JPH0756277B2 - Scroll compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a scroll compressor, and in particular, enables stable oil supply to each bearing.

[Conventional technology]

First, the principle of the scroll fluid machine will be briefly described.

FIG. 6 shows basic constituent elements and a compression principle when a scroll fluid machine is used as a compressor. In FIG. 6, 1 is a fixed scroll, 2 is an orbiting scroll, 3 is a suction chamber, and 4 is a suction chamber. The discharge ports 5 are compression chambers. Also, O
Is the center of the fixed scroll 1.

The fixed scroll 1 and the orbiting scroll 2 have spirals 1a and 2a having the same shape but opposite winding directions, and the shapes of these spirals 1a and 2a are, as has been conventionally known, from an involute curve, an arc, and the like. It is configured.

Next, the operation will be described. The fixed scroll 1 is stationary with respect to the space, and the orbiting scroll 2 is combined with the fixed scroll 1 in a phase shift of 180 °, so that the orbiting scroll 2 does not revolve around the center O of the fixed scroll 1. Perform 0 °, 90 °, 18 as shown in Fig. 1 a-d.
Exercise like 0 °, 270 °. In the figure, 0 shown in FIG.
In the state of °, the confinement of gas in the suction chamber 3 is completed, and the swirl 1
A compression chamber 5 is formed between a and 2a. Then, with the movement of the orbiting scroll 2, the volume of the compression chamber 5 is gradually reduced, and the gas therein is compressed and discharged from the discharge port 4 provided at the center of the fixed scroll 1.

The outline of the device known by the name of the scroll compressor is as described above.

Next, a specific configuration and operation of the scroll compressor will be described. FIG. 5 shows the structure of an embodiment of a scroll compressor as disclosed in, for example, Japanese Patent Application No. 59-42503 (Japanese Patent Application Laid-Open No. 60-187789). In particular, the scroll compressor is a hermetic refrigerant compressor. When applied to. In the figure, 1 is a fixed scroll having a spiral 1a on one side of a base plate 1b, 2 is an orbiting scroll having a spiral 2a on one side of a base plate 2b, 3 is a suction port (suction chamber), 4 is a The discharge port, 5 is a compression chamber formed between the spirals 1a and 2a when the spirals 1a and 2a are combined with each other, 6 is a main shaft, 7 has a suction port 7a, and the main shaft lower end has a predetermined gap and a main shaft lower end. Oil cap mounted to cover, 8 and 9 bearing frame, 10 motor rotor, 11 motor stator, 12 shell, 13 Oldham coupling, 14 baffle plate, 15 at the bottom of shell 12 An oil sump provided,
16 is a suction pipe, 17 is a discharge pipe, 18 is eccentric with respect to the main shaft 6,
Also, an orbiting scroll bearing rotatably fitted to the orbiting scroll shaft 2c provided on the other side of the base plate 2b is fixed in the eccentric hole 60a formed in the large diameter portion 6a at the upper end of the main shaft 6. There is. Reference numeral 19 is a first main bearing that supports the outer peripheral surface 61a of the large diameter portion 6a above the main shaft 6, 20 is a second main bearing that supports the small diameter portion 6b below the main shaft 6, and 21 is the base plate of the orbiting scroll 2. 2b is a first thrust bearing that axially supports the lower surface 20b, 22 is a second thrust bearing that axially supports a step 6c between the large diameter portion 6a and the small diameter portion 6b of the main shaft 6, and 23 is the main shaft 6 Opening at bottom 23
A bearing hole is provided in the main shaft 6 eccentrically from the shaft center of the main shaft 6, and communicates with the bearings 18 and 20. 24 is the spindle 6
A first gas vent hole provided inside, 25 and 26 are oil return holes for the oil passage, and 27 and 28 are communication holes for the suction gas passage.

Here, in the orbiting scroll 2, the orbiting scroll shaft 2c is engaged with the main shaft 6 via the orbiting scroll bearing 18 in a state of being meshed with the fixed scroll 1, and is attached to the orbiting scroll bearing 18 and the bearing frame 8. It is supported by a first thrust bearing 21 arranged. Further, the main shaft 6 is supported by a first main bearing 19, a second main bearing 20 and a second thrust bearing 22 which are arranged in bearing frames 8 and 9 which are connected to each other by a spigot or the like. Also, the Oldham coupling 13
Is disposed between the orbiting scroll 2 and the bearing frame 8 and is configured to prevent the orbiting scroll 2 from rotating and to perform only a revolution movement. In this state,
The fixed scroll 1 is fastened together with the bearing frames 8 and 9 with bolts or the like. The motor / rotor 10 is fixed to the main shaft 6 and the motor / stator 11 is fixed to the bearing frame 9 by press fitting, shrink fitting or screwing. Further, the oil cap 7 is fixed to the main shaft 6 by press fitting, shrink fitting, or the like. The machine part assembled in this manner is fixed and accommodated in the shell 12 by press fitting, shrink fitting, etc., with the fixed and oscillating scrolls 1 and 2 on the upper side and the motor rotor 10 and the stator rotor 11 on the lower side. .

