JP2000249083A - Scroll fluid machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eminently improve durability of a scroll compression element and to perform smooth operation. SOLUTION: A scroll fluid machinery 1 comprises a scroll compression element 2 consisting of a fixed scroll 6 and an oscillating scroll 7; a motor-drive element 3 to drive the oscillation scroll 7; and an Oldham's coupling 36 not rotating the oscillating scroll 7 with respect to the fixed roll 6 but revolving the scroll over a circular orbit. A thrust ring is embedded in the outer peripheral part on the fixed scroll 6 side of the end plate 11 of the oscillating scroll 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-lubricated scroll fluid machine including a scroll compression element composed of a fixed scroll and an orbiting scroll, and an electric element for driving the scroll compression element. is there.

[0002]

2. Description of the Related Art A conventional scroll fluid machine, particularly a compressor, is disclosed in, for example, JP-A-7-103150. That is, this type of scroll fluid machine includes a scroll compression element and an electric element, and the scroll compression element is provided with a housing having a main bearing in the center, a head plate fixed to the housing, and an upright standing on the head plate. A fixed scroll having a spiral wrap, an orbiting scroll having a head plate, a spiral wrap provided upright on one surface of the head plate, and a boss provided upright on the other surface. ing.

[0003] The fixed scroll and the orbiting scroll are assembled with their laps engaged with each other, and a driving device provided on the rotating shaft of the electric element is fitted to the boss of the orbiting scroll. Was.

[0004]

However, since an overturning moment is applied to the orbiting scroll, a galling phenomenon easily occurs between the outer peripheral portion of the end plate of the orbiting scroll and the fixed scroll. When such a galling phenomenon occurs, there is a problem that the durability of the scroll compression element is significantly reduced.

On the other hand, a back pressure chamber is formed between the back surface of the orbiting scroll and the housing, and the back pressure chamber is communicated with a compression space for intermediate pressure between both wraps, so that the orbiting scroll is raised and driven. This may prevent the orbiting scroll from overturning. However, if the orbiting scroll is pressed against the fixed scroll to such an extent that the orbiting scroll does not overturn, there is a problem that the surface pressure increases and the operation becomes difficult especially in the case of no lubrication.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional technical problem, and provides a scroll fluid machine in which durability of a scroll compression element is remarkably improved and smooth operation is possible. With the goal.

[0007]

That is, a scroll fluid machine according to the present invention has a head plate, a spiral wrap erected on the head plate, a fixed scroll fixed to a housing, a head plate and the head plate. A scroll compression element composed of an orbiting scroll having a fixed scroll wrap and a spiral wrap meshing with each other, an electric element having a rotating shaft for driving the orbit scroll, and an orbiting scroll And an Oldham coupling for revolving on a circular orbit without rotating with respect to the fixed scroll, wherein the thrust is provided on the outer peripheral portion of the end plate of the orbiting scroll on the fixed scroll side. The ring is buried.

In the scroll fluid machine according to the second aspect of the present invention, a back pressure chamber is provided between the back surface of the orbiting scroll and the housing, and a compression space for intermediate pressure between the back pressure chamber and the two wraps. And a sensor for detecting a load against which the orbiting scroll is pressed against the fixed scroll, a valve device interposed in the communication passage, and a control device for controlling the valve device based on the output of the sensor. It is characterized by having.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of a non-lubricated (oil-free) scroll type air compressor 1 as an embodiment of a scroll fluid machine of the present invention, and FIG. 2 is a housing 5, an orbiting scroll 7, an Oldham coupling 36 and a thrust plate. It is an exploded perspective view of 41 etc.

The scroll-type air compressor 1 of the embodiment includes an upper scroll compression element 2 and a lower electric element 3. The scroll compression element 2 has a main bearing 4 in the center.
, A fixed scroll 6 fixed to the upper surface of the housing 5 with bolts 51, and an oscillating scroll 7 sandwiched between the fixed scroll 6 and the housing 5.

