US20050158181A1 - Expansion engine - Google Patents
Expansion engine Download PDFInfo
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- US20050158181A1 US20050158181A1 US10/501,521 US50152105A US2005158181A1 US 20050158181 A1 US20050158181 A1 US 20050158181A1 US 50152105 A US50152105 A US 50152105A US 2005158181 A1 US2005158181 A1 US 2005158181A1
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- Prior art keywords
- rotor
- expansion chamber
- cylinder sleeve
- heat
- piston
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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
- F01B3/00—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F01B3/0032—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
Definitions
- the present invention relates to an expander that includes a casing, a rotor rotatably supported in the casing, and an axial piston cylinder group arranged annularly in the rotor so as to surround the axis of the rotor, the rotor being rotated by supplying, via a rotary valve, high-temperature, high-pressure steam to an expansion chamber defined between a piston and a cylinder sleeve of the axial piston cylinder group.
- Such an expander has been proposed by the present applicant in Japanese Patent Application No. 2001-61424.
- This expander is used in a Rankine cycle system, and steam is supplied and discharged, via a rotary valve, to and from a plurality of expansion chambers within cylinder sleeves provided in a rotor.
- Each cylinder sleeve is retained by being fitted in a bottomed cylindrical recess bored in one end face of the rotor, and the expansion chamber is defined by an inner face of the cylinder sleeve, a base of the recess of the rotor, and a top face of a piston fitted in the cylinder sleeve.
- the present invention has been achieved under the above-mentioned circumstances, and it is an object thereof to minimize the escape of heat, that is, the heat loss, via expansion chambers of an axial piston cylinder group of an expander.
- an expander that includes a casing, a rotor rotatably supported in the casing, and an axial piston cylinder group arranged annularly in the rotor so as to surround the axis of the rotor, the rotor being rotated by supplying, via a rotary valve, high-temperature, high-pressure steam to an expansion chamber defined between a piston and a cylinder sleeve of the axial piston cylinder group, characterized in that a heat-insulating space is provided at a position facing the expansion chamber of the rotor.
- the expansion chamber is defined between the piston and the cylinder sleeve of the axial piston cylinder group provided in the rotor of the expander, and the heat-insulating space is provided at the position facing the expansion chamber of the rotor, it is possible to minimize the escape to the rotor of the heat of the high-temperature, high-pressure steam supplied to the expander, thereby preventing the thermal efficiency from decreasing.
- an expander wherein the rotor is formed by joining, in the axial direction of the rotor, a first rotor half retaining the cylinder sleeve, which is separate from the first rotor half, and a second rotor half housing the rotary valve, and the expansion chamber is sealed by interposing a metal gasket between end faces of the first rotor half and the cylinder sleeve and an end face of the second rotor half.
- the expansion chamber is sealed by interposing the metal gasket between the end faces of the first rotor half and the cylinder sleeve and the end face of the second rotor half when the rotor is formed by axially joining the second rotor half housing the rotary valve to the first rotor half retaining the cylinder sleeve, which is separate from the first rotor half, in comparison with a case in which the expansion chamber is sealed via a thick annular seal, unnecessary volume around the seal can be reduced, thus ensuring that the expander has a large volume ratio (expansion ratio) and thereby improving the thermal efficiency, which enables the output to be increased.
- the material of the cylinder sleeve is not limited by the material of the rotor and can be selected while taking into consideration thermal conductivity, heat resistance, strength, abrasion resistance, etc. and, moreover, it is possible to replace only a worn or damaged cylinder sleeve, which is economical.
- an expander wherein a cutout is formed circumferentially in the rotor, an outer peripheral face of the cylinder sleeve being exposed through the cutout.
- Sleeve support flanges 33 , 34 , and 35 of an embodiment correspond to the first rotor half of the present invention, and a rotor head 38 of the embodiment corresponds to the second rotor half of the present invention.
- FIG. 1 to FIG. 13 show one embodiment of the present invention
- FIG. 1 is a vertical sectional view of an expander
- FIG. 2 is a sectional view along line 2 - 2 in FIG. 1 ,
- FIG. 3 is a view from arrowed line 3 - 3 in FIG. 1 ,
- FIG. 4 is an enlarged view of part 4 in FIG. 1 ,
- FIG. 5 is an enlarged view of part 5 in FIG. 1 ,
- FIG. 6 is an exploded perspective view of a rotor
- FIG. 7 is a sectional view along line 7 - 7 in FIG. 4 .
- FIG. 8 is a sectional view along 8 - 8 in FIG. 4 .
- FIG. 9 is an enlarged view of part 9 in FIG. 4 .
- FIG. 10 is a sectional view along line 10 - 10 in FIG. 5 .
- FIG. 11 is a sectional view along line 11 - 11 in FIG. 5 .
- FIG. 12 is a sectional view along line 12 - 12 in FIG. 5 .
- FIG. 13 is a sectional view along line 13 - 13 in FIG. 5 .
- an expander M of this embodiment is used in, for example, a Rankine cycle system, and converts the thermal energy and the pressure energy of high-temperature, high-pressure steam as a working medium into mechanical energy and outputs it.
- a casing 11 of the expander M is formed from a casing main body 12 , a front cover 15 joined via a seal 13 to a front opening of the casing main body 12 by a plurality of bolts 14 , a rear cover 18 joined via a seal 16 to a rear opening of the casing main body 12 by a plurality of bolts 17 , and an oil pan 21 joined via a seal 19 to a lower opening of the casing main body 12 by a plurality of bolts 20 .
- a rotor 22 disposed rotatably around an axis L extending in the fore-and-aft direction in the center of the casing 11 has a front part thereof supported by a ball bearing 23 provided in the front cover 15 and a rear part thereof supported by a ball bearing 24 provided in the casing main body 12 .
- a swash plate holder 28 is fitted in a rear face of the front cover 15 via two seals 25 and 26 and a knock pin 27 , and fixed thereto via a plurality of bolts 29 , and a swash plate 31 is rotatably supported by the swash plate holder 28 via an angular ball bearing 30 .
- the axis of the swash plate 31 is inclined relative to the axis L of the rotor 22 , and the angle of inclination is fixed.
- the rotor 22 includes an output shaft 32 supported by the front cover 15 via the ball bearing 23 , three sleeve support flanges 33 , 34 , and 35 formed integrally with a rear part of the output shaft 32 via cutouts 57 and 58 having predetermined widths (see FIG. 4 and FIG.
- a rotor head 38 that is joined by a plurality of bolts 37 to the rear sleeve support flange 35 via a metal gasket 36 and supported by the casing main body 12 via the ball bearing 24 , and a heat-insulating cover 40 that is fitted over the three sleeve support flanges 33 , 34 , and 35 from the front and joined to the front sleeve support flange 33 by a plurality of bolts 39 .
- Sets of five sleeve support holes 33 a , 34 a , and 35 a are formed in the three sleeve support flanges 33 , 34 , and 35 respectively at intervals of 72° around the axis L, and five cylinder sleeves 41 are fitted into the sleeve support holes 33 a , 34 a , and 35 a from the rear.
