JP2011241765A - Rotary expansion machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary expansion machine capable of reducing pushing force of a suction control member to a first blocking member.SOLUTION: The rotary expansion machine 4A has the first blocking member 46 and a second blocking member 49 blocking an operation chamber 43. A suction hole 4a is arranged in the first blocking member 46 so as to extend from a pressure receiving surface 46b facing an opposite side of the operation chamber 43 to the operation chamber 43. The suction hole 4a is opened and closed by a suction control member 48 sliding on the pressure receiving surface 46b with the rotation of a shaft 81A. A recess 40a in communication with a suction space 40 covered with one of the sliding side 48d of the suction control member 48 and the pressure receiving surface 46b of the first blocking member 46, forming a pressure chamber surrounded by the suction control member 48 and the first blocking member 46, and filled with operation fluid before expansion is arranged in the other one thereof.

Description

  The present invention relates to a rotary expander.

  Conventionally, a rotary expander that expands a working fluid by eccentrically rotating one piston is known. In such a rotary expander, the suction stroke into the working chamber and the expansion stroke in the working chamber are executed by opening and closing the suction hole. For example, Patent Document 1 discloses a rotary expander 100 as shown in FIG.

  The rotary expander 100 includes a shaft 111 having an eccentric portion 112, a piston 122 fitted to the eccentric portion 112, and a cylinder 121 that houses the piston 122. A crescent-shaped working chamber 123 is formed between the inner peripheral surface of the cylinder 121 and the outer peripheral surface of the piston 122. The working chamber 123 is partitioned into a suction side and a discharge side by a partition member (not shown).

  Furthermore, the rotary expander 100 includes a first closing member 124 that closes the working chamber 123 from one axial direction of the shaft 111, and a second closing member 125 that closes the working chamber 123 from the other axial direction of the shaft 111. It has. Further, a bearing member 126 is laminated on the first closing member 124, and the bearing member 126 is provided with a suction passage 127 through which the working fluid before expansion flows.

  The first closing member 124 is provided with a suction hole 101 for introducing the working fluid from the suction passage 127 to the working chamber 123. The suction hole 101 is opened and closed by a rotating plate 130 disposed between the first closing member 124 and the bearing member 126. As shown in FIG. 12B, the rotating plate 130 has a shielding part 132 that shields the suction hole 101 and an opening 131 that exposes the suction hole 101, and slides on the first closing member 124. It rotates with the shaft 111.

JP-A-8-82296

  By the way, in the rotary expander 100 shown in FIG. 12A, a stepped portion that is slightly deeper than the thickness of the rotating plate 130 is provided on the surface of the first closing member 124 on the bearing member 126 side. A rotating plate 130 is disposed on the surface. However, in such a configuration, the high-pressure working fluid before expansion enters between the rotating plate 130 and the bearing member 126, and the rotating plate 130 is pressed against the first closing member 124 by the working fluid. Thereby, the frictional force between the rotating plate 130 and the first closing member 124 increases, and the force required to rotate the rotating plate 130 increases. As a result, for example, when the rotary expander 100 is used for the purpose of recovering power from the expanding working fluid, the recoverable power decreases.

  In view of such circumstances, an object of the present invention is to provide a rotary expander that can reduce the pressing force of the suction control member to the first closing member.

  In order to solve the above-mentioned problems, the present invention is a rotary expander that expands the working fluid sucked from the suction hole and discharges it from the discharge hole, and is fitted to the shaft having an eccentric part and the eccentric part. A piston, a cylinder that houses the piston, a partition member that divides a working chamber formed between the piston and the cylinder into a suction side and a discharge side, and the working chamber from one of the axial directions of the shaft A first closing member that closes, having a pressure receiving surface facing away from the working chamber, wherein the suction hole extends from the pressure receiving surface to the working chamber; A second closing member that closes the chamber from the other axial direction of the shaft, and the pressure receiving surface, which is disposed so as to face the suction space filled with the working fluid before expansion together with the pressure receiving surface, and the pressure receiving surface as the shaft rotates Up A suction control member that opens and closes the suction hole by sliding, and covers one of the pressure receiving surface of the suction control member and the pressure receiving surface of the first closing member with the other. A rotary expander is provided in which a pressure chamber surrounded by the suction control member and the first closing member is formed and a recess communicating with the suction space is provided.

