JP2012007518A - Scroll expander - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce leakage of working fluid between the ends of orbiting scroll wraps and a panel of a fixed scroll by increasing orbital torque to obtain stable orbiting force.SOLUTION: The wraps of the fixed scroll and the orbiting scroll form involute curves. The wraps of the fixed scroll are constituted of two rolls of wraps 72a, 72b in which phases are shifted by 180° with each other around an involute base circle I, and the wraps of the orbiting scroll are constituted of two rolls of wraps 74a, 74b in which phases are shifted by 180° with each other around an involute base circle I. The fixed scroll wraps and the orbiting scroll wraps are arranged with the phases shifted by 90° with each other to the involute base circles. With this, load acting points D generated by pressure differences of gas pockets Gadjacent with the orbiting scroll wraps interposed between them are increased and high torque is loaded to the orbiting scroll wraps.

Description

  The present invention relates to a scroll expander that can efficiently convert energy of a high-pressure working fluid into rotational force.

  The scroll expander introduces a high-pressure working fluid into a gas pocket formed by meshing spiral wraps provided on the orbiting scroll and the fixed scroll, and orbits the orbiting scroll by the energy at the time of expansion of the working fluid. The turning force of the scroll is taken out as a rotational force. The extracted rotational force can be used as an auxiliary force for rotating the scroll compressor integrated with the scroll expander, or the revolving motion of the orbiting scroll can be transmitted to the rotating shaft of the generator to obtain regenerative power. Or used as power for fluid machinery such as pumps.

The scroll expander has an advantage that it can be driven by a small-scale facility and with small power compared to the turbine expander. As the working fluid, for example, surplus compressed air used in a factory can be used, or surplus high-pressure steam of a steam turbine plant can be used.
In addition, steam can be produced in the ship by the heat of the engine, high pressure steam can be introduced into the scroll expander to obtain regenerative power, and the power can be used in the ship. Alternatively, electric power obtained by using high-pressure steam with ground equipment can be supplied to a commercial power source. Patent Document 1 discloses a scroll expander including such a regenerative generator.

The curvilinear shape of the spiral wrap is appropriately selected from curvilinear shapes such as an involute curve, an arc, an ellipse, and a number of spirals based on the design purpose. As the wrap shape of the conventional scroll expander, the wrap shape of the scroll compressor is adopted as it is.
FIG. 7 shows a wrap structure of a conventional scroll expander. In FIG. 7, the fixed scroll wrap 102 forms a one-turn involute curve starting from one point on the circumference of the involute basic circle I ₁ (center O ₁ ) and spreading in a spiral shape. The orbiting scroll wrap 104 forms an involute curve that spreads in a spiral shape starting from one point on the circumference of the involute basic circle I ₂ (center O ₂ ). The starting points of both laps are arranged with a phase shift of 180 °.

The radius of the involute basic circles I ₁ and I ₂ is the same, and the center of the orbital trajectory C around which the orbiting scroll revolves coincides with the center O ₁ of the involute basic circle I ₁ of the fixed scroll wrap 102. A working fluid is introduced from an inflow port (not shown) provided at the center of the end plate of the fixed scroll, and a torque for turning the orbiting scroll around O ₁ is generated by the pressure of the working fluid. The rotating shaft of the orbiting scroll is rotated by this orbiting torque, and the rotational force is taken out as a driving force.

The fixed scroll wrap 102 and the turning scroll wrap 104 form sealed gas pockets G _{1 to} G ₈ by forming sealing points S _{1 to} S ₁₀ . The orbiting scroll is swung by the pressure of the high-pressure fluid introduced from the inflow port into the gas pocket. At this time, each gas pocket expands in volume and simultaneously moves outward along a spiral path along the wrap while the inside of the gas pocket is decompressed. The gas pocket is opened on the outer peripheral side of the wrap, and the fluid released from the gas pocket is discharged from a discharge port (not shown) provided outside the wrap.

  When the pressures of the gas pockets adjacent to each other with the orbiting scroll wrap 104 being the same, no load is applied to the orbiting scroll wrap 104, and no orbiting torque is generated in the orbiting scroll wrap 104. In the scroll compressor, in order to reduce the load on the drive motor, the wrap structure is designed so that an extra load is not applied to the orbiting scroll wrap 104 in the process of compressing the fluid to be compressed. Therefore, the fixed scroll wrap and the orbiting scroll wrap are each a single wrap, the phase of the starting point on the circumference of the involute basic circle of these wraps is shifted by 180 °, and the gas pockets of the same pressure are arranged symmetrically as much as possible. I am doing so.

