JPH0626482A - Fluid compressor - Google Patents

Abstract

PURPOSE:To obtain a fluid compressor which is not influenced by operation frequency by simplifying a structure of an oil supply pump, and improving abrasion resistance of a pump case of the oil supply pump being in sliding contact with a rotary shaft. CONSTITUTION:A motor part 7 is connected to one side of a rotary shaft 3, while a compression mechanism 4 is connected to the other side, and all of them are arranged inside a sealed case 1. An oil reservoir 18 for gathering and storing lubricating oil is formed on an inner bottom of the sealed case. An oil supply pump P suctions the lubricating oil in the oil reservoir together with rotation of the rotary shaft, and introduces the oil to a sliding contact part of the compression mechanism through an oil supply passage 32. Cast iron is selected for material of the rotary shaft. The oil supply pump is a volume type pump. Aluminum is used for material of a pump case which composes the oil supply pump. At least a surface of the sliding contact part of the rotary shaft is anodic oxide coated by impregnating molybdenum disulfide.

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 refrigerating 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 motion noise as compared with an ordinary rotary compressor, and a suction valve and a discharge valve are not required and the number of parts is small. There is a tendency for scroll-type compressors that are small in number and have good compression performance to be used frequently.

This type of scroll compressor accommodates an electric compressor main body in which a motor unit is connected to one end side of a rotating shaft and a compressor unit is connected to the other end side in a hermetically sealed case, and the hermetically sealed case of the hermetically sealed case is described. An oil sump portion for collecting lubricating oil is formed on the inner bottom portion.

The compression mechanism section comprises a fixed scroll blade and an orbiting scroll blade, and the spiral blade portions of each scroll blade are meshed with each other, and a compression space is formed by these blade portions and the end plate portion of each scroll blade. To do.

With the rotation of the rotary shaft, the orbiting scroll blade orbits, and sucks the low-pressure gas refrigerant, which is the gas to be compressed, into the compression space, and the volume of the compression space is reduced, so that the gas is compressed and discharged. There is. Further, an oil supply pump is connected to the end of the rotary shaft so as to suck up the lubricating oil by the rotational force of the rotary shaft and supply it to the sliding contact part of the compression mechanism part.

[0006]

By the way, also in such a scroll type compressor, a type in which an operating frequency is controlled by being electrically connected to an inverter circuit is often used. In recent years, there has been a growing need for expanding the operating frequency, and this tendency is particularly large in the low operating frequency range.

Although the operating frequency of the compression mechanism portion does not have any problem, there is a problem in the operation of the oil supply pump which sucks up the lubricating oil in the oil sump into the sliding contact portion. That is, when the operating frequency is high, the rotation shaft rotates at a high speed, so that the lubricating oil is efficiently sucked up and a smooth oil supply operation is performed. However,
If the operating frequency is set to an extremely low level, the suction force of the oil supply pump also becomes small and the amount of oil supply decreases. Therefore, in order to secure a sufficient amount of oil supply even at a low operating frequency, oil supply pumps of various structures have been provided.

For example, in JP-A-1-96490, a positive displacement pump is used as an oil supply pump. With this pump, a sufficient amount of oil can be secured at the normal operating frequency, and the amount of oil can be relatively reduced even at low operating frequencies.

On the other hand, in spite of these advantages, as the operating frequency is lowered, the sliding contact between the rotary shaft and the pump case constituting the oil supply pump is apt to be worn. Further, this positive displacement pump has a number of parts, is large in size, and is heavy in weight as compared with other vane pumps and centrifugal pumps. The present invention has been made in view of the above circumstances,

A first object of the present invention is to simplify the structure of the oil supply pump and to improve the wear resistance of the oil supply pump in sliding contact with the rotary shaft so that the fluid compressor is not affected by the operating frequency. Is to provide.

A second object of the present invention is to simplify the structure of the oil supply pump and to improve the wear resistance of the rotary shaft that is in sliding contact with the oil supply pump so that the fluid compressor is not affected by the operating frequency. Is to provide.

