricating water distribution member 62.
- the distribution channel 62b of the lubricating water distribution member 62 extends in six directions, and the extremities thereof communicate with six orifices 61b, 61c, and 61d of the orifice-forming plate 61.
- the structures of the orifice-forming plate 61, the lubricating water distribution member 62, and the nut 63 provided at the outer end portion of the other pipe member 56 are identical to the structures of the above-mentioned orifice-forming plate 61, lubricating water distribution member 62, and nut 63.
- annular channel 67 is defined by a pair of O rings 66 on the outer periphery of the cylinder 44, and the sixth water passage W6 formed within said one of the pipe members 55 communicates with the annular channel 67 via four through holes 55c running through the pipe member 55 and a tenth water passage W10 formed within the rotor core 42.
- the annular channel 67 communicates with sliding surfaces of the cylinder bore 44b and the piston 47 via an orifice 44c. The position of the orifice 44c of the cylinder 44 is set so that it stays within the sliding surface of the piston 47 when the piston 47 moves between top dead center and bottom dead center.
- the first water passage W1 formed in the lubricating water supply member 24 communicates with the small diameter portion 55a of said one of the pipe members 55 via a second water passage W2 formed in the seal block 25, third water passages W3 formed in the small diameter portion 21b of the rotating shaft 21, an annular channel 68a formed in the outer periphery of a water passage forming member 68 fitted in the center of the rotating shaft 21, a fourth water passage W4 formed in the rotating shaft 21, a pipe member 69 bridging the rotor core 42 and the rotor segments 43, and fifth water passages W5 formed so as to bypass the knock pin 52 on the radially inner side of the rotor segment 43.
- each of the vanes 48 has a substantially U-shaped form comprising parallel faces 48a following the parallel faces 14a of the rotor chamber 14, an arc-shaped face 48b following the arc-shaped face 14b of the rotor chamber 14, and a notch 48c positioned between the parallel faces 48a.
- Rollers 71 having a roller bearing structure are rotatably supported on a pair of support shafts 48d projecting from the parallel faces 48a.
- a U-shaped synthetic resin seal 72 is retained in the arc-shaped face 48b of the vane 48, and the extremity of the seal 72 projects slightly from the arc-shaped face 48b of the vane 48 and comes into sliding contact with the arc-shaped face 14b of the rotor chamber 14.
- Two recesses 48e are formed on each side of the vane 48, and these recesses 48e are opposite the two radially inner lubricating water outlets 43e that open on the end faces of the rotor segment 43.
- a piston receiving member 73 which is provided so as to project radially inward in the middle of the notch 48c of the vane 48, abuts against the radially outer end of the piston 47.
- two pseudo-elliptical annular channels 74 having a similar shape to that of a rhombus with its four apexes rounded are provided in the flat faces 14a of the rotor chamber 14 defined by the first and second casing halves 12 and 13, and the pair of rollers 71 of each of the vanes 48 are rollably engaged with these annular channels 74.
- the distance between these annular channels 74 and the arc-shaped face 14b of the rotor chamber 14 is constant throughout the whole circumference.
- a pair of circular seal channels 76 are formed in the flat faces 14a of the rotor chamber 14 so as to surround the outside of the annular channels 74.
- a pair of ring seals 79 equipped with two O rings 77 and 78 are slidably fitted in the circular seal channels 76, and the seal surfaces are opposite the recesses 43a and 43b (see FIG. 4) formed in each of the rotor segments 43.
- the pair of ring seals 79 are prevented from rotating relative to the first and second casing halves 12 and 13 by knock pins 80.
- an opening 16b is formed at the center of the transit chamber outer wall 16; a boss portion 81a of a fixed shaft support member 81 disposed on the axis L is secured to the inner face of the opening 16b by a plurality of bolts 82, and secured to the first casing half 12 by means of a nut 83.
- a cylinder-shaped ceramic sleeve 84 is fixed to the hollow portion 21a of the rotating shaft 21.
- the outer peripheral face of the fixed shaft 85 which is integral with the fixed shaft support member 81, is relatively rotatably fitted within the inner peripheral face of this sleeve 84.
- a gap between the left-hand end of the fixed shaft 85 and the first casing half 12 is sealed by a seal 86, and a gap between the right-hand end of the fixed shaft 85 and the rotating shaft 21 is sealed by a seal 87.
- a steam supply pipe 88 is fitted into the fixed shaft support member 81, which is disposed on the axis L, and is secured by a nut 89, and the right-hand end of the steam supply pipe 88 is press-fitted into the center of the fixed shaft 85.
- the first steam passage S1 which communicates with the steam supply pipe 88, is formed in the center of the fixed shaft 85 in the axial direction, and the pair of second steam passages S2 run radially through the fixed shaft 85 with a phase difference of 180°.
- the twelve third steam passages S3 run through the sleeve 84 and the small diameter portions 44a of the twelve cylinders 44 retained at intervals of 30° in the rotor 41 fixed to the rotating shaft 21, and radially inner end portions of these third steam passages S3 are opposite the radially outer end portions of the second steam passages S2 so as to be able to communicate therewith.
- a pair of notches 85a are formed on the outer peripheral face of the fixed shaft 85 with a phase difference of 180°, and these notches 85a can communicate with the third steam passages S3.
- the notches 85a and the transit chamber 19 communicate with each other via a pair of fourth steam passages S4 formed axially in the fixed shaft 85, a fifth annular steam passage S5 formed axially in the fixed shaft support member 81, and through holes 81b opening on the outer periphery of the boss portion 81a of the fixed shaft support member 81.
- a plurality of radially aligned intake ports 90 are formed in the first casing half 12 and the second casing half 13 at positions that are advanced by 15° in the direction of rotation R of the rotor 41 relative to the minor axis of the rotor chamber 14.
- the interior space of the rotor chamber 14 communicates with the transit chamber 19 by means of these intake ports 90.
- a plurality of exhaust ports 91 are formed in the second casing half 13 at positions that are retarded by 15° to 75° in the direction of rotation R of the rotor 41 relative to the minor axis of the rotor chamber 14.
- the interior space of the rotor chamber 14 communicates with the exhaust chamber 20 by means of these exhaust ports 91.
- the second steam passages S2 and the third steam passages S3, and the notches 85a of the fixed shaft 85 and the third steam passages S3, form a rotary valve V, which provides periodic communication therebetween by rotation of the rotating shaft 21 relative to the fixed shaft 85 (see FIG. 10).
- pressure chambers 92 are formed at the rear face of the ring seals 79 fitted in the circular seal channels 76 of the first and second casing halves 12 and 13.
- An eleventh water passage W11 formed in the first and second casing halves 12 and 13 communicates with the two pressure chambers 92 via a twelfth water passage W12 and a thirteenth water passage W13, which are formed from pipes, and the ring seals 79 are urged toward the side face of the rotor 41 by virtue of water pressure applied to the two pressure chambers 92.
- the eleventh water passage W11 communicates with the outer peripheral face of the annular filter 30 via a fourteenth water passage W14, which is a pipe, and the inner peripheral face of the filter 30 communicates with a sixteenth water passage W16 formed in the second casing half 13 via a fifteenth water passage W15 formed in the second casing half 13.
- Water supplied to the sixteenth water passage W16 lubricates sliding surfaces of the fixed shaft 85 and the sleeve 84.
- Water supplied to the outer periphery of the bearing member 23 from the inner peripheral face of the filter 30 via a seventeenth water passage W17 lubricates the outer peripheral face of the rotating shaft 21 through an orifice penetrating the bearing members 23.
- water supplied to the outer periphery of the bearing members 22 from the eleventh water passage W11 via an eighteenth water passage W18, which is a pipe lubricates the outer peripheral face of the rotating shaft 21 through an orifice penetrating the bearing member 22, and then lubricates the sliding surfaces between the fixed shaft 85 and the sleeve 84.
- the third steam passages S3 communicating with the corresponding cylinders 44 also communicate with the notches 85a of the fixed shaft 85, the pistons 47 are pushed by the vanes 48 whose rollers 71 are guided by the annular channels 74 and move radially inward, and the steam within the cylinders 44 accordingly passes through the third steam passages S3, the notches 85a, the fourth passages S4, the fifth passage S5, and the through holes 81b, and is supplied to the transit chamber 19 as a first decreased temperature, decreased pressure steam.
- the first decreased temperature, decreased pressure steam is the high temperature, high pressure steam that has been supplied from the steam supply pipe 88, has finished the work of driving the pistons 47 and, as a result, has a decreased temperature and pressure.
- the thermal energy and the pressure energy of the first decreased temperature, decreased pressure steam are lower than those of the high temperature, high pressure steam, but are still sufficient for driving the vanes 48.
- the first decreased temperature, decreased pressure steam within the transit chamber 19 is supplied to the vane chambers 75 within the rotor chamber 14 via the intake ports 90 of the first and second casing halves 12 and 13, and further expands therein to push the vanes 48, thus rotating the rotor 41.
