JP2003155985A - Gas compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas compressor suitable for preventing excessive compression. SOLUTION: When a rotation angle of a rotor 2 is θ, a distance from the center of rotation of the rotor 2 to an inner peripheral face of a cylinder 1 is R, and a chart showing an inner peripheral shape of the cylinder 1 by θand R is an Rθ chart, this Rθ chart has three points of inflection or more in a scope of 0 deg.<θ<180 deg. and in a scope in which R is again changed to the minimum value via the maximum value from the minimum value and R is reduced to the minimum value from the maximum value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vane rotary type gas compressor used in a car air conditioner system or the like.

[0002]

2. Description of the Related Art Conventionally, in a vane rotary type gas compressor of this type, as shown in FIG.
A structure for accommodating a perfectly circular rotor 2 rotatably installed inside is adopted. In this structure, the inner peripheral shape of the cylinder 1 is an elliptical shape represented by a n-th power of a sin function or a mathematical expression close to this.

That is, the rotation angle of the rotor 2 is θ, and the distance from the rotation center of the rotor 2 to the inner peripheral surface of the cylinder 1 is R.
Then, the inner circumference of the cylinder 1 has an elliptical shape represented by R = sin ⁿ θ, for example, R = 25 + 10 * sin ² θ when 0 ° <θ <180 °, and , 180 ° <θ <360 °, 0 ° ≦ θ ≦ 18
The shape is centrosymmetric with the elliptical shape at 0 °.

Compression chamber forming space portions 10 and 10 are formed between the outer peripheral surface of the rotor 2 and the inner peripheral surface of the cylinder 1. The compression chamber forming space portions 10 and 10 are formed from the outer peripheral surface of the rotor 2 to the inner peripheral surface of the cylinder 1. By the vanes 9, 9 ... Which are provided so as to be retractable toward the surface, the plurality of compression chambers 11, 11 ... Are partitioned and formed.
The volume of the compression chamber 11 formed by the partition is changed by the movement of the vane 9 accompanying the rotation of the rotor 2, and the volume change sucks the refrigerant from the suction hole 12, compresses it, and discharges it. It has a structure of discharging from the hole 13.

However, in the conventional gas compressor, the inner peripheral shape of the cylinder 1 is R = si as described above.
Since the elliptical shape represented by n ⁿ θ is adopted, there are the following problems.

Immediately after the compression of the refrigerant in the compression chamber 11 is started, that is, when the volume of the compression chamber 11 starts to decrease from the maximum to the minimum due to the movement of the vane 9 accompanying the rotation of the rotor 2, the compression chamber 11 is compressed. Volume reduction rate is small,
Thereafter, when the vane 9 further moves and the volume of the compression chamber 11 becomes further smaller, and the refrigerant pressure in the compression chamber 11 reaches the discharge pressure, the volume reduction rate of the compression chamber 11 becomes large, There is a problem that the pressure increase rate (pressure increase rate) of the refrigerant in the compression chamber 11 per unit time is large and the refrigerant pressure in the compression chamber 11 exceeds the discharge pressure, causing so-called overcompression.

This is because when the refrigerant in the compression chamber 11 reaches the discharge pressure, the refrigerant pressure causes the reed valve (not shown) of the discharge hole 13 to open, and the refrigerant in the compression chamber 11 is discharged through the discharge hole 13. When the pressure rise rate of the refrigerant per unit time in the compression chamber 11 is large immediately before such a refrigerant discharge process, the compression chamber may be delayed due to a delay in opening the reed valve. This is because the refrigerant from 11 to the discharge chamber 19 cannot be discharged in time, and the refrigerant left in the compression chamber 11 is further compressed. When the rotation speed is high or the discharge pressure is high, the higher the pressure increase rate at the time when the discharge pressure is reached, the greater the overcompression.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a gas compressor suitable for preventing overcompression. .

