JPH08541Y2 - Scroll type fluid machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a scroll type fluid machine suitable for use in, for example, an air compressor, a pump, a blower or the like.

[Conventional technology]

Generally, a scroll type fluid machine of this type includes a casing, a fixed scroll fixedly attached to the casing and having a spiral wrap portion provided upright, and rotatably supported by the casing, and a crank at the tip side. A drive shaft having a shaft, a revolving scroll rotatably supported by the crankshaft, and an orbiting scroll in which a spiral wrap portion that overlaps the wrap portion of the fixed scroll and revolves is erected, and the revolving scroll and the casing. A thrust bearing which is interposed between the thrust bearing and the thrust bearing which receives the load in the thrust direction applied to the orbiting scroll. When this scroll fluid machine is used as an air compressor, the air sucked from the suction port is sealed in a compression chamber that is a sealed space formed between the fixed scroll and the orbiting scroll, and the orbiting scroll revolves. On the other hand, the compression chamber is compressed while being compressed, and the compressed air is discharged from a discharge port formed at the center of the fixed scroll.

[Problems to be solved by the invention]

As described above, since the scroll compressor continuously compresses air while gradually compressing the compression chamber, the fixed scroll and the orbiting scroll forming the compression chamber, particularly the wrap portion of each scroll. Will be heated by the heat of compression. Further, in the oil-free scroll compressor that is not cooled by oil, there is a problem that the thermal expansion of each lap portion becomes large and the tooth tips of the lap portion are pressed against the end plate, which prevents smooth swiveling motion.

Therefore, in the prior art, there is known one in which a gap is provided between the end plate and the tooth tip of the lap portion in consideration of the thermal expansion of the lap portion due to the temperature rise of each scroll in advance (Japanese Patent Laid-Open Publication No. Sho. 58-67902 publication). However, in this way, when the compression heat is low and the thermal expansion of the wrap tooth tip is small as in the initial stage of operation of the scroll compressor, the compressed air flows through the gap between the wrap tooth tip and the end plate to the low pressure side in the compression chamber. Therefore, there is a drawback that compressed air having a predetermined pressure cannot be obtained promptly after the start of operation.

The present invention has been made in view of the above-described drawbacks of the prior art.By finely adjusting the gap between the end plate and the tooth tip of the lap portion, it is possible to quickly obtain a predetermined performance from the beginning of operation, and further, due to thermal expansion. As a result of reliably preventing the galling phenomenon of the end plate of the end plate and the wrap portion, it is not necessary to perform strict surface treatment of the end of the tooth, and tip seal and the like can be dispensed with. The purpose is to provide.

[Means for solving problems]

In order to solve the above-mentioned problems, a feature of the configuration adopted by the present invention is that it is provided in at least one of a fixed scroll and an orbiting scroll, and an axial direction formed between the orbiting scroll and the fixed scroll is formed. A gap detection sensor for detecting a gap and a fine movement mechanism provided in the casing for finely moving the orbiting scroll in the axial direction via a thrust bearing based on a signal from the gap detection sensor are provided.

[Action]

With the above configuration, when the gap between the fixed scroll and the orbiting scroll detected by the gap detection sensor is large, the orbiting scroll can be minutely moved in the axial direction by the minute movement mechanism so as to reduce the gap, and conversely, When the gap becomes too small, the orbiting scroll can be slightly moved in the axial direction so as to increase the gap. Then, by finely moving the orbiting scroll in the axial direction by the fine movement mechanism based on the signal from the gap detection sensor, the gap between both scrolls can be always kept optimal.

〔Example〕

Hereinafter, as an embodiment of the present invention, an oil-free scroll compressor will be described as an example and described in detail with reference to the drawings.

In the figure, reference numeral 1 denotes a casing, and the casing 1 is composed of a small-diameter tubular bearing portion 1A and a large-diameter tubular portion 1B, and a thrust slide bearing 14 described later is supported on the inner peripheral side of the large-diameter tubular portion 1B. The bearing support portion 1C is formed in a ring shape.