  According to the above configuration, since the working fluid before expansion can be guided into the pressure chamber surrounded by the suction control member and the first closing member, both the suction control member and the first closing member can be guided by this working fluid. A separating force can be applied. Thereby, the pressing force by which the suction control member is pressed against the first closing member by the working fluid in the suction space can be reduced, and the suction control member can be operated with a small force.

1 is a longitudinal sectional view of a fluid machine using a rotary expander according to a first embodiment of the present invention. II-II sectional view of FIG. III-III sectional view of FIG. FIG. 1 is an enlarged partial longitudinal sectional view of the rotary expander according to the first embodiment of the present invention. (A) is the perspective view which looked at the suction | inhalation control member employ | adopted in 1st Embodiment of this invention from the lower side, (b) is the perspective view which looked at the same suction | inhalation control member from the upper side Partial longitudinal sectional view of a rotary expander according to a second embodiment of the present invention Partial longitudinal sectional view of a rotary expander according to a third embodiment of the present invention Partial longitudinal sectional view of a rotary expander according to a fourth embodiment of the present invention Partial longitudinal sectional view of a rotary expander according to a fifth embodiment of the present invention The perspective view which looked at the suction | inhalation control member and 1st closure member which were employ | adopted in 5th Embodiment of this invention from the lower side 1 is a configuration diagram of a refrigeration cycle apparatus in which the fluid machine shown in FIG. 1 is incorporated. (A) is a longitudinal cross-sectional view of a conventional rotary expander, (b) is a perspective view of a rotary plate and a shaft used in the rotary expander.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by the following embodiment.

(First embodiment)
FIG. 1 shows a fluid machine 8 using a rotary expander 4A according to a first embodiment of the present invention. The fluid machine 8 houses a rotary expander 4A (hereinafter simply referred to as “expander 4A”), a rotary compressor 6 (hereinafter simply referred to as “compressor 6”), and these 4A and 6. The closed container 80 is provided. In the fluid machine 8, the shaft 81 </ b> A of the expander 4 </ b> A and the shaft 81 </ b> B of the compressor 6 are integrated so that their axial centers are aligned on the same straight line. Is driven.

  In the present embodiment, the shafts 81 </ b> A and 81 </ b> B extend in the vertical direction, the expander 4 </ b> A is disposed in the lower part in the sealed container 80, and the compressor 6 is disposed in the upper part in the sealed container 80. However, the positional relationship between the expander 4A and the compressor 6 may be upside down, the shafts 81A and 81B extend in the horizontal direction, and the expander 4A and the compressor 6 are arranged in the horizontal direction. Also good.

  The sealed container 80 is filled with lubricating oil to such an extent that the oil level is located above the compressor 6. The shafts 81A and 81B are formed with oil supply passages 81a that penetrate the shafts 81A and 81B in the axial direction and open to outer peripheral surfaces of eccentric portions 81b and 81c, which will be described later. The lubricating oil in the sealed container 80 is supplied to the sliding portion of the expander 4A and the compressor 6 through the oil supply path 81a.

  The fluid machine 8 is incorporated in the refrigeration cycle apparatus 1 as shown in FIG. That is, the main compressor 2, the radiator 3, the expander 4A, the evaporator 5, and the compressor 6 as a sub-compressor that preliminarily boosts the working fluid are first to fifth flow paths (pipes) 7a to 7e. Thus, a working fluid circuit 7 that circulates the working fluid (refrigerant) is configured in this order. As the working fluid, for example, carbon dioxide or alternative chlorofluorocarbon can be used. In the refrigeration cycle apparatus 1 shown in FIG. 11, the first bypass 91 that bypasses the evaporator 5 and the compressor 6, and the expander as a configuration for easily starting the fluid machine 8 independently by the pressure of the working fluid. 4 and a second bypass path 92 that bypasses the evaporator 5.

