JP2726418B2 - Fluid compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a hermetic fluid compressor for compressing a refrigerant gas of a refrigeration cycle, for example. (Prior Art) Conventionally, a screw pump of the type shown in FIG. 7 is known (US Pat. No. 2,527,536). In this pump, a helical groove 2 is formed on the outer periphery of a rotary shaft body 1, and a helical blade 3 is slidably fitted in the groove 2, and a rotary component wound and wound is disposed in a sleeve 4. It is.
Then, by rotating the rotating shaft 1, a spiral blade 3 is formed between the outer periphery and the inner surface of the sleeve 4.
Is transferred from one end to the other end. That is, the screw pump does not compress the fluid only by transferring the fluid. Bearings 5 and 6 for supporting the sleeve 4 in this type of screw pump are provided outside the sleeve 4 and separately from the sleeve 4. Further, a seal 7 for a high-pressure portion on the transfer side and a low-pressure portion on the front side of the transfer when transferring the fluid is provided on the outer peripheral portion of the sleeve 4 separately from the bearings 5 and 6. Therefore, in the configuration of this method, the structure of the bearing portion and the seal portion is complicated, and the number of parts increases. In addition, there is a problem that the number of places to be precisely processed increases. (Problems to be Solved by the Invention) By the way, the screw pump of the above-described type simply transfers fluid, but the same problem occurs when a fluid compressor is configured by using this type. That is, there are problems in that the structure of the bearing portion and the seal portion is complicated, the number of parts increases, and the number of places to be precisely processed increases. Further, when a packing ring is used to seal between the high pressure side and the low pressure side in the fluid compressor, there is a problem that the packing ring is easily worn by driving the compressor. The present invention has been made in view of the above problems, and has as its object a simple structure that does not seal between the high-pressure side and the low-pressure side in the compressor body, and furthermore, the sealing ability due to wear and the like. It is an object of the present invention to provide a fluid compressor which seals without lowering the number of parts and reduces the number of places having precise processing, thereby facilitating the manufacture and assembly of parts. [Constitution of the Invention] (Means and Actions for Solving the Problems) In order to achieve the above object, the present invention provides a closed case,
The two bearing members installed opposite to each other in the sealed case, and the open ends of both ends are fitted to the bearing peripheral surface of each bearing member to form a bearing sliding portion. A cylinder rotatably supported by the member, a piston rotatably supported by the bearing member in an eccentric state inside the cylinder, a helical groove formed on the outer periphery of the piston, The cylinder is rotatably fitted into and out of the spiral groove, and the outer peripheral edge is in close contact with the inner peripheral surface of the cylinder to form an operating chamber between the cylinder and the piston. A helical blade for transferring the fluid to be compressed, which has been taken into the operation chamber by a relative movement with respect to the piston, to the discharge side in the axial direction of the cylinder. Further, of the two bearing sliding portions, the bearing sliding portions disposed at least on the side having a pressure difference of the compressed fluid inside and outside the cylinder are made airtight. By doing so, the present invention achieves a seal between the high-pressure side and the low-pressure side in the closed case with a simple configuration,
The present invention is configured to efficiently compress and transfer the fluid taken in between the blades by the relative movement of the cylinder and the piston. Another object of the present invention is to make it possible to perform sealing without lowering the sealing ability due to abrasion and the like, and to reduce the number of places requiring precise processing, thereby facilitating the manufacture and assembly of parts. (Embodiment) FIG. 1 shows an embodiment of the present invention. FIG. 1 shows a hermetic compressor 10 for a refrigerant gas used in a refrigeration cycle.
Is shown. This compressor 10 incorporates an electric element 12 and a compression element 13 in a closed case 11. The electric element 12 includes a stator 14 attached and fixed to the inner wall surface of the closed case 11 and a rotor 15 disposed inside the stator 14. The compression element 13 is mainly composed of two bearing members 16 and 17 installed and fixed to face each other in the closed case 11 and the rotor 15.
And a cylinder 19 in which a piston 18 is eccentrically arranged. The bearing members 16 and 17 have cylindrical bearing peripheral portions 20 and 21 protruding coaxially with each other, respectively.
The bearing 7 is tightly fitted to and supported by the bearing peripheral surface portions 20 and 21. The piston 18 has shafts 23, 24 protruding from both ends thereof, and the shafts 23, 24 are provided with bearing holes 25, 26 of the bearing members 16, 17, respectively.
