JPS60259790A - Rotary compressor - Google Patents

Abstract

PURPOSE:To minimize a mechanical friction loss as well as to aim at improvements in compressor efficiency, by setting each value of ratios of height of a cylinder, an inner radius of the cylinder and an outer radius of a roller of a rotary compressor. CONSTITUTION:In this rotary compressor, when height of a cylinder is set down to H, an inner radius of the cylinder to Rc and an outer radius of a roller to Rr, respectively, these values of ratio Rr/Rc and H/Rc are made so as to be set within the range of 0.84-0.92 and 0.4-0.8 in design. As a result, a form of the cylinder comes to being flat and thereby a leakage of gas and oil from a roller end face is reduced in consequence, so that compressor efficiency is thus improvable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a rotary compressor, and particularly to a rotary compressor that aims to reduce mechanical friction loss and improve compressor efficiency.

[Background of the invention]

Conventionally, the optimal compressor component dimensions for increasing the efficiency of a rotary compressor have been disclosed in, for example, Japanese Patent Application Laid-Open No. 57-1.
As shown in Japanese Patent No. 19190, the height H of the cylinder
, the inner diameter of the cylinder, and the outer diameter D of row 2 (
D, -D,), i.e. H/ (1), -D,)
It is known to set the value around 1.65.

This study investigated the effects of mechanical friction loss, leakage, and refrigerant temperature rise in the cylinder on the compressor efficiency of a rotary compressor, limited the H/(D.-ri,) ratio, and H at which the effective energy ratio EER is maximum under the conditions
/(D, -D,) ratio was experimentally found.

However, when determining the optimal compressor component dimensions for an arbitrary theoretical displacement amount Vtb (i.e., cylinder volume), the theoretical displacement amount ■th is expressed as If two of these dimensions (or two dimensional parameters related to the above dimensions) are not determined, the compressor component dimensions cannot be determined, and H
/ (D, -D, ) ratio alone is not unambiguous. Therefore, at present, the optimal dimensions of compressor components for improving compressor efficiency have not been clarified.

[Purpose of the invention]

An object of the present invention is to provide a rotary compressor in which compressor component dimensions can be optimized to minimize mechanical friction losses and improve compressor efficiency.

[Summary of the invention]

The rotary compressor according to the present invention includes at least a cylinder, a roller that rotates within the cylinder, a crank that rotates the roller, and a drive device that drives a rotating shaft integrated with the crank. A rotary compressor having a vane whose tip abuts the roller and reciprocates according to the rotation of the rotating shaft to partition the inside of the cylinder into a suction chamber and a compression chamber, and an end plate that covers openings at both ends of the cylinder. , the height of the cylinder is H1, the inner radius of the cylinder is Ro, and the outer radius of the roller is R, then the ratio R,
The values of /R and H/R are respectively 0.84 to 0.
92 and in the range of 0.4 to 0.8.

[Embodiments of the invention]

Hereinafter, the present invention will be explained using examples and drawings.

FIG. 1 is a cross-sectional view of a rotary compressor according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line -■ in FIG.

In the figure, 1 is a cylinder of the rotary compressor 15 (inner radius H1, details will be described later), 2 is a roller rotating inside this cylinder 1 (outer radius R1, details will be described later), 3 is a crank that gives rotation to this roller 2;
The crank 3 is integrated with a rotating shaft 4, and its upper portion is directly connected to a motor (not shown) associated with a drive device.

5 is a rube vane that partitions the inside of the cylinder 1 into a suction chamber 7 and a compression chamber 8; the tip of this vane 5 contacts the roller 2;
From the rear end to the spring 6 and the pressure inside the sealed container 13 outside the cylinder l (
Discharge Pressure) Pressed by the VC, it reciprocates within the vane groove la formed in the cylinder 1 according to the rotation of the rotating shaft 4. Above cylinder 1.

As shown in FIG. 2, the lower end surface is provided with an upper end plate 9 and a lower end plate 10, which serve as bearings for the rotating shaft 4 and which cover the openings at both ends of the cylinder 1. Upper end plate 9. Lower end plate 10. The roller 2 and the vane 5 constitute the suction chamber 7 and the compression chamber 8. Reference numeral 14 denotes lubricating oil stored at the bottom of the closed container 13, which is supplied to each sliding portion by the pump action of the rotary shaft 4.

By the way, when considering the optimization of the component dimensions of this type of rotary compressor, the biggest influence of the compressor component dimensions is the mechanical friction loss, and the authors' research on loss analysis shows that this mechanical friction loss It has also been confirmed that they account for a major portion of total losses. Furthermore, in recent years, the rotational speed of motors has been controlled by inverters, and as speeds have increased, the proportion of mechanical friction loss has been on the rise. Therefore, in order to improve compressor efficiency, it is most effective to reduce this mechanical friction loss, and the optimization of compressor component dimensions also focuses on reducing this mechanical friction loss. , the height H of the cylinder 1, the inner radius R of the cylinder 1, and the dimensions of the compressor component parts.
The values of the shape parameters ζ (=R, /R,) and ξ (=H/R,) that dimensionlessly express the relationship between the outer radius Rr of the roller 2 are as follows.
ζ=0.84~0.92, respectively. ξ=0,4~0.
It was set to be in the range of 8.

