JP3051866B2 - Scroll compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type compressor used as a compressor constituting a refrigeration cycle of an air conditioner, for example.

[0002]

2. Description of the Related Art For example, a compressor constituting a refrigeration cycle of an air conditioner has extremely low kinetic noise as compared with a normal rotary compressor, and does not require a suction valve or a discharge valve and has a reduced number of parts. There is a tendency to use scroll compressors that require less and have good compression performance.

[0003] This type of scroll compressor is conventionally configured as shown in FIG.

[0004] In the figure, reference numeral 1 denotes a sealed case, and a support frame 2 is provided in an upper portion of the sealed case 1, and rotatably supports a rotating shaft 3. A compression mechanism 4 is connected to the eccentric portion of the upper end of the rotary shaft 3, and a motor 5 is provided at a lower portion.

The compression mechanism 4 includes a fixed scroll blade 6 attached to and fixed to the support frame 2, a orbiting scroll blade 7 pivotally supported by an eccentric portion at the upper end of the rotating shaft 3, and restricts rotation of the orbiting scroll blade 7. And an Oldham ring 8 that performs only a turning motion.

A discharge port 9 is provided at the center of the upper surface of the fixed scroll blade 6, and a suction pipe communicating with an evaporator (not shown) constituting a refrigeration cycle and penetrating the upper surface of the closed case 1 is provided at a peripheral end of the upper surface. 10 is connected.

[0007] A gap is formed between the closed case 1, the fixed scroll blade 6 and a part of the peripheral end surface of the support frame 2, and a gas passage 11 is formed. A discharge pipe 12 communicating with a condenser (not shown) constituting a refrigeration cycle is provided on the side of the closed case 1.
Is connected.

An intermediate pressure introducing hole 13 is formed in the end plate portion of the orbiting scroll blade 7, and communicates with an intermediate pressure chamber 14 which is a closed recess formed on the back side of the orbiting scroll blade 7 of the support frame 2. I have.

When the electric motor 5 is energized to drive the compression mechanism 4, the low-pressure refrigerant gas, which is the gas to be compressed, flows from the suction pipe 10 to the fixed scroll blade 6 as shown by the arrow in FIG. It is sucked into the compression chamber S formed by the space meshed with the scroll blade 7.

[0010] The refrigerant gas sucked into the compression chamber S is transferred to the center with the orbital movement of the orbiting scroll blades 7, and is compressed due to a decrease in space capacity.
When the pressure rises to a predetermined pressure, the gas is discharged from the discharge port 9 into the sealed case 1, further guided along the gas passage 11, and discharged from the discharge pipe 12 to an external condenser.

On the other hand, a part of the refrigerant gas being compressed in the compression chamber S is led to the intermediate pressure chamber 14 through the intermediate pressure introduction hole 13. A differential pressure is generated between the compression chamber S and the intermediate pressure chamber 14, so that the orbiting scroll blade 7 receives a large pressure on the back side thereof and floats as a whole.

Accordingly, the orbiting scroll blades 7 and the fixed scroll blades 6 are sealed to prevent gas leakage from the compression chamber S.

[0013]

In this type of scroll type compressor, it is of course to prevent the gas leak from the compression chamber S, but in particular, how to reduce the load in the thrust direction generated in the compressor in a well-balanced manner. This is a major technical problem, and affects the reduction of thrust sliding loss between the scroll blades 6 and 7. Intermediate pressure chamber 14 described above
Are formed for that purpose.

However, in order to reduce the sliding loss, it is important not only to reduce the opposing thrust force (pressing force) but also to prevent deformation of the end plate portion of the orbiting scroll blade 7 as much as possible.

That is, if the end plate of the orbiting scroll blade 7 is deformed and receives a concentrated load, the smooth orbital motion is impaired before the sliding loss is reduced, and the respective scroll blades 6, 7
It may cause a malfunction such as an accident of galling between the wings.

It is well known that a constant compression ratio operation is performed based on the compression principle of a scroll-type compression mechanism.
The operating compression ratio constantly fluctuates.

For example, in a refrigeration cycle operation in a region where the operation compression ratio is low, the suction pressure of the compressor is high, and as a result,
The pressure in the intermediate pressure chamber also increases, and the pressing force of the orbiting scroll blade 7 against the fixed scroll blade 6 becomes excessive, which causes an accident.

The present invention has been made in view of the above circumstances, and an object of the present invention is to ensure the balance with the thrust force generated in the compression space regardless of the fluctuation of the operating compression ratio condition. Enhance the sealing performance in space,
An object of the present invention is to provide a scroll-type compressor that improves sliding performance by reducing sliding loss.