It is pivotally supported by being inserted into. At this time, there is a slight gap between the bearing peripheral surfaces 20, 21 of the bearing members 16, 17 and the inner surface of the cylinder 19 due to the rotation of the cylinder 19, and this gap is filled with lubricating oil. I have. The piston 18 is axially supported at both ends in the axial direction by the bearing members 16 and 17 and is mounted so as to inwardly rotate with respect to the inner surface of the cylinder 19. For example, a pin 16a protruding toward the center is provided on the inner wall of the cylinder 19, and a hole 16b for inserting the pin 16a is provided on the inner wall of the cylinder 19. Means for securing the engagement relationship of moving forward and backward with the 16a inserted is adopted. As shown in FIG. 2, the center axis of the cylinder 19 (and the rotor 15) and the center axis of the piston 18 are shifted and eccentric by e. That is, the central axis l ₂ of the piston 18 is eccentrically mounted by e with respect to the rotation center axis l ₁ of the cylinder 19. The center axis of the cylinder 19 is provided to match the rotation center axis l ₁ of the rotor 15. Further, the piston 18 has a spiral groove 28 formed around the outer periphery thereof for winding the blade 27 thereon. The pitch of the spiral groove 28 is formed so that the other end side is gradually reduced as shown in FIG. Into the spiral groove 28, a spiral blade 27 formed so that the outer peripheral edge is in close contact with the inner surface of the cylinder 19 and rolls is fitted in a freely movable manner. In other words, the width of this groove 28 is
It is adjusted to the thickness t of 27. The blade 27 is made of an elastic material such as Teflon, for example, and is screwed into the spiral groove 28 of the piston 18 while deforming by utilizing its elasticity. In addition, a suction hole 29 is formed in one of the bearing members 16 so as to communicate with a blade 27 on the outer peripheral portion of the piston 18, and a suction tube 30 in a refrigeration cycle is connected to the suction hole 29. ing. In addition, bearing members
A discharge hole 31 communicating with the inside of the closed case 11 is formed in the 17. A discharge tube 32 is connected to the sealed case 11. Next, the operation of the hermetic compressor 10 having the above configuration will be described. By operating the electric element 12, the rotor 15 rotates, and the cylinder 19 integral therewith also rotates. At this time,
The gap between the cylinder 19 and the bearing peripheral surfaces 20, 21 of the bearing members 16, 17, which support the cylinder 19, is filled with an oil film of the injected lubricating oil, and the inside of the cylinder is completely sealed. Then, the piston 18 with the blade 27 that comes into contact with the inner surface of the cylinder 19 also rotates. Central axis l ₂ of the piston 18 is eccentrically mounted by e with respect to the rotation center axis l ₁ of the cylinder 19, the central axis of the cylinder 19 above the rotor 15
It is provided to match the rotational center axis l _1. And
The piston 18 comes into contact with the inner surface of the cylinder 19 in an eccentric state. This relative rotational movement is ensured by the above-described restricting means including the pin 16a and the hole 16b. That is,
The rotation speeds of the piston 18 and the cylinder 19 match. For this reason, the spiral blade 27 fitted in the groove 28 of the piston 18 moves in and out of the groove 28 following the eccentric rotation of the cylinder 16 while rotating with the piston 18. Then, the spiral blade 27 comes into contact with the inner peripheral surface of the cylinder 16 in a state of being always in close contact therewith. The outer peripheral edge of the blade 27 is always in close contact with the inner surface of the cylinder 19 and smoothly follows, so that a state of partition between the operation chambers 33 bordering the blade 27 is ensured. As described above, the helical blade 27 partitions the space between the inner peripheral surface of the cylinder 19 and the outer peripheral surface of the piston 18 to form an operation chamber 33 that is hermetically closed between the pitches of the blades 27.
Each of the partitioned operation chambers 33 has a certain three-month shape. That is, the operating chamber 33 to be partitioned starts from the position where the cylinder 19 and the piston 18 are in contact with each other, and the gap gradually increases and then becomes smaller again to reach the contact position. Since the pitch of the spiral blade 27 is set so as to gradually decrease on the other end side, that is, on the transfer side, the operation chamber 33
Reduces the volume as it moves to the transfer side to compress the transfer gas. Then, the refrigerant gas flowing into the cylinder 19 from the suction tube 30 through the suction hole 29 enters the operation chamber 33 and is compressed when confined and transferred. The compressed refrigerant gas is discharged into the closed case 11 through the discharge hole 31 and returned to the refrigeration cycle through the discharge tube 32. Thus, according to the configuration of the above embodiment, the high-pressure side, that is, the high-pressure side and the low-pressure side in the closed case 11, that is, the cylinder
In particular, the seal between the inside of the suction port 29 and the inside of the cylinder 19 is formed by the inner surface of the cylinder 19 located on the suction side and the peripheral surface 20 of the bearing member 16.
Are sufficiently contacted with each other via an oil film of the lubricating oil. Therefore, the high pressure side and the low pressure side can be sealed without using a sealing material such as a packing ring. In addition, the precision machined bearing is generally fitted with the precision machined cylinder inner surface, so there is no need for new precision work, and there is no need to use a sealing material. Assembly becomes easy. In addition, since the sucked refrigerant gas is sequentially taken into the operation chamber 33, closed and compressed while being transferred, it can be efficiently compressed without necessarily providing a discharge valve on the discharge side. Further, the displacement volume is determined by the pitch of the first spiral portion of the blade 27. Therefore, as shown in FIG. 4, the rejection volume can be increased over the entire length of the piston 18 as compared with the case of the same pitch. Further, as the number of turns of the blade 27 increases, the pressure difference between the adjacent operation chambers 33 decreases, the gas leakage decreases, and the compression efficiency can be increased. In addition, according to this configuration and the compression method, a seal material is not used, and a discharge valve is not necessarily required, so that the configuration of the compression element portion is simplified and the number of parts is reduced. Moreover, since the compression element 13 is incorporated in the rotor 15 of the electric element 12, a shaft or a frame for supporting the electric element 12 is not required, so that the number of parts can be reduced and the size can be reduced. In addition, since the blade 27 moves in and out of the groove 28 and always follows the inner surface of the cylinder 19, the precision of parts such as a right angle does not have to be so strict, and the manufacture and assembly thereof are easy. Further, since the cylinder 19 and the piston 18 with the blade 27 are in rolling contact with each other, the friction is small and the operation is smooth, and the noise and vibration are small. In this embodiment, as shown in FIG. 5, the pitch of the grooves 28 has been described as being gradually reduced from one end to the other end, but the present invention is not limited to this. Not the groove 28, as shown in FIG.