[0012]

In order to satisfy the first object, the first invention is to accommodate an electric motor portion at one end side of a rotary shaft and a compression mechanism portion at the other end side, and to accommodate them in a sealed case. Then, an oil reservoir for collecting lubricating oil is formed in the bottom of the closed case, the lubricating oil in the oil reservoir is sucked up as the rotary shaft rotates, and the oil is supplied to the rotary shaft through an oil supply passage provided on the rotary shaft. An oil supply pump that guides to a sliding contact portion of the compression mechanism section is selected, and cast iron is selected as a material of the rotating shaft.
A fluid compression characterized by being a positive displacement pump, using an aluminum material as the material of the pump case that constitutes this refueling pump, and applying at least the surface of the rotating shaft sliding contact surface with molybdenum disulfide for alumite treatment. It is a machine.

In order to satisfy the second object, a second aspect of the present invention is to connect an electric motor section to one end side of a rotary shaft and a compression mechanism section to the other end side of the rotary shaft so as to be housed in a hermetically sealed case. An oil reservoir is formed at the bottom to collect lubricating oil, and the lubricating oil in the oil reservoir is sucked up as the rotary shaft rotates, and the compression mechanism is slidably contacted via an oil supply passage provided on the rotary shaft. And a lubrication pump that guides the oil supply pump to the section, the lubrication pump is a positive displacement pump, cast iron is selected as a material of the rotary shaft, and at least the surface of the sliding contact portion of the rotary shaft with respect to the oil supply pump is nitrided. It is a characteristic fluid compressor.

[0014]

According to this structure, the first invention is

For the rotary shaft, a cast iron material is selected from the viewpoint of cost, and since the oil supply pump is connected to this rotary shaft,
In order to reduce the weight of the fuel pump, an aluminum material is selected as the material for the pump case, which accounts for a large proportion of the weight.

Then, at least the surface of the sliding contact portion of the rotating shaft of this pump case is anodized by impregnating it with molybdenum disulfide to ensure the wear resistance of the pump case when the rotating shaft rotates at a low speed.

According to a second aspect of the present invention, the material of the rotary shaft and the oil supply pump is selected in the same manner as in the first aspect of the present invention, and at least the surface of the oil supply pump sliding contact portion of the rotary shaft is subjected to nitriding treatment so that the rotary shaft is Ensures the wear resistance of the rotating shaft when rotating at low speed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1 by applying a horizontal scroll type compressor as a fluid compressor. This compressor is electrically connected to the inverter circuit and the operating frequency is controlled.

In the figure, reference numeral 1 is a closed case. A support frame 2 is provided on the right side of the closed case 1 in the figure, and a rotary shaft 3 extending in the horizontal direction is rotatably supported. A compression mechanism section 4 described later is connected to the rotation shaft 3 on the support frame 2 side, and an electric motor section 7 including a stator 5 and a rotor 6 is provided at another position.

The compression mechanism section 4 includes the support frame 2
The orbiting scroll blade 11 is rotatably supported via the Oldham ring 10, and the fixed scroll blade 12 meshes with the orbiting scroll blade 11. The Oldham ring 10 regulates the rotation of the orbiting scroll blade 11 and causes only the orbiting motion.

The orbiting scroll blade 11 has an end plate portion 11a having a boss portion 11c that engages with the eccentric portion 3a of the rotary shaft 3, and a spiral blade integrally projecting on the upper surface side of the end plate portion 11a. And part 11b.

The fixed scroll blade 12 has an end plate portion 12
a and a spiral blade portion 12b that is integrally projected on the lower surface side of the end plate portion 12a and meshes with the blade portion 11b of the orbiting scroll blade 11.

These orbiting and fixed scroll blades 11, 12
A pair of compression spaces a are formed by the end plate portions 11a, 12a and the blade portions 11b, 12b of the above, and the refrigerant gas that is the gas to be compressed is taken in from the peripheral end side and moves to the central part side and its volume is increased. It can be reduced and compressed. A discharge port 13 is provided through the central portion of the fixed scroll blade end plate portion 12a so as to communicate with the spiral center of the compression space a. A valve cover 14 is attached to the end surface of the end plate portion 12a to form a high pressure discharge chamber 15 which is a closed space facing the discharge port 13.