[0009]

In order to achieve the above object, the present invention is directed to a rotor rotatably installed, a cylinder accommodating the rotor, and an outer peripheral surface of the rotor toward an inner peripheral surface of the cylinder. And a vane for partitioning the compression chamber forming space formed between the rotor outer peripheral surface and the cylinder inner peripheral surface into a plurality of compression chambers. Is θ, the distance from the rotation center of the rotor to the inner peripheral surface of the cylinder is R, and when the diagram representing the inner peripheral shape of the cylinder by θ and R is the Rθ diagram, this Rθ diagram Is 0
Within the range of ° <θ <180 °, R changes from the minimum value to the maximum value and again to the minimum value, and within the range in which R decreases from the maximum value to the minimum value, it has three or more inflection points. It is characterized by that.

In the present invention, by adopting the above Rθ diagram, when the refrigerant pressure in the compression chamber reaches the discharge pressure, the volume reduction rate of the compression chamber becomes small, and the refrigerant pressure becomes the discharge pressure. When it reaches, the pressure rise of the refrigerant in the compression chamber becomes milder than before.

In the present invention, R can be provided so as to have a maximum value before θ = 90 °, for example, when θ = 70 ° to 90 °.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a gas compressor according to the present invention will be described in detail below with reference to FIGS.

FIG. 1 is a sectional view of a gas compressor showing an embodiment of the present invention, and FIG. 2 is a sectional view of a cylinder taken along the line AA of FIG.

The gas compressor of this embodiment has the configuration shown in FIG.
As shown in FIG. 2, a structure is adopted in which the perfectly circular rotor 2 rotatably installed is housed inside the cylinder 1.

The rotor 2 is provided with a rotor shaft 3 provided integrally with the shaft center thereof and a pair of bearings 4 and 5 for supporting the rotor shaft 3.
It is rotatably installed at the center of the cylinder 1.

Side blocks 6 and 7 are attached to the front end surface and the rear end surface of the cylinder 1, respectively, and both the front and rear side blocks 6,
Bearings 4 for supporting the rotor shaft 3 near the center of 7,
5 is formed.

As shown in FIG. 2, five vane grooves 8 are formed in the rotor 2 in the radial direction, and one vane 9 is slidable in each of these vane grooves 8, 8 ... Each of the vanes 9, 9 ... Is mounted so as to be retractable from the outer peripheral surface of the rotor 2 toward the inner peripheral surface of the cylinder 1.

Compression chamber forming space portions 10 and 10 are formed between the inner peripheral surface of the cylinder 1 and the outer peripheral surface of the rotor 2. The compression chamber forming space portions 10 and 10 are formed by the vanes 9 into a plurality of compression chambers. Partitions are formed into 11, 11, ....

The compression chamber 1 formed as a partition as described above
The volumes of the vanes 1, 11 ... Change with the movement of the vanes 9 as the rotor 2 rotates, and the low-pressure refrigerant is sucked from the suction holes 12 due to the volume change, and is compressed as high-pressure refrigerant to the discharge holes. It is configured to discharge from 13.

The suction hole 12 is formed in the side block 6 facing the front end surface of the cylinder 1, and the discharge hole 13 is formed in the body abdomen of the cylinder 1.

By the way, the gas compressor of this embodiment also employs the structure in which the rotor 2 is housed inside the cylinder 1 as described above, but the inner peripheral shape of the cylinder 1 is different from the conventional one.

That is, in the case of this embodiment, the cylinder 1
The inner peripheral shape of is different from the conventional shape of a simple ellipse represented only by R = sin ⁿ θ (hereinafter referred to as “conventional ellipse”), and a part of the ellipse is a plane.

The inner peripheral shape of the cylinder 1 in this embodiment is an elliptical shape deformed as described above. When the deformed elliptical shape of the inner peripheral surface of the cylinder 1 is represented by R and θ, FIG. It becomes like the Rθ diagram. in this case,
The volume of the compression chamber 11 increases and decreases as shown in the diagram of FIG. 4, the refrigerant pressure in the compression chamber 11 changes as shown in the diagram of FIG. 5, and the torque (load) applied to the rotor 2 is shown in FIG. It changes like the diagram.