<Compressor>
The compressor 6 pressurizes the working fluid sucked from the compressor suction hole 6a and discharges it from the compressor discharge hole 6b. Specifically, as shown in FIG. 2, the compressor 6 includes a shaft 81B having an eccentric portion 81c, a compressor piston 62 fitted to the eccentric portion 81c, and a compressor cylinder 61 that houses the compressor piston 62. have. The compressor cylinder 61 has an inner peripheral surface that forms a cylindrical surface whose central axis coincides with the axis of the shaft 81B, and the compressor piston 62 is located inside the compressor cylinder 61 as the shaft 81B rotates. Eccentric rotation along the circumference. That is, a crescent-shaped compressor working chamber 63 is formed between the inner peripheral surface of the compressor cylinder 61 and the outer peripheral surface of the compressor piston 62.

  The compressor working chamber 63 is partitioned into a suction side 63a and a discharge side 63b by a compressor partition member 64. A compressor suction hole 6a is opened in a portion adjacent to the compressor partition member 64 on the suction side 63a, and a compressor discharge hole 6b is opened in a portion adjacent to the compressor partition member 64 on the discharge side 63b. Yes.

  The compressor partition member 64 has a plate shape and is reciprocally inserted into a groove 61 a provided in the compressor cylinder 61. The groove 61 a opens into the compressor working chamber 63 on a straight line passing through the axis of the shaft 81. Between the bottom of the groove 61 a and the compressor partition member 64, an urging means 65 that presses the compressor partition member 64 against the outer peripheral surface of the compressor piston 62 is disposed.

  The biasing means 65 can be constituted by, for example, a compression coil spring. Further, the biasing means 65 may be a so-called gas spring or the like in which a back space between the rear end of the compressor partition member 64 and the bottom of the groove 61a is a sealed space. Of course, the urging means 65 may be constituted by a plurality of types of springs such as a compression coil spring and a gas spring. The compressor piston 62 and the compressor partition member 64 may be integrated, and the urging unit 65 may not be provided.

  As shown in FIG. 1, the compressor 6 includes a first closing member 66 that closes the compressor working chamber 63 from the side opposite to the expander 4, and a cover member 67 that is disposed above the first closing member 46. And a second closing member 49 that closes the compressor working chamber 63 from the expander 4 side.

  The first closing member 66 also has a function as a bearing member that rotatably supports the upper portion of the shaft 81B. The compressor cylinder 61, the first closing member 66, and the cover member 67 are stacked on the second closing member 49 in this order. A suction pipe 84 that penetrates the sealed container 80 is connected to the compressor cylinder 61, and a discharge pipe 85 that penetrates the sealed container 80 is connected to the first closing member 66.

  Both the first closing member 66 and the second closing member 49 have a flat disk shape in the axial direction of the shaft 81B, the shaft 81B penetrates the center of the first closing member 66, and the center of the second closing member 49 The shafts 81B and 81A pass therethrough. The cover member 67 also has a flat disk shape in the axial direction of the shaft 81B, and an opening for exposing the upper end portion of the shaft 81B is provided at the center thereof. In the illustrated example, the compressor cylinder 61 is provided with a compressor suction hole 6a, and the first closing member 66 is provided with a compressor discharge hole 6b.

  The compressor suction hole 6 a penetrates the compressor cylinder 61 sideways, opens in a substantially circular shape on the inner peripheral surface of the compressor cylinder 61, and communicates with the suction pipe 84. That is, the low-pressure working fluid from the evaporator 5 shown in FIG. 11 is guided to the suction side 63a of the compressor working chamber 63 from the compressor suction hole 6a via the suction pipe 84.

