JP2901681B2 - Hermetic scroll compressor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive displacement compressor applied to refrigeration and air conditioning, and more particularly to a scroll compressor in which a compression mechanism and an electric element are housed in a closed container. About the machine.

[Conventional technology]

Regarding the arrangement and structure of bearings in a conventional scroll compressor, for example, as described in JP-A-59-28088, a crankshaft coupled to a motor rotor has bearings arranged on both sides of the motor. Supported.
The bearings arranged on both sides of the motor constitute a sliding bearing fixed together. Further, the bearings at the lower part of the motor are housed in a bottom case, and the oil supply to each bearing is forcibly performed from outside via the bottom case.

[Problems to be Solved by the Invention] In the above-mentioned prior art, a bearing provided at a lower portion of a motor is housed and fixed in a bearing housing which is also used as a bottom plate and is fixed to an airtight container by bolts. Since the container is positioned by a so-called spigot portion, it is necessary to be careful enough during assembly to align the center of the main shaft with the center of the bearing under the motor. Also, when the scroll compressor is operated, the centrifugal force of the orbiting scroll and the centrifugal force of the balance weight are applied to the main shaft, and the electromagnetic attraction force caused by unevenness of the stator of the electric element and the gap between the rotors. Causes a complicated deformation of the main shaft. As seen in the prior art, in many scroll compressors, the rigidity is higher at the upper part of the main shaft (the part on the orbiting scroll side from the motor). In this case, there is a problem that the contact of the bearing occurs due to the deformation of the crankshaft and the reliability of the bearing is reduced.

In addition, the bottom plate also serves as a lower bearing so that it can be positioned accurately with respect to the center of the shaft. However, it is necessary to exercise caution, and there is a problem of lack of productivity. As another problem, since the lubricating oil for the bearing portion and the sliding portion must be supplied from the outside of the container, it is necessary to add a lubricating oil pump device and piping, and the overall size and size become complicated or complicated. There was a problem.

An object of the present invention is to improve the assemblability of a hermetic scroll compressor.

[Means for solving the problem]

In order to achieve the above object, a fixed scroll having a spiral wrap, a orbiting scroll having a wrap that meshes with the wrap of the fixed scroll, and a position that sandwiches the orbiting scroll with the fixed scroll are provided. Frame, a crankshaft for driving the orbiting scroll, an electric element for rotating the crankshaft, a first bearing provided on the frame to support the crankshaft, and the frame with the electric element interposed therebetween. In a hermetic scroll compressor having, in a container, a plate member provided at a position opposite to the above and a second bearing portion provided on the plate member and rotatably supporting the crankshaft, the second bearing portion is provided. The bearing portion may have an angle between the crankshaft and the plate material.

[Operation] Even when the positional relationship between the crankshaft and the second bearing is slightly deviated when the second bearing portion is incorporated, the angle between the crankshaft and the plate material of the second bearing is free. The posture is changed, and the one-side contact of the crankshaft is reduced, so that the setting in a correct state is possible.

〔Example〕

Hereinafter, an embodiment of the present invention will be described. First, a principle of an embodiment will be described, and then a detailed description will be given.

Since the bearing 7c provided on the side opposite to the scroll portion of the motor 10 has a spherical outer peripheral portion, the posture can be freely changed in the bearing housing. Therefore,
When the center of the closed vessel 16 and the center of the crankshaft 6 are slightly misaligned during assembly, or during operation, the centrifugal force of the orbiting scroll 2 and the centrifugal force of the balance weight 4 act on the crankshaft 6, resulting in Even when the crankshaft 6 is deformed, the cylindrical portion of the shaft 6 and the inner cylindrical portion of the bearing 7c can always keep the parallelism correctly with each other by the self-aligning function. In particular, it is technically very difficult to completely balance the unbalance with respect to the rotation of the crankshaft 6, and it is generally unavoidable that some unbalance remains. But,
Due to this imbalance, when the motor 10b reaches a high speed of 5,000 revolutions / minute or more by an inverter (variable rotation speed device, not shown), the motor 10b tends to be bent by receiving a large force from the crank shaft 6, but the automatic adjustment is performed. By the arrangement of the core bearing 21,
The amount of deformation is suppressed to a small value, and the posture of the bearing itself can be suitably changed according to a slight deformation, so that the crank shaft 6 can be supported in a state where the bearing does not hit one side. As a result, the degree of contact with the main bearing 7a can be reduced, so that the reliability of the bearing can be kept high even during high-speed rotation.