That is, in FIG. 7, the gas pockets G ₁ and G ₂ , G ₃ and G ₄ , G ₅ and G ₆ , and G ₇ and G ₈ that are adjacent to each other with the orbiting scroll wrap 104 interposed therebetween have the same pressure. Therefore, no load is generated on the orbiting scroll wrap in these gas pocket regions. A load is generated only in a region where there is a pressure difference between adjacent gas pockets, and loads f _{1 to} f ₅ are generated at five locations as shown in the figure.
Therefore, in the scroll expander that employs the wrap shape of the scroll compressor, the number of load application points D at which a load for obtaining the turning torque is generated is small. Therefore, the turning torque generated in the turning scroll wrap does not increase.

  Patent Document 2 discloses a scroll compressor or scroll expander that has an improved wrap structure for fixed scrolls and orbiting scrolls in order to eliminate fluctuations in driving torque applied to the orbiting scrolls due to gas pocket pressure changes. It is disclosed.

JP 2007-32291 A JP-A-11-141473

  When the wrap structure used in the scroll compressor is employed in the scroll expander as in the prior art, the torque for turning the orbiting scroll cannot be increased. Therefore, a stable turning force cannot be obtained unless the amount and pressure of the working fluid are stable.

  In addition, since the wrap structure shown in FIG. 7 is one turn for both the fixed scroll wrap and the orbiting scroll wrap, if an attempt is made to increase the number of load application points E, the radius of the involute base circle is reduced and the spiral wrap between It is necessary to narrow the interval and increase the winding length. However, if the radius of the involute foundation circle is reduced, the turning radius C of the orbiting scroll must be reduced. Therefore, there is a problem that the distance between the turning center and the load application point cannot be obtained, and the turning torque cannot be increased.

  Moreover, since the wrap structure is a single turn, the pressure difference between adjacent gas pockets sandwiching the orbiting scroll wrap increases. On the contrary, there is also a problem that the working fluid leaks between the gas pockets sandwiching the orbiting scroll wrap.

  In view of the above-described problems of the prior art, a first object of the present invention is to increase a turning torque and obtain a stable turning force in a scroll expander. A second object is to reduce the leakage of the working fluid between the gas pockets sandwiching the orbiting scroll wrap.

In order to solve such a problem, the scroll expander of the first aspect of the present invention is:
A fixed scroll and a orbiting scroll, each of which comprises an end plate and a spiral wrap standing on the end plate, and the wrap is engaged to form a plurality of gas pockets; a rotation regulating mechanism for regulating the rotation of the orbiting scroll; A scroll expander that includes a rotating shaft that rotates in conjunction with the orbiting motion of the scroll and that orbits the orbiting scroll by the action force of the high-pressure fluid flowing into the gas pocket;
The wrap forms an involute curve, and the fixed scroll wrap and the orbiting scroll wrap are each composed of two wraps whose phases are shifted from each other by 180 ° around the involute base circle,
The fixed scroll wrap and the orbiting scroll wrap are arranged so that the phases are shifted from each other by 90 °.

  In the first device of the present invention, the fixed scroll wrap and the orbiting scroll wrap each have two windings. Therefore, even if the winding length of one wrap is not taken long, the winding length of the two wraps is summed up. The length can be long enough. Therefore, since it is not necessary to reduce the radius of the involute basic circle of each lap, the turning radius of the orbiting scroll can be increased. Thereby, since the distance between the turning center of the orbiting scroll and the load application point can be increased, the orbiting torque acting on the orbiting scroll can be increased.

In addition, by using two turns, the area of each gas pocket in the direction along the wrap can be halved compared to the conventional case. Therefore, the number of gas pockets can be increased, and thereby the number of load application points can be increased, so that the turning torque can be increased.
In addition, since the starting points on the circumference of the involute foundation circle of each of the two scrolls of the fixed scroll or the orbiting scroll are arranged 180 degrees apart from each other, while forming the involute curve between the two rolls, It becomes easy to arrange the laps while keeping them at regular intervals.