Reference numeral 2 denotes a fixed scroll fixed to the opening side of the large-diameter cylindrical portion 1B of the casing 1. The fixed scroll 2 includes an end plate 2A, a spiral wrap portion 2B erected on the inner surface of the end plate 2A, and the wrap. It is composed of a cylindrical portion 2C which is located on the outer side of the portion 2B and is formed on the outer peripheral edge of the end plate 2A, and a plurality of heat radiation fins 3, 3, ... .

Reference numeral 4 denotes a drive shaft that is provided in the casing 1 and is located on the same axis O ₁ -O _{1 as the} fixed scroll 2. The drive shaft 4 is rotatably supported by bearings 1A via bearings 5 and 5. There is.
One end of the drive shaft 4 projects outside the casing 1 and is connected to a motor (not shown), and the other end side is a large-diameter cylindrical portion.
It is located within 1B and serves as a counterweight mounting portion 4A. Further, the tip end side of the counterweight mounting portion 4A is a crankshaft 4B, and the axis O ₂ -O ₂ of the crankshaft 4B is eccentric to the axis O ₁ -O ₁ of the drive shaft 4 by a distance δ. There is.

Reference numeral 6 denotes a boss member which is fitted to the crankshaft 4B via a slewing bearing 7 which is a roller bearing so as to be rotatable and capable of making a minute movement in the axial direction. The boss member 6 is fitted to the outer ring side of the slewing bearing 7. It is composed of a bottomed cylindrical portion 6A that fits together, and flanges 6B, 6B, ... Protruding in a cross shape from the outer peripheral surface of the cylindrical portion 6A.

Reference numeral 8 denotes an orbiting scroll fixed to the boss member 6 through tightening bolts 9, 9, ..., The orbiting scroll 8 is an end plate 8A facing the end plate 2A of the fixed scroll 2, and an outer periphery of one end surface of the end plate 8A. Ring bearing slide contact part 8B formed to project to the side
And a spiral wrap portion 8C provided upright on the other side surface of the end plate 8A. A plurality of compression chambers 10, 10, ... Are formed between the fixed scroll 2 and the orbiting scroll 8 by overlapping the wrap portion 8C with the wrap portion 2B of the fixed scroll 2 by shifting them by a predetermined angle. .

11 is the suction port, 12 is the discharge port, suction port
11 is bored in the cylindrical portion 2C of the fixed scroll 2 so as to communicate with the outermost compression chamber 10, and the discharge port 12 is bored in the center of the end plate 2A so as to communicate with the outermost compression chamber 10. ing.

Further, 13 is an auxiliary crank as a rotation preventing mechanism for preventing the orbiting scroll 8 from rotating, and the auxiliary crank 13 is located between the orbiting scroll 8 and the fixed scroll 2 and is spaced a predetermined distance in the circumferential direction. A plurality of roller bearings 13A and 13B are provided and are axially supported.

Next, 14, 14, ... Are thrust and slide bearings as thrust bearings, which are fixed between the bearing support portion 1C of the casing 1 and the end plate 8A of the orbiting scroll 8 and fixed to the tip of a piezoelectric actuator 22 described later. The sliding bearings 14 are made of a self-lubricating resin such as a fluorinated resin or a metal material such as gun metal formed into a small-diameter disc shape, and are orbiting scrolled by compressed air compressed in the compression chamber 10. The load in the thrust direction applied to 8 is received, and the circular motion of the orbiting scroll 8 is smoothed.

Further, 15 is a cooling fan provided together with the counter weight 16 in the counter weight mounting portion 4A of the drive shaft 4,
The fan 15 is integrally rotated by the drive shaft 4. , 17, 18 are located near the opening side of the large-diameter cylindrical portion 1B of the casing 1 and are provided with cooling air inlets formed in the large-diameter cylindrical portion 1B at predetermined intervals in the circumferential direction. , ... are cooling air outlets axially formed on the end surface side of the large-diameter cylindrical portion 1B, which are located closer to the bearing portion 1A side of the casing 1, and are the fan 15
The cooling air is sucked into the casing 1 through the respective inlets 17, cooled by the sliding bearing 14, the slewing bearing 7, etc., and then discharged from the respective outlets 18.

