JP2009197702A - Rotary type fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that the super-compression of a high-pressure working fluid remaining in a working chamber before a piston 106 reaches the top dead center after a discharge process is ended, and the phenomenon of the forcible expansion of the working fluid of an extremely small amount before the suction process is started after the piston 106 reaches the top dead center cannot be prevented at the same time. <P>SOLUTION: A vane tip groove 107a and a vane tip groove 107b are formed on a suction hole 105b side of the 107 and a discharge hole 104a side, respectively, on the tip of a vane 107, and a connection groove 104b is formed in a part for covering a vane groove 105a of an upper bearing 104. Installation positions of the vane tip grooves 107a, 107b and the connection groove 104b are determined so that they communicate with each other before and after a state (the top dead center) that the vane 107 is maximally pressed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotary fluid machine.

  Conventionally, as a type of rotary fluid machine, a rolling piston compressor and a swinging piston compressor that are used in a compression process of a refrigeration cycle are known.

  4A and 4B are enlarged views of the vicinity of the vane 107 in the working chamber of the rolling piston compressor. A shaft 103 shown in FIG. 1 passes through a cylinder 105 and is rotatably supported by a bearing. The shaft 103 is provided with an eccentric portion 103a, and a piston 106 is fitted to the eccentric portion 103a. A vane groove 105a shown in FIG. 2 is formed in the cylinder 105, and the vane 107 is held so as to freely reciprocate. A crescent-shaped space formed by the cylinder 105 and the piston 106 is partitioned into a working chamber 110a in the suction side space and a 110b in the discharge side space by a vane 107 that is a partition member. 4A and 4B, the shaft 103 and the piston 106 rotate clockwise. The working fluid is sucked from the suction hole 105b that leads to the working chamber 110a in the suction side space, compressed to a high pressure as the piston 106 rotates, and then discharged from the discharge hole 104a that leads to the working chamber 110b in the discharge side space. .

  FIG. 4A shows the working chamber of the rolling piston compressor after the discharge process of discharging the high-pressure working fluid from the discharge hole 104a and before the moment when the vane 107 is most pushed in (top dead center). In this state, the working chamber 110b does not communicate with either the suction hole 105b or the discharge hole 104a. Therefore, if a part of the high-pressure working fluid remains in the working chamber 110 b even after the discharge process is finished, the high-pressure working fluid is further compressed (overcompressed) with the rotation of the shaft 103. Therefore, an extra load is applied to the motor 101. As a result, the efficiency of the rolling piston compressor 100 is lowered.

  FIG. 4B shows the working chamber of the rolling piston compressor after the moment when the vane 107 is pushed in most (top dead center) and before the working chamber 110a communicates with the suction hole 105b. In this state, the working chamber 110a does not communicate with either the suction hole 105b or the discharge hole 104a. When the piston 106 reaches the top dead center, the volume of the working chamber 110a is very small, and the working fluid existing in the working chamber 110a is very small. Therefore, until the working chamber 110a communicates with the suction hole 105b, this small amount of working fluid is forcibly expanded along with the rotation of the shaft 103, and the motor 101 performs work for expanding the working fluid. It will be extra. As a result, the efficiency of the rolling piston compressor 100 is lowered.

As a technique for preventing over-compression of the high-pressure working fluid remaining in the working chamber 110b, for example, a technique disclosed in Patent Document 1 is known. FIG. 5 is an enlarged view of the vicinity of the vane 107 in Patent Document 1. In FIG. According to the technique disclosed in Patent Document 1, the cylinder side groove 105c that allows the working fluid remaining in the working chamber 110b to always flow out to the nearest hole (the discharge hole 104a in FIG. 5) that does not straddle the vane 107 is provided. By providing, overcompression of the working fluid can be prevented.
JP 2006-97624 A

  The technique disclosed in Patent Document 1 has an effect of preventing overcompression of the high-pressure working fluid that remains in the working chamber 110b from the end of the discharge process until the piston 106 reaches the top dead center. There is no solution to avoiding a phenomenon in which a small amount of working fluid is forcibly expanded until the working chamber 110a communicates with the suction hole 105b after reaching the top dead center, and the efficiency of the rolling piston compressor 100 is improved. The factor of lowering remained.

  The present invention has been made in view of such problems. The over-compression of the high-pressure working fluid remaining in the working chamber after the discharge process is finished and the piston reaches the top dead center, and the piston is It is an object of the present invention to provide a rotary fluid machine capable of preventing a phenomenon in which a minute amount of working fluid is forcibly expanded after reaching the dead point until the inhalation process starts.