Next, the operation of the scroll compressor configured as described above will be described. When the motor rotor 10 rotates, the spindle 6
Also, the orbiting scroll 2 starts revolving movement via the Oldham's joint 13, and compression starts according to the operating principle described in FIG. At this time, the refrigerant gas is sucked into the shell 12 through the suction pipe 16 and the bearing frame 9 and the motor, as shown by the solid arrow.
After cooling the motor by passing through a communication hole 27 between the stator 11 and the air gap between the motor rotor 10 and the motor stator 11, a communication hole between the shell 12 and the bearing frames 8 and 9. Inlet 3 provided in the fixed scroll 1 through 28
It is further taken into the compression chamber 6 and compressed. The compressed gas is discharged from the compressor through the discharge pipe 17 through the discharge port 4. Further, the lubricating oil is supplied from the oil reservoir 15 as shown by a broken line arrow to the oil cap 7 and the oil supply hole 23 provided on the main shaft 6.
By means of the centrifugal pump action, the bearings 18 and 20 are refueled through the suction port 7a of the oil cap 7 and the refueling hole 23, and then the bearings 18 and 21 are refueled in this order. The oil used for lubrication is returned to the oil sump 15 mainly through oil return holes 25 and 26 provided in the bearing frames 8 and 9. A baffle plate 14 is provided so as to close the gap between the bearing frame 8 and the outer peripheral surface of the orbiting scroll 2 so that the oil leaked from the bearing 21 or the like is not directly sucked into the suction port (suction chamber) 3. The baffle plate 14 and the rocking scroll 2 separate the suction port (suction chamber) 3 and the rocking machine section. Further, the gas vent hole 24 provided in the main shaft 6 is for quickly expelling the gas in the oil cap 7 to the outside of the shaft during operation, thereby improving pump efficiency.

[Problems to be solved by the invention]

In such a device, when the oil sucked from the oil cap 7 passes through the oil supply hole 23 in the main shaft 6 and flows out to the eccentric hole 60a, the oil is blown to the bearing surface 18 of the orbiting scroll due to the centrifugal force. In particular, when the scroll compressor is applied to a refrigerant compressor, the refrigerant mixes or dissolves in the oil, so that the refrigerant foams and gasifies. This is due to the fact that in the oil flow that passes through the oil supply hole 23 and reaches the bearing surface 18,
This is because the pressure at the position where 23 opens in the eccentric hole 60a becomes the lowest, but when this foamed gas fills the eccentric hole 60a, it is sent to the bearings 18, 20 and the thrust bearing 21 with the oil. Caused local oil shortage, resulting in bearing damage and seizure due to poor lubrication. Furthermore, in the low rotation range when the inverter is installed in the scroll compressor, The above-mentioned poor lubrication becomes remarkable because the oil-lifting head formed by the oil-filling hole 23 is lowered and the amount of oil-lifted is reduced. Here, r is the eccentric amount of the oil supply hole 23, ω is the angular velocity of the main shaft 6, and g is the weight acceleration.

The present invention has been made in order to solve the above problems, and eliminates the gas filled in the eccentric hole to allow the bearing to be stably lubricated, and also in the low speed range of the compressor controlled by the inverter. It is an object of the present invention to provide a scroll compressor capable of exhibiting the function of.

[Means for solving problems]

A scroll compressor according to the present invention has respective spirals, and a fixed scroll and an orbiting scroll that form a compression chamber between both spirals by combining these spirals with each other, and a main shaft that drives the orbiting scroll. An eccentric hole formed at the upper end of the main shaft and having an oscillating bearing for supporting the oscillating scroll fixed thereto; and an eccentric hole for oil supply from the lower end of the main shaft to the eccentric hole and penetrating in the axial direction of the main shaft. In the hermetic scroll compressor having the above-mentioned main shaft, the main shaft is communicated with the gas reservoir at the center of rotation of the eccentric hole, and extends in the direction opposite to the eccentric direction in the middle of the oil supply hole near the gas reservoir. Is provided with a gas vent hole that communicates with the external space.

[Operation] The gas vent hole communicates with the gas reservoir at the center of rotation of the eccentric hole through the oil supply hole, which causes the gas reservoir to have almost the same pressure as the outer space of the spindle where the gas vent hole is opened. Even if the gas foams in the eccentric hole and the pressure in the gas pool rises,
To alleviate this, the increased gas is discharged from the gas vent hole to keep the pressure of the gas reservoir constant, and the bearing is constantly lubricated to prevent damage and seizure of the bearing.