- a second decreased temperature, decreased pressure steam that has finished work and accordingly has a further decreased temperature and pressure is discharged from the exhaust ports 91 of the second casing half 13 into the exhaust chamber 20, and is supplied therefrom to the condenser 5.
- the expansion of the high temperature, high pressure steam enables the twelve pistons 47 to operate in turn to rotate the rotor 41 via the rollers 71 and the annular channels 74, and the expansion of the first decreased temperature, decreased pressure steam, which is the high temperature, high pressure steam whose temperature and pressure have decreased, enables the rotor 41 to rotate via the vanes 48, thereby providing an output from the rotating shaft 21.
- Supply of lubricating water is carried out by utilizing the supply pump 6 (see FIG. 1) for supplying under pressure water from the condenser 5 to the evaporator 3, and a portion of the water discharged from the supply pump 6 is supplied to the first water passage W1 of the casing 11 for lubrication.
- Utilizing the feed pump 6 in this way for supplying water for hydrostatic bearings of each section of the expander 4 eliminates the need for a special pump and enables the number of components to be reduced.
- the water that has been supplied to the first water passage W1 of the lubricating water supply member 24 flows into the small diameter portion 55a of one of the pipe members 55 via the second water passages W2 of the seal block 25, the third water passages W3 of the rotating shaft 21, the annular channel 68a of the water passage forming member 68, the fourth water passage W4 of the rotating shaft 21, and the fifth water passages W5 formed in the pipe member 69 and the rotor segment 43, and the water that has flowed into the small diameter portion 55a flows into the small diameter portion 56a of the other pipe member 56 via the through hole 55b of said one of the pipe members 55, the sixth water passage W6 formed in the pipe members 55 and 56, and the through hole 56b formed in the other pipe member 56.
- the water issuing from the lubricating water outlets 43e and 43f on the end faces of each of the rotor segments 43 into the vane channel 49 supports the vane 48 in a floating state by forming a hydrostatic bearing between the vane channel 49 and the vane 48, which is slidably fitted in the vane channel 49, thus preventing physical contact between the end face of the rotor segment 43 and the vane 48 and thereby preventing the occurrence of seizing and wear.
- the vane 48 reciprocates, the radial position of the vane 48 relative to the rotor 41 changes, and since the recesses 48e are provided not on the rotor segment 43 side but on the vane 48 side and in the vicinity of the rollers 71, where the largest load is imposed on the vane 48, the reciprocating vane 48 can always be kept in a floating state, and the sliding resistance can thereby be reduced effectively.
- Water that has lubricated the surface of the vane 48 that slides against the rotor segment 43 moves radially outward by virtue of centrifugal force, and lubricates the sliding sections of the arc-shaped face 14b of the rotor chamber 14 and the seal 72 provided on the arc-shaped face 48b of the vane 48. Water that has completed the lubrication is discharged from the rotor chamber 14 via the exhaust ports 91.
- the ring seals 79 and the rotor 41 are isolated from each other by a film of water supplied from the lubricating water outlets 43c and 43d and do not make physical contact with each other, and even if the rotor 41 tilts, tilting of the ring seals 79 within the circular seal channels 76 so as to track the tilting of the rotor 41 enables stable sealing characteristics to be maintained while minimizing the frictional force.
- the water that has lubricated the sliding section between the ring seals 79 and the rotor 41 is supplied to the rotor chamber 14 by virtue of centrifugal force, and discharged therefrom to the exterior of the casing 11 via the exhaust ports 91.
- water that has been supplied from the sixth water passage W6 within the pipe member 55 to the sliding surfaces between the cylinder 44 and the piston 47 via the tenth water passage W10 within the rotor segments 43 and the annular channel 67 of the outer periphery of the cylinder 44 exhibits a sealing function by virtue of the viscous properties of the film of water formed on the sliding surfaces, thereby preventing effectively the high temperature, high pressure steam supplied to the cylinder 44 from leaking past the sliding surfaces with the piston 47.
- the first water passage W1 and the eleventh water passage W11 are independent from each other, and water is supplied at a pressure that is required for each of the lubrication sections. More specifically, the water that is supplied from the first water passage W1 is mainly for floatingly supporting the vanes 48 and the rotor 41 by means of a hydrostatic bearing as described above, and it is required to have a high pressure that can counterbalance variations in the load.
- the water that is supplied from the eleventh water passage W11 mainly lubricates the surroundings of the fixed shaft 85, and since it is for sealing the high temperature, high pressure steam that leaks from the third steam passages S3 past the outer periphery of the fixed shaft 85 so as to reduce the influence of thermal expansion of the fixed shaft 85, the rotating shaft 21, the rotor 41, etc., it is only required to have a pressure that is at least higher than the pressure of the transit chamber 19.
- FIG. 14A shows the shape of the annular channel 74 of the present embodiment
- FIG. 14B shows the shape of an annular channel 74 of a conventional example
- the annular channel 74 of the conventional example is elliptical
- the shape of the annular channel 74 of the present invention is a rhombus having its four apexes rounded.
- the clearance between the inner peripheral face 93 of the rotor chamber 14 and the outer peripheral face 94 of the rotor 41 is maintained at a constant minimum value over the range of ⁇ 16° with reference to points P1 and P2, and the clearance gradually increases before and after this range. That is, in the above range of ⁇ 16° the inner peripheral face 93 of the rotor chamber 14 and the annular channel 74 form a partial arc shape with the axis L as the center.
- FIG. 15A shows the intake and exhaust timing of the present embodiment
- FIG. 15B shows the intake and exhaust timing of the conventional example.
- twelve vanes 48 are supported on the rotor 41 at equal intervals, and the central angle formed by a pair of adjacent vanes 48 is therefore 30°.
- the phase of the vane 48 for which communication between the exhaust ports 91 and the vane chamber 75 defined by a pair of vanes 48 is blocked is set at -24° with reference to point P1 and point P2
- the phase of the vane 48 for which communication between the vane chamber 75 and the intake ports 90 is provided is set at +4° with reference to point P1 and point P2. Therefore, at the moment when communication between the vane chamber 75 and the exhaust ports 91, which are at low pressure, is blocked, steam is introduced because the vane chamber 75 is already in communication with the intake ports 90, which are at high pressure.
- the exhaust completion phase and the intake initiation phase are set at -15° and +15° respectively, and in a section in which the phase is -16° to +16°, the clearance between the inner peripheral face 93 of the rotor chamber 14 and the outer peripheral face 94 of the rotor 41 is set so as to be constant.
- both the amount of projection of the vane 48 on the retarded side in the rotational direction R and the amount of projection of the vane 48 on the advanced side in the rotational direction R are equal to the clearance, and it is thus possible to prevent a torque from being generated in the opposite direction to the rotational direction R of the rotor 41, thereby preventing the occurrence of backward rotation of the rotor 41 and variation in torque.
- the volume of the vane chamber 75 which has a constant clearance, does not change, and there is therefore no possibility of the water hammer phenomenon occurring even if water is trapped in the vane chamber 75, thereby reliably preventing vibration, noise, degradation of durability, etc.
- the intake initiation phase of the present embodiment is +15°, which is retarded relative to the intake initiation phase of +4° of the conventional example, the present embodiment is disadvantageous from the viewpoint of ensuring a large expansion ratio.
- the present embodiment therefore employs for the inner peripheral face 93 of the rotor chamber 14 a shape that makes the intake volume of steam at the beginning of the intake stroke small (that is, the shape of the annular channel 74), thus ensuring that the expansion ratio is the same as that of the conventional example.
- FIG. 16 shows a state in which a seal 72 (f) on the advanced side in the rotational direction R of the rotor 41 (hereinafter, simply called the advanced side) has reached the intake ports 90, and a seal 72 (r) on the retarded side in the rotational direction R of the rotor 41 (hereinafter, simply called the retarded side) has passed the exhaust ports 91.
- FIG. 17 shows a state in which the rotor 41 has rotated further from the state of FIG. 16, and the seal 72 (r) on the retarded side has reached a position substantially midway between the intake ports 90 and the exhaust ports 91
- FIG. 18 shows a state in which the rotor 41 has rotated further from the state of FIG. 17, and the seal 72 (r) on the retarded side has reached a position immediately prior to the intake ports 90.
- the labyrinths 43g present in the -16° to +16° section exhibit sealing characteristics due to the labyrinth effect, and it is therefore possible to prevent effectively steam from leaking through the seal 72 (r) on the retarded side.
- FIG. 19 to FIG. 21 A second embodiment of the present invention is now explained with reference to FIG. 19 to FIG. 21.
- the phases of vanes 48 in FIG. 19 to FIG. 21 correspond to the phases of the vanes 48 in FIG. 16 to FIG. 19 respectively.
