JP2005105990A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll compressor capable of preventing it from being reversely rotated by the reverse flow of a refrigerant when an operation is stopped in the inside low pressure type scroll compressor. <P>SOLUTION: The end plate 421 of a turning scroll 42 is always brought into slide contact with a fixed scroll 41. A refrigerant suction hole 44 allowing a compression chamber 43 to communicate with an electric motor chamber 24 is formed in the fixed scroll 41. A reverse flow prevention valve 45 for preventing the high-pressure refrigerant from being reversely flown is installed in the refrigerant suction hole 44. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a scroll compressor used in a refrigeration cycle such as an air conditioner, and more particularly to a technique for preventing reverse rotation when the compressor is stopped in an internal low-pressure scroll compressor.

  Immediately after the operation of the scroll compressor is stopped, the high-pressure refrigerant flows back through the compression chamber toward the low-pressure side due to the pressure difference between the discharge pressure and the suction pressure, so that the scroll compressor rotates in reverse and generates noise. Therefore, a normal scroll compressor is provided with a backflow prevention valve to prevent the backflow of the refrigerant immediately after the operation is stopped.

  The backflow prevention valve is generally mounted on either the discharge side or the suction side of the compression chamber. However, if a backflow prevention valve is provided on the discharge side, it is operated by valve fluttering due to pulsation of the discharge gas. Sometimes noise may be generated. Therefore, in order to further suppress the generation of noise, for example, as described in Patent Document 1, it is preferable to provide a backflow prevention valve on the suction side with less refrigerant gas pulsation.

  Patent Document 1 discloses a cylinder valve arranged so as to close an opening of a refrigerant suction pipe inserted toward a suction space of a compression chamber, and a spring that constantly biases the cylinder valve toward the opening. A backflow prevention valve is provided. According to this, it is easy to assemble, and the backflow prevention valve is attached to a part of the suction passage, so that it is possible to suppress a decrease in suction efficiency.

  However, since the scroll compressor described in Patent Document 1 is an internal high-pressure type in which the electric motor chamber has a discharge pressure, the above-described backflow prevention valve cannot be directly applied to the internal low-pressure type scroll compressor.

  That is, most of the internal low-pressure type scroll compressor takes in the suction chamber (low-pressure refrigerant) entering the motor chamber from the suction hole formed in the outer peripheral portion of the wrap groove of the fixed scroll. The part is sucked into the compression chamber from the outer peripheral part of the wrap groove of the fixed scroll which is not covered by the end plate of the orbiting scroll.

  Therefore, when the scroll compressor is stopped, for example, even if the backflow prevention valve provided in the suction hole is activated, the discharge gas (high-pressure refrigerant) leaks from the back of the end plate of the orbiting scroll, so that the backflow of the refrigerant is generated and compressed. The machine rotates in reverse. Therefore, generation of noise cannot be prevented.

Japanese Patent Publication No. 1-334312

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to scroll in an internal low-pressure scroll compressor that can prevent reverse rotation due to a reverse flow of refrigerant when operation is stopped. It is to provide a compressor.

  In order to achieve the above-described object, the present invention has several features described below. That is, the invention of claim 1 includes a refrigerant compression section formed by engaging spiral scroll wraps standing on the end plates of the fixed scroll and the orbiting scroll to form a compression chamber therein, and the orbiting. A motor having a rotary drive shaft for driving the scroll is disposed opposite to the sealed shell across the main frame, and has a refrigerant suction passage for guiding low-pressure refrigerant to the refrigerant compression section via the motor chamber. In the internal low-pressure type scroll compressor, a refrigerant suction hole that communicates the compression chamber and the electric motor chamber is provided in an outer peripheral portion of the wrap groove of the fixed scroll, and the electric motor is provided in the refrigerant suction hole. It is characterized in that backflow prevention means for preventing backflow of the high-pressure refrigerant generated in the compression chamber when stopped is provided.

  The invention of claim 2 is characterized in that the end plate of the orbiting scroll is formed in a size that always covers the lap groove of the fixed scroll.

