JPS62153591A - Rotary compressor - Google Patents

Abstract

PURPOSE:To enhance the durability of a slide bearing, by setting the compensating amounts of balancers disposed at the lower ends of a rotor and a rotary shaft to values which are less than a value realizing the static balance thereof. CONSTITUTION:Balancers 12a, 12b are attached to the lower end surfaces of a rotor 10 and a rotary shaft 4, respectively. The following relationships are established: U1=(0.8U0L2)/(L1+L2), U2=(0.8U0L1)/(L1+L2) where U0 is an unbalance value of a piston 6, L1, L2 are the distances from the center of the piston 6 to the centers of the balancers 12a, 12b, respectively. Accordingly, the U1, U2 are set to values which are less than a value realizing the static balance of the compressor. Accordingly, it is possible to greatly enhance the durability of a slide bearing.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a rotary compressor using a sliding bearing as a bearing, and in particular to a rotary compressor that optimizes a balancer for correcting unbalance of a rotating part. Regarding type compressors.

[Technical background of the invention and its problems]

As is well known, refrigerators, air conditioners, and the like require gas compressors. Gas compression compensation for such applications is as follows:
A rotary compression mechanism that can be easily miniaturized; a rotary compression mechanism that has a rotating part fixed on the outer periphery of one end of the rotary shaft (ff111) to inhale and compress gas; : The rotor is fixed on the outer periphery on the shore side, and the rotational pressure f11>'l The motor that provides rotational power to the IM, the pair of bearings that support the rotating shaft at both ends of the rotational pressure 11 structure, and the unbalance of the entire rotating part. A device consisting of a pair of balancers for correcting the predetermined balance usually has these elements built into a container.

Incidentally, in recent years, in refrigerators, air conditioners, etc., a method of variable speed control of the compressor has been adopted in order to improve efficiency and expand controllability. Along with this, rotary compressors are also required to improve their rotational performance.

The most important points to keep in mind when improving the rotational performance of a rotary compressor are vibration reduction and bearing durability. In a rotary compressor, the rotating part of the rotary compression R mechanism is fixed eccentrically with respect to the rotating shaft, so that large image pickup is likely to occur. Therefore, it is necessary to provide the above-mentioned balancer so that the rotational unbalance can be accurately offset. Furthermore, regarding the durability of the bearing part, it is desirable to use a sliding bearing, which is more durable than a ball bearing, for the bearing part.

However, when a sliding bearing is incorporated into a rotary compressor,
The whirling of the rotating shaft becomes relatively large, making it difficult to avoid contact between the sliding bearing and the rotating shaft, which may cause a decrease in rotational efficiency, or in the worst case, cause damage to the bearing. There was a problem with it.

[Purpose of the invention]

The present invention was made in consideration of such circumstances, and
The object of the present invention is to provide a rotary compressor that incorporates a sliding bearing as a bearing and is capable of improving the durability and rotational efficiency of the bearing.

[Summary of the invention]

The gist of the present invention is to improve durability and rotational efficiency by reducing the amount of correction by the balancer to Ml.

That is, the present invention includes a rotating shaft, a rotary compression mechanism having a rotating part eccentrically fixed to the outer periphery of one end of the rotating shaft and sucking and compressing gas, and a rotor fixed to the outer periphery of the other end of the rotating shaft. a motor that provides rotational power to the rotary compression mechanism;
A rotary compression mechanism comprising a pair of sliding bearings that support the rotary shaft at both end positions of the rotary compression mechanism, and a balancer that is provided at the lower end of the rotor and the rotary shaft to correct imbalance of the entire rotating portion. In the machine, the correction amount of at least one of the balancers is set to a value smaller than a value that realizes static balance.

〔Effect of the invention〕

According to the present invention, by setting the balancer correction a to a value smaller than the value that achieves static balance, it is possible to significantly improve the durability of the sliding bearing, and also to improve the rotational efficiency.