A discharge pipe 1 is provided on the fixed scroll end plate 12a.
6 is connected and communicates with the high pressure discharge chamber 15. The discharge pipe 16 extends through the closed case 1 to the outside, and communicates with a condenser of a refrigeration cycle (not shown).

A suction pipe 17 is connected to the center of the upper part of the closed case 1 in the drawing, and communicates with the internal space of the case 1. The suction pipe 17 communicates with a condenser of a refrigeration cycle (not shown).

Further, an oil reservoir 18 for collecting lubricating oil is formed on the inner bottom of the closed case 1. An end portion of an oil suction pipe 20 that constitutes an oil supply pump P, which will be described later, is immersed in the lubricating oil of the oil reservoir 18. A filter 21 is attached to the end of the oil suction pipe 20. Next,
The oil supply pump P will be described. This employs a positive displacement pump called a trochoid pump. A stay 22 is attached and fixed to the support frame 2 and the stator 5, and a pump support portion 23 for inserting and supporting the oil supply pump P is formed in a central portion of the stay 22.

As shown in an enlarged view in FIG. 2, a recess 25 formed at one end of the pump case 24 is engaged with the tip of the rotary shaft 3. The recessed portion 25 of the pump case 24
The flange portion 26 is integrally provided on the side outer peripheral surface,
A pump spring 27 is interposed between this and the stay 22.

Accordingly, the pump spring 27 presses and urges the pump case 24 so that the recess 25 is elastically and forcibly inserted into the end of the rotary shaft 3.

An oil guide hole 24a is formed along the central axis extending from the bottom surface of the recess 25 of the pump case 24 to the end surface to which the oil suction pipe 20 is connected. Therefore,
The oil guide hole 24a communicates with the oil suction pipe 20.

Further, an oil suction guide groove 24b communicating with a part of this peripheral surface is continuously provided at the end of the oil guide hole 24a on the concave portion 25 side. A projecting portion 3b is integrally provided at the tip of the rotary shaft 3 so as to face the opening end of the oil guide hole 24a and closes the same, but faces the oil suction guide groove 24b. Without it, the tip projection 3b is not closed.

Between the end surface of the rotary shaft 3, which is the peripheral portion of the tip projection 3b of the rotary shaft 3, and the bottom surface of the recessed portion 25 of the pump case 24, the inner rotor 28 constituting the fuel pump P, the outer rotor 29, and the side wall. The plate 30 is interposed.

As shown in FIG. 3A, the inner rotor 2
No. 8 has four projections 28a ... Radially projected at equal intervals on the circumferential surface. A fitting hole 28b is provided in the center portion, the tip projection 3b of the rotary shaft 3 is fitted therein, and the inner rotor 28 is adapted to rotate integrally with the rotary shaft 3. (In the figure, the connecting structure between the pump case 24 and the oil suction pipe 20 is omitted.)

On the other hand, the outer rotor 29 is
This center is eccentric with the inner rotor 28,
Further, on the inner peripheral surface, five recesses 29a are radially provided at equal intervals. Each of the recesses 29a and the protrusion 28a has a semicircular shape that can engage with each other, and in the figure, the recess 29a on the upper end side and the protrusion 28a always engage with each other.

When the inner rotor 28 rotates in this state, the outer rotor 29 is driven to rotate by the engagement of the protrusion 28a and the recess 29a. The outer rotor 29 is eccentric with respect to the inner rotor 28, and the protrusion 28a and the recess 2
Due to the difference in the number from 9a, the volume of the space formed between them is gradually expanded and gradually reduced.

On the side of the volume expansion of the space portion, the curved oil discharge guide groove 30a provided on the side plate 30 is opposed, and on the side of the space volume reduction, the oil provided in the pump case 24 is arranged. The suction guide grooves 24b face each other.

As shown in FIG. 3 (B), the side plate 30 has the same diameter as the outer rotor 29, has the oil discharge guide groove 30a, and has a latching projection on a part of its peripheral surface. 30b is integrally provided and engages with a rotation stop groove (not shown) provided on the peripheral surface of the recess 25 of the pump case 24. At the center, the rotary shaft tip projection 3
An insertion hole 30c through which b is inserted is opened. In this way, the oil supply pump P is configured.