May be formed at a substantially equal pitch over the entire length of the piston 18. In this case, as shown in FIG. 6 (A), the groove 35 at the final end to which the fluid is transferred is formed substantially perpendicular to the axial direction of the piston 18, and is formed with this groove 35 at another equal pitch. Fluid is transferred at an intersection a where the groove 28 intersects, and the fluid is concentrated and compressed at the intersection a. That is, the working chamber 33a at the final end formed by the blade 27 is normally closed, and fluid is transferred one after another until the internal pressure reaches a certain pressure. When the pressure inside the operation chamber 33a reaches a certain value, the groove 35 perpendicular to the axial direction is formed at the intersection a.
The blade 27 fitted into the space causes elastic deformation as shown by an arrow b in the enlarged circle of FIG. 6B, and releases the compressed fluid concentrated in the operation chamber 33a to the outside of the operation chamber 33a. That is, at the intersection a, the blade 27 also has a discharge check valve mechanism. Here, FIG. 6 (B) is an enlarged view of a portion surrounded by a circle c in FIG. 6 (A), and a part of the blade 27 is cut off at the intersection a. In addition, it allows elastic deformation.
As described above, if the blade 27 functions as a discharge check valve mechanism, it is not necessary to provide another check valve on the discharge side. Further, since it is not necessary to fit the blade 27 into the groove 28 formed at a variable pitch while largely deforming the blade 27, assembly is easy, and the material and selection of the blade 27 can be more freely performed. Also, as shown in FIG. 6 (c), the piston 18 is divided into two parts in the axial direction with the groove 35 at the final end as a boundary, and the blade 27 is divided into grooves.
If the piston 18 can be connected after being fitted into the 28, 35, the assembling work is further facilitated. Further, in this embodiment, the axis of the rotor 15 and the axis of the cylinder 19 are made to coincide with each other, and the axis of the piston 18 is made eccentric with respect to this. However, the present invention is not limited to this. The axis of the cylinder 18 may be made coincident, and the axis of the cylinder 19 may be eccentric. [Effect of the Invention] As described above, in the present invention, both ends of a rotatable cylinder are fitted to a bearing member, and the fitted portion seals the high pressure side and the low pressure side. Therefore, the seal between the high-pressure side and the low-pressure side in the closed case is performed by a simple configuration, and the object taken in between the blades can be efficiently compressed and transferred by the relative movement between the cylinder and the piston. it can. In addition, since no sealing material is required, it is possible to seal without reducing the sealing ability due to wear of the sealing material, etc. Has the effect of doing

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 5 show an embodiment of the present invention. FIG. 1 is a side sectional view of a compressor, and FIG. 2 is a sectional view of a compression element portion thereof. , Fig. 3 is a development view of the compression element part,
4 and 5 are explanatory views of the helical pitch of a groove formed in the piston, FIGS. 6 (a) and (b) are explanatory views of a piston having an equal pitch groove having a compressive action, and FIG. 6 (c). 7) is an explanatory view of a split type piston, and FIG. 7 is a side sectional view of a conventional example. 10 …… Compressor, 16,17 …… Bearing member, 18 …… Piston, 19…
… Cylinder, 27 …… Blade, 28 …… Groove.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Yoshinori Sone               70, Yanagicho, Saiwai-ku, Kawasaki-shi, Kanagawa               Inside the Toshiba Yanagimachi Plant                (56) References JP-A-7-107391 (JP, A)                 JP-A-64-36991 (JP, A)

Claims (1)

(57) [Claims] A sealed sliding part is formed by fitting a sealed case, two bearing members installed opposite to each other in the sealed case, and the open ends at both ends to the bearing peripheral surface of each bearing member. A cylinder rotatably supported by each of the bearing members, a piston rotatably supported by the bearing members in an eccentric state inside the cylinder, and a helical spiral formed on the outer periphery of the piston. A groove, and an outer peripheral edge closely fitted to the inner peripheral surface of the cylinder to form an operating chamber between the cylinder and the piston, and the rotating cylinder and the cylinder; And a helical blade for transferring the compressed fluid taken into the working chamber to the axial discharge side of the cylinder by relative movement with the piston rotating together with the piston. Fluid compressor. 2. 2. The bearing sliding part of the two bearing sliding parts, which is disposed at least on the side having a pressure difference of the compressed fluid inside and outside the cylinder, is made airtight. Fluid compressor.