The durability of sliding bearings decreases during high-speed rotation due to the following reasons. That is, the centrifugal force caused by the unbalanced amount of the balancer and crank eccentric portion causes bending deformation of the rotating shaft, which causes whirling force to act on the bearing. When examined in more detail, at the end of each bearing that is far from the first compression groove, the influence of the gas compression force is small and the whirling force is dominant. On the other hand, the influence of the gas compression force is greater at the end of the compression (1 structure side).
By subtracting the balancer correction amount from the static balance suspension, the force applied to the end of each bearing in the direction away from the compression mechanism of each bearing, especially during high-speed rotation, is reduced, resulting in high bearing durability and high rotational efficiency. I can do it.

In addition, when performing targeted balancing during high-speed rotations, the whirling force due to the unbalanced can of the eccentric part of the crank (
There is a concern that a load (larger than in static balance) may move to the compression mechanism side end of the bearing.

If we also consider this, the unbalanced force in the crank-center direction will act in the opposite direction to the direction in which the gas compression force acts in the rotational phase where a large gas compression force moves, for example at a rotation angle θ = 240°. Therefore, the two cancel each other out, and a smaller force acts on the end of the bearing on the compression mechanism side than when the above-mentioned turning force does not act. Therefore, even during low-speed rotation, higher durability and rotational efficiency can be obtained than in the case of static balance.

As described above, it is possible to improve the durability and rotational efficiency of the sliding bearing both during high-speed rotation and low-speed rotation.

[Embodiments of the invention]

Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.

FIG. 1 is a longitudinal cross-sectional view showing a schematic configuration of a rotary compressor according to an embodiment of the present invention. In the figure, 1 is a container provided with its axis oriented in the direction of gravity. This container 1
A rotary pressure w6 mechanism 2 is disposed in the lower part of the container 1, and a motor 3 that provides rotational power to the rotary compression mechanism 2 is disposed in the upper part of the container 1. And rotational pressure L1! 1 horizontal 2
and the motor 3 are connected by a rotating shaft 4.

The rotary compression mechanism 2 includes a cylinder 5 fixed to the inner surface of the container 1 and the rotating shaft 4 inserted into the cylinder 5.
The piston 6 is eccentrically fixed to the outer periphery of the lower end of the cylinder 5, and slide bearings 7a and 7b close the upper and lower openings of the cylinder 5 and rotatably support the rotating shaft 4. Then, the cylinder 5 and the bearings 7a and 7b
The suction side of the compression space surrounded by is connected to the outside via a suction pipe 8, and the discharge side is connected to the inside of the container 1 via a discharge valve 9.

The motor 3 is constituted by an induction motor including a rotor 10 fixed to the outer periphery of the other end of the rotating shaft 4 and a stay 911 fixed to the inner surface of the container 1. The lower end surface of the rotor 10 and the lower end surface of the rotating shaft 4 are provided with base sensors 12a and 12 set to ff1Ut and U2, which will be described below.
b are attached respectively. That is, now let Uo be the unbalance of the piston part, Ll be the distance from the center of the piston 6 to the center of the balancer 12a, and L2 be the distance from the center of the piston 6 to the balancer 12b. are respectively Ur − (0,8U
Mouth L2) / (Lt +12)U
2- <0.8 UOLt ) , / (Lt +12
) is set. As can be seen from the above formula, Ul.

U2 is set to a value smaller than the value that achieves static balance.

In addition, 13 in FIG. 1 indicates a discharge member, and 14 indicates a power feeding mechanism to the motor 3.

In such a configuration, when the motor 3 is driven, the piston 6 rotates, and gas is sucked into the compression space through the suction pipe 8. After this gas is compressed, it is sent into the container 1 via the discharge valve 9, and then sent out to the outside via the discharge pipe 13. Therefore, the function as a compressor is exhibited here.

Next, whirling in the rotary compression line of the above configuration will be explained with reference to FIG. 2.

Figure 2 (a) shows the state when stopped, and Figure 2 (b)
Figure (C) shows the state of shooting at high speed when static balance is applied, and (C) is the real IJI! This shows the state of whirling at high speed in 1FIA. When static balance is applied, the amount of whirling becomes extremely large as shown in FIG. 2(b), and the bearing 7a.