The lower end of the crankshaft 6 is immersed in oil, and a refrigerating machine oil 26 is provided in the crankshaft 6 by a pressure difference between an upper portion and a lower portion of the crankshaft 6.
The oil is supplied to each of the slide bearings 7 through the base 31, and the supplied oil is returned to the lower portion of the closed container again, and when it is used for lubrication again, the self-recirculation system is used as usual. Is composed.

Further, depending on the arrangement of the bearing 7c, the stator of the motor 10 is
Since the air gap between the rotor 10a and the rotor 10b is always kept in a suitable state, there is an effect that the loss of the electromagnetic torque is reduced and the efficiency is improved.

Next, a first embodiment will be described with reference to FIG. The casing 16 forms a closed container with a lid casing 17 and a bottom casing 18, and includes a motor 10, a compression mechanism section including the fixed scroll 1 and the orbiting scroll 2, and a lubricating oil.
26 are stored. The motor 10 includes a stator 10a and a rotor 1
0b, and the rotor 10b has a crankshaft 6
Key 25 between the motor 10
Is transmitted to the crankshaft 6. The crank shaft 6 is supported by a slide bearing 7a provided on the frame 3 and a lower bearing (slide bearing) 7c provided on the lower bearing housing 21. The crank shaft 6 includes a straight portion 6a and a portion (crank portion) 6b eccentric to the straight portion 6a, and has an oil supply hole 31 penetrating from the upper end to the lower end. Further, in order to maintain the balance of the rotating body during operation, a balance weight 4 is provided above the crankshaft 6 and a counterweight 11 is provided below the motor 10. The crank shaft 6 and the motor rotor 10b are fixed by a lock nut 12. The frame 3 is fixed to the casing 16 by special bolts 30 provided on the circumference. Further, the frame 3 includes the orbiting scroll 2
An Oldham ring 8 for preventing the rotation of the ring is slidably provided. Further, the orbiting scroll 2 is arranged thereon, and the Oldham ring 8 is provided between the frame 3 and the frame 3. Oldham ring 8
Has a convex portion (not shown) which is engaged with the frame 3 and the back surface of the orbiting scroll 2 respectively. The engaging portion with the frame 3 and the engaging portion with the orbiting scroll are arranged to be orthogonal to each other. The orbiting scroll 2 has a bearing portion 7b, which is engaged with an eccentric portion of the crank shaft 6. The orbiting scroll 2 has a wrap portion formed in a spiral shape.
2a and an end plate portion 2b. Fixed scroll 1
Also, a wrap portion 1a formed in a spiral shape,
It is composed of a head plate 1b. The orbiting scroll 1 and the fixed scroll 2 are engaged with each other with the wrap portions inside each other, and together form a compression working chamber 19. The compression operation chamber 19 and the back pressure chamber 20 are provided on the end plate 2b of the orbiting scroll 2.
Are communicated with each other by an intermediate pressure hole 20 provided in each of them. Also, the orbiting scroll 2 is sandwiched between the frame 3 and the outer periphery of the fixed scroll 1 in a sanitary manner so that the orbiting scroll 2 can engage with the fixed scroll 1 and smoothly move when engaged therewith. The fixed scroll 1 has its outer peripheral portion fixed to the frame 3 by bolts 32. Further, the fixed scroll 1 has a suction port 23 extending to the outer peripheral portion and a discharge port 13 at the center thereof.
A check valve 14 and a retainer 15 are provided.

 Next, the operation will be described with reference to FIG.