[0019]

According to the present invention, a thrust ring is provided in the thrust direction by providing a recessed portion on the back side of the end plate portion of the orbiting scroll wing and having a closed space in the recessed portion. An intermediate pressure chamber that fits movably, guides the compressed gas under compression in the compression space to the enclosed space formed by the thrust ring and the recess, and orbits with the orbiting scroll blades. It is a scroll compressor.

[0020]

Since the intermediate pressure chamber orbits together with the orbiting scroll blades, the pressing force from the back side of the orbiting scroll blades always balances the thrust force generated in the compression space, and there is no deviation.

[0021]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a scroll compressor partially omitted, and will be described as being used in, for example, a refrigeration cycle of an air conditioner.

In the figure, reference numeral 20 denotes a closed case, and a support frame 21 is provided in a lower portion of the closed case 20 to rotatably support a lower end of a rotating shaft 22. The rotating shaft 22
The lower part is connected to a compression mechanism part 23 to be described later, and the upper part is provided with an electric motor part (not shown).

The compression mechanism 23 includes a support frame 21
Scroll wing 27 attached to and fixed to the rotating shaft 2
The orbiting scroll blade 28 is pivotally supported by an eccentric hole 22a provided at the lower end of the vehicle 2 and includes an Oldham ring 29 and a thrust ring 30 that regulate the rotation of the orbiting scroll blade 28 and perform only a orbital motion.

The fixed scroll blades 27 and the orbiting scroll blades 28 are respectively composed of head plates 31 and 32 and a spiral blade (not shown) provided integrally with the head plates 31 and 32. You.

The wing portions are meshed with each other, and a compression chamber S, which is a compression space, is formed which is surrounded by the fixed scroll wing end plate portion 31 and the orbiting scroll wing end plate portion 32.

A boss 33 is integrally formed in the center of the orbiting scroll wing 28 on the rear surface side of the end plate 32, and is rotatably engaged with the eccentric hole 22 a at the lower end of the rotating shaft 22. A discharge port 34 is provided from the center bottom surface of the end plate 32 to the upper end of the boss 33, and communicates with a high-pressure gas passage 35 provided along the axis of the rotating shaft 22. The upper end (not shown) of the high-pressure gas passage 35 opens into the closed case 20.

A circular recess 36a is provided around the boss 33 of the orbiting scroll blade 28, and the thrust ring 30 is fitted therein.

In other words, a sealing material (not shown) is interposed between the sliding surface of the recess 36a and the thrust ring 30 to form a sealed space between the thrust ring 30 and the bottom of the recess 36a. , Thrust ring 3
0 is movable in the thrust direction.

Further, the bottom of the recess 36a and the compression chamber S
Are communicated with each other through an intermediate pressure introducing hole 37 which is a small hole so that the gas to be compressed which is being compressed from the compression chamber S is guided from the intermediate pressure introducing hole 37 to the closed space in the concave portion 36a. Has become.

The closed space defined by the thrust ring 30 and the recess 36a is called an intermediate pressure chamber 36. The thrust ring 30 is lifted by receiving the pressure, and the upper end surface is in sliding contact with a thrust ring receiving portion 21 a formed on the lower surface of the support frame 21.

On the other hand, a suction pipe 35 communicating with the evaporator constituting the refrigeration cycle is provided so as to penetrate the closed case 20 side and communicate with the compression chamber S on the peripheral end side. At the upper end of the closed case 20, a discharge pipe communicating with a condenser constituting a refrigeration cycle is provided. (The evaporator, the condenser, and the discharge pipe are not shown.) In the scroll compressor thus configured, when the electric motor section is energized to drive the compression mechanism section 23, the evaporator draws a suction pipe. The low-pressure refrigerant gas, which is the gas to be compressed, is sucked into the compression chamber S on the peripheral end side through the cylinder 38.

The refrigerant gas sucked into the compression chamber S is transferred to the center with the orbital movement of the orbiting scroll blades 28, and is compressed by the reduction of its space capacity. When the pressure has risen to a predetermined pressure, the gas is discharged from the discharge port 34 and passes through the high-pressure gas passage 35 to the closed case 20.
Guided inside and charged. Furthermore, it is led to a condenser via a discharge pipe.

A part of the gas being compressed in the compression chamber S is guided to the intermediate pressure chamber 36 through the intermediate pressure introduction hole 37. Under this pressure, the thrust ring 30 rises and comes into sliding contact with the thrust ring receiving portion 21 a of the support frame 21 with the turning movement of the turning scroll blade 28.