  Further, since the fixed scroll wrap and the orbiting scroll lap are arranged with the phases shifted from each other by 90 °, a sealed gas pocket can be formed between the fixed scroll wrap and the orbiting scroll wrap. Therefore, many load action points can be generated in the orbiting scroll wrap, and thereby the orbiting torque can be increased.

  Further, as described above, the area in the direction along the lap of each gas pocket can be halved, so that the pressure difference between the gas pockets sandwiching the orbiting scroll wrap is reduced, so that the working fluid leaks between the gas pockets. Can be reduced.

The scroll expander of the second invention is
A fixed scroll and a orbiting scroll, each of which comprises an end plate and a spiral wrap standing on the end plate, and the wrap is engaged to form a plurality of gas pockets; a rotation regulating mechanism for regulating the rotation of the orbiting scroll; A scroll expander that includes a rotating shaft that rotates in conjunction with the orbiting motion of the scroll and that orbits the orbiting scroll by the action force of the high-pressure fluid flowing into the gas pocket;
The wrap forms an involute curve, and the fixed scroll wrap and the orbiting scroll wrap are each composed of three winding wraps whose phases are shifted from each other by 120 ° around the involute basic circle,
The fixed scroll wrap and the orbiting scroll wrap are arranged with the phases shifted from each other by 60 °.

  In the second device of the present invention, the fixed scroll wrap and the orbiting scroll wrap are each made up of three windings. Therefore, compared with the first device of the present invention, it is not necessary to take a longer winding length of one wrap. The turning radius of the scroll can be further increased. For this reason, the distance between the turning center of the orbiting scroll and the load application point can be further increased, and thereby a larger turning torque can be generated.

  In addition, because the phases of the three wraps of the fixed scroll and the orbiting scroll are shifted by 60 ° from each other, it is easy to keep the wraps at regular intervals while forming an involute curve. Become. Further, since the fixed scroll wrap and the orbiting scroll wrap are arranged with the phases shifted from each other by 60 °, a sealed gas pocket can be formed between the fixed scroll wrap and the orbiting scroll wrap. Further, similarly to the first device of the present invention, the leakage of the working fluid between the gas pockets sandwiching the orbiting scroll wrap can be reduced.

  According to the first device of the present invention, the fixed scroll and the orbiting scroll, which are composed of the end plate and the spiral wrap erected on the end plate, and which are engaged with each other to form a plurality of gas pockets, In a scroll expander that includes a rotation restricting mechanism that restricts rotation and a rotating shaft that rotates in conjunction with the orbiting motion of the orbiting scroll and that orbits the orbiting scroll by the action force of the high-pressure fluid that has flowed into the gas pocket. An involute curve is formed, and the fixed scroll wrap and the orbiting scroll wrap are each composed of two wraps whose phases are shifted from each other by 180 ° around the involute basic circle, and the fixed scroll wrap and the orbiting scroll wrap are in phase with each other. Since it is arranged 90 ° apart, it can generate high turning torque, Therefore, even when the inflow amount and pressure of the working fluid are not stable, a stable turning force can be generated. Further, since the pressure difference between the adjacent gas pockets with the orbiting scroll wrap interposed therebetween can be reduced, the leakage of the working fluid can be reduced.

  Further, according to the second invention apparatus, the fixed scroll and the orbiting scroll which are composed of the end plate and the spiral wrap standing on the end plate, and the wrap is engaged to form a plurality of gas pockets, and the orbit. In a scroll expander that includes a rotation restricting mechanism that restricts rotation of the scroll and a rotating shaft that rotates in conjunction with the orbiting motion of the orbiting scroll, and that orbits the orbiting scroll by the action force of the high-pressure fluid that has flowed into the gas pocket. The wrap forms an involute curve, and the fixed scroll wrap and the orbiting scroll wrap are each composed of three wraps whose phases are shifted from each other by 120 ° around the involute basic circle, and the fixed scroll wrap and the orbiting scroll wrap are mutually connected. Since the phase is shifted by 60 °, it is the same as the first device of the present invention. The effect of this can be obtained.

