JPS61123791A - Scroll type compressor - Google Patents

Abstract

PURPOSE:To aim at stabilizing the performance of a scroll type compressor upon no load operation, by providing a flexible joint in the drive section of the scroll type compressor to optionally change the turning radius of a movable scroll. CONSTITUTION:A drive shaft for driving a movable scroll 8 is connected in its intermediate section with a flexible joint 22, and is provided with swingable bearings 19, 23 in the front and rear of the flexible joint 22. One 23 of the bearings is provided with an air cylinder 4 for adjusting the axial position of the bearing 23, and therefore, this cylinder 22 is actuated by the discharge side pressure. Therefore, when the length of the drive shaft is changed due to the operation of the air cylinder, the turning radius of the swingable scroll is changed in accordance with the displacement of the drive shaft with the swingable shaft 19 serving as a fulcrum, thereby it is possible to drive the compressor with no load.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention compresses a gas such as air or a refrigerant (DV
c) The present invention relates to a scroll compressor used, and particularly relates to a scroll compressor that can effectively control no-load operation.

[Prior art]

In general, a scroll compressor consists of a fixed scroll fixed to a casing, a rotary scroll that overlaps the fixed scroll and forms a compression chamber while rotating, and a rotating scroll that is rotatably supported by the casing and has a distal end. and a drive shaft that serves as a crankshaft and rotates the orbiting scroll, and a power source connected to the drive shaft causes the orbiting scroll to rotate so as not to rotate upward, and during this time, the gas sucked in from the suction port is The compression chamber is hermetically sealed, and the compression chamber is continuously reduced as the orbiting scroll revolves, and the discharge is discharged from the discharge port.

By the way, the scroll compressor configured as described above automatically closes the pressure regulating valve provided at the suction port when the discharge side pressure reaches a predetermined pressure, and the flow of gas to the suction port is stopped. The supply is stopped and the power source is placed in a no-load operating state to prevent the discharge side pressure from becoming abnormally high.

However, as mentioned above, in the no-load operation system with suction capacity adjustment that closes the suction port during no-load operation, after the pressure regulating valve automatically closes, the area near the suction port becomes extremely negative. Despite this, the compression chamber in the vicinity of the discharge port continues to be in a state where the "C" air is continuously compressed, and there is a drawback that the power of the driving means is not reduced.

In order to improve such drawbacks, for example, Japanese Patent Application Laid-Open No. 53-1
No-load operation mechanisms using slide valves are also known, as shown in Japanese Patent Application Laid-open No. 41913 and Japanese Patent Application Laid-open No. 124696/1983, but such structures have the disadvantage of increasing leakage during compression operation. Unfortunately, it's not a good thing.

[Problem that the invention seeks to solve]

The present invention was made in view of the drawbacks of the prior art described above. Conventionally, the turning radius of an orbiting scroll was given by the amount of eccentricity of the crankshaft provided at the tip of the drive shaft. It is an object of the present invention to provide a scroll compressor in which no-load operation can be realized only by adjusting the non-rotating portion by changing the direction of rotation.

[Means for solving problems]

In order to solve the above problems, the present invention includes a cylindrical casing, a fixed scroll fixed to one side of the casing, and a rotating scroll that overlaps the fixed scroll and forms a compression chamber while rotating. a scroll; an adjustment mechanism provided on the other side of the casing and movable in the axial direction of the casing; a tenth drive shaft supported via a bearing, and a third bearing located on one side within the casing and bendably connected to the tenth drive shaft, the middle of which is occupied by the adjustment mechanism. and a second drive shaft supported by the shaft.

〔Example〕

Hereinafter, this embodiment will be described in detail with reference to FIGS. 1 to 3, taking an air compressor as an example.

In the drawings, reference numeral 1 denotes a cylindrical casing with a hollow section inside, and one side of the casing 10 becomes a flange 2 to which a fixed scroll 5, which will be described later, is attached, and the inside of the hollow section IA is biased towards the 7 lange 2 side and the rear A bearing mounting part 3 is formed on the inner side of the casing 10, and a cylinder part 4 consisting of four small cylinder parts and a large diameter cylinder part 4B is formed on the other side of the casing 10. A piston 11, which will be described later, is slidably inserted into the annular cylinder 4C.