On the back side of the orbiting scroll blade end plate portion 32, the space on the inner peripheral side of the thrust ring 30, that is, the space on the boss portion 33 side communicates with the inside of the sealed case 20, and thus has a high discharge pressure Pd.

Since the outer peripheral side of the thrust ring 30 is surrounded by the support frame 21 and the fixed scroll blades 27 and communicates with the outer peripheral side of the compression chamber S, the suction pressure is almost equal to the low pressure Ps.

As schematically shown in FIG. 2, the thrust force FS generated in the compression chamber S, which is a force directed upward from the lower portion of the lower stage, is applied to the thrust force directed downward from the upper portion of the upper stage. Orbiting scroll wing end plate 32 against power
The pressing force FR from the back side is balanced.

That is, the pressing force FR from the back side of the orbiting scroll blade end 32 is the discharge pressure Pd at the center, the intermediate pressure Pn around it, and the suction pressure Pn around it.
s and three stages.

In particular, the portion on which the intermediate pressure Pn acts appears in the intermediate pressure chamber 36 formed on the back side of the orbiting scroll blade end plate portion 32, and the position thereof fluctuates with the orbital movement of the orbiting scroll blade 28. Eggplant

The thrust force FS generated by the orbiting scroll blade 28 performing the orbital movement and the pressing force FR
Are always correctly opposed to each other to prevent the orbiting scroll blade 28 from falling down.

When the operating compression ratio of the refrigeration cycle is set to a higher compression ratio operating condition, the suction pressure Ps is further reduced, and the pressing force acting from the intermediate pressure chamber 36 is reduced. The influence of the part receiving Pd becomes large. In addition, when the operating condition is such that the compression ratio is low, the pressing force in the intermediate pressure chamber 36 increases because the suction pressure Ps increases,
The effect of the discharge pressure Pd decreases.

Therefore, the area receiving the discharge pressure Pd is:
By setting the area for forming the intermediate pressure chamber 36 in a well-balanced manner, the wings of the scroll wings 27 and 28 are not always separated from each other with an appropriate pressing force FR, that is, the compression chamber S is sealed. As a result, gas leakage is prevented, and in the state where there is no excessive pressing, sliding loss does not occur, compression loss and mechanical loss are prevented from increasing, and compression performance is improved.

Note that such a scroll compressor is
The invention is not necessarily limited to those provided in the equipment constituting the refrigeration cycle, and can be used for compressing other types of compressed gas or air.

[0044]

As described above, according to the present invention, a concave portion is provided on the rear side of the end plate portion of the orbiting scroll blade, and a thrust ring is fitted in the concave portion with a closed space portion. Since the compressed gas of intermediate pressure is guided to the sealed space formed by the ring and the recess, and the intermediate pressure chamber revolves with the orbiting scroll blade, the orbiting scroll blade exerts an appropriate pressing force on the fixed scroll blade. As a result, the compression space is securely sealed to prevent gas leakage, and there is no sliding loss, preventing an increase in compression loss and mechanical loss, and improving compression performance and reliability. Play.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a scroll compressor according to an embodiment of the present invention, with a part thereof omitted;

FIG. 2 is a diagram schematically showing a state in which a force is generated in a compression mechanism of the embodiment.

FIG. 3 is a longitudinal sectional view of a scroll compressor of a conventional example, with a part thereof omitted.

[Explanation of symbols]

27: fixed scroll wing, 28: orbiting scroll wing, S
… Compression space (compression chamber), 32… (of orbiting scroll blades)
End plate part, 36a ... concave part, 30 ... thrust ring, 36
... intermediate pressure chamber.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yutaka Sasahara 336 Tatehara, Fuji-shi, Shizuoka Prefecture Inside the Toshiba Fuji Plant (56) References JP-A-3-78586 (JP, A) JP-A-60-224989 (JP, A) JP-A-61-11485 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F04C 18/02 311

Claims (1)

(57) [Claims] A swirling wing portion of a fixed scroll wing and a spiral wing portion of an orbiting scroll wing mesh with each other, and a compression space is formed by these wing portions and a mirror plate of each scroll wing; In a scroll type compressor in which the wings are engaged with an eccentric portion of a rotating shaft to orbit, and a compressed gas is sucked into the compression space, compressed and discharged, a concave portion is provided on the rear side of the end plate portion of the orbiting scroll wing. The thrust ring is movably fitted in the thrust direction while the closed space is present in the recess, and the compressed space is compressed by the intermediate pressure in the compression space in the closed space formed by the thrust ring and the recess. A scroll compressor in which an intermediate pressure chamber that guides gas and orbits with the orbiting scroll blades.