When electricity is supplied to the motor 10 from the outside via the hermetic terminal 22, the motor rotor 10b rotates, and the crankshaft 6 rotates accordingly. As a result, the orbiting scroll 2 orbits with the intervention of the Oldham ring 8, the working fluid flows in from the suction port 23 and is taken into the compression working chamber 19, and the working fluid is compressed with the movement of the orbiting scroll, The high-pressure working fluid is discharged from a discharge port 13 provided at the center of the fixed scroll 1. During this compression operation, the appropriately pressurized fluid fills the back pressure chamber 5 through the intermediate pressure hole 20. As a result, the thrust force on the orbiting scroll 2 generated by the pressure in the back pressure chamber 5 becomes:
Since it exceeds the magnitude of the total thrust force generated by the gas force in the compression working chamber, the orbiting scroll is pressed against the fixed scroll 1 during operation, so that a stable compression operation is performed. The high-pressure gas discharged from the discharge port 13 flows into the motor chamber 9 from between the closed container 16 and the compression mechanism unit including the scroll unit 2 and the like, where the gas and the lubricating oil are separated and the gas is separated. It flows out of the compressor from the discharge pipe 24. On the other hand, the separated lubricating oil flows downward due to gravity and reaches the oil reservoir 26. The lubricating oil is supplied from the oil reservoir 26 to the bearings 7 through oil supply holes 31 provided in the crank shaft 6 by a pressure difference. In particular,
After being provided for lubrication of the bearing portions 7a and 7b, the gas is discharged into the back pressure chamber 5, then enters the compression working chamber 19 through the intermediate pressure hole 20, and is further discharged from the discharge port 13 together with gas. Returns to the original oil reservoir 26. The valve plate 14 and the retainer 15 provided opposite to the discharge port 13 are provided in a closed container 16 when the compressor is stopped.
The high-pressure gas remaining inside is prevented from flowing back toward the suction pipe 23, and when the maximum pressure in the compression working chamber is lower than the pressure in the closed vessel 16, the high-pressure gas flows back into the compression working chamber. Acts to prevent

Next, still another embodiment will be described with reference to FIG. In the case of this embodiment, the basic configuration is the same as that of the first embodiment. Therefore, points different from FIG. 1 will be additionally described. This embodiment is different from the case 16 in the upper case.
17 and the bottom case 18 are combined with each other and welded to form a closed container. Furthermore, the suction pipe 23
Is press-fitted so as to penetrate the case 16 to reach the fixed scroll 1 and to maintain the hermeticity.
And the suction pipe 23 are welded. The frame 3 supporting the compression element and the like is fixed to the case 16. Further, the motor rotor 10b is also fixed to the shaft 6a by means such as press fitting. The spherical bearing 7c provided at the lower end of the shaft 6a is positioned by bearing holders 42a and 42b, and is fixed to the bearing support plate 21 by a plurality of fixing bolts 41. The bearing support plate 21 is fixed to the case 16 by means such as welding. A plurality of support legs 40 are arranged along the circumferential direction of the case 16, thereby constituting a vertical compressor. The operation and operation of this embodiment are not significantly different from those of the embodiment shown in FIG. 1, and therefore, the bearing 7c will be described below. First, a procedure for assembling will be described. The motor stator 10a is fixed to the case 16. Next, a shaft 6 is assembled on the frame 3 and a motor rotor 10b is further attached to the shaft 6 to prepare a shaft.
To fix the outer peripheral portion of the frame 3 to the case 16. With this, the frame 3, the motor 10 and the shaft 6 are positioned. In this state, the lower end of the shaft 6
There is no compensation where case 16 and the center of shaft 6 match. Therefore, when the lower bearing 7c is assembled, the spherical portion is appropriately changed in attitude, and the bearing 7c can be set in a correct state without hitting the shaft 6 in one side.
Then, in such a state, the fixing bolt 41 of the lower bearing 7c is tightened to fix the spherical bearing 7c via the bearing holder. By the fixing of the fixing bolt 41, the relative slip of the spherical portion of the bearing 7c does not occur even during operation after that. Therefore, the contact portion between the inside of the bearing 7c and the crank shaft 6a keeps the form of the plain bearing.