  According to a third aspect of the present invention, there is provided a refrigerant compression section formed by engaging spiral scroll wraps standing on the end plates of the fixed scroll and the orbiting scroll to form a compression chamber therein, and the orbiting scroll. An electric motor having a rotary drive shaft to be driven is disposed opposite to the inside of the hermetic shell with the main frame interposed therebetween, and an Oldham chamber is provided on the rear surface of the end plate of the orbiting scroll, and an Oldham chamber is housed, and a low-pressure refrigerant is supplied to the electric motor chamber. In the internal low-pressure type scroll compressor having a refrigerant suction passage leading from the Oldham chamber to the refrigerant compression section, the end plate of the orbiting scroll communicates with the Oldham chamber and the outer periphery of the wrap groove of the scroll wrap. A communication portion is provided, and a mating surface of the fixed scroll and the main frame is provided on the entire circumference, and The main chamber is provided with a refrigerant suction hole that divides the dam chamber and the motor chamber, and the Oldham chamber and the motor chamber communicate with each other. The motor is stopped at the refrigerant suction hole. In this case, a backflow prevention means for preventing a backflow of the high-pressure refrigerant generated in the compression chamber is provided.

  According to a fourth aspect of the present invention, the backflow preventing means includes a valve body movable along the axial direction of the refrigerant suction hole, a spring that urges the valve body in a direction to always close the valve body, and the valve body as described above. It is characterized by comprising a stopper that prevents it from falling off from the refrigerant suction hole.

  According to the first and second aspects of the present invention, since the wrap groove of the fixed scroll is always covered by the end plate of the orbiting scroll, only the refrigerant suction hole provided in the fixed scroll connects the compression chamber and the motor chamber. By providing a backflow prevention valve in the only path, it is possible to reliably prevent backflow of refrigerant from the compression chamber to the motor chamber.

  According to the third aspect of the present invention, the Oldham chamber communicating with the suction space of the compression chamber is provided on the back surface of the end plate of the orbiting scroll, and the mating surface of the fixed scroll is covered by the main frame over the entire circumference, and the Oldham is provided on the mainframe. By providing a refrigerant suction hole that connects the chamber and the motor chamber and providing a backflow prevention valve there, only the refrigerant suction hole provided in the main frame is the only path connecting the compression chamber and the motor chamber. By providing the backflow prevention valve, the backflow of the refrigerant from the compression chamber to the motor chamber can be reliably prevented.

  According to the invention described in claim 4, the backflow prevention valve can be incorporated at a low cost with a simple configuration of the cylinder valve, the spring, and the stopper.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing the internal structure of a scroll compressor according to an embodiment of the present invention, and FIG.

  The scroll compressor 1 includes a cylindrical hermetic shell 2 that is disposed vertically, and a refrigerant compression unit 4 and an electric motor 5 are vertically opposed to each other with a main frame 3 interposed therebetween.

  A disk-shaped partition plate 21 is provided above the refrigerant compression portion 4 in the sealed shell 2, and the upper space of the sealed shell 2 is made a discharge chamber 23 through the partition plate 21, and the lower space is an electric motor chamber. 24. A certain amount of lubricating oil O is stored at the bottom of the sealed shell 2.

  The motor chamber 24 is provided with a refrigerant suction pipe 25 that draws low-pressure refrigerant (intake gas) that has finished an external refrigeration cycle (not shown) into the motor chamber 24. The discharge chamber 23 is provided with a refrigerant delivery pipe 26 that sends out the high-pressure refrigerant (discharge gas) generated in the refrigerant compression unit 4 to the refrigeration cycle.

  In the present invention, the configuration of the electric motor 5 only needs to include components necessary for providing the scroll compression mechanism, and the configuration may be the same as the conventional one. The detailed explanation is omitted.

  The refrigerant compressor 4 includes a fixed scroll 41 in which a spiral scroll wrap 412 is formed on one surface of a disk-shaped end plate 411 and a spiral scroll wrap 422 on one surface of a disk-shaped end plate 421. A compression chamber 43 is formed in the interior by engaging the scroll wraps 412 and 422 with each other.

  The fixed scroll 41 is provided with a discharge port 413 for discharging high-pressure refrigerant generated in the compression chamber 43 to the discharge chamber 23 in the center. A refrigerant suction hole 44 that connects the compression chamber 43 and the motor chamber 24 is formed on the side of the scroll wrap groove 412 of the fixed scroll 41, that is, on the outer periphery of the wrap groove (right side in FIG. 1).