It can be seen that there is a problem in durability at the end portion of 7b remote from the compression mechanism. On the other hand, as in this embodiment, when the balancer distance is subtracted from the static balance, the run-out transmission becomes smaller even during high-speed rotation, as shown in Fig. 2 (C), especially at the upper part of the bearing 7a and the lower part of the bearing 7b. The reliability of the system is greatly improved.

Further, FIG. 2(d) shows the state at low speed rotation in the case of static balance, and FIG. 2(e) shows the state at low speed rotation in this embodiment.

When static balance is applied, the center of whirling becomes smaller as shown in FIG. 2(d). On the other hand, in the case of the present embodiment, by reducing the number of the springs 12a and 12b from the value that realizes static balance, the whirling force in the eccentric direction of the crank is reduced during low-speed rotation when the bending deformation of the rotary shaft 4 is small. It will be larger than in the case of static balance.

However, Fig. 2(e) is an investigation of whirling components due to bending imbalance, etc., and in reality, the crank part (U
Gas compression force acts on the part α). The gas compression force acts in the direction of 1/2 of the rotation angle of the rotation shaft 4 as shown in FIG. °, as shown in Fig. 3(b), the whirling force acting in the eccentric direction of the crank and the gas compression force tend to cancel each other out, and the resultant force of the two is greater than that in the case of only the gas compression force. Therefore, due to the interaction between the rotation angle component and the gas compression force component, it is possible to obtain high durability and high rotational efficiency even during low speed rotation.

As described above, according to this embodiment, the balancer 12a.

12b is set smaller than the value that achieves static balance, the force acting on the slide bearings 7a and 7b during high-speed rotation and low-speed rotation (combined force of the rotation component and the gas compression component) is reduced. can do. Therefore, it is possible to improve the durability of the slide bearings 7a and 7b, and also to improve the rotational efficiency. Further, if the dimensions are the same, if the Young's modulus of the rotary shaft 4 is set to 150 GPa or more and the rotary shafts are the same, operation at a high rotational speed becomes possible, and a wider range of operating capability can be obtained.

Note that the present invention is not limited to the embodiments described above. For example, the balancer is not limited to the two provided at the lower end of the rotor and the lower end of the rotating shaft, but may be provided at the upper and lower ends of the rotor and the lower end of the rotating shaft. In general, it is not necessary to subtract all of the balancers from the static balance amount, and it is sufficient to set at least one correction value of the balancer to a value smaller than the value that realizes the static balance. In addition, various modifications can be made without departing from the gist of the present invention.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a vertical cross-sectional view showing the schematic structure of a rotary compressor according to an example of the gutter of the present invention, Fig. 2 is a schematic view showing the whirling state of the rotating shaft, and Fig. 3 is a schematic diagram showing the whirling state of the rotating shaft. The figure is a schematic diagram for explaining the interaction between the turning force and the compression force. DESCRIPTION OF SYMBOLS 1... Container, 2... Rotary compression mechanism, 3... Motor, 4... Rotating shaft, 5... Cylinder, 6... Piston, 7a. 7b...Sliding bearing, 8...Suction pipe, 9...Discharge valve, 10...Rotor, 11...Stator, 12a,
12b... Balancer, 13... Discharge pipe. Applicant's agent Patent attorney Takehiko Suzue Figure 1 (a) 7 (B - 9 due to 9 (b) Figure 3

Claims (3)

[Claims] (1) A rotating shaft, a rotary compression mechanism having a rotating part eccentrically fixed to the outer periphery of one end of the rotating shaft and sucking and compressing gas, and a rotor fixed to the outer periphery of the other end of the rotating shaft; A motor that provides rotational power to a rotary compression mechanism, a pair of sliding bearings that support the rotating shaft at both end positions of the rotary compression mechanism, and an unbalance amount of the entire rotating portion provided at the lower end of the rotor and the rotating shaft. A rotary compressor comprising: a balancer for correcting the balancer, wherein a correction amount of at least one of the balancers is set to a value smaller than a value that realizes static balance. (2) The rotary compressor according to claim 1, wherein the rotating shaft is made of a material having a Young's modulus of 150 GPa or more. (3) The rotary compressor according to claim 1, wherein the rotating shaft is made of spheroidal graphite cast iron.