Still another embodiment will be described with reference to FIG.
FIG. 3 shows a horizontal type hermetic scroll compressor. In this embodiment, the crankshaft 6 is supported by bearings 7a and 7c arranged on both sides of the motor 10, and further, an oil supply pipe 44 is provided on the end face of the shaft to provide lubricating oil 26.
Is supplied to each slide bearing 7 from an oil supply hole in the shaft 6. Further, the back pressure chamber 5 is at an intermediate pressure between the suction pressure and the discharge pressure by the intermediate pressure hole 19,
In particular, the lubricating oil after lubrication of the bearings 7a and 7b
And flows into the compression working chamber through the intermediate pressure hole 19 and the like, and is discharged from the discharge hole 13 and returns to the original oil reservoir. On the other hand, the suction gas is sucked from the suction port 23, and the high pressure gas is discharged from the discharge port 13. The high-pressure gas flows out of a discharge pipe 24 shown on the right side of FIG. 3 into a cycle pipe (not shown) of the air conditioner. Especially in the compressor configured as above, the installation of the self-aligning bearing 7c is very important,
The crankshaft can be supported so as to prevent the bearing from hitting halfway and to always keep the clearance between the stator 10a and the rotor 10b optimal.

〔The invention's effect〕

According to the present invention, even if an assembly error occurs at the time of assembling the compressor and the center of the crankshaft 6 and the center of the closed casing 16 are slightly misaligned, the centering of the bearing 7c allows the bearing 7c to perform one-sided operation. Since it is possible to maintain a suitable bearing state that does not occur, the lubrication state of the bearing is improved, the reliability of each bearing is improved, the friction loss generated in the bearing part is reduced, and the energy efficiency of the entire compressor is reduced. Has the effect of improving.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an entire compressor showing one embodiment of the present invention, FIG. 2 is a longitudinal sectional view of an entire compressor showing another embodiment, and FIG. 3 is still another embodiment. FIG. 1 ... fixed scroll 2 ... orbiting scroll 3 ...
Frame, 6 ... crank shaft, 7c ... lower bearing, 8
... Oldham ring, 10 ... motor, 16 ... casing, 21 ... lower bearing housing, 23 ... suction port, 24 ... discharge port, 26 ... lubricating oil.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuo Sekigami 800 Tomita, Ohira-machi, Shimotsuga-gun, Tochigi Prefecture Inside the Tochigi Plant of Hitachi, Ltd. Inside the Machinery Research Laboratory (72) Inventor Kazuo Ikeda 800 Tomita, Ohira-machi, Shimotsuga-gun, Tochigi Prefecture Inside the Tochigi Plant, Hitachi, Ltd. (56) References JP-A-58-172402 (JP, A) JP-A-2-196188 (JP, A) Japanese Utility Model Showa 63-177691 (JP, U) Japanese Utility Model Showa 61-65292 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F04C 18/02 311

Claims (3)

(57) [Claims] A fixed scroll having a spiral wrap; a orbiting scroll having a wrap which meshes with the wrap of the fixed scroll; and a frame provided at a position sandwiching the orbiting scroll with the fixed scroll. A crankshaft for driving the orbiting scroll, and an electric element for rotating the crankshaft;
A first bearing portion provided on the frame to support the crankshaft, a plate member provided at a position opposite to the frame with the electric element interposed therebetween, and a plate member provided on the plate member;
A hermetic scroll compressor having a second bearing portion rotatably supporting the crankshaft in a container,
A hermetic scroll compressor in which the second bearing portion is a bearing portion in which an angle between the crankshaft and the plate member can be freely adjusted. 2. The hermetic scroll compressor according to claim 1, wherein said first bearing portion is a slide bearing. 3. The second bearing portion according to claim 1, wherein the inner peripheral surface into which the crankshaft is inserted has a cylindrical shape,
A hermetic scroll compressor with a spherical outer peripheral bearing.