On the other hand, the inner peripheral shape of the conventional cylinder 1 shown in FIG. 8, that is, the conventional elliptical shape is represented by R and θ as shown in the Rθ diagram of FIG. In this case, the volume of the compression chamber 11 increases and decreases as shown in the diagram of FIG. 4, the refrigerant pressure in the compression chamber 11 changes as shown in the diagram of FIG. 5, and the torque (load) applied to the rotor 2 is It changes like the diagram of FIG.

Based on the Rθ diagram of FIG. 3, R and θ
The inner peripheral shape of the cylinder 1 in this embodiment will be described in more detail.

In the cylinder 1 of this embodiment, basically, in the range of 0 ° <θ <180 °, R goes from the minimum value Rmin to the maximum value Rmax and then again to the minimum value Rmin.
Change to.

The minimum value Rmin and the maximum value Rmax of R are θ
In the cylinder 1 of the present embodiment, R is θ = 0.
When θ and θ = 180 °, the minimum value becomes Rmin, and before R becomes θ = 90 °, specifically, θ = about 80 °
The maximum value Rmax is reached at. In the case of the conventional cylinder 1, R reaches a maximum at θ = 90 ° (see the Rθ diagram in FIG. 3). Therefore, comparing the rising edges of R, the rising edge of R is higher in the cylinder 1 of the present embodiment. early.

As described above, the structure in which R rises quickly is adopted in order to lengthen the compression process of the refrigerant in the compression chamber 11 so that the portion where the volume reduction rate of the compression chamber 11 becomes small can be made as long as possible. This is to finish the refrigerant suction process into the compression chamber 11 early.

Further, in the case of the cylinder 1 of this embodiment, θ
From about 80 ° to θ = 110 ° to 120 °, the amplitude of R decreases to about 40% so that the volume of the compression chamber 11a is about 20% of its maximum. here,
The amplitude of R is R-Rmin.

Further, the cylinder 1 of this embodiment is shown in FIG.
As shown in the Rθ diagram of R, the range in which R decreases from the maximum value Rmax to the minimum value Rmin (about 80 ° <θ <180
°), especially when θ = 125 ° to 135 °, R
Is constant or increases slightly.

That is, looking at the Rθ diagram of the present embodiment, in the range in which R decreases from the maximum value Rmax to the minimum value Rmin (about 80 ° <θ <180 °), three inflection points P1, P2, There is P3, and the first inflection point P1 is θ = 1
00 °, the second inflection point P2 is θ = 129 °, and the third inflection point P3 is θ = 153 °. Then, R is constant or slightly increases before and after the second inflection point P2 (θ = 129 °).

As described above, the second inflection point (θ = 129
The configuration in which R is constant or slightly increases before and after the rotation is adopted in the region where the pressure of the refrigerant in the compression chamber 11 reaches the normal discharge pressure (a little over θ = 120 ° in the diagram of FIG. 5). This is because at the time point), as shown in the diagram of FIG. 4, the volume reduction rate of the compression chamber 11 is reduced.

In this embodiment, R is changed so that three inflection points P1, P2, and P3 are formed as shown in the Rθ diagram of FIG. 3, so that a part of the ellipse is flat as described above. The deformed elliptic cylinder 1 has an inner peripheral shape.

Next, the operation of the gas compressor configured as described above will be described with reference to FIG. Since the rotor 2 and the vane 9 rotate integrally, the rotation angle of the vane 9 is also represented by θ.

In the gas compressor of this embodiment, when the operation is started and the rotor 2 shown in FIG. 1 rotates in the direction of arrow a in the figure, the five vanes 9 and 9 are integrated with the rotor 2. ... turns around the rotor rotation center axis. At this time, centrifugal force due to rotation and vane back pressure of the lubricating oil supplied from the vane groove 8 to the bottom of the vane 9 act on each of the vanes 9, 9, ...
9 are urged toward the inner peripheral surface of the cylinder 1.