- the labyrinths 43g are provided on the entire circumference of the rotor 41, but in the second embodiment labyrinths 43g are provided on only about a quarter of each of rotor segments 43 on the retarded side, and the labyrinths 43g are therefore provided at a position adjacent to the advanced side of a seal 72 of the vane 48.
- the high pressure of intake ports 90 is therefore reduced in pressure by the labyrinth effect of the labyrinths 43g adjacent to the advanced side of the seal 72, and the difference in pressure between the two sides of the seal 72 can be moderated, thus preventing effectively the leakage of steam.
- the number of labyrinths 43g can be reduced while maintaining the steam leakage preventing effect, thereby contributing to a reduction in the machining cost.
- the forward movement of the pistons 47 can be directly transmitted to rollers 71 without involving vanes 48, and can be converted into rotational movement by engagement with annular channels 74.
- the vanes 48 are always spaced from the inner peripheral face of a rotor chamber 14 by a substantially constant gap as a result of cooperation between the rollers 71 and the annular channels 74 as described above, the pistons 47 and the rollers 71, and also the vanes 48 and the rollers 71, can independently work together with the annular channels 74.
- the expander 4 When the expander 4 is used as a compressor, the rotor 41 is rotated by the rotating shaft 21 in a direction opposite to the arrow R in FIG. 4, outside air is drawn in by the vanes 48 from the exhaust ports 91 into the rotor chamber 14 and compressed, and the low pressure compressed air thus obtained is drawn in from the intake ports 90 into the cylinders 44 via the transit chamber 19, the through holes 81b, the fifth steam passages S5, the fourth steam passages S4, the notches 85a of the fixed shaft 85 and the third steam passages S3, and compressed there by the pistons 47 to give high pressure compressed air.
- the high pressure compressed air thus obtained is discharged from the cylinders 44 via the third steam passages S3, the second steam passages S2, the first steam passage S1, and the steam supply pipe 88.
- the steam passages S1 to S5 and the steam supply pipe 88 are read instead as air passages S1 to S5 and air supply pipe 88.
- the expander 4 is illustrated as the rotary fluid machine, but the present invention can also be applied to a compressor.
- steam and water are used as the gas-phase working medium and the liquid-phase working medium, but other appropriate working media can also be employed.
- the labyrinths 43g are provided on the rotor 41 side, but the same operational effect can be achieved by providing labyrinths on the rotor chamber 14 side.
- the labyrinths 43g of the embodiments are U-shaped channels extending within a plane containing the axis L, but they may be divided into a plurality of small cells by means of partitions extending in the circumferential direction.
- the present invention can desirably be applied to an expander employing steam (water) as a working medium, but can also be applied to an expander employing any other working medium and a compressor employing any working medium.
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- General Engineering & Computer Science (AREA)
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Abstract
Description
- The present invention relates to a rotary fluid machine for interconverting the pressure energy of a gas-phase working medium and the rotational energy of a rotor.
- A rotary fluid machine disclosed in Japanese Patent Application Laid-open No. 2000-320543 is equipped with a vane piston unit in which a vane and a piston are combined; the piston, which is slidably fitted in a cylinder provided radially in a rotor, interconverts the pressure energy of a gas-phase working medium and the rotational energy of the rotor via a power conversion device comprising an annular channel and a roller, and the vane, which is radially and slidably supported in the rotor, interconverts the pressure energy of the gas-phase working medium and the rotational energy of the rotor.
- Such a rotary fluid machine comprises an elliptical rotor chamber formed in a casing and a circular rotor rotatably housed within the rotor chamber, and by setting the diameter of the rotor substantially equal to the minor axis of the rotor chamber, the clearance between the rotor and the rotor chamber becomes a minimum at positions at opposite ends of the minor axis. An intake port and an exhaust port are provided on either side, circumferentially, of these minimum clearance positions, and leakage of a gas-phase working medium from a high pressure vane chamber, with which the intake port communicates, into a low pressure vane chamber, with which the exhaust port communicates, is prevented by making a seal at the extremity of the vane abut against the inner peripheral face of the rotor chamber. However, it is difficult to completely prevent the leakage of the gas-phase working medium using only the seal at the extremity of the vane, and there is the problem that the gas-phase working medium leaks between vane chambers having different pressures, thus degrading the performance of the rotary fluid machine.
- The present invention has been achieved under the above-mentioned circumstances, and an object thereof is to prevent leakage of a gas-phase working medium from an intake port to an exhaust port via a clearance between a rotor and a rotor chamber of a rotary fluid machine.
- In order to attain the above object, in accordance with a first aspect of the present invention, there is proposed a rotary fluid machine that includes a rotor chamber formed in a casing, a rotor rotatably housed within the rotor chamber, a plurality of vane channels formed radially in the rotor, a plurality of vanes slidably supported in the respective vane channels, vane chambers defined by the rotor, the casing, and the vanes, and an intake port and an exhaust port for supplying and discharging a gas-phase working medium to and from the vane chambers, characterized in that gas-phase working medium leakage preventing means is provided on at least one of the outer peripheral face of the rotor and the inner peripheral face of the rotor chamber in a region in which there is a large difference in pressure between adjacent vane chambers that are in between the trailing edge of the exhaust port and the leading edge of the intake port.
- In accordance with this arrangement, since the gas-phase working medium leakage preventing means is provided on at least one of the outer peripheral face of the rotor and the inner peripheral face of the rotor chamber in a region in which there is a large difference in pressure between adjacent vane chambers that are in between the trailing edge of the exhaust port and the leading edge of the intake port, it is possible to prevent the gas-phase working medium from leaking from the intake port, which is at high pressure, to the exhaust port, which is at low pressure, thereby improving the performance of the rotary fluid machine.
- Furthermore, in accordance with a second aspect of the present invention, in addition to the first aspect, there is proposed a rotary fluid machine wherein the leakage preventing means is a labyrinth.
- In accordance with this arrangement, since the leakage preventing means is formed from a labyrinth, a problem such as seal wear, which occurs when the leakage preventing means is formed from a seal, can be avoided.
-
Labyrinths 43g of embodiments correspond to the leakage preventing means of the present invention, and steam and water of the embodiments correspond to the gas-phase working medium and the liquid-phase working medium respectively of the present invention. - FIG. 1 to FIG. 18 illustrate a first embodiment of the present invention; FIG. 1 is a schematic view of a waste heat recovery system of an internal combustion engine; FIG. 2 is a longitudinal sectional view of an expander, corresponding a sectional view along line 2-2 of FIG. 4; FIG. 3 is an enlarged sectional view around the axis of FIG. 2; FIG. 4 is a sectional view along line 4-4 of FIG. 2; FIG. 5 is a sectional view along line 5-5 of FIG. 2; FIG. 6 is a sectional view along line 6-6 of FIG. 2; FIG. 7 is a sectional view along line 7-7 of FIG. 5; FIG. 8 is a sectional view along line 8-8 of FIG. 5; FIG. 9 is a sectional view along line 9-9 of FIG. 8; FIG. 10 is a sectional view along line 10-10 of FIG. 3; FIG. 11 is an exploded perspective view of a rotor; FIG. 12 is an exploded perspective view of a lubricating water distribution section of the rotor; FIG. 13 is a schematic view showing cross-sectional shapes of a rotor chamber and the rotor; FIG. 14A is a view showing the shape of an annular channel of a casing (embodiment); FIG. 14B is a view showing the shape of an annular channel of a casing (conventional example); FIG. 15A is a view showing the shape of the inner peripheral face of a rotor chamber and the intake and exhaust timing (embodiment); FIG. 15B is a view showing the shape of the inner peripheral face of a rotor chamber and the intake and exhaust timing (conventional example); and FIG. 16 to FIG. 18 are views for explaining the operation of labyrinths. FIG. 19 to FIG. 21 are views for explaining the operation of labyrinths of a second embodiment of the present invention.
- A first embodiment of the present invention is explained below with reference to FIG. 1 to FIG. 18.