The fixed scroll 6 has a disk-shaped end plate 8, an annular wall 9 protruding from one peripheral edge of the end plate 8, and a spiral-shaped spiral wall surrounded by the annular wall 9 and erected on the end plate 8. And a wrap 10. And fixed scroll 6
Makes the projecting direction of the annular wall 9 and the wrap 10 downward.

The orbiting scroll 7 has a disk-shaped end plate 11,
The end plate 11 includes a spiral wrap 12 erected on one surface of the end plate 11 and a boss 13 protruding from the center of the other surface of the end plate 11. The orbiting scroll 7 has the wrap 12 projecting upward.

The fixed scroll 6 and the orbiting scroll 7 are engaged with each other with the wraps 10 and 12 facing each other to form a plurality of compression spaces 14 therein. The case 15 is attached to the lower surface of the housing 5 with bolts 26, and the electric element 3 is housed in the case 15.

The case 15 communicates with the outside through a window. The electric element 3 includes a stator 16 fixed in a case 15, a rotor 17 disposed inside the stator 16, and a rotating shaft 18 inserted in the center of the rotor 17. ing.

A rotating shaft 1 is provided at the center of the lower surface of the case 15.
An auxiliary bearing 19 that supports the lower end of 8 via a ball bearing 54 is provided. The main bearing 4 is provided with a ball bearing 24 fitted to the step portion 20 of the rotating shaft 18.

Reference numeral 25 denotes a driving device for transmitting the rotational force of the electric element 3 to the orbiting scroll 7. The driving device 25 is inserted into the boss hole 13 A of the boss portion 13 of the orbiting scroll 7 and controls the orbiting scroll 7. The bush 28 includes a revolving bush 28 and a bolt 30 for fixing the bush 28 to an eccentric portion 29 at the upper end of the rotating shaft 18.

The fixed scroll 6 has a suction port (not shown) communicating with the compression space 14 outside the end plate 8, and a discharge port 32 communicating with the compression space 14 at the center of the end plate 8.
Are formed respectively. An Oldham coupling 36 revolves around a circular orbit so that the orbiting scroll 7 does not rotate with respect to the fixed scroll 6.

The Oldham coupling 36 includes a frame 37 formed of a ring of hard synthetic resin such as PPS (polyphenylene sulfide), and a plurality of claws 39, 39, 39A,
9A. The frame 37 has a predetermined width,
One surface (upper surface) comes into contact with the orbiting scroll 7 and the other surface (lower surface) comes into contact with the housing 5 and slides. The pair of claw portions 39, 39 are provided at opposing positions on one surface (lower surface) of the frame 37, and the pair of claw portions 39A, 39A oppose at a position shifted by 90 degrees on the other surface (upper surface) side. Is provided.

Here, a thrust ring 33 is provided on the outer peripheral portion of the end plate 11 of the orbiting scroll 7. The thrust ring 33 is buried on one surface of the end plate 11 of the orbiting scroll 7, that is, on the periphery of the surface on the fixed scroll 6 side, as shown in an enlarged view in FIG. 3. The thrust ring 33 is made of carbon and a galling resistant material containing carbon as a main component, and is provided so as to be flush with the end plate 11 surface or several tens μm higher (thick).

The thrust ring 33 comes into contact with the lower surface of the annular wall 9 of the fixed scroll 6 so that the end plate 11
The sliding resistance between the scroll scroll and the annular wall 9 is reduced, and the galling phenomenon caused by the overturning moment applied to the orbiting scroll 7 is prevented.

The thrust ring 33 may be made of an iron-based material coated with the above-mentioned carbon and carbon as a main component.

On the other hand, a groove 11A is formed on the back surface of the end plate 11 of the orbiting scroll 7, and a groove 58 is also formed on the upper surface of the housing 5. And the Oldham coupling 36
A pair of claw portions 39, 3 formed on the lower surface at the opposite positions of
9 is slidably engaged with the groove 58, and a pair of opposing claw portions 39A, 3A, 3A formed on the upper surface at positions shifted by 90 degrees.
The orbiting scroll 7 revolves by 9A slidably engaging with the groove 11A of the orbiting scroll 7.