The vanes 9, 9 ... Which move as described above sequentially pass through the compression chamber forming space 10 at the tip end side. At this time, the vanes 9a preceding the vanes 9b and the vanes 9b behind the vanes 9b form the compression chambers. The space 10 is partitioned to form a compression chamber 11a.

While the rear vane 9b partitioning the compression chamber 11a as described above moves until it reaches around θ = 40 ° (correctly 39 °), the compression chamber 11a has a volume. The compression chamber 1 communicates with the suction hole 12 side while being greatly increased, and due to such an effect of increasing the volume of the compression chamber 11a, the compression chamber 1 is compressed from the suction chamber 18 through the suction hole 12.
Low-pressure refrigerant is sucked into the inside of 1a.

Further, the rotor 2 rotates, and the compression chamber 11a
When the rear vane 9b forming the partition exceeds θ = 40 °, the compression chamber 11a is completely separated from the suction hole 12 and the refrigerant is confined in the compression chamber 11a.

In the conventional gas compressor, the suction process is completed immediately before the rear vane 9b partitioning the compression chamber 11a moves to θ = 52 °, but in the gas compressor of this embodiment, At an earlier stage, that is, immediately before the rear vane 9b moves to θ = 40 °, the suction process ends and the refrigerant is trapped in the compression chamber 11a.

Further, the rotor 2 rotates, and the compression chamber 11a
When the rear vane 9b forming the partition exceeds θ = 40 °, as shown in the diagram of FIG.
The volume of 1a begins to decrease. Then, due to such a volume reduction effect of the compression chamber 11a, the refrigerant confined in the compression chamber 11a is compressed.

At the time when the refrigerant is confined in the compression chamber 11a as described above, the rotation angle θ of the rear vane 9b is set.
What is indicated by is the refrigerant confinement angle. This refrigerant confinement angle is about 52 ° in the conventional gas compressor, but θ = 40 ° to 4 ° in the gas compressor of the present embodiment.
At 5 °, the volume of the compression chamber 11a after the start of compression is reduced more quickly than in the conventional case (see the comparison between the diagram and the diagram in FIG. 4), and the refrigerant pressure in the compression chamber 11a immediately increases. Then, when the refrigerant in the compression chamber 11a exceeds the discharge pressure, the reed valve (not shown) of the discharge hole 13 is opened by the refrigerant pressure, and the refrigerant in the compression chamber 11a is discharged to the discharge chamber 19 side through the discharge hole 13. Be exhaled.

By the way, as shown in the diagram of FIG.
In the case of the gas compressor of the present embodiment, assuming that the suction pressure of the refrigerant into the compression chamber 11a is 0.2 MPaG, the refrigerant pressure in the compression chamber 11a is equal to the discharge pressure 1 at a point slightly exceeding θ = 120 °. However, when the refrigerant pressure in the compression chamber 11a reaches the discharge pressure, the volume reduction rate of the compression chamber 11a becomes small (see the diagram in FIG. 4). The pressure increase of the refrigerant in 11a becomes moderate.

Therefore, in the gas compressor of the present embodiment, even if the reed valve has a slight opening delay, the refrigerant pressure in the compression chamber 11a exceeds the discharge pressure and before the pressure rises high. Since the refrigerant in the compression chamber 11a is smoothly discharged from the discharge hole 13 to the discharge chamber 19 side, overcompression is reduced.

When the over-compression becomes small as described above, unnecessary work is reduced and the temperature of the discharged refrigerant is lowered, so that the power required for operating the gas compressor is reduced and the efficiency of the entire refrigeration system is improved. Can be achieved.

In the above embodiment, R in FIG.
Although the inner peripheral shape of the cylinder 1 represented by the θ diagram is adopted, instead of this, the inner peripheral shape of the cylinder 1 represented by the Rθ diagram of FIG. 3 can be adopted. The inner peripheral shape of No. 1 is as shown in FIG. 7, the volume of the compression chamber 11 increases and decreases as shown in the diagram of FIG. 4, and the refrigerant pressure in the compression chamber 11 is as shown in the diagram of FIG. And the torque (load) applied to the rotor 2 fluctuates as shown in the diagram of FIG.