  On the other hand, the first closing member 66 is formed with a discharge chamber 66 a that opens on the upper surface and is closed by the cover member 67, and a discharge path 66 b that extends from the discharge chamber 66 a to the discharge pipe 85. The compressor discharge hole 6b has a circular cross section and extends through the first closing member 66 in the axial direction of the shaft 81B so as to extend straight from the lower surface of the first closing member 66 to the discharge chamber 66a. It communicates with the discharge pipe 85 through 66b. That is, the working fluid in the discharge side 63b of the compressor working chamber 63 is discharged to the main compressor 2 shown in FIG. 11 through the compressor discharge hole 6b, the discharge chamber 66a, the discharge passage 66b, and the discharge pipe 85.

  A discharge valve 68 that automatically opens and closes the compressor discharge hole 6b by the pressure on the discharge side 63b of the compressor working chamber 63 by elastic deformation is disposed in the discharge chamber 66a.

<Expander>
The expander 4A recovers power from the working fluid by expanding the working fluid sucked from the expander suction hole 4a and discharging it from the expander discharge hole 4b. Specifically, as shown in FIG. 3, the expander 4A includes a shaft 81A having an eccentric portion 81b, an expander piston 42 fitted to the eccentric portion 81b, and an expander cylinder 41 that accommodates the expander piston 42. have. The expander cylinder 41 has an inner peripheral surface that forms a cylindrical surface whose central axis coincides with the axis of the shaft 81A, and the expander piston 42 is located inside the expander cylinder 41 as the shaft 81A rotates. Eccentric rotation along the circumference. That is, a crescent-shaped expander working chamber 43 is formed between the inner peripheral surface of the expander cylinder 41 and the outer peripheral surface of the expander piston 42.

  The expander working chamber 43 is partitioned into an intake side 43a and a discharge side 43b by an expander partition member 44. An expander suction hole 4a is opened in a portion adjacent to the expander partition member 44 on the suction side 43a, and an expander discharge hole 4b is opened in a portion adjacent to the expander partition member 44 on the discharge side 43b. Yes.

  The expander partition member 44 has a plate shape and is reciprocally inserted into a groove 41 a provided in the expander cylinder 41. The groove 41a opens into the expander working chamber 43 on a straight line passing through the axis of the shaft 81A. Between the bottom of the groove 41a and the expander partition member 44, an urging means 45 that presses the expander partition member 44 against the outer peripheral surface of the expander piston 42 is disposed.

  The biasing means 45 can be constituted by, for example, a compression coil spring. Further, the urging means 45 may be a so-called gas spring or the like in which the back space between the rear end of the expander partition member 44 and the bottom of the groove 41a is a sealed space. Of course, the biasing means 45 may be constituted by a plurality of types of springs such as a compression coil spring and a gas spring. Note that the expander piston 42 and the expander partition member 44 may be integrated, and the biasing means 45 may not be provided.

  Further, as shown in FIG. 1, the expander 4 </ b> A includes a first closing member 46 that closes the expander working chamber 43 from the side opposite to the compressor 6 (one in the axial direction of the shaft 81 </ b> A), and the first closing member 46. And a second closing member 49 that closes the expander working chamber 43 from the compressor 6 side (the other in the axial direction of the shaft 81A). That is, the second closing member 49 is shared by the compressor 6 and the expander 4A. However, the compressor 6 and the expander 4A may have a second closing member separately.

  The bearing member 47 is fixed to the inner peripheral surface of the hermetic container 80, and rotatably supports the lower portion of the shaft 81A. The first closing member 46, the expander cylinder 41, and the second closing member 49 are stacked on the bearing member 47 in this order. A suction pipe 82 and a discharge pipe 83 that pass through the sealed container 80 are connected to the bearing member 47.

  The first closing member 46 has a flat disk shape in the axial direction of the shaft 81A, and the shaft 81A passes through the center thereof. In the present embodiment, the first closing member 46 is provided with an expander suction hole 4a, and the second closing member 49 and the expander cylinder 41 are provided with an expander discharge hole 4b. However, the expander discharge hole 4 b may be provided in the first closing member 46.