A thrust plate 41 having a predetermined thickness and having a pair of engagement holes 41A is provided between the housing 5 and the orbiting scroll 7. This thrust plate 41
Is provided on the surface (upper surface) of the housing 5 on the side of the orbiting scroll 7 and supports the thrust surface of the end plate 11 of the orbiting scroll 7 to reduce the sliding resistance between the orbiting scroll 7 and the housing 5. is there.

Reference numerals 21 and 21 denote positioning pins for engaging engagement holes 41A and 41A formed in the thrust plate 41, respectively. Thus, the thrust plate 41 is positioned on the housing 5 in a state where the movement in the horizontal direction is prevented.

Here, the space below the orbiting scroll 7
That is, a back pressure chamber G1 is formed in a space between the back surface of the orbiting scroll 7 and the housing 5, and the back pressure chamber G1 is formed as shown in FIG.
As shown in the block diagram, the communication passage 43A communicates with the compression space 14 at the intermediate pressure.

A valve device 42 is interposed in the communication passage 43A. A load sensor 44 is embedded at the tip of the wrap 10 of the fixed scroll 6, and detects a load against which the orbiting scroll 7 is pressed against the fixed scroll 6. The valve device 42 is connected to the load sensor 44
The opening and closing of the valve device is controlled by a control device (not shown) based on the output of the valve.

In the scroll type air compressor 1 configured as described above, when the electric element 3 is rotated, the rotational force is transmitted to the orbiting scroll 7 via the rotating shaft 18. That is, the orbiting scroll 7 is driven by the bush 28 of the driving device 25 attached to the rotating shaft 18 inserted into the boss hole of the boss portion 13 of the scroll, and the Oldham coupling 36
As a result, the fixed scroll 6 revolves on a circular orbit so as not to rotate.

The fixed scroll 6 and the orbiting scroll 7 are formed by a compression space 14 formed by these scrolls.
Is gradually reduced from the outside to the inside to compress the air flowing from the suction port. The compressed air is discharged from the discharge port 32 of the end plate 8 of the fixed scroll 6.

At this time, the compression space 14 (in this case, an intermediate pressure portion of the compression space 14) and the back pressure chamber G1 are connected to the control valve 4
2 through the communication passage 43A through the control valve 4
2 is supplied to the back pressure chamber G1, and the orbiting scroll 7 is pressed against the fixed scroll 6 by the pressure.

Here, if the pressure in the back pressure chamber G1 is too high,
The load with which the orbiting scroll 7 is pressed against the fixed scroll 6 becomes large, and it becomes difficult to perform a non-lubricating operation. Conversely, when the pressure in the back pressure chamber G1 is low, the orbiting scroll 7 is easily overturned.

Therefore, the control device detects the load of the orbiting scroll 7 pressed against the fixed scroll 6 by the load sensor 44. If the detected load becomes high (the pressure of the back pressure chamber G1 becomes the upper limit), the valve is opened. When the device 42 is closed and the load becomes low (the pressure in the back pressure chamber G1 becomes the lower limit), the valve device 42 is closed.
open.

Thus, the pressure in the back pressure chamber G1 is adjusted to an optimum pressure on average, and smooth driving without lubrication is realized while preventing the orbiting scroll 7 from overturning. FIG.
Indicates the optimum pressure of the back pressure chamber G1 according to the discharge pressure during operation and the upper and lower limits.

FIG. 6 shows an orbiting scroll 7 according to another embodiment of the present invention. In this case, the orbiting scroll 7
A thrust ring 33 similar to that described above is embedded in an outer peripheral portion of one surface of the end plate 11, and a similar thrust ring 33 is embedded in an outer peripheral portion of the other surface of the end plate 11.

Thus, the thrust rings 33, 33 are connected to the lower surface of the annular wall 9 of the fixed scroll 6 and the housing 5
The swing scroll 7 can be smoothly swung by contacting the surface. Therefore, the durability of the scroll compression element 2 can be further improved.