It is front view sectional drawing of the scroll expander which concerns on 1st Embodiment of this invention apparatus. It is sectional drawing which shows the wrap structure of the scroll expander which concerns on 1st Embodiment. FIG. 3 is a partially enlarged view of FIG. 2. It is an effect | action figure of the synthetic | combination load added to the turning scroll lap of the scroll expander which concerns on 1st Embodiment. It is sectional drawing which shows the wrap structure of the comparative example with respect to the scroll expander which concerns on 1st Embodiment. It is sectional drawing which shows the wrap structure of the scroll expander which concerns on 2nd Embodiment of this invention apparatus. It is sectional drawing which shows the wrap structure of the conventional scroll expander.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention to that unless otherwise specified.

(Embodiment 1)
An embodiment of the first device of the present invention will be described with reference to FIGS. First, the overall configuration of the scroll expander 10 according to the present embodiment will be described with reference to FIG. In FIG. 1, the inside of the housing 12 is sealed except for an inlet opening 58 and an outlet opening 64 described later. A generator casing 14 incorporating a generator 16 is connected to the upper portion of the housing 12. An orbiting scroll 18 and a fixed scroll 24 are provided in the lower part of the housing 12. The orbiting scroll 18 includes an end plate 20 and a spiral wrap 22 that is erected integrally with the end plate 20. The fixed scroll 24 includes an end plate 26 and a spiral wrap 28 erected integrally with the end plate 26.

  The wrap 22 of the orbiting scroll 18 and the wrap 28 of the fixed scroll 24 are arranged to face each other, and are engaged with each other to form a sealed gas pocket G. An introduction path 66 for introducing a high-pressure working fluid s is provided in the rear casing of the fixed scroll 24, and an inlet 67 for introducing the working fluid into the gas pocket G is formed in the end plate 26 of the fixed scroll 24. . A dust seal 29 is interposed on the seal surface W where the end plate 20 of the orbiting scroll 18 and the housing end surface of the fixed scroll 24 abut.

  A support plate 19 is fixed to the rear surface of the orbiting scroll 18. A boss 30 is integrally formed at the center of the back surface 19 a of the support plate 19. An eccentric shaft 34 is fitted to the boss portion 30 via a sleeve 32. The eccentric shaft 34 is in a position where the axis is eccentric with respect to the rotary shaft 36 provided integrally therewith.

  A shaft housing part 60 integrated with the housing 12 is provided inside the housing 12, and a bearing device 38 including a rotary roller bearing is housed in the shaft housing part 60. In the generator casing 14, bearing devices 40 and 41 including rotary roller bearings are provided, and the rotating shaft 36 is rotatably supported by the bearing device 38 and the bearing devices 40 and 41. Further, on the back surface 19a of the support plate 19, a rotation restricting mechanism 42 that restricts the rotation of the orbiting scroll 18 and causes the orbiting scroll 18 to perform only a revolving motion is provided.

  Hereinafter, the configuration of the rotation restriction mechanism 42 will be described. A shaft housing portion 44 is formed in the housing 12, and a bearing device 48 including a rotary roller bearing is housed in the shaft housing portion 44. A pin crankshaft 46 is rotatably supported via a bearing device 48. In addition, a shaft storage portion 50 is integrally provided on the back surface 19 a of the support plate 19, and a bearing device 54 including a rotary roller bearing is stored in the shaft storage portion 50. An eccentric pin 52 connected to a position where the axis is eccentric with respect to the pin crankshaft 46 is rotatably supported via a bearing device 54.

  A plurality (four) of blower blades 56 are mounted on the outer peripheral surface of the rotating shaft 36 between the bearing device 38 and the bearing device 40. A plurality of inlet openings 58 are formed in the circumferential direction in the housing 12 in the vicinity of the upper side of the blower blades 56. A plurality of ventilation holes 62 are formed in the shaft housing 60 in the circumferential direction of the rotation shaft 36. A plurality of circular outlet openings 64 are formed in the housing 12 near the outer peripheral surface of the fixed scroll 24 in the circumferential direction.

  In the scroll expander 10 having such a configuration, when the high-pressure working fluid provided in the central portion of the fixed scroll 24 is, for example, high-pressure steam s, the high-pressure steam s is supplied to the gas pocket G, and the pressure of the working fluid The orbiting scroll 18 is turned. Since the rotation of the orbiting scroll 18 is restricted by the rotation restricting mechanism 42, only the revolution movement (orbiting movement) is performed by the eccentric shaft 34. When the orbiting scroll 18 performs the orbiting motion, the rotating shaft 36 rotates. And when the rotating shaft 36 rotates, the rotor 16a of the generator 16 rotates and electric power is generated.