The reason why the values of the shape parameters ζ and e are limited in this way will be explained using FIGS. 3 to 8.

In Figure 3, the theoretical valve displacement vth is constant (here, 12
, 5 crB3/rev) is a relationship diagram between the shape parameters ζ, ξ and compressor component dimensions.

In FIG. 3, D, % (=2FL, ) is the inner diameter of the cylinder 1, and a (-R, -R,) is the eccentricity of the crank 3. It can be seen from FIG. 3 that once the values of the shape parameters ζ and ξ are determined, all the dimensions of the compressor components can be determined. The characteristics of the changes in the compressor components due to the shape parameters ζ and ξ are as follows: The larger the shape parameters ζ and ξ, the smaller the eccentricity a becomes. The inner diameter of the cylinder 1 and the height H of the cylinder 1 become larger as the shape parameter ζ becomes larger, but the influence of the shape parameter ξ tends to be contradictory, and D6 becomes larger as ξ becomes smaller. H becomes larger as ξ becomes larger.

By the way, the main locations where mechanical friction loss occurs within the cylinder 1 of the rotary compressor 15 are the following three locations shown in FIG. 4 (indicated by diagonal lines).

FIG. 4 is a cross-sectional view showing the main locations where mechanical friction loss occurs in the rotary compressor.

■ Side surface of the vane (section A) ■ Tip of the vane (section B) ■ Inner circumference of the roller (section C) Here, the friction on the side surface of the vane is the suction chamber 7 in the cylinder 1.
This is caused by the load F8 applied to the side surface of the vane due to the pressure difference (pc pg) between
In order to reduce the eccentricity ia and the height H of the cylinder 1, it is necessary to reduce the eccentricity ia and the height H of the cylinder 1. Looking at the shape parameters ζ and ξ, from Fig. 3, in order to reduce the eccentricity a, ζ.

It is necessary to increase both ξ, but the height H of cylinder 1
It can be seen that the smaller both ζ and ξ, the smaller ξ, and from both, there are optimal shape parameters ζ and ξ.

Next, the friction at the vane tip is caused by the vane pressing force FN due to the pressure difference between the inside and outside of the cylinder 1 and the sliding speed between the vane 5 and the roller 2, and the magnitude of this vane tip friction loss Lm is is influenced by the rotational angular velocity ωP. On the other hand, roller inner circumference friction loss Lc due to roller inner circumference friction is:
This is caused when the load Fp due to the pressure difference in the cylinder 1 is applied to the roller 22 as a load, and the relative speed between the angular velocity ω of the crank 30 and the rotational angular velocity ωP of the roller 2 (ω-ωP
). Therefore, the rotational angular velocity ω of the row 22
Vane tip friction loss Lm with respect to P.

The relationship between roller inner circumferential friction loss Lc is as shown in FIG.

FIG. 5 is a characteristic diagram of roller rotation angular velocity, vane tip friction loss, and roller inner circumference friction loss.

From this Fig. 5, the friction losses L+i and Lc with respect to the roller rotational angular velocity ωP have contradictory characteristics, and (LI++L
There exists ωP such that c) is minimized. It is only necessary to select the dimensions of the compressor components that provide such a roller rotation angular velocity ωP.

The roller rotation angular velocity ωP can be theoretically determined from the relationship between the moments applied to the roller 2, and its relationship with the shape parameters ζ and ξ is as shown in FIG.

FIG. 6 is a diagram showing the relationship between the shape parameters ζ and ξ and the roller rotation angular velocity.

From FIG. 6, it can be seen that the larger ζ is and the smaller ξ is, the smaller ωP is, which is advantageous for the vane tip friction loss Lm.

FIG. 7 is a diagram showing the relationship between the shape parameters ζ and ξ and the maximum load.

(9) From FIG. 7, it can be seen that the smaller both ζ and ξ, the smaller the maximum load Fp□8, and the smaller the roller inner circumferential friction loss Lc. Also, this load load is above.

Since it also acts on the bearings of the lower end plates 9 and 10, the smaller ζ and ξ are, the more advantageous it is in reducing the friction loss of the bearings.

The above describes the relationship between the shape parameters ζ and ξ and the friction losses LA, L++, and Lc of the individual sliding parts.

The influence of ξ shows contradictory tendencies, and it is inferred that there are shape parameters ζ and ξ that minimize the total mechanical friction loss LA+Li++Lc of the rotary compressor.