- In FIG. 1, a waste
heat recovery system 2 for aninternal combustion engine 1 includes anevaporator 3 that generates high temperature, high pressure steam by vaporizing a high pressure liquid (e.g. water) using as a heat source the waste heat (e.g. exhaust gas) of theinternal combustion engine 1, anexpander 4 that generates an output by expansion of the steam, acondenser 5 that liquefies steam having decreased temperature and pressure as a result of conversion of pressure energy into mechanical energy in theexpander 4, and asupply pump 6 that pressurizes the liquid (e.g. water) from thecondenser 5 and resupplies it to theevaporator 3. - As shown in FIG. 2 and FIG. 3, a
casing 11 of theexpander 4 is formed from first andsecond casing halves second casing halves main body portions rotor chamber 14, andcircular flanges main body portions circular flanges metal gasket 15. The outer face of thefirst casing half 12 is covered with a transit chamberouter wall 16 having a deep bowl shape, and acircular flange 16a, which is joined integrally to the outer periphery of the transit chamberouter wall 16, is superimposed on the left face of thecircular flange 12b of thefirst casing half 12. The outer face of thesecond casing half 13 is covered with an exhaust chamberouter wall 17 for housing a magnet coupling (not illustrated) for transmitting the output of theexpander 4 to the outside, and acircular flange 17a, which is joined integrally to the outer periphery of the exhaust chamberouter wall 17, is superimposed on the right face of thecircular flange 13b of thesecond casing half 13. The above-mentioned fourcircular flanges bolts 18 disposed in the circumferential direction. Atransit chamber 19 is defined between the transit chamberouter wall 16 and thefirst casing half 12, and anexhaust chamber 20 is defined between the exhaust chamberouter wall 17 and thesecond casing half 13. The exhaust chamberouter wall 17 is provided with an outlet (not illustrated) for guiding the decreased temperature, decreased pressure steam that has finished work in theexpander 4 to thecondenser 5. - The
main body portions casing halves tubes shaft 21 having ahollow portion 21 a is rotatably supported by thesehollow bearing tubes members rotating shaft 21 thus passes through the intersection of the major axis and the minor axis of therotor chamber 14, which has a substantially elliptical shape. - A
seal block 25 is housed within a lubricatingwater supply member 24 screwed onto the right-hand end of thesecond casing half 13, and secured by anut 26. Asmall diameter portion 21b at the right-hand end of the rotatingshaft 21 is supported within theseal block 25, a pair ofseals 27 are disposed between theseal block 25 and thesmall diameter portion 21b, a pair ofseals 28 are disposed between theseal block 25 and the lubricatingwater supply member 24, and aseal 29 is disposed between the lubricatingwater supply member 24 and thesecond casing half 13. Afilter 30 is fitted in a recess formed in the outer periphery of thehollow bearing tube 13c of thesecond casing half 13, and is prevented from falling out by means of afilter cap 31 screwed into thesecond casing half 13. A pair ofseals 32 and 33 are provided between thefilter cap 31 and thesecond casing half 13. - As is clear from FIG. 4, FIG. 13, FIG. 14A, and FIG. 14B, a
circular rotor 41 is rotatably housed within therotor chamber 14, which has a pseudo-elliptical shape. Therotor 41 is fitted onto and joined integrally to the outer periphery of therotating shaft 21, and the axis of therotor 41 and the axis of therotor chamber 14 coincide with the axis L of therotating shaft 21. The shape of therotor chamber 14 viewed in the axis L direction is pseudo-elliptical, and is similar to a rhombus with its four apexes rounded, the shape having a major axis DL and a minor axis DS. The shape of therotor 41 viewed in the axis L direction is a perfect circle having a diameter DR that is slightly smaller than the minor axis DS of therotor chamber 14. - The cross-sectional shapes of the
rotor chamber 14 and therotor 41 viewed in a direction orthogonal to the axis L are all racetrack-shaped. That is, the cross-sectional shape of therotor chamber 14 is formed from a pair offlat faces 14a extending parallel to each other at a distance d, and arc-shaped faces 14b having a central angle of 180° that are smoothly connected to the outer peripheries of theflat faces 14a and, similarly, the cross-sectional shape of therotor 41 is formed from a pair offlat faces 41a extending parallel to each other at the distance d, and arc-shaped faces 41b having a central angle of 180° that are smoothly connected to the outer peripheries of theflat faces 41a. Theflat faces 14a of therotor chamber 14 and theflat faces 41a of therotor 41 are in contact with each other, and a pair of crescent-shaped spaces are formed between the inner peripheral face of therotor chamber 14 and the outer peripheral face of the rotor 41 (see FIG. 4). - The structure of the
rotor 41 is now explained in detail with reference to FIG. 3 to FIG. 6, and FIG. 11. - The
rotor 41 is formed from arotor core 42 that is formed integrally with the outer periphery of therotating shaft 21, and twelverotor segments 43 that are fixed so as to cover the periphery of therotor core 42 and form the outer shell of therotor 41. Twelve ceramic (or carbon)cylinders 44 are mounted radially in therotor core 42 at 30° intervals and fastened by means ofclips 45 to prevent them falling out. Asmall diameter portion 44a is projectingly provided at the inner end of each of thecylinders 44, and a gap between the base end of thesmall diameter portion 44a and asleeve 84 is sealed via aC seal 46. The extremity of thesmall diameter portion 44a is fitted into the outer peripheral face of thesleeve 84, which is hollow, and acylinder bore 44b communicates with first and second steam passages S1 and S2 within the rotatingshaft 21 via twelve third steam passages S3 running through thesmall diameter portion 44a and the rotatingshaft 21. Aceramic piston 47 is slidably fitted within each of thecylinders 44. When thepiston 47 moves to the radially innermost position, it retracts completely within the cylinder bore 44b, and when it moves to the radially outermost position, about half of the whole length projects outside the cylinder bore 44b. - Each of the
rotor segments 43 is a hollow wedge-shaped member having a central angle of 30°, and has tworecesses flat faces 14a of therotor chamber 14, therecesses water outlets recesses water outlets rotor segments 43, that is, the faces that areopposite vanes 48, which will be described later. A large number oflabyrinths 43g are recessed in the arc-shaped face of each of therotor segments 43 forming the arc-shaped face 41b of therotor 41 so as to extend within a plane containing the axis L. Thelabyrinths 43g are channels having a U-shaped cross section and, for example, sixteen of thelabyrinths 43g are provided on each of therotor segments 43. - The
rotor 41 is assembled as follows. The twelverotor segments 43 are fitted around the outer periphery of therotor core 42, which is preassembled with thecylinders 44, theclips 45, and theC seals 46, and thevanes 48 are fitted in twelvevane channels 49 formed betweenadjacent rotor segments 43. At this point, in order to form a predetermined clearance between thevanes 48 and therotor segments 43, shims having a predetermined thickness are disposed on opposite faces of thevanes 48. In this state, therotor segments 43 and thevanes 48 are tightened inward in the radial direction toward therotor core 42 by means of a jig so as to precisely position therotor segments 43 relative to therotor core 42, and each of therotor segments 43 is then provisionally retained on therotor core 42 by means of provisional retention bolts 50 (see FIG. 8). Subsequently each of therotor segments 43 and therotor core 42 are co-machined so as to make twoknock pin holes 51 run therethrough, and fourknock pins 52 are press-fitted in the twoknock pin holes 51 so as to join each of therotor segments 43 to therotor core 42. - As is clear from FIG. 8, FIG. 9, and FIG. 12, a through
hole 53 running through therotor segment 43 and therotor core 42 is formed between the twoknock pin holes 51, andrecesses 54 are formed at opposite ends of thethrough hole 53. Twopipe members 55 and 56 are fitted within the throughhole 53 viaseals 57 to 60, and an orifice-formingplate 61 and a lubricatingwater distribution member 62 are fitted into each of therecesses 54 and secured by anut 63. The orifice-formingplate 61 and the lubricatingwater distribution member 62 are prevented from rotating relative to therotor segments 43 by twoknock pins 64 running throughknock pin holes 61a of the orifice-formingplate 61 and fitted intoknock pin holes 62a of the lubricatingwater distribution member 62, and a gap between the lubricatingwater distribution member 62 and thenut 63 is sealed by anO ring 65. - A
small diameter portion 55a formed in an outer end portion of one of thepipe members 55 communicates with a sixth water passage W6 within thepipe member 55 via athrough hole 55b, and thesmall diameter portion 55a also communicates with aradial distribution channel 62b formed on one side face of the lubricatingwater distribution member 62. Thedistribution channel 62b of the lubricatingwater distribution member 62 extends in six directions, and the extremities thereof communicate with sixorifices plate 61. The structures of the orifice-formingplate 61, the lubricatingwater distribution member 62, and thenut 63 provided at the outer end portion of the other pipe member 56 are identical to the structures of the above-mentioned orifice-formingplate 61, lubricatingwater distribution member 62, andnut 63. - Downstream sides of the two