  Further, the rotation blade 36 rotates, whereby the blower blade 56 rotates. As the air blowing blade 56 rotates, the outside air a is introduced into the housing 12 from the inlet opening 44. The outside air “a” introduced into the housing 12 passes through the ventilation hole 62, flows along the back surface 18 a of the orbiting scroll 18, and passes around the rotation restricting mechanism 42. Further, it flows along the outer peripheral portions of the orbiting scroll 18 and the fixed scroll 24, and is discharged from the outlet opening 64 to the outside of the housing 12.

  According to the scroll expander 10 having such a configuration, the high-pressure steam s leaked from the sealing surface W due to the wind pressure of the flow of the outside air a formed in the housing 12 is not directed to the back side of the orbiting scroll 18 but is reversed. It is discharged in the direction from the outlet opening 64 to the outside of the housing. Therefore, in-housing devices such as the bearing devices 38, 40, 48, and 54 disposed on the back side of the orbiting scroll 18 do not rust due to the condensed water of the steam s leaked from the seal surface W. In addition, the condensed water is not mixed into the lubricant to reduce the viscosity of the lubricant, so that the lubricant does not flow out or the lubricant is not emulsified.

  Further, the flow path of the outside air a is formed so as to face the outer peripheral portion of the bearing device 38 of the rotating shaft 36, the bearing devices 48 and 54 of the rotation restricting mechanism 42, and the seal surface W. There is also the additional effect of cooling the class. Therefore, even if the device pair in the housing 12 is heated by the high-temperature and high-pressure steam s, the temperature of these devices can be lowered, so that the reliability of the devices can be maintained.

  Further, since the blower blades 56 are mounted on the rotary shaft 36, a driving device for the blower blades 56 is not necessary, and the configuration of the blower blades 56 can be simplified and reduced in cost. Therefore, it is easy to secure a ventilation path for the outside air a in the housing 12.

Next, the configuration of the wrap 22 of the orbiting scroll 28 and the wrap 28 of the fixed scroll 24 will be described with reference to FIGS. The fixed scroll wrap 72 and the orbiting scroll wrap 74 are each composed of two wraps 72a, 72b and 74a, 74b. These wraps form an involute curve. The fixed scroll wraps 72a and 72b start from one point A ₁ and A ₂ on the circumference of the involute basic circle I ₁ (center O ₁ ), respectively. The starting points A ₁ and A ₂ have a phase difference of 180 ° on the circumference of the involute basic circle I ₁ .

The orbiting scroll wraps 74a and 74b start from one point B ₁ and B ₂ on the circumference of the involute basic circle I ₂ (center O ₂ ), respectively. The starting points B ₁ and B ₂ have a phase difference of 180 ° on the circumference of the involute basic circle I ₂ . The starting points A ₁ and A ₂ and the starting points B ₁ and B ₂ are arranged with a phase difference of 90 ° from each other on the circumference of the involute basic circles I ₁ and I ₂ . Note that the involute basic circle I ₁ and the involute basic circle I ₂ have the same radius.

Further, the center O ₂ of the involute basic circle I ₁ coincides with the starting point B _2, and the center O ₁ coincides with the center of the turning trajectory C of the orbiting scroll wraps 74a and 74b. Further, a working fluid inlet 67 is formed in the end plate 26 of the fixed scroll 24 concentrically with the involute basic circle I ₁ .
Sealing points S ₁ to ₉ are formed between the wraps, and a plurality (seven) of gas pockets G ₁ to ₇ are formed in the region between the sealing points. Each gas pocket expands due to the pressure of the working fluid flowing into the central inlet 67, and at the same time reduces the internal pressure while following a spiral path along the wrap toward the outside, and is provided on the outer peripheral side of the wrap. Discharged from the outlet.

As shown in FIG. 3, when there is a pressure difference between the pressure Pi of the inner gas pocket and the pressure Pφ of the outer gas pocket across the orbiting scroll wrap (Pφ <Pi, ΔP = Pi−Pφ), the orbiting scroll wrap the load due to the pressure difference of the two gas pockets that acts on each of the regions of the acts in the tangential direction of the circumference of the involute base circle I _2. The resultant force of the load acting on each area of the orbiting scroll wrap is added to the load application point D.