FIG. 8 shows the relationship between the total mechanical friction loss and the shape parameters ζ and ξ.

FIG. 8 is a diagram showing the relationship between shape parameters ζ and ξ and total mechanical friction loss. From this Figure 8, the shape parameter ζ that minimizes the total mechanical friction loss for various rotation speeds of the rotary compressor from the normal rotation speed to the target high speed rotation speed
, ξ exists (10) At n=1500 rpm, ζ=0.92. ξ＝
0.4, ζ= 0.84 for nn=1000OrI,
The total mechanical friction loss is minimized at ξ=0.8. Therefore, the optimal compressor component dimensions that take these rotational speed changes into consideration are the shape parameter ζ = 0.84 to 0.92. ξ＝
This can be obtained by setting it within the range of 0.4 to 0.8.

Linda 1 sets the shape parameters ζ and ξ in this way.
The diameter D0 of the cylinder 1 is large, and the height H of the cylinder 1 is small. Radius R of roller 2.

is also larger than before, and if the diameter of the crank 3 is kept constant, the thickness of the roller 2 will increase. Along with this,
The amount of lubricating oil and refrigerant gas leaking from the roller end face into the cylinder, which conventionally accounted for the main part of leakage loss and reduced compressor efficiency, This not only reduces mechanical friction loss (which is inversely proportional to thickness) (11), but is also effective in reducing leakage loss in the low range, and can improve the efficiency of the p1 compressor.

The compression operation of the rotary compressor 15 configured as above will be explained.

When the rotating shaft 4 is driven by the motor, the crank 3
A roller 2, which is freely rotatable, rotates within the cylinder 1, and the volumes of a suction chamber 7 and a compression chamber 8, which are partitioned by vanes 5, change. When the crank 3 rotates in the direction of the arrow (Fig. 1), the volume of the suction chamber 7 increases and sucks refrigerant gas from the suction boat 11, while the volume of the compression chamber 8 decreases and the refrigerant gas is compressed. It is discharged from the discharge boat 12 into the closed container 13 and compressed.

In this case, the height H of cylinder 1, the inner radius R of cylinder 1
0 and the outer radius R1 of the roller 2 are set as described above, mechanical friction loss is reduced compared to the conventional case, and compressor efficiency is improved.

According to the embodiment described above, in a rotary compressor that maintains the pressure inside the closed container 13 at the discharge pressure, the height of the cylinder 1 is H1, the diameter of the cylinder 1 is Ro, and the outer radius of the roller 2 is H1. When R1 is the shape parameter ζ(-R,/几) of the compressor component.

) and ξ (=H/R,), respectively, from ζ=0.84 to
0.92. By setting ξ in the range of 0.4 to 0.8, it is possible to minimize the total mechanical friction loss (=L + LB + LC) and provide a rotary compressor with high compressor efficiency. be.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide a rotary compressor that can optimize compressor component dimensions, minimize mechanical friction loss, and improve compressor efficiency.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a rotary compressor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG.
Figure 8 is for explaining the reason for limiting the shape parameters ζ and ξ, and Figure 3 shows the shape parameters ζ and ξ and compressor component dimensions when the theoretical displacement is constant. Fig. 4 is a cross-sectional view showing the main locations where mechanical friction loss occurs in rotary compressors (13), and Fig. 5 shows the relationship between roller rotational angular velocity, vane tip friction loss, and roller inner circumferential friction loss. Figure 6 is a diagram of the relationship between the shape parameters ζ, ξ and the roller rotation angular velocity, Figure 7 is a diagram of the relationship between the shape parameters ζ, ξ and the maximum load, and Figure 8 is a diagram of the relationship between the shape parameters ζ and ξ and the maximum load. , ξ and total mechanical friction loss. 1... Cylinder, 2... Roller, 3... Crank, 4... Rotating shaft, 5... Vane, 7... Suction chamber,
8... Compression chamber, 9... Upper end plate, 10... Lower end plate,
15...Rotary compressor, H...Cylinder height,
Ro...inner radius of cylinder, Rr...outer radius of roller. Agent Patent attorney Kosaku Fukuda (and 1 other person) (14) $1 K1 '2x $2 K3 Mekyo 4 K $S Prisoner P

Claims (1)

[Claims] 1. At least a cylinder, a roller that rotates within the cylinder, a crank that rotates the roller, a drive device that drives a rotating shaft that is integrated with the crank, a tip of which is in contact with the roller, and a roller that rotates within the cylinder. In a rotary compressor having a vane that reciprocates according to the rotation of a rotating shaft and partitions the inside of the cylinder into a suction chamber and a compression chamber, and an end plate that covers openings at both ends of the cylinder, the height of the cylinder is H1. The inner radius of the roller is Raz, and the outer radius of the roller is R.
1, the values of the ratios R, /R, and H/R are set in the ranges of 0.84 to 0.92 and 0.4 to 0.8, respectively. compressor.