orifices 61b of the orifice-formingplate 61 communicate with the two lubricatingwater outlets 43e, which open so as to be opposite thevane 48, via seventh water passages W7 formed within therotor segments 43; downstream sides of the twoorifices 61c communicate with the two lubricatingwater outlets 43f, which open so as to be opposite thevane 48, via eighth water passages W8 formed within therotor segment 43; and downstream sides of the twoorifices 61d communicate with the two lubricatingwater outlets rotor chamber 14, via ninth water passages W9 formed within therotor segment 43. - As is clear from reference in addition to FIG. 5, an
annular channel 67 is defined by a pair of O rings 66 on the outer periphery of thecylinder 44, and the sixth water passage W6 formed within said one of thepipe members 55 communicates with theannular channel 67 via four throughholes 55c running through thepipe member 55 and a tenth water passage W10 formed within therotor core 42. Theannular channel 67 communicates with sliding surfaces of thecylinder bore 44b and thepiston 47 via anorifice 44c. The position of theorifice 44c of thecylinder 44 is set so that it stays within the sliding surface of thepiston 47 when thepiston 47 moves between top dead center and bottom dead center. - As is clear from FIG. 3 and FIG. 9, the first water passage W1 formed in the lubricating
water supply member 24 communicates with thesmall diameter portion 55a of said one of thepipe members 55 via a second water passage W2 formed in theseal block 25, third water passages W3 formed in thesmall diameter portion 21b of therotating shaft 21, anannular channel 68a formed in the outer periphery of a waterpassage forming member 68 fitted in the center of therotating shaft 21, a fourth water passage W4 formed in therotating shaft 21, apipe member 69 bridging therotor core 42 and therotor segments 43, and fifth water passages W5 formed so as to bypass theknock pin 52 on the radially inner side of therotor segment 43. - As shown in FIG. 7, FIG. 9, and FIG. 11, twelve
vane channels 49 are formed betweenadjacent rotor segments 43 of therotor 41 so as to extend in the radial direction, and the plate-shapedvanes 48 are slidably fitted in therespective vane channels 49. Each of thevanes 48 has a substantially U-shaped form comprisingparallel faces 48a following the parallel faces 14a of therotor chamber 14, an arc-shapedface 48b following the arc-shapedface 14b of therotor chamber 14, and anotch 48c positioned between theparallel faces 48a.Rollers 71 having a roller bearing structure are rotatably supported on a pair ofsupport shafts 48d projecting from theparallel faces 48a. - A U-shaped
synthetic resin seal 72 is retained in the arc-shapedface 48b of thevane 48, and the extremity of theseal 72 projects slightly from the arc-shapedface 48b of thevane 48 and comes into sliding contact with the arc-shapedface 14b of therotor chamber 14. Tworecesses 48e are formed on each side of thevane 48, and theserecesses 48e are opposite the two radially innerlubricating water outlets 43e that open on the end faces of therotor segment 43. Apiston receiving member 73, which is provided so as to project radially inward in the middle of thenotch 48c of thevane 48, abuts against the radially outer end of thepiston 47. - As is clear from FIG. 4, two pseudo-elliptical
annular channels 74 having a similar shape to that of a rhombus with its four apexes rounded are provided in theflat faces 14a of therotor chamber 14 defined by the first and second casing halves 12 and 13, and the pair ofrollers 71 of each of thevanes 48 are rollably engaged with theseannular channels 74. The distance between theseannular channels 74 and the arc-shapedface 14b of therotor chamber 14 is constant throughout the whole circumference. Therefore, when therotor 41 rotates, thevane 48 having therollers 71 guided by theannular channels 74 reciprocates radially within thevane channel 49, and theseal 72 mounted on the arc-shapedface 48b of thevane 48 slides along the arc-shapedface 14b of therotor chamber 14 with a constant amount of compression. This enables direct physical contact between therotor chamber 14 and thevanes 48 to be prevented andvane chambers 75 defined betweenadjacent vanes 48 to be reliably sealed while preventing any increase in the sliding resistance or the occurrence of wear. - As is clear from FIG. 2, a pair of
circular seal channels 76 are formed in theflat faces 14a of therotor chamber 14 so as to surround the outside of theannular channels 74. A pair of ring seals 79 equipped with two O rings 77 and 78 are slidably fitted in thecircular seal channels 76, and the seal surfaces are opposite therecesses rotor segments 43. The pair of ring seals 79 are prevented from rotating relative to the first and second casing halves 12 and 13 by knock pins 80. - As is clear from FIG. 2, FIG. 3, and FIG. 10, an
opening 16b is formed at the center of the transit chamberouter wall 16; aboss portion 81a of a fixedshaft support member 81 disposed on the axis L is secured to the inner face of theopening 16b by a plurality ofbolts 82, and secured to thefirst casing half 12 by means of anut 83. A cylinder-shapedceramic sleeve 84 is fixed to thehollow portion 21a of therotating shaft 21. The outer peripheral face of the fixedshaft 85, which is integral with the fixedshaft support member 81, is relatively rotatably fitted within the inner peripheral face of thissleeve 84. A gap between the left-hand end of the fixedshaft 85 and thefirst casing half 12 is sealed by aseal 86, and a gap between the right-hand end of the fixedshaft 85 and therotating shaft 21 is sealed by aseal 87. - A
steam supply pipe 88 is fitted into the fixedshaft support member 81, which is disposed on the axis L, and is secured by anut 89, and the right-hand end of thesteam supply pipe 88 is press-fitted into the center of the fixedshaft 85. The first steam passage S1, which communicates with thesteam supply pipe 88, is formed in the center of the fixedshaft 85 in the axial direction, and the pair of second steam passages S2 run radially through the fixedshaft 85 with a phase difference of 180°. As described above, the twelve third steam passages S3 run through thesleeve 84 and thesmall diameter portions 44a of the twelvecylinders 44 retained at intervals of 30° in therotor 41 fixed to therotating shaft 21, and radially inner end portions of these third steam passages S3 are opposite the radially outer end portions of the second steam passages S2 so as to be able to communicate therewith. - A pair of
notches 85a are formed on the outer peripheral face of the fixedshaft 85 with a phase difference of 180°, and thesenotches 85a can communicate with the third steam passages S3. Thenotches 85a and thetransit chamber 19 communicate with each other via a pair of fourth steam passages S4 formed axially in the fixedshaft 85, a fifth annular steam passage S5 formed axially in the fixedshaft support member 81, and throughholes 81b opening on the outer periphery of theboss portion 81a of the fixedshaft support member 81. - As shown in FIG. 2 and FIG. 4, a plurality of radially aligned
intake ports 90 are formed in thefirst casing half 12 and thesecond casing half 13 at positions that are advanced by 15° in the direction of rotation R of therotor 41 relative to the minor axis of therotor chamber 14. The interior space of therotor chamber 14 communicates with thetransit chamber 19 by means of theseintake ports 90. Furthermore, a plurality ofexhaust ports 91 are formed in thesecond casing half 13 at positions that are retarded by 15° to 75° in the direction of rotation R of therotor 41 relative to the minor axis of therotor chamber 14. The interior space of therotor chamber 14 communicates with theexhaust chamber 20 by means of theseexhaust ports 91. Theseexhaust ports 91 open inshallow depressions 13d formed within thesecond casing half 13 so that theseals 72 of thevanes 48 are not damaged by the edges of theexhaust ports 91. - The second steam passages S2 and the third steam passages S3, and the
notches 85a of the fixedshaft 85 and the third steam passages S3, form a rotary valve V, which provides periodic communication therebetween by rotation of therotating shaft 21 relative to the fixed shaft 85 (see FIG. 10). - As is clear from FIG. 2,
pressure chambers 92 are formed at the rear face of the ring seals 79 fitted in thecircular seal channels 76 of the first and second casing halves 12 and 13. An eleventh water passage W11 formed in the first and second casing halves 12 and 13 communicates with the twopressure chambers 92 via a twelfth water passage W12 and a thirteenth water passage W13, which are formed from pipes, and the ring seals 79 are urged toward the side face of therotor 41 by virtue of water pressure applied to the twopressure chambers 92. - The eleventh water passage W11 communicates with the outer peripheral face of the
annular filter 30 via a fourteenth water passage W14, which is a pipe, and the inner peripheral face of thefilter 30 communicates with a sixteenth water passage W16 formed in thesecond casing half 13 via a fifteenth water passage W15 formed in thesecond casing half 13. Water supplied to the sixteenth water passage W16 lubricates sliding surfaces of the fixedshaft 85 and thesleeve 84. Water supplied to the outer periphery of the bearingmember 23 from the inner peripheral face of thefilter 30 via a seventeenth water passage W17 lubricates the outer peripheral face of therotating shaft 21 through an orifice penetrating the bearingmembers 23. On the other hand, water supplied to the outer periphery of the bearingmembers 22 from the eleventh water passage W11 via an eighteenth water passage W18, which is a pipe, lubricates the outer peripheral face of therotating shaft 21 through an orifice penetrating the bearingmember 22, and then lubricates the sliding surfaces between the fixedshaft 85 and thesleeve 84. - Operation of the present embodiment having the above-mentioned arrangement is now explained.