5 is a fixed scroll fixed to the end face of the 7 langes 2, and the fixed scroll 5 is aligned with the axes o and -O of the casing 10.
It is arranged so as to be coaxial with t. here,
The fixed scroll 5 includes a head plate 5A, a lug portion 5B formed of an indelute curve or a curve similar to this, and a peripheral wall portion 5C rising from the periphery of the five head plates.
It is composed of. A suction port 6 is formed in the peripheral wall portion 5C of the fixed scroll 5, and a discharge lower is formed in the center of the five end plates.

Reference numeral 8 indicates an orbiting scroll which is driven to rotate by a drive shaft 17.21 which will be described later. It is formed from a wrap portion 8B having a close curve and a cylindrical bearing box 8C provided on the other side of the eight end plates.

Then, the axis of the orbiting scroll 8 is 0. -0. is bearing box 8
It is defined as an axis including the axis center of C, and is set to be eccentric by a distance δ with respect to the axis 01-Ox of the fixed scroll 5 during load operation. Furthermore, the wrap portion 8B of the orbiting scroll 8 is the wrap portion 5 of the fixed scroll 5.
The wrap portions 5B and 8B are attached to overlap each other at a predetermined angle, and a closed space is formed between the wrap portions 5B and 8B to form a plurality of compression chambers 9.91.

Reference numeral 10 denotes an Oldham joint as a stop mechanism during rotation, and when the orbiting scroll 8 is rotated by a drive shaft 17.21 (described later), the Oldham joint 10 rotates the orbiting scroll 8 about the axis Ox -0° of the fixed scroll 5. It guides the object so that it revolves with a turning radius of δ.

Further, 11 is a piston for moving a bearing which is movable in the axial direction within the cylinder portion 4, and the piston 11 includes an annular piston portion 11A that slides within the annular cylinder 4C, and a piston portion 11A that slides within the annular cylinder 4C. It is formed from a lid-shaped bearing mounting part 11B provided so as to be closed. A ring-shaped lid member 12 is provided on the end face of the large-diameter cylindrical portion 4B forming the cylinder portion 4, and a compression spring 13 is stretched between the back side of the piston 110 and the lid member 12.

The piston 11 is always biased to the left in the figure, and the male piston 1
is in contact with the end face of the four small diameter cylinders, and the annular cylinder 4C
A pressure chamber 14 is formed therein. Reference numeral 15 denotes a supply/discharge hoard bored in the large diameter cylindrical portion 4B for supplying and discharging compressed air to the pressure chamber 14.

Thus, in this embodiment, the adjustment mechanism 16 is connected to the cylinder portion 4, piston 11, compression spring 13, pressure chamber 14, etc.
It consists of

Further, 17 indicates a 10th drive shaft, one end side of the drive shaft 17 is supported via a 10th bearing 18 provided in a bearing box 8C formed in the orbiting scroll 8, and an intermediate portion thereof is attached to the casing 10. Second bearing 19 provided in section 3
Supported through. Here, each of the bearings 18, 1
9 is a self-aligning bearing for swingably supporting the drive shaft 17;

Alternatively, a spherical bearing with a spherical outer ring is used. The inner ring of the tenth bearing 18 is fixed to the tenth drive shaft 17, but the outer ring is slightly movable in the axial direction with respect to the bearing box 8C, and is prevented from being removed by the holding plate 20. has been done.

On the other hand, the inner ring of the second bearing 19 is connected to the tenth drive shaft 17.
The outer rings are press-fitted into the bearing mounting portions 3 and fixed in the axial direction.