- a flange 41 a is formed on the rear end of each of the cylinder sleeves 41 , and axial positioning is carried out by abutting this flange 41 a against the metal gasket 36 while fitting the flange 41 a into a step 35 b formed in the sleeve support holes 35 a of the rear sleeve support flange 35 (see FIG.
- a piston 42 is slidably fitted within each of the cylinder sleeves 41 , the front end of the piston 42 abutting against a dimple 31 a formed on the swash plate 31 , and a steam expansion chamber 43 is defined between the rear end of the piston 42 and the rotor head 38 .
- An oil passage 32 a is formed so as to extend on the axis L within the output shaft 32 , which is integral with the rotor 22 , and the front end of the oil passage 32 a branches in a radial direction and communicates with an annular channel 32 b on the outer periphery of the output shaft 32 .
- An oil passage blocking member 45 is screwed into the inner periphery of the oil passage 32 a via a seal 44 at a radially inner position of the middle sleeve support flange 34 of the rotor 22 , and a plurality of oil holes 32 c extending radially outward from the oil passage 32 a in the vicinity of the oil passage blocking member 45 open on the outer periphery of the output shaft 32 .
- a trochoidal oil pump 49 is disposed between a recess 15 a provided in a front face of the front cover 15 and a pump cover 48 fixed via a seal 46 to the front face of the front cover 15 by a plurality of bolts 47 , and includes an outer rotor 50 that is rotatably fitted in the recess 15 a , and an inner rotor 51 that is fixed to the outer periphery of the output shaft 32 and meshes with the outer rotor 50 .
- An internal space of the oil pan 21 communicates with an intake port 53 of the oil pump 49 via an oil pipe 52 and an oil passage 15 b of the front cover 15 , and a discharge port 54 of the oil pump 49 communicates with the annular channel 32 b of the output shaft 32 via an oil passage 15 c of the front cover 15 .
- the piston 42 which is slidably fitted into the cylinder sleeve 41 , is formed from an end part 61 , a middle part 62 , and a top part 63 .
- the end part 61 is a member having a spherical part 61 a that abuts against the dimple 31 a of the swash plate 31 , and is joined by welding to the forward end of the middle part 62 .
- the middle part 62 is a cylindrical member having a large volume hollow space 62 a ; an outer peripheral part of the middle part 62 close to the top part 63 has a small diameter part 62 b whose diameter is slightly reduced, a plurality of oil holes 62 c are formed so as to run radially through the small diameter part 62 b , and a plurality of spiral oil channels 62 d are formed in an outer peripheral part that is present forward of the small diameter part 62 b .
- the top part 63 faces the expansion chamber 43 and is formed integrally with the middle part 62 , and a heat-insulating space 65 is formed between a dividing wall 63 a formed on an inner face of the top part 63 and a cover member 64 fitted into and welded to a rear end face of the top part 63 (see FIG. 9 ).
- Two compression rings 66 and one oil ring 67 are mounted on the outer periphery of the top part 63 , and an oil ring channel 63 b into which the oil ring 67 is fitted communicates with the hollow space 62 a of the middle part 62 via a plurality of oil holes 63 c.
- the end part 61 and the middle part 62 of the piston are made of high-carbon steel, and the top part 63 is made of stainless steel; among these, the end part 61 is subjected to induction hardening, whereas the middle part 62 is subjected to hardening.
- high surface pressure resistance can be imparted to the end part 61 , which abuts against the swash plate 31 at a high surface pressure
- abrasion resistance can be imparted to the middle part 62 , which is in sliding contact with the cylinder sleeve 41 under severe lubrication conditions
- heat resistance and corrosion resistance can be imparted to the top part 63 , which faces the expansion chamber 43 and is exposed to high temperature and high pressure.
- An annular channel 41 b is formed on the outer periphery of a middle part of the cylinder sleeve 41 (see FIG. 6 and FIG. 9 ), and a plurality of oil holes 41 c are formed in the annular channel 41 b .
- the oil holes 32 c formed in the output shaft 32 and oil holes 34 b formed in the middle sleeve support flange 34 of the rotor 22 communicate with the annular channel 41 b .
- An annular cover member 69 is welded to the front, or expansion chamber 43 side, of the rotor head 38 , which is joined to the rear face of the front sleeve support flange 33 of the rotor 22 by the bolts 37 , and an annular heat-insulating space 70 is defined at the back, or rear face of the cover member 69 (see FIG. 9 ).
- the rotor head 38 is positioned rotationally relative to the rear sleeve support flange 35 by a knock pin 55 .
- the five cylinder sleeves 41 and the five pistons 42 form an axial piston cylinder group 56 of the present invention.
- the rotary valve 71 which is disposed along the axis L of the rotor 22 , includes a valve main body 72 , a stationary valve plate 73 , and a movable valve plate 74 .
- the movable valve plate 74 is fixed to a rear face of the rotor 22 by a bolt 76 screwed into the oil passage blocking member 45 (see FIG. 4 ) while being positioned in the rotational direction by a knock pin 75 .
- the bolt 76 also has the function of fixing the rotor head 38 to the output shaft 32 .
- the stationary valve plate 73 which abuts against the movable valve plate 74 via flat sliding surfaces 77 , is fixed to the center of a front face of the valve main body 72 by one bolt 78 , and also to an outer peripheral part of the valve main body 72 by an annular fixing ring 79 and a plurality of bolts 80 .
- a step 79 a formed on the inner periphery of the fixing ring 79 is press-fitted around the outer periphery of the stationary valve plate 73 so as to be fitted in a socket-and-spigot type
- a step 79 b formed on the outer periphery of the fixing ring 79 is fitted in a socket-and-spigot type around the outer periphery of the valve main body 72 , thereby ensuring that the stationary valve plate 73 is coaxial with the valve main body 72 .
- a knock pin 81 is disposed between the valve main body 72 and the stationary valve plate 73 , and determines the position of the stationary valve plate 73 in the rotational direction.
- the stationary valve plate 73 and the movable valve plate 74 are made of a material having excellent durability, such as carbon or a ceramic, and the durability can be further improved by providing or coating the sliding surfaces 77 with a member having heat resistance, lubricating properties, corrosion resistance, and abrasion resistance.
- the valve main body 72 which is made of stainless steel, is a stepped cylindrical member having a large diameter part 72 a and a small diameter part 72 b ; outer peripheral faces of the large diameter part 72 a and the small diameter part 72 b are slidably fitted in the axial L direction into circular cross-section support faces 18 a and 18 b of the rear cover 18 via seals 82 and 83 respectively, and positioned in the rotational direction by fitting a pin 84 implanted in an outer peripheral face of the valve main body 72 into a cutout 18 c formed in the axial L direction in the rear cover 18 .
- a plurality of preload springs 85 are supported in the rear cover 18 so as to surround the axis L, and the valve main body 72 , which has a step 72 c between the large diameter part 72 a and the small diameter part 72 b pushed by these preload springs 85 , is biased forward so as to put the sliding surfaces 77 of the stationary valve plate 73 and the movable valve plate 74 in intimate contact.