In FIG. 2, the load action points D that the gas pockets G ₁ to ₇ act on the orbiting scroll lap and the resultant forces that act on the load action points D are represented by fa 1 to fa 4 and fb 1 to fb 3.
FIG. 4 shows load acting points of a load fa (fa = fa1 + fa2 + fa3 + fa4), a load fb (fb = fb1 + fb2 + fb3), and a resultant force F (F = fa + fb), which are obtained by combining the resultant forces added to the respective gas acting points G. Yes. In the figure, Rc is the turning radius of the orbiting scroll _{18, R i2} is the radius of the involute base circle _{I 2.}

In FIG. 4, X is calculated by the formula X = (fa−fb) · R _i2 / (fa + fb), and the torque τ generated in the orbiting scroll 18 can be calculated by τ = F (Rc−X).
In this embodiment, the center O ₁ of the involute basic circle I _{1 and} the center of the turning locus C coincide with each other, and the radius of the involute basic circle I ₁ and the radius Rc of the turning locus C are shown in FIG. Is substantially the same.

According to the present embodiment, the pressures of the gas pockets adjacent to each other with the orbiting scroll wraps 74a and 74b interposed therebetween are different from each other. Therefore, the same number (seven) of load application points D as the number of formed gas pockets G ₁ to G ₇ are generated in the orbiting scroll wrap.
Moreover, since the fixed scroll wrap and the orbiting scroll wrap are each constituted by two turns, the wrap length can be increased without reducing the radius of the involute basic circles I ₁ and I ₂ as compared with the case of one turn.

Therefore, since the radius of the turning trajectory C can be increased, the distance L between the center O ₁ of the turning trajectory C and the acting point of the resultant force F can be increased, thereby increasing the turning torque applied to the orbiting scroll. Further, since the fixed scroll wrap and the orbiting scroll wrap each have two turns, the area of each gas pocket in the direction along the wrap can be halved compared to the conventional example shown in FIG. Since the number of gas pockets formed oppositely by half is increased, the number of load application points D acting on the orbiting scroll wraps 74a and 74b increases, and this can also increase the orbiting torque τ.

As described above, since the energy of the working fluid can be efficiently converted into the rotational force, a stable rotational force can be obtained even if the inflow amount and pressure of the working fluid are not stable.
Further, compared to the conventional example, the pressure difference between the adjacent gas pockets can be reduced by increasing the number of gas pockets by sandwiching the orbiting scroll wrap. Therefore, the leakage of the working fluid between the gas pockets can be reduced.

FIG. 5 shows, as a comparative example, a wrap structure in which the phase difference on the involute basic circles I ₁ and I ₂ between the fixed scroll wrap 72a (or 72b) and the orbiting scroll wrap 74a (or 74b) is 45 °. ing. As illustrated, in this comparative example, the sealing points S _{1 to} S ₄ are formed between the fixed scroll wrap and the orbiting scroll wrap, but the number of gas pockets G to be formed and the capacity of each gas pocket G are reduced. ing. This makes it impossible to increase the turning torque that acts on the turning scroll wrap.

  In the present embodiment, the generator 16 is connected to the rotary shaft 36. Instead, a rotary machine such as a pump is connected to the rotary shaft 36, and the rotational force of the rotary shaft 36 is directly used as the driving force of the rotary machine. You may make it utilize as. Alternatively, the rotary shaft 36 may be coupled to the rotary shaft of the scroll compressor, and the rotational force obtained by the scroll expander 10 may be used as an assist for the driving force of the scroll compressor.

(Embodiment 2)
Next, an embodiment of the first inventive device will be described with reference to FIG. In FIG. 6, in this embodiment, each of the fixed scroll wrap and the orbiting scroll wrap is composed of three wraps. Fixed scroll wrap 82a~c the three is the starting point of the circumference on the involute base circle _{I 1,} these starting points _{A 1,} A 2, _{A 3} has a phase difference of 120 °. Also, three of the orbiting scroll wrap 84a~c is a starting point of the circumference on the involute base circle _{I 2,} these origins _{B 1,} B 2, _{B 3} has a phase difference of 120 °. The starting point of each fixed scroll wrap and the starting point of each orbiting scroll wrap are arranged so as to have a phase difference of 60 °. The working fluid inlet 86 is arranged concentrically with the involute foundation circle I ₁ .