  Referring to FIG. 2, the refrigerant suction hole 44 is a bottomed vertical hole formed along the axial direction from the upper surface of the end plate 411 of the fixed scroll 41, and its side portion is the outer peripheral portion of the wrap groove of the compression chamber 43. Communicating with The refrigerant suction hole 44 is provided with a backflow prevention valve 45 that prevents the backflow of the refrigerant.

  The backflow prevention valve 45 includes a cylinder valve 451 (valve element) provided movably along the axial direction of the refrigerant suction hole 44, a coil spring 452 that urges the cylinder valve 451 in a direction to always close the cylinder valve 451, and a cylinder And a stopper 453 for preventing the valve 451 from falling off.

  The cylinder 451 is a disc body having an outer diameter substantially the same as the inner diameter of the refrigerant suction hole 44, and is provided so as to be movable along the refrigerant suction hole 44. The coil spring 452 is composed of a compression spring inserted into the cylinder valve 451 and the refrigerant suction hole 44, and urges the spring toward the direction in which the cylinder valve 451 is always closed, in this embodiment, upward.

  The stopper 453 is a ring body fitted to the refrigerant suction hole 44, and a C-shaped retaining ring is used in this embodiment. In this embodiment, the stopper 453 is fitted along an annular groove formed in the inner diameter surface of the refrigerant suction hole 453.

  In this embodiment, the stopper 453 uses a C-shaped retaining ring. However, as shown in FIG. 5A, the stopper 453 has a disk shape having an outer diameter slightly larger than the inner diameter of the refrigerant suction hole 44. A stopper 453 a made of a ring member may be forcibly press-fitted along the refrigerant suction hole 44.

  Further, as shown in FIG. 5B, a plate-like stopper 453 b may be attached along the upper surface of the end plate 411 and then fixed via a screw 454. As a specific shape of the stopper 453b, for example, as shown in FIG. 6A, a suction hole 455 may be formed in the center of one plate plate and a screw hole 456 may be further provided. Then, as shown in FIG. 6B, two rectangular plates may be arranged in parallel to each other, and a part of each plate may be attached so as to cover the opening of the refrigerant suction hole 44.

  Referring to FIG. 1 again, the orbiting scroll 42 has a spiral scroll wrap 422 projecting from the upper surface of a disk-shaped end plate 421, and a bearing 423 into which the orbiting shaft 62 is inserted is formed on the rear side. Has been.

  The scroll wraps 412 and 422 of the fixed scroll 41 and the orbiting scroll 42 face each other and mesh with each other, whereby a compression chamber 43 (sealed working chamber) is formed inside the refrigerant compression section 4.

  In the present invention, it is important that the orbiting scroll 42 is formed in such a size that the end plate 421 always covers the wrap groove of the scroll wrap 412 of the fixed scroll 41. According to this, the compression chamber 43 becomes a space that is always sealed by the end plate 421 of the orbiting scroll 42, and all of the refrigerant sucked into the compression chamber 43 is introduced into the compression chamber 44 through the refrigerant suction hole 44. At the same time, the discharged gas does not leak when the operation is stopped.

  The rotational drive shaft 6 of the electric motor 5 includes a main shaft 61 that is coaxially disposed with respect to the motor 5, and a crank shaft 62 that is integrally formed on the upper end side of the main shaft 61 and that is eccentrically disposed with respect to the main shaft 61. I have.

  Inside the rotary drive shaft 6, a lubricant supply hole 63 for supplying the lubricant O accumulated in the bottom of the hermetic shell 2 to the refrigerant compressor 4 side is arranged eccentrically with respect to the rotation axis of the main shaft 61. The lower end is inserted toward the inside of the lubricating oil O stored at the bottom of the hermetic shell 2. By the rotation of the rotary drive shaft 6, the lubricating oil O passes through the lubricating oil supply hole 63 and is lifted from the lower side to the back surface of the orbiting scroll 42.

  Next, the main frame 3 is formed in a disc shape that is fixed along the inner wall surface of the hermetic shell 2 except for the refrigerant passage extending from the electric motor chamber 24 to the refrigerant compression section 4. A main bearing 31 that supports the main shaft 61 of the rotary drive shaft 6 is formed. A concave portion 32 for accommodating the bearing 423 is formed on the upper surface side of the main frame 3.

  The main frame 3 is provided with an oil discharge passage 33 for returning the lubricating oil O, which has been fed by the rotary drive shaft 6 and finished the work, into the electric motor chamber 24 again.