  In order to solve the above-described problems, the present invention provides a cylinder having a cylindrical surface, a shaft having an eccentric portion, a piston that fits into the eccentric portion and rotates eccentrically inside the cylinder, and is provided in the cylinder. A cylindrical shape that holds the shaft, and a vane that partitions the space between the cylinder and the piston into a suction-side space and a discharge-side space by being fitted into the groove and having the tip side in contact with the piston. Two bearing members having a bearing portion and sandwiching the cylinder, the piston, and the vane from an axial direction of the shaft, and the vane has a vane on a surface facing the bearing member and on a distal end side. Provided is a rotary fluid machine in which a tip groove is formed, and the bearing member is formed with a connecting groove communicating with the vane tip groove in the vicinity of the top dead center of the vane. .

  The present invention also includes a cylinder having a cylindrical surface, a shaft having an eccentric part, a piston that fits into the eccentric part and rotates eccentrically inside the cylinder, and a groove provided in the cylinder. And a vane that divides the space between the cylinder and the piston into a suction side space and a discharge side space by contacting the piston with the tip side, and a cylindrical bearing portion that holds the shaft, Two bearing members that sandwich the cylinder, the piston, and the vane from the axial direction of the shaft, and a vane tip groove is formed on a tip side of the side surface of the vane. A vane groove side surface groove is formed so as to communicate with the vane tip groove, and a coupling groove communicating with the vane side surface groove is formed in the vicinity of the top dead center of the vane. Providing rotary fluid machine.

  According to the rotary type fluid machine of the present invention, after the discharge process is over and after the piston reaches the top dead center, the high pressure working fluid remaining in the working chamber and the piston reaches the top dead center. It is possible to prevent a phenomenon in which a minute amount of working fluid is forcibly expanded before the inhalation process starts.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a longitudinal sectional view showing a configuration of a rolling piston compressor 100 according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line D1-D1 of the rolling piston compressor of FIG.

  The motor 101 includes a stator 101 a fixed to the hermetic container 102 and a rotor 101 b fixed to the shaft 103. The shaft 103 passes through the cylinder 105 and is rotatably supported by the upper bearing 104 and the lower bearing 109. The shaft 103 is provided with an eccentric portion 103a, and a piston 106 disposed inside the cylinder 105 is fitted into the eccentric portion 103a.

  A vane groove 105 a is formed in the cylinder 105. The vane 107 held reciprocally in the vane groove 105a is in close contact with the piston 106 due to the spring force of the spring 108 provided on the back side and the differential pressure. A crescent-shaped space formed by the cylinder 105 and the piston 106 is partitioned into a working chamber 110a in the suction side space and a 110b in the discharge side space by the vane 107 which is a partition member. The suction hole 105b provided in the cylinder 105 communicates with the working chamber 110a, and the discharge hole 104a provided in the upper bearing 104 communicates with the working chamber 110b. Further, a discharge valve 110 (not shown) is provided in the discharge hole 104a on the side opposite to the working chamber 110b.

  At the tip of the vane 107, a vane tip groove 107a is provided on the suction hole 105b side, and 107b is provided on the discharge hole 104a side. A connecting groove 104b is provided in a lower surface of the upper bearing 104 and a portion that covers the vane groove 105a. The vane tip grooves 107a and 107b need to be provided on at least one of the upper surface (upper bearing 104 side) and the lower surface (lower bearing 109 side) of the vane 107. The depth of the groove (direction distance perpendicular to the paper surface in FIG. 2) is not particularly limited, and may be connected from the upper surface to the lower surface. However, the vane grooves 107a and 107b are formed on the upper and lower surfaces of the vane 107 in order to minimize deterioration of the sealing performance between the upper surface of the vane and the upper bearing 104 or between the lower surface of the vane and the lower bearing 109. It is desirable to provide only one of them. The vane tip grooves 107a and 107b are set so as to communicate with the connecting groove 104b in the vicinity of the state where the vane 107 is most pushed in (top dead center). In other words, the vane tip grooves 107a and 107b are not in communication with the connecting groove 104b except near the top dead center.