On the other hand, 21 indicates a second drive shaft, and one end of the drive shaft 210 is bendably connected to the other end of the tenth drive shaft 17 via a universal joint 22 such as an Oldham joint. The piston 110 is supported slightly at the other end via a third bearing 23 provided in the bearing mounting portion 11B. Here, the third bearing 23 is a self-aligning bearing or a spherical bearing like the bearings 18 and 19 described above, and the inner ring is connected to the second drive shaft 21 and the outer ring is connected to the bearing mounting portion 11B. It is press-fitted and fixed in the axial direction. Furthermore, the second
A crowned pinion 24 is provided on the other end of the drive shaft 210, and the pinion 24 meshes with an internal gear 26 of an output shaft 25 connected to a power source (not shown). As shown in the figure, regarding the tenth drive shaft 17,
1st. The length between the second bearings 18 and 19 is tl, the length between the second bearing 19 and the universal joint 22 is t2, and regarding the second drive shaft 21, the length between the universal joint 22 and the third bearing 23 is The length between the third bearing 23 and the pinion 24 is t3 degrees, the length between the third bearing 23 and the pinion 24 is 64 degrees, and the length between the second bearing 23 and the pinion 24 is 64 degrees. Third bearing 19.23
Assuming that the axial length between them is 10, the radius of revolution δ of the orbiting scroll 8 with respect to the fixed scroll 5 is given as follows.

Therefore, in the load operation state shown in FIG. 1 or FIG. By bending the second drive shaft 17.21 as shown, the orbiting scroll 8 can be rotated with a radius of rotation δ expressed by equation (1). t
In addition, if the piston lli is displaced to the right in FIG. 1 and the third bearing 23 is moved in the axial direction to create a no-load operating state as shown in FIG. 3, to=t2-4-t,...・・・・・・・・・
・As a result of (2), the turning radius δ becomes δ=0, and the turning scroll 8 does not move at all.・Furthermore, 27 is a discharge pipe whose one end is connected to the discharge lower, The other end of the discharge pipe 27 is connected to an air tank, air equipment, etc., and a reverse valve 28 is provided in the middle thereof. 2
9 is a branch pipe, one end of the branch pipe 29 is connected to the discharge pipe 27 on the downstream side of the reverse valve 28, and the other end is connected to the supply/discharge/-
It is connected to port 15. Reference numeral 30 denotes a pressure regulating valve provided in the middle of the branch pipe 29. The pressure regulating valve 30 has a normally closed switching valve body consisting of a three-way valve, and has an exhaust port that is normally open to the atmosphere. The pilot part 30A of the pressure regulating valve 30 detects the internal pressure of the discharge pipe 27, and when the pressure reaches a predetermined value, the valve opens and supplies compressed air to the supply/discharge/-) 15. When the pressure drops to a predetermined pressure lower than the above-mentioned predetermined pressure, the valve is closed and the exhaust port is opened to the atmosphere, so that the compressed air in the pressure chamber 14 is released to the atmosphere.

The present embodiment is constructed as described above, and its operation will now be described.

First, the discharge pipe 27 is in a low pressure state, and the pressure regulating valve 3
0, the valve is closed and the pressure chamber 14 is open to the atmosphere. As a result, the piston 11 is pressed to the left in the figure by the pressure spring 13, and the 30th bearing 23 is in the state shown in the figure. The second drive shaft 17.21 is bent in a "<" shape, and the axes of the fixed scroll 5 and the orbiting scroll 8 are offset by a distance δ.

In this state, when the power source is rotated to drive the compressor,
250 rotations of the output shaft are transmitted to the orbiting scroll 8 via the second and tenth drive shafts 21.17,
performs a circular motion relative to the fixed scroll 5 with a turning radius δ. At this time, air from the suction port 6 is sucked into the compression chamber 9.

This air is gradually compressed as the orbiting scroll 8 rotates, and is discharged from the discharge lower through the check valve 28 to the discharge pipe 27.

However, when the inside of the discharge pipe 27 or the air tank connected thereto reaches a predetermined pressure, this pressure is detected by the pilot section 30A of the pressure regulating valve 30, and the pressure regulating valve 30 opens. As a result, the compressed air in the discharge pipe 27 is supplied to the pressure chamber 14 via the branch pipe 29, displacing the piston 11 to the right in the figure against the compression spring 13. Thus,
The third bearing 23 is also displaced to the right and the length Lo (see FIG. 2) between it and the second bearing 19 is extended, and the third bearing 23 is also displaced to the right. The second drive shaft 17.21 is in the state shown in FIGS. 2 to 3, and the L
o becomes the value of equation (3). Note that at this time, the 10th bearing 1
8 is slightly displaced to the left inside the bearing box 8C, and the 10th drive shaft 1
7 to compensate for the expansion.