As shown in FIG. 2 again, an oil groove 31 is provided on the end surface of the rotary shaft 3 around the tip projection 3b, and a part of the oil groove P is assembled in the assembled state of the side plate 30. Communicates with the oil discharge guide groove 30a provided in the.

The oil groove 31 is provided along the axial direction of the rotary shaft 3, and the support frame 2 for pivotally supporting the rotary shaft 3 is provided.
And the Oldham ring 10 and the orbiting scroll blade 11 described above.
And the fixed scroll vane 12, such as the meshing portion, the compression mechanism portion 4
An oil supply passage 32 that communicates with each sliding contact portion that constitutes

The material of the pump case 24 constituting the refueling pump P is an aluminum material or
An aluminum alloy material is used, and at least the sliding contact portion of the rotating shaft 3 is subjected to alumite treatment in which molybdenum disulfide is impregnated. Of course, there is no problem even if the same process is performed as a whole.

On the other hand, the rotary shaft 3 is made of cast iron as a material, but the surface treatment is not specified. It is better if a quenching process is applied if necessary. Since the side plate 30 is in contact with the end surface of the rotating shaft 3, the side plate 30 is hardened.

However, when the electric motor section 7 is energized to drive the compression mechanism section 4, the low-pressure refrigerant gas evaporated in the evaporator is introduced into the closed case 1 through the suction pipe 17 to fill the internal space. To do.

This refrigerant gas is sucked into the outer peripheral side of the compression space a formed by the orbiting scroll blade 11 and the fixed scroll blade 12. Then, as the orbiting scroll blade 11 orbits, the orbiting scroll blade 11 is gradually transferred to the central portion and the space capacity is reduced, whereby the orbiting scroll blade 11 is compressed.

When the pressure rises to a predetermined pressure, the high-pressure refrigerant gas is discharged from the discharge port 13 into the high-pressure discharge chamber 15 in the valve cover 14 and is filled there. Furthermore, the high pressure discharge chamber 1
5 is led to an external condenser via a discharge pipe 16 communicating with 5. The high-pressure refrigerant gas is condensed in this condenser and converted into a liquid refrigerant, then undergoes adiabatic expansion, is further guided to the evaporator and evaporates, and performs a cooling action for the air-conditioned room. The rotating shaft 3
The positive displacement oil supply pump P is driven by the rotation of the.

That is, the inner rotor 28 rotates integrally with the rotary shaft 3, and the protrusions 28a ... And the outer rotor 29 are rotated.
The space between the concave portions 29a ... Expands and contracts.
Lubricating oil in the oil sump 18 is introduced from the oil suction pipe 20 into the space through the oil guide hole 24a and the oil suction guide groove 24b, and is pressurized by the movement deformation.

When a predetermined pressure is applied, the space portion faces the oil discharge guide groove 30a and is led out to the oil groove 31 from here. Then, the pressurized lubricating oil is guided along the oil supply passage 32 provided on the rotary shaft 3 and is supplied to each sliding contact portion of the compression mechanism portion 4. Such a positive displacement oil supply pump P has a smaller number of parts than a vane pump, a centrifugal pump, or the like, has a small shape structure, and contributes to weight reduction. When driving the fuel pump P,
The rotating shaft 3 as a drive source and the pump case 24 in a fixed state
And are in sliding contact with each other.

Particularly, as the material of the pump case 24, an aluminum material or an aluminum alloy material is used, and at least the sliding contact portion of the rotary shaft 3 is anodized with molybdenum disulfide. Even if it is operated at a low operating frequency, molybdenum disulfide can satisfactorily lubricate the rotating shaft 3, and no burnout accident will occur even after long-term use.

In the above embodiment, the rotary shaft 3 is
Although only the material is limited and the quenching process is performed as necessary, the quenching process in particular has a large variation in hardness, which may increase the amount of wear.

Therefore, there is no change in using cast iron as the material of the rotary shaft 3, but in particular, nitriding is performed on the sliding contact portion with the pump case 24. Naturally, the same processing may be performed on the entire rotary shaft 3.

