JPH0447121B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a scroll type fluid machine, particularly one using a pin crank as a rotation prevention mechanism of an orbiting scroll.

[Conventional technology]

Recently, in a scroll-type fluid machine consisting of a fixed scroll, an orbiting scroll, a rotating shaft with a crankshaft, and a casing,
As shown in Japanese Patent No. 58188, there is a mechanism that uses a pin crank between the orbiting scroll and the fixed part as a rotation prevention mechanism for the orbiting scroll.

To explain the embodiment in FIG. 6, A is a fixed scroll, B is an orbiting scroll, C is a pin crank, D and E are bearings, and the bearings D and E are a casing that serves as the orbiting scroll B side and the fixed side. One each is installed on the F side, and the bearing has a radial clearance.
A normal clearance without a JIS clearance symbol is used, and the fit with the bearing box is an intermediate fit.

[Problem that the invention seeks to solve]

In scroll-type fluid machines that use conventional pink cranks, the pink crank bearings are not specified in any way, and those with a normal clearance without a JIS clearance symbol are used, and the fit with the bearing box is assumed to be an intermediate fit. Moreover, since there is only one bearing on both the fixed side and the rotating side, the centrifugal force and fluid pressure acting on the orbiting scroll, the accumulation of dimensional tolerances of each part, the running clearance of each bearing, the thermal expansion of the orbiting scroll, etc. The orbiting scroll attempts to eccentrically exceed a predetermined amount of eccentricity, causing the pin crank to fall down and cause what is called a "miso-suri movement," which causes an abnormal load to act on the pin crank bearing, significantly shortening the bearing life. The phenomenon also increases vibration and noise.

[Means for solving problems]

There are two bearings on the fixed side of the pink crank to prevent the pink crank from falling over, and the bearing on the orbiting scroll side has a JIS clearance symbol of C3 to C5, which has a larger radial clearance than normal, and is fitted with the bearing box. The first feature is that the fitting is a loose fit with a large clearance, and that it is supported by an elastic body with a large frictional force such as rubber, and the bearing on the orbiting scroll side is supported by the above-mentioned elastic body. The second feature is that, instead of being supported by a bearing, a particularly large radial clearance of the bearing is used to provide an intermediate fit with the bearing box.

[Effect]

Two bearings are used on the fixed side of the pink crank, so the pink crank will not fall over, and the bearing on the orbiting scroll side has a JIS clearance symbol of C3 to C5, which has a larger radial clearance than normal.
Moreover, there is a slight gap when fitting with the bearing box,
By interposing an elastic body such as rubber between it and the bearing box, even if the orbiting scroll becomes eccentric by more than a predetermined eccentric amount for some reason, parallel movement is allowed due to the gap inside and outside the bearing and the buffering force of the elastic body. Therefore, parallel support can be achieved without causing any inclination between the pin crank and the bearing. Further, on the outer peripheral side of the bearing, no slippage occurs due to the frictional force of the elastic body.

In addition, if the bearing on the orbiting scroll side has a particularly large radial clearance with a JIS clearance symbol of more than C5, this clearance alone will prevent the eccentricity of the orbiting scroll from exceeding the prescribed amount between the bearing and the pin crank. Parallel support is possible without tilting.

〔Example〕

To explain the embodiment shown in FIG. 1, reference numeral 1 denotes a fixed scroll which also serves as a lid, and is connected to a casing 2. Reference numeral 3 denotes a rotating shaft with a crankshaft supported by the casing 2 via bearings 4 and 5, and a crankshaft portion 3a is integrally formed eccentrically at the upper end.

Reference numeral 6 denotes an orbiting scroll fitted onto the crankshaft 3a through a bearing 7, and the lap 6a is meshed with the lap 1a of the fixed scroll 1.

8 is a rotation prevention mechanism for the orbiting scroll 6;
Pin cranks are arranged at multiple equal circumferential positions on the lower surface around the end plate of the orbiting scroll 6 and within the inner wall surface of the casing 2 as a fixed part, and the lower pin part is located at the upper and lower parts.
It is supported by lower ball bearings 9 and 10 to prevent it from falling. In addition, the upper pin part of the pin crank 8 uses a ball bearing 11 with a radial clearance of C3 to C5 in the JIS clearance symbol, which is larger than normal. In addition to fitting with a fit,
An O-ring 1 as an elastic body with a large frictional force such as rubber, which has an annular groove cut in the bearing box side and is fitted into the groove.
2, the bearing 11 is supported such that it can be moved slightly eccentrically.

Although not shown in the drawings, the orbiting scroll 6 also has a sliding member similar to the conventional structure shown with G ₁ and G ₂ in FIG. It's placed in the right place.

Note that 13 is a balance weight, 14 is a bearing holder, and 15 is a bearing member made of a cushioning material such as a spring.

Next, the effect will be explained. Due to the rotation of the rotating shaft 3 with a crankshaft, the orbiting scroll 6 performs an orbiting movement around the rotating shaft 3, thereby causing the lap 1
a and 6a engage to perform a compression action that sequentially compresses the fluid sucked through the suction port 1b and discharges it from the discharge port 1c.