Thus, the axis 01-o of the fixed scroll 5.

and the axis 0 of the orbiting scroll 8. -0. coincide with each other, the eccentric distance δ becomes zero, the orbiting scroll 8 does not orbit at all, and the compression chamber 9 is not formed, so that no-load operation can be achieved.

Furthermore, when the compressed air in the discharge pipe 27 or the air tank is consumed and the pressure drops to a predetermined pressure, the pressure regulating valve 30 is closed and its exhaust port is opened to the atmosphere. Therefore, the compressed air in the pressure chamber 14 is released from the branch pipe 29, and the piston 11 is moved again to the first position by the compression spring 13.
The state shown in the figure is restored and compression operation is restarted.

The embodiment of the present invention has been described above, in which the pressure in the discharge pipe 27 is detected by the pressure regulating valve 30 and the operation is controlled; however, a solenoid valve is used instead of the pressure regulating valve 30,
The pressure in the discharge pipe 27t or the air tank may be detected by a pressure switch, and the opening/closing control of the electromagnetic valve may be controlled by the pressure switch.

In addition, in the embodiment, the adjustment mechanism 16 of the present invention includes the cylinder portion 4
, a piston 11, a compression spring 13, a pressure chamber 14, etc., but a movable partition wall such as a diaphragm, a bellows, etc. may also be used. By bending the second drive shaft 17.21, the centrifugal force F of the orbiting scroll 8 and the centrifugal force F of the pinion 24 are reduced as shown in FIG.

is the centrifugal force F on the universal joint 22 side! It is possible to make the balance more balanced, and the conventionally provided balance weight can be made unnecessary.

〔Effect of the invention〕

The scroll compressor of the present invention is as described in detail above, and has a configuration in which the adjustment mechanism is operated according to the pressure on the discharge side to change the orbiting radius of the orbiting scroll. Operation control can be easily performed,
It is possible to save power during no-load operation, and to stably exhibit performance during load operation.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of the scroll compressor according to this embodiment, FIG. 2 is an explanatory diagram of the operation during load operation, and FIG. 3 is an explanatory diagram of the operation during no-load operation. DESCRIPTION OF SYMBOLS 1... Casing, 4... Cylinder part, 5... Fixed scroll, 8... Orbiting scroll, 9... Compression chamber, 10... Oldham joint, 11... Piston, 1
3... Compression spring, 15... Supply/discharge port, 16...
Adjustment mechanism, 17... 10th drive shaft, 18... 10th
Bearing, 19... Second bearing, 21... Second drive shaft, 23... Third bearing, 24... Pinion, 25...
...output shaft, 26--internal gear, 27--discharge piping,
28...Check valve, 29...Branch pipe, 30...Pressure adjustment valve.

Claims (3)

[Claims] (1) A cylindrical casing, a fixed scroll fixed to one side of the casing, and an orbiting scroll that overlaps the fixed scroll and forms a compression chamber while orbiting;
an adjustment mechanism provided on the other side of the casing and movable in the axial direction of the casing; one side supported by the orbiting scroll via a first bearing, and a second bearing provided in the casing halfway; a first drive shaft supported through the casing, and a third bearing located in the casing on one side and bendably connected to the tenth drive shaft, and supported halfway through a third bearing provided in the adjustment mechanism. A scroll compressor comprising a second drive shaft and a second drive shaft. (2) Claim (1) wherein the adjustment mechanism is actuated by the discharge pressure of the compressed gas when it reaches a predetermined pressure, and extends between the second and third bearings. The scroll compressor described. (3) The scroll compressor according to claim (1), wherein the first, second, and third bearings are self-aligning bearings or spherical bearings.