In this embodiment, a number of sealing points _S 1 to S ₈ are formed, a number of gas pockets _{G 1 to 5} is formed. That is, as in the first embodiment, the pressures of the gas pockets adjacent to each other across the orbiting scroll wrap are different at any part. Therefore, the same number (five) of load application points D as the number of gas pockets G _{1 to 5} formed are generated in the orbiting scroll wrap.
Moreover, since the fixed scroll wrap and the orbiting scroll wrap are each constituted by three turns, the wrap length can be increased without reducing the radius of the involute basic circles I ₁ and I ₂ as compared with the case of two turns.

Therefore, since the radius of the turning trajectory C can be increased, the distance L between the center O ₁ of the turning trajectory C and the acting point of the resultant force F can be increased, thereby increasing the turning torque applied to the orbiting scroll. In addition, since the fixed scroll wrap and the orbiting scroll wrap each have three turns, the area of each gas pocket in the direction along the wrap can be further reduced as compared with the first embodiment. And since the number of gas pockets formed in the opposite direction can be increased by the reduced amount, the number of load application points D acting on the orbiting scroll wrap increases, thereby increasing the orbiting torque τ.

As described above, since the energy of the working fluid can be efficiently converted into the rotational force, a stable rotational force can be obtained even if the inflow amount and pressure of the working fluid are not stable.
Further, since the number of gas pockets can be increased, the pressure difference between adjacent gas pockets can be reduced with the orbiting scroll wrap interposed therebetween. Therefore, the leakage of the working fluid between the gas pockets can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the scroll expander which can convert the energy which a working fluid has efficiently into rotational force, and can obtain the stable rotational force is realizable.

DESCRIPTION OF SYMBOLS 10 Scroll expander 12 Housing 14 Generator casing 16 Generator 16a Rotor 18 Orbiting scroll 19 Support plate 19a Back surface 20, 26 End plate 22, 28 Wrap 24 Fixed scroll 29 Dust seal 30 Boss part 32 Sleeve 34 Eccentric shaft 36 Rotating shaft 38, 40 , 41, 48, 54 Bearing device 42 Rotation restricting mechanism 44, 50, 60 Shaft storage portion 46 Pink rank shaft 52 Eccentric pin 56 Blower blade 58 Inlet opening 62 Ventilation hole 64 Outlet opening 66 Inlet path 67, 86 Inlet 72 a, 72 b , 82a, 82b, 82c fixed scroll wrap 74a, 74b, 84a, 84b, 84c orbiting scroll wrap _{A 1, A 2, B 1} , B 2 origin C turn trajectory D load application point _{G, G 1 to 8} gas pockets L distance Rc turn trajectory radius R _i2 Nboryuto base circle _{I 2} of radius S _{1 to 10} sealed point W sealing surface a fresh air s autoclaving f1~5, fa1~a4, fb1~b3 load

Claims (2)

A fixed scroll and a orbiting scroll, each of which comprises an end plate and a spiral wrap standing on the end plate, and the wrap is engaged to form a plurality of gas pockets; a rotation regulating mechanism for regulating the rotation of the orbiting scroll; A scroll expander that includes a rotating shaft that rotates in conjunction with the orbiting motion of the scroll and that orbits the orbiting scroll by the action force of the high-pressure fluid flowing into the gas pocket;
The wrap forms an involute curve, and the fixed scroll wrap and the orbiting scroll wrap are each composed of two wraps whose phases are shifted from each other by 180 ° around the involute base circle,
A scroll expander characterized in that the phase of the orbiting scroll wrap is shifted by 90 ° with respect to the fixed scroll wrap. A fixed scroll and a orbiting scroll, each of which comprises an end plate and a spiral wrap standing on the end plate, and the wrap is engaged to form a plurality of gas pockets; a rotation regulating mechanism for regulating the rotation of the orbiting scroll; A scroll expander that includes a rotating shaft that rotates in conjunction with the orbiting motion of the scroll and that orbits the orbiting scroll by the action force of the high-pressure fluid flowing into the gas pocket;
The wrap forms an involute curve, and the fixed scroll wrap and the orbiting scroll wrap are each composed of three winding wraps whose phases are shifted from each other by 120 ° around the involute basic circle,
A scroll expander characterized in that the phase of the orbiting scroll wrap is shifted by 60 ° with respect to the fixed scroll wrap.

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