- a steam supply pipe 86 connected to a rear face of the valve main body 72 communicates with the sliding surfaces 77 via a first steam passage P 1 formed in the interior of the valve main body 72 and a second steam passage P 2 formed in the stationary valve plate 73 .
- a steam discharge chamber 88 sealed by a seal 87 is formed between the casing main body 12 , the rear cover 18 , and the rotor 22 , and this steam discharge chamber 88 communicates with the sliding surfaces 77 via sixth and seventh steam passages P 6 and P 7 formed in the interior of the valve main body 72 and a fifth steam passage P 5 formed in the stationary valve plate 73 .
- a seal 89 surrounding a part where the first and second steam passages P 1 and P 2 are connected to each other and a seal 90 surrounding a part where the fifth and sixth steam passages P 5 and P 6 are connected to each other.
- Three third steam passages P 3 disposed at equal intervals so as to surround the axis L run through the movable valve plate 74 , and opposite ends of five fourth steam passages P 4 formed in the rotor 22 so as to surround the axis L communicate with the third steam passages P 3 and the expansion chambers 43 .
- the part of the second steam passage P 2 opening on the sliding surface 77 is circular, whereas the part of the fifth steam passage P 5 opening on the sliding surface 77 has an arc shape with the axis L as its center.
- High-temperature, high-pressure steam generated by heating water in an evaporator reaches the sliding surfaces 77 of the stationary valve plate 73 with the movable valve plate 74 from the steam supply pipe 86 via the first steam passage P 1 formed in the valve main body 72 of the rotary valve 71 and the second steam passage P 2 formed in the stationary valve plate 73 , which is integral with the valve main body 72 .
- the second steam passage P 2 opening on the sliding surface 77 communicates momentarily during a predetermined intake period with the corresponding third steam passage P 3 formed in the movable valve plate 74 , which rotates integrally with the rotor 22 , and the high-temperature, high-pressure steam is supplied, via the fourth steam passage P 4 formed in the rotor 22 , from the third steam passage P 3 to the expansion chamber 43 within the cylinder sleeve 41 .
- the high-temperature, high-pressure steam expands within the expansion chamber 43 and causes the piston 42 fitted in the cylinder sleeve 41 to be pushed forward from top dead center toward bottom dead center, and the end part 61 at the front end of the piston 42 pushes against the dimple 31 a of the swash plate 31 .
- the reaction force that the pistons 42 receive from the swash plate 31 gives a rotational torque to the rotor 22 .
- the high-temperature, high-pressure steam is supplied into a fresh adjoining expansion chamber 43 , thus continuously rotating the rotor 22 .
- the oil pump 49 provided on the output shaft 32 operates accompanying rotation of the rotor 22 , and oil is taken in from the oil pan 21 via the oil pipe 52 , the oil passage 15 b of the front cover 15 , and the intake port 53 , discharged from the discharge port 54 , and supplied to a space between the cylinder sleeve 41 and the small diameter part 62 b formed in the middle part 62 of the piston 42 via the oil passage 15 c of the front cover 15 , the oil passage 32 a of the output shaft 32 , the annular channel 32 b of the output shaft 32 , the oil holes 32 c of the output shaft 32 , the annular channel 41 b of the cylinder sleeve 41 , and the oil holes 41 c of the cylinder sleeve 41 .
- a portion of the oil retained by the small diameter part 62 b flows into the spiral oil channels 62 d formed in the middle part 62 of the piston 42 and lubricates the surface that slides against the cylinder sleeve 41 , and another portion of the oil lubricates surfaces of the compression rings 66 and the oil ring 67 provided at the top part 63 of the piston 42 that slide against the cylinder sleeve 41 .
- the hollow space 62 a communicates with the interior of the cylinder sleeve 41 via the plurality of oil holes 62 c running through the middle part 62 of the piston 42
- the interior of the cylinder sleeve 41 communicates with the annular channel 41 b on the outer periphery of the cylinder sleeve 41 via the plurality of oil holes 41 c .
- the oil retained in the hollow space 62 a within the piston 42 and the oil retained in the small diameter part 62 b on the outer periphery of the piston 42 are supplied from the small diameter part 62 b to the top part 63 side during an expansion stroke in which the volume of the expansion chamber 43 increases, and are supplied from the small diameter part 62 b to the end part 61 side during a compression stroke in which the volume of the expansion chamber 43 decreases, and it is therefore possible to ensure reliable lubrication over the entire axial region of the piston 42 .
- the large volume hollow space 62 a is formed within the piston 42 , not only is it possible to reduce the weight of the piston 42 , but also it is possible to reduce the heat capacity of the piston 42 , thereby enabling the escape of heat from the expansion chamber 43 to be suppressed yet more effectively.
- the expansion chamber 43 is sealed by interposing the metal gasket 36 between the rear sleeve support flange 35 and the rotor head 38 , in comparison with a case in which the expansion chamber 43 is sealed via a thick annular seal, unnecessary volume around the seal can be reduced, thus ensuring that the expander M has a large volume ratio (expansion ratio) and thereby improving the thermal efficiency, which enables the output to be increased.
- the material of the cylinder sleeve 41 can be selected without being restricted by the material of the rotor 22 , while taking into consideration the thermal conductivity, heat resistance, strength, abrasion resistance, etc., and, moreover, it is possible to replace only a worn or damaged cylinder sleeve 41 , which is economical.
- the outer peripheral face of the cylinder sleeve 41 is exposed through the two cutouts 57 and 58 formed circumferentially in the outer peripheral face of the rotor 22 , not only is it possible to reduce the weight of the rotor 22 , but it is also possible to reduce the heat capacity of the rotor 22 , thereby improving the thermal efficiency and, moreover, the cutouts 57 and 58 function as a heat-insulating space, thus suppressing the escape of heat from the cylinder sleeve 41 . Furthermore, since the outer peripheral part of the rotor 22 is covered by the heat-insulating cover 40 , it is possible to suppress the escape of heat from the cylinder sleeve 41 yet more effectively.
- the rotary valve 71 supplies and discharges steam to and from the axial piston cylinder group 56 via the flat sliding surfaces 77 between the stationary valve plate 73 and the movable valve plate 74 , it is possible to prevent the leakage of steam effectively. This is because the flat sliding surfaces 77 can easily be machined with high precision, and control of the clearance is easy compared with cylindrical sliding surfaces. Moreover, since a surface pressure is generated on the sliding surfaces 77 of the stationary valve plate 73 and the movable valve plate 74 by applying a preset load to the valve main body 72 by means of the plurality of preload springs 85 , it is possible to suppress the leakage of steam past the sliding surfaces 77 yet more effectively.