〔Example〕

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

FIGS. 1 and 2a and 2b show an embodiment of the present invention. In the drawings, reference numerals 1 to 28 are exactly the same as the conventional device shown in FIG. 29 is a large diameter portion 6a and a small diameter portion 6b of the main shaft 6
Between the oil supply hole 23, the bearing frame 9 and the second main bearing.
20, a gas vent hole communicating with a bearing space 33 surrounded by the second thrust bearing 22 and the main shaft 6 and formed through a thick wall portion of the eccentric hole 60a, which is opposite to the eccentric direction; There is a balancer chamber 3 surrounded by bearing frames 8 and 9.
4 is a communication hole that connects the bearing interchamber 33 with each other. The balancer chamber 34 is pressure-equalized with the internal space of the shell 12 by the oil return hole 26.

Since the communication hole 32 is for communicating the inner space of the shell 12 with the inter-bearing chamber 33, the position is not limited to this position, and for example, the motor surrounded by the bearing frame 9, the motor rotor 10 and the motor stator 11 can be used. It may be connected to the space 35. Further, 31 is an outline of the gas pool 30.

Next, the operation will be described.

As described in the conventional example, the oil sucked from the oil cap 7 flows out to the eccentric hole 60a through the oil supply hole 23, is accelerated by the centrifugal force, and is blown off to the bearing 18. At this time, the gas contained in the oil As described above, the foam is easily foamed. Although the gas pool 30 in the eccentric hole 60a tries to expand due to the foamed gas, the oil supply hole 23 and the bearing interspace 33
As shown in FIG. 2b, the gas in the gas reservoir 30 is kept at a constant amount because the pressure of the gas in the gas reservoir 30 is about the same as that of the bearing inter-chamber 33 and increases. The corresponding amount is discharged to the inter-bearing chamber 33 through the second gas vent hole 29. Further, since the inter-bearing chamber 33 communicates with the balancer chamber 34 through the communicating hole 32, the gas discharged into the inter-bearing chamber 33 reaches the balancer chamber 34 having the same pressure as the shell internal space through the communicating hole 32. Therefore, a series of gas discharge passages (gas reservoir 30 of eccentric hole 60a → oil supply hole 2
3 → second gas vent hole 29 → bearing interchamber 33 → communication hole 32 → balancer chamber 34 → shell inner space), so eccentric hole 60a
The gas foamed inside is smoothly discharged to the shell internal space without expanding the gas pool 30.

The other operations are the same as those in the conventional example, and therefore will be omitted. In the above embodiment, the pumping capacity of the pump is determined by the amount of eccentricity of the oil supply hole 23 from the center of the main shaft 6 and the hole diameter.
The upper limit is limited by the diameter of the spindle. Therefore, in the low speed range where the inverter is controlled, the oil pumping capacity decreases at the rate of the square of the number of revolutions, which causes a problem that the bearing cannot be sufficiently lubricated. As a countermeasure against this, if the eccentricity of the oil supply hole from the center of the main shaft is increased in the part where the main shaft diameter is larger than the minimum part, the oil pumping capacity can be increased.

FIGS. 3a and 3b show another embodiment of the present invention made correspondingly. In the figure, the first oil supply hole 23a is the same as the conventional one, but the diameter is enlarged in the middle part where the shaft diameter is thicker, and the second oil supply hole 23b is provided. The second gas vent hole 29 is provided in the middle of the second oil supply hole 23b. The solid arrow indicates the oil flow, and the broken arrow indicates the gas flow. The area indicated by the one-dotted broken line 31 is the outline of the gas reservoir 30.

In the above structure, the oil pumped up in the first oil supply hole 23a increases the oil pumping capacity in the second oil supply hole 23b and is carried to the eccentric hole 60a. This is because the oil flows by centrifugal force in a portion farther from the shaft centers of the oil supply holes 23a and 23b, so that the eccentric amount from the shaft center substantially increases from the oil supply hole 23a to the oil supply hole 23b, and This is because the pumping capacity is increased due to the relationship between the head and the amount of eccentricity. At this time, the oil supply holes 23a, 23
At the seam of b, the centrifugal force acts on the oil, and the gas foams in the same way as the oil that reaches the eccentric hole as described in the conventional example, but this foamed gas smoothly flows out of the main shaft from the second gas vent hole 29. Is discharged. Therefore, even in the low speed range during inverter control, it is possible to supply oil to the eccentric hole 60a if there is a pumping head that can be obtained with an eccentric amount of the oil supply hole 23a that is higher than the height of the head from the oil supply hole 23a to the point where the oil supply hole 23b moves. . On the contrary, in order to obtain sufficient lubricating oil in the low speed range, the height of the point from the oil supply hole 23a to the oil supply hole 23b may be adjusted. As described above, the smooth discharge of the foaming gas and the lift-up of the oil pump up make it possible to perform stable oil supply even in the low speed range during the inverter control.