[0035]

As described above in detail, according to the present invention, a fixed scroll fixed to the housing, a fixed scroll fixed to a housing, a head plate and a head plate mounted on the head plate are provided. A scroll compression element comprising a fixed scroll wrap and an orbiting scroll having a spiral wrap meshing with each other; an electric element having a rotating shaft for driving the orbiting scroll; and a fixed scroll for the orbiting scroll. In a non-lubricated scroll fluid machine having an Oldham coupling for revolving on a circular orbit without rotating, a thrust ring is embedded in the outer peripheral portion of the end plate of the orbiting scroll on the fixed scroll side. Even if the overturning moment causes galling between the outer periphery of the end plate of the orbiting scroll and the fixed scroll, the scroll pressure It is possible to significantly improve the durability of the element.

According to the second aspect of the present invention, in addition to the above, a back pressure chamber formed between the back surface of the orbiting scroll and the housing, and an intermediate pressure compression space between the back pressure chamber and both wraps. And a sensor for detecting a load against which the orbiting scroll is pressed against the fixed scroll, a valve device interposed in the communication passage, and a control device for controlling the valve device based on the output of the sensor. Therefore, this control device controls the valve device so that the load detected by the sensor becomes an appropriate value and adjusts the pressure of the back pressure chamber, thereby preventing overturning of the orbiting scroll and improving lubrication without lubrication. It is possible to realize smooth driving.

[Brief description of the drawings]

FIG. 1 is a sectional view of a non-lubricated scroll type air compressor as an embodiment of a scroll fluid machine according to the present invention.

FIG. 2 is an exploded perspective view of a scroll compression element.

FIG. 3 is an enlarged perspective view of an orbiting scroll.

FIG. 4 is a block diagram of a back pressure supply path.

FIG. 5 is a diagram showing a relationship between a discharge pressure during operation and a pressure of a back pressure chamber.

FIG. 6 is an enlarged perspective view of an orbiting scroll according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Scroll type air compressor (scroll fluid machine) 2 Scroll compression element 3 Electric element 4 Main bearing 5 Housing 6 Fixed scroll 7 Swing scroll 8, 11 End plate 10, 12 Lapping 14 Compression space 15 Case 18 Rotary shaft 19 Auxiliary bearing 24 , 54 Ball bearing 25 Drive unit 28 Bush 32 Discharge port 33 Thrust ring 36 Oldham coupling 42 Valve unit 43A Communication path 44 Load sensor G1 Back pressure chamber

Continued on the front page (72) Inventor Yuki Takahashi 2-5-5-1 Keihanhondori, Moriguchi-shi, Osaka F-term (reference) in Sanyo Electric Co., Ltd. 3H039 AA03 AA10 AA12 BB05 BB21 CC02 CC04 CC08 CC16 CC23 CC27 CC30 CC32 CC34 CC40

Claims (2)

[Claims] 1. A fixed scroll fixed to a housing and having a head plate and a spiral wrap provided upright on the head plate, and a spiral engaged with the wrap of the fixed scroll provided upright on the head plate and the head plate. A scroll compression element composed of an orbiting scroll having an annular wrap, an electric element having a rotating shaft for driving the orbiting scroll, and a circle without rotating the orbiting scroll with respect to the fixed scroll. A non-lubricated scroll fluid machine having an Oldham coupling for orbiting on a track, wherein a thrust ring is embedded in an outer peripheral portion of the end plate of the orbiting scroll on the fixed scroll side. machine. 2. A back pressure chamber formed between a back surface of an orbiting scroll and a housing, a communication passage communicating between the back pressure chamber and a compression space of an intermediate pressure between both wraps, and wherein the orbiting scroll is fixed. 2. The apparatus according to claim 1, further comprising: a sensor for detecting a load pressed against the scroll; a valve device provided in the communication passage; and a control device for controlling the valve device based on an output of the sensor. Scroll fluid machinery.