- valve main body 72 of the rotary valve 71 is made of stainless steel, which has a large coefficient of thermal expansion
- the stationary valve plate 73 fixed to the valve main body 72 is made of carbon or a ceramic, which has a small coefficient of thermal expansion
- the fixing ring 79 is fixed to the valve main body 72 by means of the plurality of bolts 80 in a state in which the step 79 a on the inner periphery of the fixing ring 79 is press-fitted over the outer periphery of the stationary valve plate 73 in a socket-and-spigot type fitting and the step 79 b on the outer periphery of the fixing ring 79 is press-fitted over the outer periphery of the valve main body 72 in a socket-and-spigot type fitting, it is possible to carry out precise centering of the stationary valve plate 73 relative to the valve main body 72 by the aligning action of the
- the rotary valve 71 can be attached to and removed from the casing main body 12 merely by removing the rear cover 18 from the casing main body 12 , the ease of maintenance operations such as repair, cleaning, and replacement can be greatly improved. Furthermore, although the rotary valve 71 through which the high-temperature, high-pressure steam passes reaches a high temperature, since the swash plate 31 and the output shaft 32 , where lubrication by oil is required, are disposed on the opposite side of the rotor 22 to the rotary valve 71 , degradation of the lubrication performance of the swash plate 31 and the output shaft 32 due to heating of the oil by the heat of the rotary valve 71 , which reaches a high temperature, can be prevented. Moreover, the oil also exhibits the function of cooling the rotary valve 71 , thus preventing overheating.
- the expander M is illustrated for a Rankine cycle system in the embodiment, but the expander M of the present invention can be applied to any other purpose.
- the expander of the present invention is suitable for application to a Rankine cycle system, but the present invention can be applied to an expander for any purpose as long as the thermal energy and the pressure energy of a high-temperature, high-pressure working medium is converted into mechanical energy and output.
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Abstract
An expander is provided in which a rotor (22) is rotated by supplying high-temperature, high-pressure steam to an expansion chamber (43) defined between a piston (42) and a cylinder sleeve (41) so that the piston (42) pushes a swash plate (31). Since an annular heat-insulating space (70) is formed in a rotor head (38) facing the expansion chamber (43), it is possible to suppress the escape, to the rotor (22), of the heat of high-temperature, high-pressure steam supplied to the expansion chamber (43), thereby preventing the heat efficiency from deteriorating. Moreover, since the expansion chamber (43) is sealed by interposing a metal gasket (36) between the end face of the cylinder sleeve (41) and the end face of the rotor head (38), in comparison with a case in which the expansion chamber (43) is sealed via a thick annular seal, unnecessary volume around the seal can be reduced, thus ensuring that the expander has a large volume ratio (expansion ratio) and thereby improving the thermal efficiency, which enables the output to be increased.
Description
- The present invention relates to an expander that includes a casing, a rotor rotatably supported in the casing, and an axial piston cylinder group arranged annularly in the rotor so as to surround the axis of the rotor, the rotor being rotated by supplying, via a rotary valve, high-temperature, high-pressure steam to an expansion chamber defined between a piston and a cylinder sleeve of the axial piston cylinder group.
- Such an expander has been proposed by the present applicant in Japanese Patent Application No. 2001-61424. This expander is used in a Rankine cycle system, and steam is supplied and discharged, via a rotary valve, to and from a plurality of expansion chambers within cylinder sleeves provided in a rotor. Each cylinder sleeve is retained by being fitted in a bottomed cylindrical recess bored in one end face of the rotor, and the expansion chamber is defined by an inner face of the cylinder sleeve, a base of the recess of the rotor, and a top face of a piston fitted in the cylinder sleeve.
- In order to make the high-temperature, high-pressure steam supplied to the expansion chambers carry out sufficient work, it is necessary to suppress the escape of heat past walls of the expansion chambers and minimize the decrease in temperature of the steam. However, in the above-mentioned conventional arrangement, since the expansion chambers directly face the rotor, which is a member having a large heat capacity, the heat within the expansion chambers can easily escape to the rotor, thus giving rise to the problem that the thermal efficiency is degraded.
- The present invention has been achieved under the above-mentioned circumstances, and it is an object thereof to minimize the escape of heat, that is, the heat loss, via expansion chambers of an axial piston cylinder group of an expander.
- In order to accomplish this object, in accordance with a first aspect of the present invention, there is proposed an expander that includes a casing, a rotor rotatably supported in the casing, and an axial piston cylinder group arranged annularly in the rotor so as to surround the axis of the rotor, the rotor being rotated by supplying, via a rotary valve, high-temperature, high-pressure steam to an expansion chamber defined between a piston and a cylinder sleeve of the axial piston cylinder group, characterized in that a heat-insulating space is provided at a position facing the expansion chamber of the rotor.
- In accordance with this arrangement, since the expansion chamber is defined between the piston and the cylinder sleeve of the axial piston cylinder group provided in the rotor of the expander, and the heat-insulating space is provided at the position facing the expansion chamber of the rotor, it is possible to minimize the escape to the rotor of the heat of the high-temperature, high-pressure steam supplied to the expander, thereby preventing the thermal efficiency from decreasing.
- Furthermore, in accordance with a second aspect of the present invention, in addition to the first aspect, there is proposed an expander wherein the rotor is formed by joining, in the axial direction of the rotor, a first rotor half retaining the cylinder sleeve, which is separate from the first rotor half, and a second rotor half housing the rotary valve, and the expansion chamber is sealed by interposing a metal gasket between end faces of the first rotor half and the cylinder sleeve and an end face of the second rotor half.
- In accordance with this arrangement, since the expansion chamber is sealed by interposing the metal gasket between the end faces of the first rotor half and the cylinder sleeve and the end face of the second rotor half when the rotor is formed by axially joining the second rotor half housing the rotary valve to the first rotor half retaining the cylinder sleeve, which is separate from the first rotor half, in comparison with a case in which the expansion chamber is sealed via a thick annular seal, unnecessary volume around the seal can be reduced, thus ensuring that the expander has a large volume ratio (expansion ratio) and thereby improving the thermal efficiency, which enables the output to be increased. Furthermore, since the cylinder sleeve is separate from the rotor, the material of the cylinder sleeve is not limited by the material of the rotor and can be selected while taking into consideration thermal conductivity, heat resistance, strength, abrasion resistance, etc. and, moreover, it is possible to replace only a worn or damaged cylinder sleeve, which is economical.
- Moreover, in accordance with a third aspect of the present invention, in addition to the first or second aspect, there is proposed an expander wherein a cutout is formed circumferentially in the rotor, an outer peripheral face of the cylinder sleeve being exposed through the cutout.
- In accordance with this arrangement, since the outer peripheral face of the cylinder sleeve is exposed through the cutout formed circumferentially in the rotor, it is possible to reduce the heat capacity of the rotor, thereby improving the thermal efficiency and reducing the weight and, moreover, the cutout functions as a heat-insulating space, thereby suppressing the escape of heat via the cylinder sleeve.
- Furthermore, in accordance with a fourth aspect of the present invention, in addition to the third aspect, there is proposed an expander wherein the surroundings of the cutout are covered by a heat-insulating cover.
- In accordance with this arrangement, since the surroundings of the cutout of the rotor are covered by the heat-insulating cover, it is possible to suppress yet more effectively the escape of heat via an exposed outer wall of the cylinder sleeve.