4a and 4b show still another embodiment of the present invention,
The oil supply hole 23b in the illustrated embodiment is replaced with an oil supply hole 23c having a larger eccentricity from the axial center than the oil supply hole 23a.
The effect of this embodiment is the same as that of the embodiment shown in FIG. Further, in FIG. 4, 23a is a conventional oil supply hole, and the eccentricity is increased from the middle. The oil supply hole with the larger eccentricity is designated as 23c. In the middle of the oil supply hole 23c, a second gas vent hole 29 is provided in the thick portion in the direction opposite to the eccentric direction. In the figure, the solid arrow indicates the oil flow, and the broken arrow indicates the gas flow. At the bends of the oil supply holes 23a and 23c, the oil receives centrifugal force and the gas contained in the oil foams, but the foamed gas is smoothly discharged from the second gas vent hole 29 to the outside of the shaft. Further, as in the case of FIG. 3, by adjusting the height of the bend portion, stable oil supply can be performed even in the low speed range during inverter control.

〔The invention's effect〕

As described above, according to the present invention, it communicates with the gas pool at the center of rotation of the eccentric hole of the main shaft and extends in the direction opposite to the eccentric direction in the middle of the eccentric oil supply hole near the gas pool. Since a gas vent hole communicating with the external space of the main shaft is provided, the foaming gas of the pumped oil in the eccentric hole of the main shaft is separated into a gas reservoir by centrifugal force, and the oil supply hole and the gas vent hole are communicated with this. The oil can be discharged more smoothly into the shell space, and as a result, gas is not mixed in the oil supplied from the eccentric hole, stable oil supply can be achieved, and accidents such as bearing damage and seizure can be prevented.

In addition, the spindle oil supply hole is enlarged in the middle of reaching the eccentric hole of the main shaft, or the eccentricity of the oil supply hole is increased, and by providing a gas vent hole in the middle of these spaces, even in the low speed range during inverter control. Stable and sufficient refueling can be performed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a scroll compressor showing an embodiment of the present invention, FIG. 2a is a view showing an operation state of refueling in FIG. 1 when a main shaft portion is viewed from above, and FIG. Fig. 3a is an axial sectional view, Fig. 3a is a plan view of a spindle portion showing another embodiment of the present invention, Fig. 3b is an axial sectional view thereof, and Fig. 4a is still another embodiment of the present invention. Fig. 4 is a plan view of a main shaft portion showing an example, Fig. 4b is a sectional view in the axial direction thereof, Fig. 5 is a sectional view showing a conventional scroll compressor, and Fig. 6 is a working principle diagram of the scroll compressor. 2c …… Oscillating scroll shaft, 6 …… Main shaft, 60a …… Eccentric hole, 7 …… Oil cap, 9 …… Bearing frame, 2
3,23a, 23b, 23c ... Oil supply hole, 24 ... Gas vent hole, 29 ... Second gas vent hole, 30 ... Gas reservoir, 31 ... Outline of gas reservoir 30, 32 ... Communication hole. The same reference numerals in the drawings indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuzo Matsuki 6-5-66, Tehira, Wakayama, Wakayama Sanryo Electric Co., Ltd. Wakayama Plant (72) Masahiro Sugihara 6-5, Tehira, Wakayama, Wakayama No. 66 Sanritsu Electric Co., Ltd. Wakayama Works (56) References: 59-116593 (JP, U)

Claims (4)

[Claims] 1. A fixed scroll and an orbiting scroll which have respective spirals and form a compression chamber between the spirals by combining the spirals with each other, a main shaft for driving the orbiting scroll, and the main shaft. A hermetically sealed type having an eccentric hole formed at the upper end of the main shaft and fixed with a oscillating bearing for supporting the oscillating scroll, and an eccentric oil supply hole penetrating in the axial direction of the main shaft for supplying oil from the lower end of the main shaft to the eccentric hole. In the scroll compressor described above, the scroll compressor communicates with a gas reservoir at the center of rotation of the eccentric hole, and extends in the direction opposite to the eccentricity in the middle of the oil supply hole near the gas reservoir and communicates with the external space of the main shaft. A scroll compressor, which is provided with a gas vent hole. 2. The scroll compressor according to claim 1, wherein the gas vent hole is provided between a large-diameter first main bearing that supports the main shaft and a small-diameter second main bearing. 3. An oil supply hole according to claim 1, wherein the diameter of the oil supply hole is small on the suction side and widens on the discharge side so as to increase from the middle, and a gas vent hole is arranged in the large diameter oil supply hole section. Scroll compressor. 4. A scroll according to claim 1, wherein the oil supply hole is bent in the middle so that the eccentricity of the oil supply hole is small on the suction side and is large on the discharge side, and a gas vent hole is provided in the oil supply hole of large eccentricity. Compressor.