JPS61205390A - Two-cylinder type rotary compressor - Google Patents

Abstract

PURPOSE:To realize reduction in size and weight of a balance weight by making mass of an eccentric rotating part of a compressive mechanism on the main shaft end side of a two-cylinder type rotary enclosed compressor smaller than that of a compressive mechanism on the other side. CONSTITUTION:Balance weights 10, 11 are fitted on the upper part and to the lower part of a motor rotor 9 of a two-cylinder type rotary enclosed compressor. Crank parts 4, 5 and rollers 6, 7, which are eccentric rotating parts of a compressive mechanism, are connected to a main shaft 8 connected to the rotor 9, while the crank part 5 and the roller 7 for the compressive mechanism on the main shaft end side, of two compressive mechanisms, are partially made thin and light. Due to this, as a balance weight to balance an eccentric rotating part of this compressive mechanism, small-sized and light one can be used, therefore, the compressor itself can be made small in size.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention aims to reduce the weight and size of a counterweight provided for dynamic and static balance of a rotor in a two-cylinder rotary compressor. It is something.

[Conventional technology]

Figure 3 is a sectional view showing a conventional two-cylinder rotary compressor disclosed in Japanese Utility Model Application Publication No. 59-111984. T21 +31 is arranged, and a common crankshaft +8 is installed in each cylinder 121 (3).
An eccentric part 141 (51) provided adjacent to 1, a rolling piston +61 (71) and a vane rotatably fitted into each of these eccentric parts are housed.

α1 and (111) are an upper counterweight and a lower counterweight respectively provided on both upper and lower end surfaces of the rotor (9) in the electric element α2 fixed to the crankshaft +81.

Dynamic and static balance in the conventional two-cylinder rotary compressor with the above configuration
The upper counterweight αG and the lower counterweight I of the rotor (9) are provided to balance the eccentric rotating mass consisting of the eccentric portion (41+51) and the rolling pistons +61 and +71 fitted therein. This balancing action is illustrated in Figure 4, where m (H is the eccentric rotating mass of each eccentric part of the crankshaft (81) and each rolling piston; r
is its radius of rotation, m6 is the eccentric rotating mass of the lower counterweight of the rotor, m[ is the eccentric rotating mass of the upper counterweight, rl is the respective radius of rotation, (a) is the distance between the upper and lower eccentric parts, (b ) is the distance between the lower eccentric part and the lower counterweight, and (C) is the distance between the lower eccentric part and the upper counterweight.

These dynamic and static balances can be expressed as the following formula f
It becomes like tl +21.

mc-r-a ten mB-rl-b=mu-rl-c −
(11mc-r+m5-rl =mc'r+mu-r
l-+21 From these two equations, m6. When mu is determined, the following equation (3) is obtained.

The dynamic and static balance in a conventional two-cylinder rotary compressor is achieved as described above.
The counterweights provided on the upper and lower end surfaces of the rotor have the same size, and are therefore relatively large, which is disadvantageous in terms of space and cost.

In order to solve the above-mentioned problems, this invention provides a method in which the eccentric rotating masses of the upper and lower eccentric parts of the link shaft and the rolling piston fitted therein are set in advance to have a difference in size according to the distance from the rotor. The purpose is to reduce the size and weight of the attached counterweight.

[Means for solving problems]

In the two-cylinder rotary compressor according to the present invention, the eccentric rotating mass of one of the eccentric parts of the crankshaft and the rolling piston, for example on the non-electric element side, is made smaller than that of the other one, taking into account the respective distances from the rotor. This is what I did.

Since the difference in size is effectively provided, the counterweight, which is separately provided on the rotor, can be made smaller and lighter.

〔Example〕

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

That is, in FIGS. 1 and 2, parts that are the same as or correspond to those in the conventional system are indicated by the same reference numerals.

In the case of this invention, the crankshaft (
The lower eccentric part (5) of 81 has an eccentric hole (5) for weight reduction.
a), and an annular relief part (7a) for weight reduction is bored in the upper and lower inner circumferential surfaces of the rolling piston (7), which is also fitted into this lower eccentric part (5). The thickness of the portion (5) is characterized in that it is set to be particularly smaller than the thickness of the upper eccentric portion (41) of the crankshaft (8).