  On the lower surface of the first closing member 46, a stepped portion 46a, which is a circular recess whose center coincides with the axis of the shaft 81A, is provided. The step 46 a and the bearing member 47 form an annular suction chamber that surrounds the shaft 81 </ b> A. In other words, the first closing member 46 separates the expander working chamber 43 and the suction chamber. Further, the flat bottom surface of the stepped portion 46a, that is, the ceiling surface of the suction chamber constitutes a pressure receiving surface 46b facing the opposite side of the expander working chamber 43.

  A suction control member 48 that opens and closes the expander suction hole 4a by sliding on the pressure receiving surface 46b as the shaft 81A rotates is disposed in the suction chamber. The suction control member 48 is fixed to the shaft 81 so as to rotate together with the shaft 81A.

  As will be described in detail later, the suction control member 48 has a disk shape that is flat in the axial direction of the shaft 81A and is slightly smaller than the suction chamber. Therefore, a suction space 40 is formed around and below the suction control member 48 in the suction chamber. That is, the suction control member 48 faces the suction space 40 together with the pressure receiving surface 46b. Further, the bearing member 47 is provided with a suction passage 47 a that communicates the suction space 40 and the suction pipe 82. For this reason, the suction space 40 is filled with the working fluid before expansion.

  The expander suction hole 4a passes through the first closing member 46 in the axial direction of the shaft 81A so as to extend from the pressure receiving surface 46b to the expander working chamber 43. Thus, the expander suction hole 4a communicates with the suction pipe 82 via the suction space 40 and the suction path 47a. That is, the high-pressure working fluid from the radiator 3 shown in FIG. 11 is guided from the expander suction hole 4a to the suction side 43a of the expander working chamber 43 through the suction pipe 82, the suction passage 47a, and the suction space 40. . The expander suction hole 4a does not necessarily extend in the axial direction of the shaft 81A, and may extend obliquely with respect to the axial direction of the shaft 81A.

  In the present embodiment, as shown in FIG. 3, the expander suction hole 4 a extends in an arc shape from the vicinity of the expander partition member 44 along the inner peripheral surface of the expander cylinder 41. However, the expander suction hole 4ag may be circular as shown in FIG. 10, for example.

  On the other hand, as shown in FIG. 3, the expander discharge hole 4 b includes a vertical groove 41 b that is formed on the inner peripheral surface of the expander cylinder 41 and that is recessed outward in the radial direction, and a lower surface of the second closing member 49. 41b and a lateral groove 43a formed so as to extend radially outward from a corresponding position. The outer end of the expander discharge hole 4 b communicates with the discharge pipe 83 via a discharge path 4 c formed so as to extend across the expander cylinder 41, the first closing member 46 and the bearing member 47. That is, the working fluid in the discharge side 43b of the expander working chamber 43 is discharged to the evaporator 5 shown in FIG. 11 through the expander discharge hole 4b, the discharge path 4c, and the discharge pipe 83.

  Next, the suction control member 48 will be described in detail with reference to FIG. 4 and FIGS. 5 (a) and 5 (b).

  The suction control member 48 includes a shielding portion 48c that shields the expander suction hole 4a and an opening 48a that exposes the expander suction hole 4a. In the present embodiment, the opening 48a is formed by an arc-shaped through hole that penetrates the suction control member 48 in the axial direction of the shaft 81A. In addition, a fitting hole 48e inserted through the shaft 81A is formed at the center of the suction control member 48. For example, the suction control member 48 is engaged with the shaft 81 </ b> A by a key in the fitting hole 48.

  The angular range and position of the opening 48a is such that, for example, the expander suction hole 4a is partially or completely exposed while the expander piston 41 rotates about 140 ° from the top dead center, and the expander suction hole 4a is exposed during other periods. Is set to be completely shielded by the shield 48c. Here, the top dead center is a position where the sliding point of the expander piston 42 sliding on the inner peripheral surface of the expander cylinder 41 coincides with the expander partition member 44.