  The low-pressure working fluid is sucked into the working chamber 110a of the cylinder 105 from the suction pipe 120 through the suction hole 105b. In FIG. 2, the shaft 103 rotates clockwise, and the volume of the working chamber 110a increases as the shaft 103 rotates. Eventually, the working chamber 110a moves to the working chamber 110b, and the suction stroke ends. The volume of the working chamber 110b decreases as the shaft 103 rotates, and the working fluid is compressed. When the pressure of the working fluid in the working chamber 110b becomes higher than the pressure of the working fluid outside the working chamber across the discharge valve 110 when viewed from the working chamber 110b, the discharge valve 110 opens and the working fluid is sealed from the discharge hole 104a. It is discharged into the container 102.

  3A and 3B are enlarged views of the vicinity of the vane 107. FIG.

  FIG. 3A shows the working chamber of the rolling piston compressor after the discharge process of discharging the high-pressure working fluid from the discharge hole 104a and before the moment when the vane 107 is most pushed in (top dead center).

  FIG. 3B shows the working chamber of the rolling piston compressor after the moment when the vane 107 is most pushed in (top dead center) and before the working chamber 110a communicates with the suction hole 105b.

  In the state of FIG. 3A, the vane tip grooves 107a and 107b and the connecting groove 104b are in communication. For this reason, even if communication with the discharge hole 104a is interrupted and a part of the high-pressure working fluid remains in the working chamber 110b, the high-pressure working fluid passes through the vane tip grooves 107a and 107b and the connection groove 104b, It can move to the working chamber 110a. That is, overcompression of the high-pressure working fluid remaining in the working chamber 110b can be prevented.

  Even in the state of FIG. 3B, the state where the vane tip grooves 107a and 107b and the connecting groove 104b communicate with each other is maintained. For this reason, even if the action of forcibly inflating a small amount of working fluid from when the piston 106 reaches top dead center until the suction process starts, a part of the working fluid in the working chamber 110b remains in the vane. It is possible to move to the working chamber 110a through the tip grooves 107a and 107b and the connecting groove 104b. That is, it is possible to prevent a phenomenon in which a small amount of working fluid is forcibly expanded.

  Next, a method for determining the length of the vane tip grooves 107a and 107b and the position of the connecting groove 104b will be described. The origin O is set at the center of the cylinder 105, and the rotation angle θ of the shaft 103 with the piston 106 reaching the top dead center is set to 0 °. Further, the x-axis is taken in the direction of θ = 0 ° from the origin O. The rotation angle of the shaft 103 where the discharge of the working fluid is completed is θde, and the rotation angle at which the working fluid starts to be sucked is θss. The lengths of the vane tip grooves 107 a and 107 b are preferably the same, and the connecting groove 104 b is preferably provided perpendicular to the longitudinal direction of the vane 107. The reason why the lengths of the vane tip grooves 107a and 107b are the same and the installation position of the connecting groove 104b is perpendicular to the longitudinal direction of the vane 107 is an operation formed by the vane tip grooves 107a and 107b and the connecting groove 104b. This is because the flow path length of the fluid becomes the shortest.

  In a state where the piston 106 has reached the top dead center (θ = 0 °), the distances from the origin 0 to the portions of the vane tip grooves 107a and 107b farthest from the origin 0 are Xva and Xvb, respectively. If the width of the connecting groove 104b is 2b and the position of the center line of the connecting groove 104b is x = Xc, the connecting groove 104b exists in the region of Xc−b <x <Xc + b.

  The vane tip grooves 107a and 107b and the connecting groove 104b communicate with each other when the piston 106 reaches the top dead center. When the shaft 103 rotates clockwise from the top dead center (θ = 0), θ < In θss, the vane tip grooves 107a and 107b and the connection groove 104b are in communication, and communication is interrupted when θ = θss, and communication is maintained when θss <θ <θde. The vane tip grooves 107a and 107b and the connecting groove 104b communicate with each other again when θ = θss, and the communication is maintained when θ> θde. That is, Xva, Xvb, Xc, b may be set so as to satisfy the following mathematical expression.

(Equation 1) Xva-Rc (1-cosθss) = Xc-b
(Expression 2) Xvb-Rc (1-cosθde) = Xc-b
Further, with respect to Xc, even when the vane tip grooves 107a and 107b and the connecting groove 104b are not in communication, the following formula is satisfied so that the sealing performance from the tip of the vane 107 to the connecting groove 104b is sufficiently maintained. Set to.

(Expression 3) Xc−b> Rc + α
In Equation 3, α is the seal length.

  As is apparent from the above description, in the compressor according to the present embodiment, overcompression of the high-pressure working fluid that remains in the working chamber from the end of the discharge process until the piston 106 reaches the top dead center, It is possible to prevent a phenomenon in which a minute amount of working fluid is forcibly expanded from the time when 106 reaches the top dead center until the inhalation process starts. Therefore, the efficiency of the rolling piston compressor 100 can be improved.