By obtaining the rotating shaft 3 that has been subjected to the nitriding treatment, it is possible to prevent the sliding contact partner, which is the pump case 24, from being adversely affected. Further, wear and surface roughness of the rotating shaft 3 itself are reduced. As in the case of performing quenching treatment, quench cracking does not occur, and a reduction in the defect occurrence rate in the manufacturing process can be obtained.

Further, since the side plate 30 constituting the oil supply pump P is in direct sliding contact with the end surface of the rotary shaft 3,
Although it has been described that the quenching process is performed, the present invention is not limited to this.

For example, if the material of the rotary shaft 3 is cast iron,
Regardless of whether or not the surface is hardened, the side plate 30 uses carbon tool steel, and the surface is nitrided. Therefore, the sliding contact property with the rotating shaft 3 is improved, and this wear amount can be reduced.

Although the scroll compressor has been described as constituting a refrigeration cycle of an air conditioner, the scroll compressor is not limited to this and can be used as a compressor for compressing another gas to be compressed.

Further, the invention is not limited to the horizontal type scroll type compressor, but may be the same type of vertical type compressor, or even a compressor such as a rotary type compressor having a different compression mechanism may be attached to the sliding contact portion. The provision of refueling means remains unchanged.

[0054]

As described above, according to the first aspect of the present invention, a cast iron rotary shaft is used as a positive displacement pump, a pump case is made of aluminum, and at least a rotary shaft sliding contact portion is used. Since the surface is treated with alumite impregnated with molybdenum disulfide, the structure of the oil supply pump can be simplified and the wear resistance of the pump case of the oil supply pump that makes sliding contact with the rotating shaft can be maintained even at low operating frequencies. It has the effect of improving the durability and reliability.

According to the second aspect of the present invention, since the oil supply pump is a positive displacement pump, and at least the surface of the oil supply pump sliding contact portion of the rotary shaft is nitrided with the rotary shaft of cast iron, the structure of the oil supply pump can be simplified. At the same time, even if the operation is performed at a low operation frequency, the wear resistance of the rotary shaft that is in sliding contact with the oil supply pump is improved, and durability and reliability are improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a scroll compressor showing an embodiment of the present invention.

FIG. 2 is an enlarged view of an oil supply pump of the embodiment.

FIG. 3A is a combination diagram of an inner rotor and an outer rotor that constitute the oil supply pump of the embodiment. (B)
[Fig. 3] is a view of a side plate that constitutes the fuel pump.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sealed case, 3 ... Rotating shaft, 7 ... Electric motor part, 4 ... Compression mechanism part, 18 ... Oil sump part, 32 ... Oil supply passage, P ... Oil supply pump, 24 ... Pump case.

Claims (2)

[Claims] 1. An electric motor section is connected to one end side of a rotary shaft, and a compression mechanism section is connected to the other end side of the rotary shaft so as to be housed in a hermetically sealed case, and an oil sump section for collecting lubricating oil is formed at a bottom section of the hermetically sealed case. An oil supply pump that sucks up the lubricating oil in the oil sump along with the rotation of the rotary shaft and guides it to the sliding contact portion of the compression mechanism through an oil supply passage provided in the rotary shaft. Cast iron is selected as the material for the oil supply pump, the oil pump is a positive displacement pump, aluminum is used as the material for the pump case that constitutes this oil pump, and at least the surface of the rotary shaft sliding contact part is impregnated with molybdenum disulfide. A fluid compressor characterized by being subjected to alumite treatment. 2. An electric motor section is connected to one end side of a rotary shaft, and a compression mechanism section is connected to the other end side of the rotary shaft so as to be housed in a hermetically sealed case, and an oil sump section for collecting lubricating oil is formed at a bottom section of the hermetically sealed case. And an oil supply pump that sucks up the lubricating oil in the oil sump with the rotation of the rotary shaft and guides it to a sliding contact portion of the compression mechanism through an oil supply passage provided in the rotary shaft. Is a positive displacement pump, cast iron is selected as a material of the rotary shaft, and at least the surface of a sliding contact portion of the rotary shaft with respect to the oil supply pump is nitrided.