Next, in order to detect the gap t between the tooth tip of the wrap portion 2B of the fixed scroll 2 and the end plate 8A of the orbiting scroll 8, a gap 19 is attached to the tooth end of the wrap portion 2B so as to face the end plate 8A. In the detection sensor, as the gap detection sensor 19, for example, an ultrasonic sensor, a temperature sensor that detects temperature and indirectly detects a change in the gap due to thermal expansion, or the like is used. The detection signal from the gap detection sensor 19 is sent to the control device 21 via the wiring 20.

On the other hand, reference numerals 22, 22, ... Denote a plurality of piezoelectric actuators as a minute moving mechanism for minutely moving the orbiting scroll 8 in the axial direction via the thrust slide bearings 14, and each piezoelectric actuator 22 is an electric quantity such as an electric field or a magnetic field. It has a piezoelectric element that extends in the axial direction according to the size, and is electrically connected to the control device 21 via a wiring 23. And
The piezoelectric actuator 22 is a bearing support portion 1C of the casing 1.
A mounting hole formed in the axial direction at a predetermined distance in the circumferential direction
When the power supply is turned on at the time of starting, it is inserted into 24, 24, ...
It extends to the maximum length and pushes the orbiting scroll 8.

The present embodiment is configured as described above, and the operation itself of compressing the air sucked into each compression chamber 10 from the suction port 11 while rotating the orbiting scroll 8 and discharging the compressed air from the discharge port 12 is conventional. There is no difference from technology.

Thus, according to the present embodiment, the lap portion 2B of the fixed scroll 2 is provided with the gap detection sensor 19 for detecting the gap with the end plate 8A of the orbiting scroll 8, and the bearing support portion 1C of the casing 1 is provided. The piezoelectric actuator 22 is provided to adjust the axial movement of the orbiting scroll 8 during operation of the scroll compressor as follows. That is, when the scroll compressor is not in operation, the piezoelectric actuator 22 is in the most contracted state, and the fixed scroll 2 and the orbiting scroll 8 face each other within the range of the longest axial clearance t set in consideration of thermal expansion. is there.

Turn on the power to start the scroll compressor from this state
Then, the gap detection sensor 19 first detects the gap t between the tooth top of the wrap portion 2B of the fixed scroll 2 and the end plate 8A of the orbiting scroll 8. At this time, the compression heat of each compression chamber 10 is low at the beginning of operation of the scroll compressor, and the wrap portion 2B
Since the thermal expansion of the tooth tip is also small, each piezoelectric actuator 22 is applied with the maximum amount of electricity (current or voltage) based on the signal from the gap detection sensor 19, the piezoelectric element extends to the maximum length, and the thrust slide bearing 14 The orbiting scroll 8 is pushed to the fixed scroll 2 side via the. As a result, the gap t between the orbiting scroll 8 and the fixed scroll 2 can be reduced, and the gap t between the scrolls 8 and 2 can be optimally set.

Then, the orbiting motion of the orbiting scroll 8 reaches a predetermined number of revolutions, and the compression heat at this time causes the fixed scroll 2 and the wrap portions 2B and 8C of the orbiting scroll 8 to start thermal expansion, and the wrap portions 2B and 8C When the gap t between the end plates 8A, 2A decreases, the control device 21 reduces the amount of electricity applied to each piezoelectric actuator 22 based on the detection signal from the gap detection sensor 19 and reduces each piezoelectric actuator 22. As a result, the orbiting scroll 8 is separated from the fixed scroll 2 by the reduced length of the piezoelectric actuator 22 due to the separating force of the compressed air, and the wrap portion 2B of the fixed scroll 2 and the end plate of the orbiting scroll 8 are separated. The gap t between 8A (the tip of the wrap portion 8C and the end plate 2A) can be kept at an optimum gap.