-
Sleeve support flanges rotor head 38 of the embodiment corresponds to the second rotor half of the present invention. -
FIG. 1 toFIG. 13 show one embodiment of the present invention;FIG. 1 is a vertical sectional view of an expander, -
FIG. 2 is a sectional view along line 2-2 inFIG. 1 , -
FIG. 3 is a view from arrowed line 3-3 inFIG. 1 , -
FIG. 4 is an enlarged view ofpart 4 inFIG. 1 , -
FIG. 5 is an enlarged view ofpart 5 inFIG. 1 , -
FIG. 6 is an exploded perspective view of a rotor, -
FIG. 7 is a sectional view along line 7-7 inFIG. 4 , -
FIG. 8 is a sectional view along 8-8 inFIG. 4 , -
FIG. 9 is an enlarged view of part 9 inFIG. 4 , -
FIG. 10 is a sectional view along line 10-10 inFIG. 5 , -
FIG. 11 is a sectional view along line 11-11 inFIG. 5 , -
FIG. 12 is a sectional view along line 12-12 inFIG. 5 , and -
FIG. 13 is a sectional view along line 13-13 inFIG. 5 . - One embodiment of the present invention is explained below with reference to the attached drawings.
- As shown in
FIG. 1 toFIG. 9 , an expander M of this embodiment is used in, for example, a Rankine cycle system, and converts the thermal energy and the pressure energy of high-temperature, high-pressure steam as a working medium into mechanical energy and outputs it. Acasing 11 of the expander M is formed from a casingmain body 12, afront cover 15 joined via aseal 13 to a front opening of the casingmain body 12 by a plurality ofbolts 14, arear cover 18 joined via aseal 16 to a rear opening of the casingmain body 12 by a plurality ofbolts 17, and anoil pan 21 joined via aseal 19 to a lower opening of the casingmain body 12 by a plurality ofbolts 20. - A
rotor 22 disposed rotatably around an axis L extending in the fore-and-aft direction in the center of thecasing 11 has a front part thereof supported by a ball bearing 23 provided in thefront cover 15 and a rear part thereof supported by aball bearing 24 provided in the casingmain body 12. Aswash plate holder 28 is fitted in a rear face of thefront cover 15 via twoseals knock pin 27, and fixed thereto via a plurality ofbolts 29, and aswash plate 31 is rotatably supported by theswash plate holder 28 via an angular ball bearing 30. The axis of theswash plate 31 is inclined relative to the axis L of therotor 22, and the angle of inclination is fixed. - The
rotor 22 includes anoutput shaft 32 supported by thefront cover 15 via the ball bearing 23, threesleeve support flanges output shaft 32 viacutouts FIG. 4 andFIG. 9 ), arotor head 38 that is joined by a plurality ofbolts 37 to the rearsleeve support flange 35 via ametal gasket 36 and supported by the casingmain body 12 via the ball bearing 24, and a heat-insulatingcover 40 that is fitted over the threesleeve support flanges sleeve support flange 33 by a plurality ofbolts 39. - Sets of five sleeve support
holes sleeve support flanges cylinder sleeves 41 are fitted into thesleeve support holes flange 41 a is formed on the rear end of each of thecylinder sleeves 41, and axial positioning is carried out by abutting thisflange 41 a against themetal gasket 36 while fitting theflange 41 a into astep 35 b formed in thesleeve support holes 35 a of the rear sleeve support flange 35 (seeFIG. 9 ). Apiston 42 is slidably fitted within each of thecylinder sleeves 41, the front end of thepiston 42 abutting against adimple 31 a formed on theswash plate 31, and asteam expansion chamber 43 is defined between the rear end of thepiston 42 and therotor head 38. - An
oil passage 32 a is formed so as to extend on the axis L within theoutput shaft 32, which is integral with therotor 22, and the front end of theoil passage 32 a branches in a radial direction and communicates with anannular channel 32 b on the outer periphery of theoutput shaft 32. An oilpassage blocking member 45 is screwed into the inner periphery of theoil passage 32 a via aseal 44 at a radially inner position of the middlesleeve support flange 34 of therotor 22, and a plurality ofoil holes 32 c extending radially outward from theoil passage 32 a in the vicinity of the oilpassage blocking member 45 open on the outer periphery of theoutput shaft 32. - A
trochoidal oil pump 49 is disposed between arecess 15 a provided in a front face of thefront cover 15 and apump cover 48 fixed via aseal 46 to the front face of thefront cover 15 by a plurality ofbolts 47, and includes anouter rotor 50 that is rotatably fitted in therecess 15 a, and aninner rotor 51 that is fixed to the outer periphery of theoutput shaft 32 and meshes with theouter rotor 50. An internal space of theoil pan 21 communicates with anintake port 53 of theoil pump 49 via anoil pipe 52 and anoil passage 15 b of thefront cover 15, and adischarge port 54 of theoil pump 49 communicates with theannular channel 32 b of theoutput shaft 32 via anoil passage 15 c of thefront cover 15. - The
piston 42, which is slidably fitted into thecylinder sleeve 41, is formed from anend part 61, amiddle part 62, and atop part 63. Theend part 61 is a member having aspherical part 61 a that abuts against the dimple 31 a of theswash plate 31, and is joined by welding to the forward end of themiddle part 62. Themiddle part 62 is a cylindrical member having a large volumehollow space 62 a; an outer peripheral part of themiddle part 62 close to thetop part 63 has asmall diameter part 62 b whose diameter is slightly reduced, a plurality ofoil holes 62 c are formed so as to run radially through thesmall diameter part 62 b, and a plurality ofspiral oil channels 62 d are formed in an outer peripheral part that is present forward of thesmall diameter part 62 b. Thetop part 63 faces theexpansion chamber 43 and is formed integrally with themiddle part 62, and a heat-insulatingspace 65 is formed between adividing wall 63 a formed on an inner face of thetop part 63 and acover member 64 fitted into and welded to a rear end face of the top part 63 (seeFIG. 9 ). Twocompression rings 66 and oneoil ring 67 are mounted on the outer periphery of thetop part 63, and anoil ring channel 63 b into which theoil ring 67 is fitted communicates with thehollow space 62 a of themiddle part 62 via a plurality ofoil holes 63 c. - The