(Second Embodiment)
In this embodiment, the positions of the vane tip grooves 107a and 107b provided in the vane 107 are different. In the first embodiment, the vane tip grooves 107 a and 107 b are provided on at least one of the upper and lower surfaces of the vane 107, but in this embodiment, they are not provided on the upper and lower surfaces of the vane 107 but on the side surface of the vane 107. The high-pressure working fluid in the working chamber 110b leaks to the working chamber 110a side through a gap between the upper surface of the vane 107 and the upper bearing 104 and a gap between the lower surface of the vane 107 and the lower bearing 109 due to a pressure difference. By providing the vane tip grooves 107a and 107b on the side surface of the vane 107, the length in the leakage direction of the upper and lower surfaces of the vane 107, that is, the width of the vane 107 is not reduced. And the sealing performance against leakage of working fluid in the gap between the lower surface of the vane 107 and the lower bearing 109 does not deteriorate.

  A vane groove side surface groove 105c is formed in the vane groove 105a of the cylinder 105 so as to communicate with the connection groove 104b. When the vane 107 reaches a predetermined position, the vane tip grooves 107a and 107b and the connection groove 104b are formed. The vane groove side surface groove 105c communicates, and, as in the first embodiment, the high pressure working fluid remaining in the working chamber 110b is overcompressed and the suction process starts after the piston 106 reaches top dead center. A phenomenon in which a minute amount of working fluid is forcibly expanded can be prevented at the same time.

  Further, since grooves are not provided on the upper and lower surfaces of the vane 107, compared to the first embodiment, the working fluid leaks between the upper surface of the vane 107 and the upper bearing 104 or between the lower surface of the vane 107 and the lower bearing 109. Sealability can be secured.

  The present invention is useful for a compressor that compresses a fluid or an expander that expands a fluid. For example, a compressor, an expander, and an expander that are provided in a refrigerant circuit such as a refrigeration apparatus, an air conditioner, and a water heater. Useful for body type compressors.

A longitudinal sectional view showing a configuration of a conventional rolling piston compressor 100 1 is a cross-sectional view taken along line D1-D1 of the rolling piston compressor of FIG. An enlarged view of the vicinity of the vane 107 in the compressor 100 An enlarged view of the vicinity of the vane 107 in the compressor 100 Enlarged view of the working chamber of a conventional rolling piston compressor Enlarged view of the working chamber of a conventional rolling piston compressor The figure which expanded a part of working room of the rolling piston type compressor of patent documents 1

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Compressor 101 Motor 101a Stator 101b Rotor 102 Sealed container 103 Shaft 104 Upper bearing 104a Discharge hole 104b Connection groove 105 Cylinder 105a Suction hole 105b Vane groove 106 Piston 107 Vane 107a Vane tip groove (suction hole side)
107b Vane tip groove (discharge hole side)
108 Vane spring 109 Lower bearing

Claims (3)

A cylinder having a cylindrical surface;
A shaft having an eccentric part;
A piston that fits into the eccentric part and rotates eccentrically inside the cylinder;
A vane that fits into a groove provided in the cylinder and has a tip end side in contact with the piston, thereby partitioning a space between the cylinder and the piston into a suction side space and a discharge side space;
A cylindrical bearing portion that holds the shaft, and two bearing members that sandwich the cylinder, the piston, and the vane from an axial direction of the shaft,
The vane is formed with a vane tip groove on a surface facing the bearing member and on the tip side, and the bearing member is formed with a connecting groove communicating with the vane tip groove in the vicinity of the top dead center of the vane. Rotary fluid machine. The rotary fluid machine according to claim 1, wherein the vane tip groove is provided on at least one surface facing two bearing members. A cylinder having a cylindrical surface;
A shaft having an eccentric part;
A piston that fits into the eccentric part and rotates eccentrically inside the cylinder;
A vane that fits into a groove provided in the cylinder and has a tip end in contact with the piston to partition a space between the cylinder and the piston into a suction side space and a discharge side space;
A cylindrical bearing portion that holds the shaft, and two bearing members that sandwich the cylinder, the piston, and the vane from an axial direction of the shaft,
A vane tip groove is formed on the tip side of the side surface of the vane, and a vane groove side surface groove is formed in the vane groove so as to communicate with the vane tip groove. A rotary type fluid machine in which a connection groove communicating with the vane side surface groove is formed in the vicinity of a point.

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