Even in the Rθ diagram of FIG. 3, R is the maximum value Rmax to the minimum value R, as in the Rθ diagram of FIG.
In the process of decreasing to min (about 80 ° <θ <180 °), there are three inflection points P4, P5, and P6. When the positions of these inflection points are indicated by θ, the first inflection point P4 is θ = 102 °, the second inflection point P5 is θ = 122 °, and the third inflection point P5 is
The inflection point P6 is θ = 154 °.

In the above embodiment, an example in which R has the maximum value when θ = 80 ° has been described, but R is θ =
The maximum value can be set at any time between 70 ° and 90 °.

[0048]

In the gas compressor according to the present invention, the distance R from the center of rotation of the rotor to the inner peripheral surface of the cylinder is represented by the relationship with the rotation angle θ of the rotor, and 0 ° <
In the range of θ <180 °, R changes from the minimum value to the maximum value and again to the minimum value, and in the range where R decreases from the maximum value to the minimum value, the Rθ line having three or more inflection points Since the figure is adopted, when the refrigerant pressure in the compression chamber reaches the discharge pressure, the volume reduction rate of the compression chamber also decreases, and the pressure rise of the refrigerant in the compression chamber when the refrigerant pressure reaches the discharge pressure is the same as before. Since it is milder than the above, overcompression can be reduced under standard pressure conditions. When the over-compression becomes small in this way, unnecessary work is reduced and the temperature of the discharged refrigerant is lowered, so that the power required for operating this kind of gas compressor is reduced and the efficiency of the entire refrigeration system is improved. Can be achieved.

[Brief description of drawings]

FIG. 1 is a sectional view of a gas compressor showing an embodiment of the present invention.

FIG. 2 is a sectional view of the cylinder taken along the line AA in FIG.

FIG. 3 shows R when the inner peripheral shape of the cylinder is represented by θ and R.
Explanatory drawing of a θ diagram.

FIG. 4 is an explanatory diagram showing a state in which the volume of the compression chamber increases or decreases in relation to θ.

FIG. 5 is an explanatory diagram showing a state in which the pressure of the refrigerant in the compression chamber changes in relation to θ.

FIG. 6 is an explanatory diagram showing a state in which the torque applied to the rotor changes in relation to θ.

FIG. 7 is a sectional view of a cylinder according to another embodiment of the present invention.

FIG. 8 is a sectional view of a conventional gas compressor.

[Explanation of symbols]

1 cylinder 2 rotor 3 rotor shaft 4,5 bearing 6, 7 Side block 8 vane grooves 9 vanes 10 Compression chamber forming space 11 compression chamber 12 suction hole 13 Discharge hole 16 reed valve 17 Discharge chamber room 18 Inhalation chamber 19 Discharge chamber

Claims (3)

[Claims] 1. A rotor rotatably installed, a cylinder for accommodating the rotor, a rotor outer surface and an inner peripheral surface of the cylinder that are retractable, and the outer peripheral surface of the rotor and the inside of the cylinder. A vane for partitioning and forming a compression chamber forming space portion formed between the compression chamber forming space and a peripheral surface into a plurality of compression chambers, wherein a rotation angle of the rotor is θ, a rotation center of the rotor to an inner peripheral surface of the cylinder. Let R be the distance of R, and if the diagram showing the inner peripheral shape of the cylinder by θ and R is the Rθ diagram, this Rθ diagram is in the range of 0 ° <θ <180 °. The value changes from the maximum value to the minimum value again,
A gas compressor having three or more inflection points in a range in which R decreases from the maximum value to the minimum value. 2. The gas compressor according to claim 1, wherein R reaches a maximum value before θ = 90 °. 3. The gas compressor according to claim 2, wherein R has a maximum value when θ = 70 ° to 90 °.