end part 61 and themiddle part 62 of the piston are made of high-carbon steel, and thetop part 63 is made of stainless steel; among these, theend part 61 is subjected to induction hardening, whereas themiddle part 62 is subjected to hardening. As a result, high surface pressure resistance can be imparted to theend part 61, which abuts against theswash plate 31 at a high surface pressure, abrasion resistance can be imparted to themiddle part 62, which is in sliding contact with thecylinder sleeve 41 under severe lubrication conditions, and heat resistance and corrosion resistance can be imparted to thetop part 63, which faces theexpansion chamber 43 and is exposed to high temperature and high pressure. - An
annular channel 41 b is formed on the outer periphery of a middle part of the cylinder sleeve 41 (seeFIG. 6 andFIG. 9 ), and a plurality ofoil holes 41 c are formed in theannular channel 41 b. Regardless of where rotationally thecylinder sleeve 41 is mounted, theoil holes 32 c formed in theoutput shaft 32 andoil holes 34 b formed in the middlesleeve support flange 34 of the rotor 22 (seeFIG. 4 andFIG. 6 ) communicate with theannular channel 41 b. Aspace 68 formed between the heat-insulatingcover 40 and the front and rearsleeve support flanges rotor 22 communicates with the internal space of thecasing 11 viaoil holes 40 a formed in the heat-insulating cover 40 (seeFIG. 4 andFIG. 7 ). - An
annular cover member 69 is welded to the front, orexpansion chamber 43 side, of therotor head 38, which is joined to the rear face of the frontsleeve support flange 33 of therotor 22 by thebolts 37, and an annular heat-insulatingspace 70 is defined at the back, or rear face of the cover member 69 (seeFIG. 9 ). Therotor head 38 is positioned rotationally relative to the rearsleeve support flange 35 by aknock pin 55. - The five
cylinder sleeves 41 and the fivepistons 42 form an axialpiston cylinder group 56 of the present invention. - The structure of a
rotary valve 71 for the supply and discharge of steam to and from the fiveexpansion chambers 43 of therotor 22 is now explained with reference toFIG. 5 , andFIG. 10 toFIG. 13 . - As shown in
FIG. 5 , therotary valve 71, which is disposed along the axis L of therotor 22, includes a valvemain body 72, astationary valve plate 73, and amovable valve plate 74. Themovable valve plate 74 is fixed to a rear face of therotor 22 by abolt 76 screwed into the oil passage blocking member 45 (seeFIG. 4 ) while being positioned in the rotational direction by aknock pin 75. Thebolt 76 also has the function of fixing therotor head 38 to theoutput shaft 32. - As is clear from
FIG. 5 , thestationary valve plate 73, which abuts against themovable valve plate 74 via flat slidingsurfaces 77, is fixed to the center of a front face of the valvemain body 72 by onebolt 78, and also to an outer peripheral part of the valvemain body 72 by anannular fixing ring 79 and a plurality ofbolts 80. During this process, astep 79 a formed on the inner periphery of the fixingring 79 is press-fitted around the outer periphery of thestationary valve plate 73 so as to be fitted in a socket-and-spigot type, and astep 79 b formed on the outer periphery of the fixingring 79 is fitted in a socket-and-spigot type around the outer periphery of the valvemain body 72, thereby ensuring that thestationary valve plate 73 is coaxial with the valvemain body 72. Aknock pin 81 is disposed between the valvemain body 72 and thestationary valve plate 73, and determines the position of thestationary valve plate 73 in the rotational direction. - When the
rotor 22 rotates, themovable valve plate 74 and thestationary valve plate 73 therefore rotate relative to each other on the slidingsurfaces 77 in a state in which they are in intimate contact with each other. Thestationary valve plate 73 and themovable valve plate 74 are made of a material having excellent durability, such as carbon or a ceramic, and the durability can be further improved by providing or coating the slidingsurfaces 77 with a member having heat resistance, lubricating properties, corrosion resistance, and abrasion resistance. - The valve
main body 72, which is made of stainless steel, is a stepped cylindrical member having a large diameter part 72 a and asmall diameter part 72 b; outer peripheral faces of the large diameter part 72 a and thesmall diameter part 72 b are slidably fitted in the axial L direction into circular cross-section support faces 18 a and 18 b of therear cover 18 viaseals main body 72 into acutout 18 c formed in the axial L direction in therear cover 18. A plurality of preload springs 85 are supported in therear cover 18 so as to surround the axis L, and the valvemain body 72, which has astep 72 c between the large diameter part 72 a and thesmall diameter part 72 b pushed by these preload springs 85, is biased forward so as to put the slidingsurfaces 77 of thestationary valve plate 73 and themovable valve plate 74 in intimate contact. - A
steam supply pipe 86 connected to a rear face of the valvemain body 72 communicates with the slidingsurfaces 77 via a first steam passage P1 formed in the interior of the valvemain body 72 and a second steam passage P2 formed in thestationary valve plate 73. Asteam discharge chamber 88 sealed by aseal 87 is formed between the casingmain body 12, therear cover 18, and therotor 22, and thissteam discharge chamber 88 communicates with the slidingsurfaces 77 via sixth and seventh steam passages P6 and P7 formed in the interior of the valvemain body 72 and a fifth steam passage P5 formed in thestationary valve plate 73. Provided on surfaces where the valvemain body 72 and thestationary valve plate 73 are joined are aseal 89 surrounding a part where the first and second steam passages P1 and P2 are connected to each other and aseal 90 surrounding a part where the fifth and sixth steam passages P5 and P6 are connected to each other. - Five third steam passages P3 disposed at equal intervals so as to surround the axis L run through the
movable valve plate 74, and opposite ends of five fourth steam passages P4 formed in therotor 22 so as to surround the axis L communicate with the third steam passages P3 and theexpansion chambers 43. The part of the second steam passage P2 opening on the slidingsurface 77 is circular, whereas the part of the fifth steam passage P5 opening on the slidingsurface 77 has an arc shape with the axis L as its center. - The operation of the expander M of this embodiment having the above-mentioned arrangement is now explained.