The balance effect in the case of the present invention in the above configuration will be explained with reference to FIG. In this figure, mc is the eccentric rotating mass of the upper eccentric part of the crankshaft (8) and the rolling piston fitted into it when viewed from the partition plate (1), r is the rotation radius of the upper part, and md is the eccentric rotating mass of the upper part. and the difference between the eccentric rotating mass at the bottom. mu and m6 are eccentric rotating masses caused by counterweights placed on the upper and lower end surfaces of the rotor, respectively, and rl is the radius of rotation. (a), (b), and (C) in Figure 1 are the conventional cases. is the same as These dynamic and static balances can be expressed as the following formula +11 (41).

mc・r−a−4−m(3・rl−b=rnu・rl−
a - (111nc-r+ms・r1=(me m
(1) r+mu-rl (4) m from these two equations.

, mu is determined by the following equation +51 +61.

a'r mu=□・-(me-md-)-(51Q-hrI
& m6−= □ (mc ma )
+610-brl a The above formula means that by increasing md, the counterweight to be attached can be made smaller. Specifically, in Fig. 1, the lower eccentric part (5) of the crankshaft (8) is located below the partition blade plate (1) and is far from the rotor.
) and make an eccentric hole (5a) in it.
The difference in the presence or absence of additional work such as annular relief portions (7a) bored on the upper and lower inner circumferential surfaces of the rolling piston (71) corresponds to the above md.

Similarly, in order to increase the above md, a partition plate (1
The material of the rolling piston (7) located on the lower side of the piston 1 may have a specific gravity smaller than that of the material used for the rolling piston (6) located on the upper side.

〔Effect of the invention〕

As described above, the two-cylinder rotary compressor of the present invention has two eccentric rotating masses consisting of both eccentric parts of the crankshaft located on both sides of the partition plate provided between the two cylinders, and the respective rolling pistons. , taking into account the distance from the rotor.

For example, since the eccentric rotating mass of one side of the anti-electric element is made smaller than that of the other side of the electric element, the counterweight provided separately on the rotor for dynamic and static balance can be made smaller and lighter, making it less expensive. This has the effect that a two-cylinder rotary compressor can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the two-cylinder rotary compressor of the present invention, Fig. 2 is an explanatory view showing its balancing action, and Fig. 3 is a cross-sectional view of a conventional two-cylinder rotary compressor. 4 are similar explanatory diagrams showing the balancing effect. In the figure, (1) is the partition plate, +21 (31 is the cylinder, (41 (51 is the eccentric part, (5a) is the eccentric hole,
+61 (71 is a rolling piston, (7a) is a relief part, (81 is a crankshaft. In other figures, the same - symbol indicates the same or equivalent part.

Claims (6)

[Claims] (1) The eccentric rotating mass of one of the two eccentric rotating masses consisting of both eccentric parts of the crankshaft located on both sides of the partition plate provided between the two cylinders and the rolling piston fitted into each of these eccentric parts. A two-cylinder rotary compressor characterized by being smaller than the other. (2) A two-cylinder rotary compressor according to claim 1, in which the smaller eccentrically rotating mass is formed on the opposite side of the crankshaft to the electric element. (3) A two-cylinder rotary compressor according to claim 1, wherein an eccentric hole is provided in an eccentric portion of the crankshaft on the side opposite to the electric element. (4) The two-cylinder rotary compressor according to claim 1, wherein the wall thickness of the eccentric portion of the crankshaft on the side opposite to the electric element is thinner than that of the other eccentric portion. (5) The two-cylinder rotary compressor according to claim 1, wherein the apparent wall thickness of the rolling piston on the side opposite to the electric element of the crankshaft is thinner than that of the other rolling piston. (6) The two-cylinder rotary compressor according to claim 1, wherein the specific gravity of the rolling piston material on the side opposite to the electric element is set to be smaller than the specific gravity of the other rolling piston material.