- Operation of the
expander 4 is first explained. In FIG. 3, high temperature, high pressure steam from theevaporator 3 is supplied to thesteam supply pipe 88, the first steam passage S1 passing through the center of the fixedshaft 85, and the pair of second steam passages S2 passing radially through the fixedshaft 85. In FIG. 10, when thesleeve 84 that rotates integrally with therotor 41 and therotating shaft 21 in the direction shown by the arrow R reaches a predetermined phase relative to the fixedshaft 85, the pair of third steam passages S3 that are present on the advanced side in the direction of rotation R of therotor 41 relative to the position of the minor axis of therotor chamber 14 are made to communicate with the pair of second steam passages S2, and the high temperature, high pressure steam of the second steam passages S2 is supplied to the interiors of a pair of thecylinders 44 via the third steam passages S3 and pushes thepistons 47 radially outward. In FIG. 4, when thevanes 48 pushed by thepistons 47 move radially outward, since the pair ofrollers 71 provided on thevanes 48 are engaged with theannular channels 74, the forward movement of thepistons 47 is converted into rotational movement of therotor 41. - Even after the communication between the second steam passages S2 and the third steam passages S3 is blocked as a result of the rotation of the
rotor 41, the high temperature, high pressure steam within thecylinders 44 continues to expand, thus making thepistons 47 move further forward and thereby enabling therotor 41 to continue to rotate. When thevanes 48 reach the position of the major axis of therotor chamber 14, the third steam passages S3 communicating with the correspondingcylinders 44 also communicate with thenotches 85a of the fixedshaft 85, thepistons 47 are pushed by thevanes 48 whoserollers 71 are guided by theannular channels 74 and move radially inward, and the steam within thecylinders 44 accordingly passes through the third steam passages S3, thenotches 85a, the fourth passages S4, the fifth passage S5, and the throughholes 81b, and is supplied to thetransit chamber 19 as a first decreased temperature, decreased pressure steam. The first decreased temperature, decreased pressure steam is the high temperature, high pressure steam that has been supplied from thesteam supply pipe 88, has finished the work of driving thepistons 47 and, as a result, has a decreased temperature and pressure. The thermal energy and the pressure energy of the first decreased temperature, decreased pressure steam are lower than those of the high temperature, high pressure steam, but are still sufficient for driving thevanes 48. - The first decreased temperature, decreased pressure steam within the
transit chamber 19 is supplied to thevane chambers 75 within therotor chamber 14 via theintake ports 90 of the first and second casing halves 12 and 13, and further expands therein to push thevanes 48, thus rotating therotor 41. A second decreased temperature, decreased pressure steam that has finished work and accordingly has a further decreased temperature and pressure is discharged from theexhaust ports 91 of thesecond casing half 13 into theexhaust chamber 20, and is supplied therefrom to thecondenser 5. - In this way, the expansion of the high temperature, high pressure steam enables the twelve
pistons 47 to operate in turn to rotate therotor 41 via therollers 71 and theannular channels 74, and the expansion of the first decreased temperature, decreased pressure steam, which is the high temperature, high pressure steam whose temperature and pressure have decreased, enables therotor 41 to rotate via thevanes 48, thereby providing an output from the rotatingshaft 21. - Lubrication of the
vanes 48 and thepistons 47 of theexpander 4 with water is now explained. - Supply of lubricating water is carried out by utilizing the supply pump 6 (see FIG. 1) for supplying under pressure water from the
condenser 5 to theevaporator 3, and a portion of the water discharged from thesupply pump 6 is supplied to the first water passage W1 of thecasing 11 for lubrication. Utilizing thefeed pump 6 in this way for supplying water for hydrostatic bearings of each section of theexpander 4 eliminates the need for a special pump and enables the number of components to be reduced. - In FIG. 3 and FIG. 8, the water that has been supplied to the first water passage W1 of the lubricating
water supply member 24 flows into thesmall diameter portion 55a of one of thepipe members 55 via the second water passages W2 of theseal block 25, the third water passages W3 of therotating shaft 21, theannular channel 68a of the waterpassage forming member 68, the fourth water passage W4 of therotating shaft 21, and the fifth water passages W5 formed in thepipe member 69 and therotor segment 43, and the water that has flowed into thesmall diameter portion 55a flows into thesmall diameter portion 56a of the other pipe member 56 via the throughhole 55b of said one of thepipe members 55, the sixth water passage W6 formed in thepipe members 55 and 56, and the throughhole 56b formed in the other pipe member 56. - A portion of the water that has passed through the six
orifices plate 61 from thesmall diameter portions pipe members 55 and 56 via thedistribution channel 62b of the lubricatingwater distribution member 62 issues from the fourlubricating water outlets rotor segment 43, and another portion of the water issues from the lubricatingwater outlets recesses rotor segment 43. - In this way, the water issuing from the lubricating
water outlets rotor segments 43 into thevane channel 49 supports thevane 48 in a floating state by forming a hydrostatic bearing between thevane channel 49 and thevane 48, which is slidably fitted in thevane channel 49, thus preventing physical contact between the end face of therotor segment 43 and thevane 48 and thereby preventing the occurrence of seizing and wear. Supplying the water for lubricating the sliding surfaces of thevane 48 via the water passages provided in a radial shape within therotor 41 in this way not only enables the water to be pressurized by virtue of centrifugal force but also enables the temperature of the periphery of therotor 41 to be stabilized, thus lessening the effect of thermal expansion and thereby minimizing the leakage of steam by maintaining a preset clearance. - Since water is retained in the
recesses 48e, two of which are formed on each of the opposite faces of thevane 48, theserecesses 48e function as pressure reservoirs, thereby suppressing any decrease in pressure due to leakage of water. As a result thevane 48, which is held between the end faces of the pair ofrotor segments 43, is in a floating state due to the water, and the sliding resistance can thereby be reduced effectively. Furthermore, when thevane 48 reciprocates, the radial position of thevane 48 relative to therotor 41 changes, and since therecesses 48e are provided not on therotor segment 43 side but on thevane 48 side and in the vicinity of therollers 71, where the largest load is imposed on thevane 48, the reciprocatingvane 48 can always be kept in a floating state, and the sliding resistance can thereby be reduced effectively. - Water that has lubricated the surface of the
vane 48 that slides against therotor segment 43 moves radially outward by virtue of centrifugal force, and lubricates the sliding sections of the arc-shapedface 14b of therotor chamber 14 and theseal 72 provided on the arc-shapedface 48b of thevane 48. Water that has completed the lubrication is discharged from therotor chamber 14 via theexhaust ports 91. - In FIG. 2, by supplying water into the
pressure chambers 92 at the bottom portions of thecircular seal channels 76 of thefirst casing half 12 and thesecond casing half 13 so as to urge the ring seals 79 toward the side faces of therotor 41, and making the water issue from the lubricatingwater outlets recesses rotor segments 43 so as to form a hydrostatic bearing on the sliding surfaces with theflat faces 14a of therotor chamber 14, theflat faces 41a of therotor 41 can be sealed by the ring seals 79 that are in a floating state within thecircular seal channels 76 and, as a result, the steam within therotor chamber 14 can be prevented from leaking through a gap with therotor 41. In this process, the ring seals 79 and therotor 41 are isolated from each other by a film of water supplied from the lubricatingwater outlets rotor 41 tilts, tilting of the ring seals 79 within thecircular seal channels 76 so as to track the tilting of therotor 41 enables stable sealing characteristics to be maintained while minimizing the frictional force. - The water that has lubricated the sliding section between the ring seals 79 and the
rotor 41 is supplied to therotor chamber 14 by virtue of centrifugal force, and discharged therefrom to the exterior of thecasing 11 via theexhaust ports 91. - Furthermore, in FIG. 5, water that has been supplied from the sixth water passage W6 within the
pipe member 55 to the sliding surfaces between thecylinder 44 and thepiston 47 via the tenth water passage W10 within therotor segments 43 and theannular channel 67 of the outer periphery of thecylinder 44 exhibits a sealing function by virtue of the viscous properties of the film of water formed on the sliding surfaces, thereby preventing effectively the high temperature, high pressure steam supplied to thecylinder 44 from leaking past the sliding surfaces with thepiston 47. Since the water that is supplied to the sliding surfaces between thecylinder 44 and thepiston 47 through the interior of theexpander 4, which is in a high temperature state, is heated, it is possible to minimize any decrease in output of theexpander 4 that might be caused by this water cooling the high temperature, high pressure steam supplied to thecylinder 44. - Furthermore, the first water passage W1 and the eleventh water passage W11 are independent from each other, and water is supplied at a pressure that is required for each of the lubrication sections. More specifically, the water that is supplied from the first water passage W1 is mainly for floatingly supporting the