  Furthermore, in the present embodiment, a recess 40a that forms a pressure chamber that is covered with the pressure receiving surface 46b and surrounded by the suction control member 48 and the first closing member 46 is formed on the sliding surface 48d that contacts the pressure receiving surface 46b of the suction control member 48. Is provided. The recess 40a is provided in a ring shape centering on the axis of the shaft 81A on the inner side of the opening 48a. The recess 48a does not necessarily have to be continuous in the circumferential direction, and may be divided in the circumferential direction.

  In addition, the suction control member 48 is provided with a plurality of communication passages 40b that allow the recess 40a and the suction space 40 to communicate with each other. Each communication passage 40b is formed of a circular through-hole that extends in the axial direction of the shaft 81A from the recess 40a and opens on the lower surface of the suction control member 48. The shape and quantity of the communication path 40b are not particularly limited. For example, even if only one arc-shaped communication path 40b having a smaller radial width than the recess 40a is provided in the suction control member 48. Good.

  In the expander 4A having such a configuration, the working fluid before expansion can be guided into the pressure chamber (recess 40a) surrounded by the suction control member 48 and the first closing member 46, and therefore suction control is performed by this working fluid. A force that separates both the member 48 and the first closing member 46 can be applied. Thereby, the pressing force by which the suction control member 48 is pressed against the first closing member 46 by the working fluid in the suction space 40 can be reduced, and the suction control member 48 can be rotated with a small force.

  Incidentally, at least one of the sliding surface 48d of the suction control member 48 and the pressure receiving surface 46b of the first closing member 46 is preferably subjected to a hard coating treatment from the viewpoint of reducing wear. Examples of such a hard coating treatment include formation of a coating with alumite, chrome plating, titanium nitride, diamond-like carbon, and the like.

  In addition, a solid lubricant is preferably applied to at least one of the sliding surface 48d of the suction control member 48 and the pressure receiving surface 46b of the first closing member 46 from the viewpoint of reducing friction between them. . Examples of such a solid lubricant include molybdenum disulfide, graphite, tungsten disulfide, graphite fluoride, and boron nitride.

(Second Embodiment)
Next, a rotary expander 4B according to a second embodiment of the present invention (hereinafter simply referred to as “expander 4B”) will be described with reference to FIG. The expander 4B of this embodiment comprises the fluid machine 8 (refer FIG. 1) integrated in the refrigerating-cycle apparatus 1 shown in FIG. 11 similarly to 1st Embodiment. This also applies to third to fifth embodiments described later. In the present embodiment and third to fifth embodiments to be described later, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the present embodiment, the first closing member 46 is provided with a communication path 40 b that communicates the recess 40 a and the suction space 40. More specifically, the communication path 40 b is configured by a groove provided on the lower surface of the first closing member 46 so as to extend from a position corresponding to the recess 40 a to the outside of the suction control member 48.

  Even with such a configuration, the same effect as in the first embodiment can be obtained.

(Third embodiment)
Next, a rotary expander 4C according to a third embodiment of the present invention (hereinafter simply referred to as “expander 4C”) will be described with reference to FIG.

  In the present embodiment, a ring-shaped recess 40 a is provided on the pressure receiving surface 46 b of the first closing member 46, and the recess 40 a is covered with the sliding surface 48 d and surrounded by the suction control member 48 and the first closing member 46. Forming a pressure chamber. The suction control member 48 is provided with a plurality of communication passages 40b so as to penetrate the suction control member 48 in the axial direction of the shaft 81A.

  Even with such a configuration, the same effect as in the first embodiment can be obtained.

(Fourth embodiment)
Next, with reference to FIG. 8, a rotary expander 4D (hereinafter simply referred to as “expander 4D”) according to a fourth embodiment of the present invention will be described.