  The oil discharge passage 33 has an inlet port at one end opened toward the peripheral wall surface of the recess 32, and a discharge port at the other end opened from the lower end surface of the main frame 3 into the motor chamber 24. It is formed in an L shape along the radial direction.

  When the scroll compressor 1 is driven, as shown in FIG. 1, the compression chamber 43 moves while decreasing its volume from the outside toward the center due to the orbiting motion of the orbiting scroll 42. It becomes.

  When the negative pressure in the compression chamber 43 is further increased and the pressure difference from the motor chamber 24 is increased, the cylinder valve 451 is pushed down against the coil spring 452 by the pressure difference, and the refrigerant suction hole 44 is opened. The suction gas flows into the outer periphery of the wrap of the compression chamber 43.

  The suction gas that has entered the compression chamber 43 is compressed by reducing the volume of the crescent-shaped compression chamber 43 formed between the scroll wraps 412 and 422 from the outside toward the center. The discharge gas (high-pressure refrigerant) thus generated is discharged to the discharge chamber 23 through the central discharge port 413, and is sent from there to the refrigeration cycle through the refrigerant discharge pipe 26.

  When the motor 5 is stopped, the discharge gas flows back into the compression chamber 43 and flows into the low-pressure side motor chamber 24. At the same time as the stop, the cylinder valve 451 is lifted by the coil spring 452 along the stopper 453. By abutting and sealing, the backflow of the discharge gas is surely prevented.

  In this embodiment, the refrigerant suction hole 44 is a vertical hole formed along the axial direction of the fixed scroll 41. In addition to this, as shown in FIG. 4, for example, the refrigerant suction hole 44 is formed along the radial direction of the fixed scroll 41. The backflow prevention valve 45 may be incorporated in the refrigerant suction hole 44.

  In this embodiment, the stopper 453 is formed of a ring body attached to the refrigerant suction hole 44. As another restricting means for restricting the movement of the cylinder valve 451, as shown in FIG. A stopper pin 455 may be provided on the upper portion of the cylinder valve 451, and may be brought into contact with a wall surface (in this embodiment, the partition plate 21) that opposes the opening of the adjacent refrigerant suction hole 44.

  Further, in this embodiment, the refrigerant suction hole 44 and the backflow prevention valve 45 are provided at one place on the fixed scroll 41, but may be provided at a plurality of places along the radial direction of the end plate 411. According to this, the pressure loss of the suction gas can be suppressed.

  Conversely, as shown in FIG. 7B, a restriction pin 211 may be set up on the wall surface (partition plate 21) side so that the tip of the restriction pin 211 contacts the cylinder valve 451. The same effect can be obtained.

  Next, FIG. 8 is a sectional view schematically showing the internal structure of the scroll compressor 1a according to the second embodiment of the present invention. In addition, the same referential mark is attached | subjected to the part considered the same as 1st Embodiment mentioned above, or the same, The description is abbreviate | omitted.

  In this scroll compressor 1a, the space between the back surface of the end plate 421 of the orbiting scroll 42 and the main frame 3 is sandwiched between the end plate support portion 36 and the storage portion 34 whose inner diameter side communicates with the motor chamber 24, and the outer diameter side is The Oldham chamber 35 communicates with the compression chamber 43.

  A cutout portion 424 communicating with the compression chamber 43 and the Oldham chamber 35 is provided on the outer periphery of the end plate 421 of the orbiting scroll 42. Note that the notch 424 is always formed within a range in which the compression chamber 43 and the Oldham chamber 35 communicate with each other during one turning motion of the turning scroll 42.

  In this embodiment, the main frame 3 is formed in a disk shape along the inner peripheral surface of the sealed shell 2, and the upper surface is in contact with the end plate 411 of the fixed scroll 41 over the entire periphery. The main frame 3 is provided with a refrigerant suction hole 44 that allows the electric motor chamber 24 and the Oldham chamber 35 to communicate with each other.

  The refrigerant suction hole 44 is a horizontal hole formed along the radial direction of the main frame 3, and the reverse flow of the discharge gas generated in the compression chamber 43 when the electric motor 5 is stopped is placed in the refrigerant suction hole 44. A backflow prevention valve 45 is provided to prevent this.