vanes 48 and therotor 41 by means of a hydrostatic bearing as described above, and it is required to have a high pressure that can counterbalance variations in the load. In contrast, the water that is supplied from the eleventh water passage W11 mainly lubricates the surroundings of the fixedshaft 85, and since it is for sealing the high temperature, high pressure steam that leaks from the third steam passages S3 past the outer periphery of the fixedshaft 85 so as to reduce the influence of thermal expansion of the fixedshaft 85, the rotatingshaft 21, therotor 41, etc., it is only required to have a pressure that is at least higher than the pressure of thetransit chamber 19. - Since there are provided in this way two water supply lines, that is, the first water passage W1 for supplying high pressure water and the eleventh water passage W11 for supplying lower pressure water, problems caused when only one water supply line for supplying high pressure water is provided can be eliminated. That is, the problem of water having excess pressure being supplied to the surroundings of the fixed
shaft 85, thus increasing the amount of water flowing into thetransit chamber 19, and the problem of the fixedshaft 85, the rotatingshaft 21, therotor 41, etc. being overcooled, thus decreasing the temperature of the steam, can be prevented, and as a result the output of theexpander 4 can be increased while reducing the amount of water supplied. - Moreover, since water, which is the same substance as steam, is used as a medium for sealing, there will be no problem even if the steam is contaminated with water. If the sliding surfaces of the
cylinder 44 and thepiston 47 were sealed by an oil, since it would be impossible to prevent the oil from contaminating the water or the steam, a special filter device for separating the oil would be required. Furthermore, since a portion of the water for lubricating the sliding surfaces of thevane 48 and thevane channels 49 is separated for sealing the sliding surfaces of thecylinder 44 and thepiston 47, it is unnecessary to specially provide an extra water passage for guiding the water to the sliding surfaces, thus simplifying the structure. - FIG. 14A shows the shape of the
annular channel 74 of the present embodiment, and FIG. 14B shows the shape of anannular channel 74 of a conventional example. Whereas theannular channel 74 of the conventional example is elliptical, the shape of theannular channel 74 of the present invention is a rhombus having its four apexes rounded. As a result, in the conventional example, the clearance between an innerperipheral face 93 of therotor chamber 14 and an outerperipheral face 94 of therotor 41 becomes a minimum at a point P1 where the phase is 0° and a point P2 where the phase is 180°, and the clearance gradually increases before and after the minimum. On the other hand, in the present embodiment, the clearance between the innerperipheral face 93 of therotor chamber 14 and the outerperipheral face 94 of therotor 41 is maintained at a constant minimum value over the range of ±16° with reference to points P1 and P2, and the clearance gradually increases before and after this range. That is, in the above range of ±16° the innerperipheral face 93 of therotor chamber 14 and theannular channel 74 form a partial arc shape with the axis L as the center. - With regard to the rotary valve V, communication between the
notch 85a of the fixedshaft 85 and the third steam passage S3 is blocked at the position of -16° with reference to point P1 having a phase of 0° and point P2 having a phase of 180°, thus ending the discharge of steam, and communication between the second steam passage S2 and the third steam passage S3 is provided at the position of +16° with reference to point P1 having a phase of 0° and point P2 having a phase of 180°, thus starting the supply of steam. Therefore, the interior space of thecylinder 44 is hermetically sealed over the range of ±16° with reference to point P1 and point P2. When thepiston 47 moves in a state in which the interior space of thecylinder 44 is hermetically sealed, there is no problem if steam, which is compressible, is present within thecylinder 44, but if water, which is non-compressible, is present, the phenomenon of water hammer occurs. Although high temperature, high pressure steam is supplied to thecylinder 44, if the high temperature, high pressure steam supplied to thecylinder 44 is cooled and liquefies when theexpander 4 is started from cold, etc., water builds up within thecylinder 44, thus giving rise to a possibility that the water hammer phenomenon might occur. - However, in the present embodiment, in the region in which the interior space of the
cylinder 44 is hermetically sealed, that is, the range of ±16° with reference to point P1 and point P2, since theannular channel 74 forms a partial arc with the axis L as the center, it is possible to stop thepiston 47 from moving relative to thecylinder 44, thereby reliably preventing the occurrence of the water hammer phenomenon. - FIG. 15A shows the intake and exhaust timing of the present embodiment, and FIG. 15B shows the intake and exhaust timing of the conventional example. In both of the above-mentioned cases, twelve
vanes 48 are supported on therotor 41 at equal intervals, and the central angle formed by a pair ofadjacent vanes 48 is therefore 30°. In the conventional example shown in FIG. 15B, the phase of thevane 48 for which communication between theexhaust ports 91 and thevane chamber 75 defined by a pair ofvanes 48 is blocked (exhaust completion phase) is set at -24° with reference to point P1 and point P2, and the phase of thevane 48 for which communication between thevane chamber 75 and theintake ports 90 is provided (intake initiation phase) is set at +4° with reference to point P1 and point P2. Therefore, at the moment when communication between thevane chamber 75 and theexhaust ports 91, which are at low pressure, is blocked, steam is introduced because thevane chamber 75 is already in communication with theintake ports 90, which are at high pressure. In this process, since the exhaust completion phase of -24° and the intake initiation phase of +4° are asymmetric, among the pair ofvanes 48 defining thevane chamber 75, thevane 48 on the retarded side in the rotational direction R projects by a larger amount than thevane 48 on the advanced side in the rotational direction R, and a higher steam pressure is applied to thevane 48 on the retarded side in the rotational direction R, thus generating a torque in the opposite direction to the rotational direction R of therotor 41. As a result, there is a possibility that therotor 41 might rotate backward when starting, or vibration might occur due to torque variation during operation. - In the conventional example shown in FIG. 15B, since the difference in phase between the exhaust completion phase and the intake initiation phase is 28°, which is less than the angle between the vanes of 30°, there is a period during which the
vane chamber 75 communicates simultaneously with theintake ports 90, which are at high pressure, and theexhaust ports 91, which are at low pressure, and during this period a small amount of steam blows through from theintake ports 90 to theexhaust ports 91. In order to avoid this steam blowing through, it is necessary to eliminate the period during which thevane chamber 75 communicates simultaneously with theintake ports 91, which are at high pressure, and theexhaust ports 91, which are at low pressure, and if, for example, the intake initiation phase is increased from +4° to +6°, at the moment when communication between thevane chamber 75 and theexhaust ports 91, which are at low pressure, is blocked and thevane chamber 75 communicates with the highpressure intake ports 90, the volume of thevane chamber 75 temporarily decreases. This is due to the front-to-back asymmetry of the exhaust completion phase and the intake initiation phase. When the volume of the hermetically sealedvane chamber 75 decreases in this way, if lubricating water or water formed by liquefaction of steam is trapped in thevane chamber 75, the water hammer phenomenon might occur, thereby resulting in vibration, noise, degradation of durability, etc. - In contrast, in the present embodiment shown in FIG. 15A, the exhaust completion phase and the intake initiation phase are set at -15° and +15° respectively, and in a section in which the phase is -16° to +16°, the clearance between the inner
peripheral face 93 of therotor chamber 14 and the outerperipheral face 94 of therotor 41 is set so as to be constant. Therefore, when steam is supplied from the highpressure intake ports 90 to thevane chamber 75, among the pair ofvanes 48 defining thevane chamber 75, both the amount of projection of thevane 48 on the retarded side in the rotational direction R and the amount of projection of thevane 48 on the advanced side in the rotational direction R are equal to the clearance, and it is thus possible to prevent a torque from being generated in the opposite direction to the rotational direction R of therotor 41, thereby preventing the occurrence of backward rotation of therotor 41 and variation in torque. Moreover, at the moment at which communication between thevane chamber 75 and the lowpressure exhaust ports 91 is blocked and thevane chamber 75 communicates with the highpressure intake ports 90, the volume of thevane chamber 75, which has a constant clearance, does not change, and there is therefore no possibility of the water hammer phenomenon occurring even if water is trapped in thevane chamber 75, thereby reliably preventing vibration, noise, degradation of durability, etc. - In order to efficiently convert the pressure energy of steam into mechanical energy, it is necessary to increase the expansion ratio of the steam after it is taken in from the
intake ports 90 into thevane chamber 75 up to the point where it is discharged via theexhaust ports 91, and it is therefore desirable to advance the intake initiation phase as much as possible. However, since the intake initiation phase of the present embodiment is +15°, which is retarded relative to the intake initiation phase of +4° of the conventional example, the present embodiment is disadvantageous from the viewpoint of ensuring a large expansion ratio. The present embodiment therefore employs for the innerperipheral face 93 of therotor chamber 14 a shape that makes the intake volume of steam at the beginning of the intake stroke small (that is, the shape of the annular channel 74), thus ensuring that the expansion ratio is the same as that of the conventional example. - In the region from the intake initiation position, which is set at +15°, to the exhaust completion position, which is set at -15°, there is disposed at least the