- High-temperature, high-pressure steam generated by heating water in an evaporator reaches the sliding
surfaces 77 of thestationary valve plate 73 with themovable valve plate 74 from thesteam supply pipe 86 via the first steam passage P1 formed in the valvemain body 72 of therotary valve 71 and the second steam passage P2 formed in thestationary valve plate 73, which is integral with the valvemain body 72. The second steam passage P2 opening on the slidingsurface 77 communicates momentarily during a predetermined intake period with the corresponding third steam passage P3 formed in themovable valve plate 74, which rotates integrally with therotor 22, and the high-temperature, high-pressure steam is supplied, via the fourth steam passage P4 formed in therotor 22, from the third steam passage P3 to theexpansion chamber 43 within thecylinder sleeve 41. - Even after the communication between the second steam passage P2 and the third steam passage P3 has been blocked due to rotation of the
rotor 22, the high-temperature, high-pressure steam expands within theexpansion chamber 43 and causes thepiston 42 fitted in thecylinder sleeve 41 to be pushed forward from top dead center toward bottom dead center, and theend part 61 at the front end of thepiston 42 pushes against thedimple 31 a of theswash plate 31. As a result, the reaction force that thepistons 42 receive from theswash plate 31 gives a rotational torque to therotor 22. For each one fifth of a revolution of therotor 22, the high-temperature, high-pressure steam is supplied into a freshadjoining expansion chamber 43, thus continuously rotating therotor 22. - While the
piston 42, having reached bottom dead center accompanying rotation of therotor 22, retreats toward top dead center by being pushed by theswash plate 31, the low-temperature, low-pressure steam pushed out of theexpansion chamber 43 is discharged into thesteam discharge chamber 88 via the fourth steam passage P4 of therotor 22, the third steam passage P3 of themovable valve plate 74, the slidingsurfaces 77, the arc-shaped fifth steam passage P5 of thestationary valve plate 73, and the sixth and seventh steam passages P6 and P7 of the valvemain body 72, and is supplied therefrom into a condenser. - The
oil pump 49 provided on theoutput shaft 32 operates accompanying rotation of therotor 22, and oil is taken in from theoil pan 21 via theoil pipe 52, theoil passage 15 b of thefront cover 15, and theintake port 53, discharged from thedischarge port 54, and supplied to a space between thecylinder sleeve 41 and thesmall diameter part 62 b formed in themiddle part 62 of thepiston 42 via theoil passage 15 c of thefront cover 15, theoil passage 32 a of theoutput shaft 32, theannular channel 32 b of theoutput shaft 32, the oil holes 32 c of theoutput shaft 32, theannular channel 41 b of thecylinder sleeve 41, and the oil holes 41 c of thecylinder sleeve 41. A portion of the oil retained by thesmall diameter part 62 b flows into thespiral oil channels 62 d formed in themiddle part 62 of thepiston 42 and lubricates the surface that slides against thecylinder sleeve 41, and another portion of the oil lubricates surfaces of the compression rings 66 and theoil ring 67 provided at thetop part 63 of thepiston 42 that slide against thecylinder sleeve 41. - Since water formed in the
expansion chamber 43 by condensation of a portion of the supplied high-temperature, high-pressure steam inevitably enters between the sliding surfaces of thecylinder sleeve 41 and thepiston 42 and contaminates the oil, the lubrication conditions of the sliding surfaces are severe, but by supplying a necessary amount of oil directly to the sliding surfaces of thecylinder sleeve 41 and thepiston 42 from theoil pump 49 via the interior of theoutput shaft 32, it is possible to maintain a sufficient oil film, thereby ensuring the lubrication performance and enabling the dimensions of theoil pump 49 to be reduced. - Oil scraped off the surface of the
cylinder sleeve 41 that thepiston 42 slides against by theoil ring 67 flows from the oil holes 63 c formed in the base of theoil ring channel 63 b into thehollow space 62 a within thepiston 42. Thehollow space 62 a communicates with the interior of thecylinder sleeve 41 via the plurality of oil holes 62 c running through themiddle part 62 of thepiston 42, and the interior of thecylinder sleeve 41 communicates with theannular channel 41 b on the outer periphery of thecylinder sleeve 41 via the plurality of oil holes 41 c. Although the surroundings of theannular channel 41 b are covered by the middlesleeve support flange 34 of therotor 22, since theoil hole 34 b is formed in thesleeve support flange 34, the oil within thehollow space 62 a of thepiston 42 is biased radially outward due to centrifugal force, discharged to thespace 68 within the heat-insulatingcover 40 via theoil hole 34 b of thesleeve support flange 34, and returned therefrom to theoil pan 21 via the oil holes 40 a of the heat-insulatingcover 40. During this process, since theoil hole 34 b is positioned toward the axis L relative to the radially outer edge of thesleeve support flange 34, the oil that is present radially outside theoil hole 34 b is retained in thehollow space 62 a of thepiston 42 by centrifugal force. - In this way, the oil retained in the
hollow space 62 a within thepiston 42 and the oil retained in thesmall diameter part 62 b on the outer periphery of thepiston 42 are supplied from thesmall diameter part 62 b to thetop part 63 side during an expansion stroke in which the volume of theexpansion chamber 43 increases, and are supplied from thesmall diameter part 62 b to theend part 61 side during a compression stroke in which the volume of theexpansion chamber 43 decreases, and it is therefore possible to ensure reliable lubrication over the entire axial region of thepiston 42. Furthermore, as a result of the oil flowing within thehollow space 62 a of thepiston 42, the heat of thetop part 63, which is exposed to high-temperature, high-pressure steam, is transmitted to theend part 61, which has a low temperature, and it is thus possible to avoid the temperature of thepiston 42 increasing locally. - When high-temperature, high-pressure steam is supplied from the fourth steam passage P4 to the
expansion chamber 43, since the heat-insulatingspace 65 is formed between themiddle part 62 and thetop part 63 of thepiston 42, which faces theexpansion chamber 43, and the heat-insulatingspace 70 is formed in therotor head 38, which faces theexpansion chamber 43, it is possible to minimize the escape of heat from theexpansion chamber 43 to thepiston 42 and therotor head 38, thereby contributing to an improvement in the performance of the expander M. Furthermore, since the large volumehollow space 62 a is formed within thepiston 42, not only is it possible to reduce the weight of thepiston 42, but also it is possible to reduce the heat capacity of thepiston 42, thereby enabling the escape of heat from theexpansion chamber 43 to be suppressed yet more effectively. - Since the
expansion chamber 43 is sealed by interposing themetal gasket 36 between the rearsleeve support flange 35 and therotor head 38, in comparison with a case in which theexpansion chamber 43 is sealed via a thick annular seal, unnecessary volume around the seal can be reduced, thus ensuring that the expander M has a large volume ratio (expansion ratio) and thereby improving the thermal efficiency, which enables the output to be increased. Moreover, since thecylinder sleeve 41 is formed separately from therotor 22, the material of thecylinder sleeve 41 can be selected without being restricted by the material of therotor 22, while taking into consideration the thermal conductivity, heat resistance, strength, abrasion resistance, etc., and, moreover, it is possible to replace only a worn or damagedcylinder sleeve 41, which is economical. - Furthermore, since the outer peripheral face of the
cylinder sleeve 41 is exposed through the twocutouts rotor 22, not only is it possible to reduce the weight of therotor 22, but it is also possible to reduce the heat capacity of therotor 22, thereby improving the thermal efficiency and, moreover, thecutouts cylinder sleeve 41. Furthermore, since the outer peripheral part of therotor 22 is covered by the heat-insulatingcover 40, it is possible to suppress the escape of heat from thecylinder sleeve 41 yet more effectively. - Since the
rotary valve 71 supplies and discharges steam to and from the axialpiston cylinder group 56 via the flat slidingsurfaces 77 between thestationary valve plate 73 and themovable valve plate 74, it is possible to prevent the leakage of steam effectively. This is because the flat slidingsurfaces 77 can easily be machined with high precision, and control of the clearance is easy compared with cylindrical sliding surfaces. Moreover, since a surface pressure is generated on the slidingsurfaces 77 of thestationary valve plate 73 and themovable valve plate 74 by applying a preset load to the valvemain body 72 by means of the plurality of preload springs 85, it is possible to suppress the leakage of steam past the slidingsurfaces 77 yet more effectively. - Furthermore, since the valve main body 72 of the rotary valve 71 is made of stainless steel, which has a large coefficient of thermal expansion, and the stationary valve plate 73 fixed to the valve main body 72 is made of carbon or a ceramic, which has a small coefficient of thermal expansion, there is the possibility that the centering between the two might be displaced due to a difference in the coefficients of thermal expansion, but since the fixing ring 79 is fixed to the valve main body 72 by means of the plurality of bolts 80 in a state in which the step 79 a on the inner periphery of the fixing ring 79 is press-fitted over the outer periphery of the stationary valve plate 73 in a socket-and-spigot type fitting and the step 79 b on the outer periphery of the fixing ring 79 is press-fitted over the outer periphery of the valve main body 72 in a socket-and-spigot type fitting, it is possible to carry out precise centering of the stationary valve plate 73 relative to the valve main body 72 by the aligning action of the socket-and-spigot type fitting of the fixing ring 79 and prevent the timing of supply and discharge of steam from deviating, thereby preventing deterioration in the performance of the expander M. Moreover, it is possible to make the abutting surfaces of the stationary valve plate 73 and the valve main body 72 come into intimate and uniform contact by virtue of the securing force of the bolts 80, thereby suppressing the leakage of steam past the abutting surfaces.