  The backflow prevention valve 45 includes a cylinder valve 451, a coil spring 452 that always urges the cylinder valve 451 in the closing direction (right direction in FIG. 8), and a stopper 453 that restricts the movement of the cylinder valve 451. In addition, since the specific structure is the same as that of 1st Embodiment mentioned above, description is abbreviate | omitted.

  When the scroll compressor 1a is driven, the suction gas taken into the motor chamber 24 from the refrigerant suction pipe 25 reaches a certain pressure, thereby pushing down the cylinder valve 451 in the opening direction (leftward in FIG. 8).

  As a result, the suction gas flows into the Oldham chamber 35 through the refrigerant suction hole 44, and further from there through the notch 424 of the end plate 421 to the compression chamber 43 on the outer periphery of the scroll wrap, and then compressed in the compression chamber 43. The

  When the electric motor 5 is stopped, the backflow can be reliably prevented by the cylinder valve 451 abutting and sealing along the stopper 453 before the discharge gas flows backward as in the first embodiment.

  In the second embodiment, the stopper 453 described in FIGS. 5A and 5B can also be applied.

Sectional drawing which showed schematically the internal structure of the scroll compressor which concerns on 1st Embodiment of this invention. The enlarged view for demonstrating the structure of the backflow prevention valve of the scroll compressor of the said 1st Embodiment. The enlarged view which shows the operating state of a backflow prevention valve. The enlarged view which shows the modification of the backflow prevention valve of 1st Embodiment. Sectional drawing which shows the modification of a stopper. The front view which shows the modification of a stopper. Sectional drawing explaining the modification of a stopper. Sectional drawing of the scroll compressor which concerns on 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a Scroll compressor 2 Sealed shell 21 Partition plate 23 Discharge chamber 24 Electric motor chamber 3 Main frame 4 Refrigerant compression part 41 Fixed scroll 411 End plate 412 Scroll wrap groove 42 Orbiting scroll 421 End plate 422 Scroll wrap 43 Compression chamber 44 Refrigerant suction hole 45 Backflow prevention valve 451 Cylinder valve 452 Coil spring 453 Stopper 5 Electric motor 6 Rotation drive shaft

Claims (4)

It has a refrigerant compression section formed by engaging spiral scroll wraps standing on the end plates of the fixed scroll and the orbiting scroll and forming a compression chamber therein, and a rotary drive shaft for driving the orbiting scroll. In the internal low-pressure type scroll compressor having a refrigerant suction path that leads the low-pressure refrigerant to the refrigerant compression section via the electric motor chamber, with the electric motor and the main frame being opposed to each other in the sealed shell,
A refrigerant suction hole that communicates the compression chamber and the electric motor chamber is provided in an outer peripheral portion of the wrap groove of the fixed scroll, and the compression chamber is provided in the refrigerant suction hole when the electric motor is stopped. A scroll compressor characterized in that it is provided with backflow prevention means for preventing backflow of the high-pressure refrigerant generated in step (1).   The scroll compressor according to claim 1, wherein the end plate of the orbiting scroll is formed in a size that always covers the wrap groove of the fixed scroll. It has a refrigerant compression section formed by engaging spiral scroll wraps standing on the end plates of the fixed scroll and the orbiting scroll and forming a compression chamber therein, and a rotary drive shaft for driving the orbiting scroll. An electric motor is disposed opposite to the inside of the hermetic shell with the main frame in between, and an Oldham chamber is provided on the back of the end plate of the orbiting scroll, and an Oldham ring is housed, and low-pressure refrigerant is passed from the electric motor chamber through the Oldham chamber. In the internal low-pressure type scroll compressor having a refrigerant suction path leading to the refrigerant compression section,
The end plate of the orbiting scroll is provided with a communication portion that communicates the Oldham chamber and the outer periphery of the wrap groove of the scroll wrap, and the fixed scroll and the main frame are provided on the entire circumference, and the Oldham chamber is provided. The main frame is provided with a refrigerant suction hole that communicates the Oldham chamber and the motor chamber, and the refrigerant suction hole is provided when the motor is stopped. A scroll compressor characterized in that backflow prevention means for preventing backflow of the high-pressure refrigerant generated in the compression chamber is provided.   The backflow prevention means includes a valve body that is movable along the axial direction of the refrigerant suction hole, a spring that urges the valve body in a direction that always closes the valve body, and a drop of the valve body from the refrigerant suction hole. 4. The scroll compressor according to claim 1, further comprising a stopper for blocking.

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