Thus, according to the present embodiment, the gap detection sensor 19 detects the change in the gap t due to the thermal expansion of the fixed scroll 2 and the orbiting scroll 8, and the piezoelectric actuator 22 is operated via the control device 21. Regardless of expansion, the gap t between each tooth tip of each lap portion 2B (8C) and the end plate 8A (2A) can always be kept in an optimum state, and a galling phenomenon or the like will surely occur between them. Can be prevented.

Even when the compression heat is low and the thermal expansion of the wrap portion 2B (8C) is small as in the initial operation of the scroll compressor, the gap t between the tooth tip of the lap portion 2B (8C) and the end plate 8A (2A) is reduced. The optimum gap can be maintained, the compressed air can be effectively prevented from escaping to the low pressure side of each compression chamber 10, and compressed air having a predetermined pressure can be promptly obtained after the start of operation.

Therefore, in this embodiment, the wrap portion 2B (8C) tooth tip and end plate
The gap t with 8A (2A) can always be set to the optimum gap, and both can be kept in a non-contact state regardless of thermal expansion, so a high degree surface treatment is applied to the tip of the lap portion 2B (8C). In addition to eliminating the need for applying a chip seal, it is possible to eliminate the need for a tip seal or the like, thereby reducing the processing cost and the component cost. Furthermore, since each piezoelectric actuator 22 can adjust the gap t (gap adjustment) at the time of assembly, it is not necessary to strictly manage the axial dimensional tolerances of the scrolls 2, 8 and the boss member 6 and the like. The workability at the time can be greatly improved.

Although the gap detection sensor 19 is provided on the fixed scroll 2 in this embodiment, it may be provided on the orbiting scroll 8 side. Further, in the present embodiment, the piezoelectric actuator 22 is used as the minute moving mechanism for minutely moving the orbiting scroll 8, but a ball screw, an electromagnetic solenoid or the like may be used.

[Effect of device]

The present invention is as described above in detail, and the axial movement distance of the orbiting scroll is adjusted according to the thermal expansion of the fixed scroll and the orbiting scroll so that the gap between both scrolls is always optimal. Predetermined performance can be obtained from the initial stage of operation. Further, since the tip of the wrap portion of each scroll and the end plate can be kept in a non-contact state regardless of thermal expansion, the tip of the wrap portion is not required to have a high degree of surface treatment and no tip seal is required. Therefore, the processing cost and the component cost can be reduced. Furthermore, since the gap can be adjusted at the time of assembly by the fine movement mechanism, it is not necessary to strictly manage the axial dimensional tolerances of the scrolls, boss members, etc., and the processing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an oil-free scroll compressor according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a portion in FIG. FIG. 1 ... Casing, 2 ... Fixed scroll, 4 ... Drive shaft, 8 ... Orbiting scroll, 14 ... Thrust bearing, 19 ...
… Gap detection sensor, 22 …… Piezoelectric actuator.

Claims (1)

[Scope of utility model registration request] 1. A casing, a fixed scroll fixedly attached to the casing and having a spiral wrap portion provided upright, and a drive shaft rotatably rotatably supported by the casing and having a crankshaft on the tip side. An orbiting scroll that is rotatably supported by the crankshaft so as to be slightly movable in the axial direction, and has a spiral wrap portion that is erected to overlap with the wrap portion of the fixed scroll and that is erected, and the orbiting scroll. And a thrust bearing interposed between the casing and the casing, in a scroll type fluid machine, which is provided on at least one of the fixed scroll and the orbiting scroll and is formed between the orbiting scroll and the fixed scroll. A gap detection sensor that detects the gap in the axial direction,
A scroll-type fluid machine, comprising: a minute movement mechanism provided in the casing and finely moving the orbiting scroll in the axial direction through a thrust bearing based on a signal from the gap detection sensor.