- Moreover, since the
rotary valve 71 can be attached to and removed from the casingmain body 12 merely by removing therear cover 18 from the casingmain body 12, the ease of maintenance operations such as repair, cleaning, and replacement can be greatly improved. Furthermore, although therotary valve 71 through which the high-temperature, high-pressure steam passes reaches a high temperature, since theswash plate 31 and theoutput shaft 32, where lubrication by oil is required, are disposed on the opposite side of therotor 22 to therotary valve 71, degradation of the lubrication performance of theswash plate 31 and theoutput shaft 32 due to heating of the oil by the heat of therotary valve 71, which reaches a high temperature, can be prevented. Moreover, the oil also exhibits the function of cooling therotary valve 71, thus preventing overheating. - Although an embodiment of the present invention is explained above, the present invention can be modified in a variety of ways without departing from the spirit and scope thereof.
- For example, the expander M is illustrated for a Rankine cycle system in the embodiment, but the expander M of the present invention can be applied to any other purpose.
- The expander of the present invention is suitable for application to a Rankine cycle system, but the present invention can be applied to an expander for any purpose as long as the thermal energy and the pressure energy of a high-temperature, high-pressure working medium is converted into mechanical energy and output.
Claims (4)
1. An expander comprising:
a casing (11);
a rotor (22) rotatably supported in the casing (11); and
an axial piston cylinder group (56) arranged annularly in the rotor (22) so as to surround the axis (L) of the rotor (22), the rotor (22) being rotated by supplying, via a rotary valve (71), high-temperature, high-pressure steam to an expansion chamber (43) defined between a piston (42) and a cylinder sleeve (41) of the axial piston cylinder group (56);
characterized in that a heat-insulating space (70) is provided at a position facing the expansion chamber (43) of the rotor (22).
2. The expander according to claim 1 , wherein the rotor (22) is formed by joining, in the axial (L) direction of the rotor (22), a first rotor half (33, 34, 35) retaining the cylinder sleeve (41), which is separate from the first rotor half (33, 34, 35), and a second rotor half (38) housing the rotary valve (71), and the expansion chamber (43) is sealed by interposing a metal gasket (36) between end faces of the first rotor half (33, 34, 35) and the cylinder sleeve (41) and an end face of the second rotor half (38).
3. The expander according to either claim 1 or claim 2 , wherein a cutout (57, 58) is formed circumferentially in the rotor (22), an outer peripheral face of the cylinder sleeve (41) being exposed through the cutout (57, 58).
4. The expander according to claim 3 , wherein the surroundings of the cutout (57, 58) are covered by a heat-insulating cover (40).
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002035613A JP2003239701A (en) | 2002-02-13 | 2002-02-13 | Expansion machine |
JP2002-35613 | 2002-02-13 | ||
PCT/JP2003/000453 WO2003069125A1 (en) | 2002-02-13 | 2003-01-21 | Expansion engine |
Publications (1)
Publication Number | Publication Date |
---|---|
US20050158181A1 true US20050158181A1 (en) | 2005-07-21 |
Family
ID=27678060
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/501,521 Abandoned US20050158181A1 (en) | 2002-02-13 | 2003-01-21 | Expansion engine |
Country Status (3)
Country | Link |
---|---|
US (1) | US20050158181A1 (en) |
JP (1) | JP2003239701A (en) |
WO (1) | WO2003069125A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102008047275A1 (en) | 2007-12-13 | 2009-06-18 | Wolfram Geipel | Expansion machine for expansion of steam, has two cylindrical modules, steam plant and driving mechanism, which are detachably connected together by connecting bar and coupling |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4223594A (en) * | 1977-04-05 | 1980-09-23 | Lidio Gherner | Hydraulic motor |
US4805516A (en) * | 1986-09-12 | 1989-02-21 | Ckd Corporation | Axial air motor |
US5950425A (en) * | 1996-03-11 | 1999-09-14 | Sanshin Kogyo Kabushiki Kaisha | Exhaust manifold cooling |
US6231315B1 (en) * | 1996-06-24 | 2001-05-15 | Kabushiki Kaisha Toyoda Jidoshokki Seisakusho | Compressor having a value plate and a gasket |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5755921Y2 (en) * | 1976-08-23 | 1982-12-02 | ||
JPS5657901U (en) * | 1979-10-08 | 1981-05-19 | ||
JP2693205B2 (en) * | 1989-02-16 | 1997-12-24 | 日本碍子株式会社 | Composite casing of ceramics and metal |
JPH08218816A (en) * | 1995-02-16 | 1996-08-27 | Mitsubishi Heavy Ind Ltd | Low temperature power generation device |
JP3409687B2 (en) * | 1998-04-13 | 2003-05-26 | 三菱自動車工業株式会社 | engine |
-
2002
- 2002-02-13 JP JP2002035613A patent/JP2003239701A/en not_active Withdrawn
-
2003
- 2003-01-21 US US10/501,521 patent/US20050158181A1/en not_active Abandoned
- 2003-01-21 WO PCT/JP2003/000453 patent/WO2003069125A1/en active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4223594A (en) * | 1977-04-05 | 1980-09-23 | Lidio Gherner | Hydraulic motor |
US4805516A (en) * | 1986-09-12 | 1989-02-21 | Ckd Corporation | Axial air motor |
US5950425A (en) * | 1996-03-11 | 1999-09-14 | Sanshin Kogyo Kabushiki Kaisha | Exhaust manifold cooling |
US6231315B1 (en) * | 1996-06-24 | 2001-05-15 | Kabushiki Kaisha Toyoda Jidoshokki Seisakusho | Compressor having a value plate and a gasket |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102008047275A1 (en) | 2007-12-13 | 2009-06-18 | Wolfram Geipel | Expansion machine for expansion of steam, has two cylindrical modules, steam plant and driving mechanism, which are detachably connected together by connecting bar and coupling |
DE102008047275B4 (en) * | 2007-12-13 | 2010-09-16 | Wolfram Geipel | expander |
DE102008047275C5 (en) * | 2007-12-13 | 2013-07-11 | Renate Geipel | expander |
Also Published As
Publication number | Publication date |
---|---|
WO2003069125A1 (en) | 2003-08-21 |
JP2003239701A (en) | 2003-08-27 |
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Owner name: HONDA GIKEN KOGYO KABUSHIKI KAISHA, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MAKINO, HIROYUKI;UDA, MAKOTO;REEL/FRAME:016327/0402 Effective date: 20041118 |
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