seal 72 of one of thevanes 48, which are disposed at intervals of 30°. Thisseal 72 prevents steam from leaking from theintake ports 90, which are at high pressure, to theexhaust ports 91, which are at low pressure, but in practice it is difficult to completely prevent the leakage of the steam using only theseal 72. In the present embodiment, since the clearance from the outerperipheral face 94 of therotor 41 is constant in the section in which the phase of the innerperipheral face 93 of therotor chamber 14 is -16° to +16°, by making thelabyrinths 43g provided on the outer periphery of therotor 41 face this section, a steam leakage preventing effect is exhibited. - FIG. 16 shows a state in which a seal 72 (f) on the advanced side in the rotational direction R of the rotor 41 (hereinafter, simply called the advanced side) has reached the
intake ports 90, and a seal 72 (r) on the retarded side in the rotational direction R of the rotor 41 (hereinafter, simply called the retarded side) has passed theexhaust ports 91. In this case, high pressure steam of theintake ports 90 tries to pass the seal 72 (r) on the retarded side and leak to theexhaust ports 91, but since thelabyrinths 43g present in the -16° to +16° section exhibit sealing characteristics due to a labyrinth effect, it is possible to prevent effectively the leakage of steam through the seal 72 (r) on the retarded side. - FIG. 17 shows a state in which the
rotor 41 has rotated further from the state of FIG. 16, and the seal 72 (r) on the retarded side has reached a position substantially midway between theintake ports 90 and theexhaust ports 91, and FIG. 18 shows a state in which therotor 41 has rotated further from the state of FIG. 17, and the seal 72 (r) on the retarded side has reached a position immediately prior to theintake ports 90. In all of the above-mentioned cases, thelabyrinths 43g present in the -16° to +16° section exhibit sealing characteristics due to the labyrinth effect, and it is therefore possible to prevent effectively steam from leaking through the seal 72 (r) on the retarded side. - Since lubricating water or water that is formed by the liquefaction of steam easily builds up in the
labyrinths 43g, a liquid sealing effect from this water also improves the sealing characteristics for steam. - A second embodiment of the present invention is now explained with reference to FIG. 19 to FIG. 21. The phases of
vanes 48 in FIG. 19 to FIG. 21 correspond to the phases of thevanes 48 in FIG. 16 to FIG. 19 respectively. - In the first embodiment, the
labyrinths 43g are provided on the entire circumference of therotor 41, but in thesecond embodiment labyrinths 43g are provided on only about a quarter of each ofrotor segments 43 on the retarded side, and thelabyrinths 43g are therefore provided at a position adjacent to the advanced side of aseal 72 of thevane 48. The high pressure ofintake ports 90 is therefore reduced in pressure by the labyrinth effect of thelabyrinths 43g adjacent to the advanced side of theseal 72, and the difference in pressure between the two sides of theseal 72 can be moderated, thus preventing effectively the leakage of steam. In accordance with the present embodiment, the number of labyrinths 43g can be reduced while maintaining the steam leakage preventing effect, thereby contributing to a reduction in the machining cost. - Other than the embodiments described above, as an arrangement for a power conversion device for converting the forward movement of
pistons 47 into the rotational movement of arotor 41, the forward movement of thepistons 47 can be directly transmitted torollers 71 without involvingvanes 48, and can be converted into rotational movement by engagement withannular channels 74. Furthermore, as long as thevanes 48 are always spaced from the inner peripheral face of arotor chamber 14 by a substantially constant gap as a result of cooperation between therollers 71 and theannular channels 74 as described above, thepistons 47 and therollers 71, and also thevanes 48 and therollers 71, can independently work together with theannular channels 74. - When the
expander 4 is used as a compressor, therotor 41 is rotated by the rotatingshaft 21 in a direction opposite to the arrow R in FIG. 4, outside air is drawn in by thevanes 48 from theexhaust ports 91 into therotor chamber 14 and compressed, and the low pressure compressed air thus obtained is drawn in from theintake ports 90 into thecylinders 44 via thetransit chamber 19, the throughholes 81b, the fifth steam passages S5, the fourth steam passages S4, thenotches 85a of the fixedshaft 85 and the third steam passages S3, and compressed there by thepistons 47 to give high pressure compressed air. The high pressure compressed air thus obtained is discharged from thecylinders 44 via the third steam passages S3, the second steam passages S2, the first steam passage S1, and thesteam supply pipe 88. When theexpander 4 is used as a compressor, the steam passages S1 to S5 and thesteam supply pipe 88 are read instead as air passages S1 to S5 andair supply pipe 88. - Although embodiments of the present invention are described in detail above, the present invention can be modified in a variety of ways without departing from the scope and spirit thereof.
- For example, in the embodiments, the
expander 4 is illustrated as the rotary fluid machine, but the present invention can also be applied to a compressor. - Furthermore, in the embodiments, steam and water are used as the gas-phase working medium and the liquid-phase working medium, but other appropriate working media can also be employed.
- Moreover, in the embodiments, the
labyrinths 43g are provided on therotor 41 side, but the same operational effect can be achieved by providing labyrinths on therotor chamber 14 side. - Furthermore, the
labyrinths 43g of the embodiments are U-shaped channels extending within a plane containing the axis L, but they may be divided into a plurality of small cells by means of partitions extending in the circumferential direction. - The present invention can desirably be applied to an expander employing steam (water) as a working medium, but can also be applied to an expander employing any other working medium and a compressor employing any working medium.
Claims (2)
- A rotary fluid machine comprising a rotor chamber (14) formed in a casing (11), a rotor (41) rotatably housed within the rotor chamber (14), a plurality of vane channels (49) formed radially in the rotor (41), a plurality of vanes (48) slidably supported in the respective vane channels (49), vane chambers (75) defined by the rotor (41), the casing (11), and the vanes (48), and an intake port (90) and an exhaust port (91) for supplying and discharging a gas-phase working medium to and from the vane chambers (75);
characterized in that gas-phase working medium leakage preventing means is provided on at least one of the outer peripheral face of the rotor (41) and the inner peripheral face of the rotor chamber (14) in a region in which there is a large difference in pressure between adjacent vane chambers (75) that are in between the trailing edge of the exhaust port (91) and the leading edge of the intake port (90). - The rotary fluid machine according to Claim 1, wherein the leakage preventing means is a labyrinth (43g).
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2001283988 | 2001-09-21 | ||
JP2001289388 | 2001-09-21 | ||
JP2001289388A JP2003097202A (en) | 2001-09-21 | 2001-09-21 | Rotary fluid machine |
PCT/JP2002/009720 WO2003027440A1 (en) | 2001-09-21 | 2002-09-20 | Rotary fluid machine |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1428978A1 true EP1428978A1 (en) | 2004-06-16 |
EP1428978A8 EP1428978A8 (en) | 2004-11-10 |
Family
ID=19111886
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP02772880A Withdrawn EP1428978A1 (en) | 2001-09-21 | 2002-09-20 | Rotary fluid machine |
Country Status (4)
Country | Link |
---|---|
US (1) | US20050031479A1 (en) |
EP (1) | EP1428978A1 (en) |
JP (1) | JP2003097202A (en) |
WO (1) | WO2003027440A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2963299A1 (en) * | 2014-07-03 | 2016-01-06 | Knut, Denecke | Method for compressing steam and steam compressor |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8936451B2 (en) | 2011-11-15 | 2015-01-20 | Gast Manufacturing, Inc., A Unit Of Idex Corporation | Rotary vane pumps with asymmetrical chamber cavities |
RU199033U1 (en) * | 2020-02-11 | 2020-08-11 | Юрий Иосипович Новицкий | ROTARY VANE MOTOR |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3196856A (en) * | 1963-04-29 | 1965-07-27 | Ward Walter | Combustion engine |
US4012180A (en) * | 1975-12-08 | 1977-03-15 | Curtiss-Wright Corporation | Rotary compressor with labyrinth sealing |
JPH02163492A (en) * | 1988-12-19 | 1990-06-22 | Nippon Carbureter Co Ltd | Vane type vacuum pump |
BR0009245A (en) * | 1999-03-05 | 2001-11-20 | Honda Motor Co Ltd | Rotary type fluid machine, vane fluid machine and residual heat recovery device for internal combustion engine |
JP2000320543A (en) | 1999-05-07 | 2000-11-24 | Nsk Ltd | Sliding bearing |
KR100426867B1 (en) * | 2001-08-09 | 2004-04-13 | 맹혁재 | compressor |
-
2001
- 2001-09-21 JP JP2001289388A patent/JP2003097202A/en active Pending
-
2002
- 2002-09-20 WO PCT/JP2002/009720 patent/WO2003027440A1/en active Application Filing
- 2002-09-20 EP EP02772880A patent/EP1428978A1/en not_active Withdrawn
- 2002-09-20 US US10/489,914 patent/US20050031479A1/en not_active Abandoned
Non-Patent Citations (1)
Title |
---|
See references of WO03027440A1 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2963299A1 (en) * | 2014-07-03 | 2016-01-06 | Knut, Denecke | Method for compressing steam and steam compressor |
Also Published As
Publication number | Publication date |
---|---|
EP1428978A8 (en) | 2004-11-10 |
US20050031479A1 (en) | 2005-02-10 |
JP2003097202A (en) | 2003-04-03 |
WO2003027440A1 (en) | 2003-04-03 |
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