  In the present embodiment, as in the third embodiment, a ring-shaped recess 40 a is provided on the pressure receiving surface 46 b of the first closing member 46. Further, similarly to the second embodiment, the first closing member 46 is provided with a communication passage 40b extending from the recess 40a to the outside of the suction control member 48.

  Even with such a configuration, the same effect as in the first embodiment can be obtained.

(Fifth embodiment)
Next, a rotary expander 4E (hereinafter simply referred to as “expander 4E”) according to a fifth embodiment of the present invention will be described with reference to FIGS.

  In the present embodiment, the opening 48a of the suction control member 48 is configured by a notch that opens radially outward. Further, the suction control member 48 is provided with a recess 40a so as to be continuous with the opening 48a. In other words, in the present embodiment, the communication path 40b is not provided, and instead, the suction control member 48 is cut to a position where the suction control member 48 reaches the recess 40a from the peripheral edge in an angular range that defines the opening 48a.

  Even with such a configuration, the same effect as in the first embodiment can be obtained. Further, with the configuration of the present embodiment, the suction control member 48 can be made into a simple shape.

(Other embodiments)
The expanders 4A to 4E do not necessarily have to be connected to the compressor 6, and may be connected to a generator, for example.

  Further, the suction control member of the present invention is not necessarily fixed to the shaft 81 so as to rotate together with the shaft 81A. For example, an eccentric portion for suction control may be provided on the shaft 81A, and a swinging plate that fits and swings in the eccentric portion may be used as the suction control member.

  Further, the first closing member 46 is not necessarily provided with the stepped portion 46a. For example, the lower surface of the first closing member 46 may be flat and a stepped portion that forms the suction space 40 may be provided in the bearing member 47.

4A to 4E Rotary expander 4a Suction hole 4b Discharge hole 40 Suction space 40a Recess 40b Communication path 41 Cylinder 42 Piston 43 Working chamber 44 Partition member 46 First closing member 46a Pressure receiving surface 48 Suction control member 48a Opening 48c Shielding part 48d Sliding Moving surface 49 Second closing member 81A Shaft 81b Eccentric part

Claims (7)

A rotary expander that expands the working fluid sucked from the suction hole and discharges it from the discharge hole,
A shaft having an eccentric part;
A piston fitted to the eccentric part;
A cylinder containing the piston;
A partition member that partitions the working chamber formed between the piston and the cylinder into a suction side and a discharge side;
A first closing member that closes the working chamber from one side in the axial direction of the shaft, and has a pressure receiving surface facing away from the working chamber, and the suction hole extends from the pressure receiving surface to the working chamber. A first closing member provided on
A second closing member that closes the working chamber from the other axial direction of the shaft;
A suction control member that is disposed so as to face the suction space filled with the working fluid before expansion together with the pressure receiving surface, and that opens and closes the suction hole by sliding on the pressure receiving surface as the shaft rotates; With
One of the sliding surface in contact with the pressure receiving surface of the suction control member and the pressure receiving surface of the first closing member is formed with a pressure chamber covered with the other and surrounded by the suction control member and the first closing member. And a rotary expander provided with a recess communicating with the suction space.   2. The rotary according to claim 1, wherein the suction control member is fixed to the shaft so as to rotate together with the shaft, and has a shielding portion that shields the suction hole and an opening that exposes the suction hole. Type expander.   3. The rotary expander according to claim 2, wherein the concave portion is provided in a ring shape centering on an axis of the shaft inside the opening.   The rotary expander according to any one of claims 1 to 3, wherein the suction control member or the first closing member is provided with a communication path that communicates the recess and the suction space.   The rotary expander according to claim 2 or 3, wherein the recess is provided in the suction control member so as to be continuous with the opening.   The rotary expansion according to any one of claims 1 to 5, wherein at least one of the sliding surface of the suction control member and the pressure receiving surface of the first closing member is subjected to a hard coating treatment. Machine.   The rotary expansion according to any one of claims 1 to 5, wherein a solid lubricant is applied to at least one of the sliding surface of the suction control member and the pressure receiving surface of the first closing member. Machine.

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