In this case, the orbiting scroll 6 tends to become eccentric by a predetermined amount or more due to centrifugal force, thermal expansion, or the like. On the other hand, the pin crank 8 has two ball bearings 9 and 1.
The orbiting scroll 6 is firmly supported on the casing 2 side to prevent it from falling down due to
A ball bearing 11 with a larger than normal radial clearance (JIS clearance symbol C3 to C6) is provided on the side, and the ball bearing 11 is fitted with a loose fit with a large clearance between it and the orbiting scroll 6, which serves as a bearing box. Since the manufactured O-ring 12 is interposed, even if the orbiting scroll 6 moves eccentrically by more than a predetermined amount,
The clearance between the bearing itself and the fitting clearance allows eccentric movement of the orbiting scroll 6 by a predetermined amount or more, and prevents tilting between the pin crank 8 and the bearing 11.
1 guides the orbiting scroll 6 while maintaining a state parallel to the pin crank 8, so that uneven contact of the bearing does not occur. In addition, the O-ring 12 provided on the outer periphery of the bearing can absorb some impact, and its frictional force also prevents creep on the outer periphery of the bearing.

The above description has been made regarding the first embodiment, but as in the second embodiment shown in FIG. It is also possible to implement the present invention in the same manner, and it is also possible to implement the present invention by using a sliding bearing 211 as the bearing as shown in the third embodiment shown in FIG. In addition, O
Similar effects can be obtained even if a rubber annular band is used in place of the rings 12, 112, 212.

Furthermore, FIG. 5 shows an embodiment of the second invention, in which the orbiting scroll 306 of the pin crank 308
On the side, a sliding bearing 311 with a particularly large radial clearance is used and is press-fitted into the orbiting scroll 306, and the other construction is the same as that of the first embodiment.

In this case, since the bearing uses a sliding bearing, the radial clearance can be particularly large, exceeding the limit that can be manufactured with normal ball bearings or arc bearings.
Therefore, with only the gap between the bearing and the shaft, the O-ring 12 as an elastic body corresponds to the gap obtained by adding the bearing gap and the fitting gap in the case of the first embodiment described above.
It is possible to perform the same parallel guiding action as in the first embodiment without using the same.

〔Effect of the invention〕

In the first aspect of the scroll-type fluid machine according to the present invention, two bearings are used to support the fixed side of the pin crank so that it does not fall down, and the support on the orbiting scroll side is such that the bearing itself has a radial clearance. A larger JIS clearance symbol of C3 to C5 was used, and the fitting with the bearing box was a loose fit with a large clearance, so the orbiting scroll would not be affected by thermal expansion or other factors due to the clearance between the two. Even if the amount of eccentricity exceeds a predetermined amount, the bearing will absorb this and move in parallel, and the parallelism between the shaft and bearing will be maintained, preventing uneven contact or overload. This greatly extends the lifespan. Furthermore, an elastic body such as rubber interposed on the outer periphery of the bearing cushions the impact on the bearing, and also prevents the creep phenomenon of the outer periphery of the bearing due to frictional force. Therefore, generation of vibrations, noise, etc. due to impact or overload can also be prevented.

In addition, in the second invention, since the support on the orbiting scroll side of the pin crank in the first invention is a bearing with a particularly large radial clearance, the same parallel guiding action as in the first invention is performed using only the clearance of the bearing itself. This provides the following effects, and there is no need to use an elastic body such as rubber between the outer periphery of the bearing and the bearing box.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the first invention;
Figure 2 is an enlarged detailed view of the main parts in Figure 1, Figure 3,
Figure 4 shows the second and third parts of the X section in Figure 2.
FIG. 5 is a partial sectional view similar to FIG. 3 showing an embodiment of the second invention, and FIG. 6 is a vertical sectional view showing an embodiment of a conventional configuration. In the figure, 1 is a fixed scroll, 2 is a casing, 3 is a rotating shaft with a crankshaft, 3a is a crankshaft, 6 is an orbiting scroll, 8 is a pin crank,
9 and 10 are upper and lower ball bearings, 11 is a ball bearing, 12
indicates an O-ring.

Claims (1)

[Scope of Claims] 1. In a scroll consisting of a fixed scroll, an orbiting scroll, a rotating shaft with a crankshaft, and a casing, and using a pin crank as a rotation prevention mechanism of the orbiting scroll, the pin crank has two bearings on the fixed side. The bearing on the orbiting scroll side should have a JIS clearance symbol of C3 to C5, which has a larger radial clearance than normal, and should be fitted with the bearing box to prevent the pin crank from falling. 1. A scroll-type fluid machine characterized in that the scroll-type fluid machine is fitted with a mating ring and is supported by interposing an elastic body having a large frictional force such as rubber. 2. The scroll-type fluid machine according to claim 1, wherein a ball bearing is used as the bearing on the orbiting scroll side of the pink crank. 3. The scroll-type fluid machine according to claim 1, wherein a roller bearing is used as the bearing on the orbiting scroll side of the pink crank. 4. The scroll-type fluid machine according to claim 1, wherein a sliding bearing is used as the bearing on the orbiting scroll side of the pink crank. 5. The scroll-type fluid machine according to claim 1, wherein the elastic body has a volume smaller than the volume of the space formed between the bearing box and the bearing. 6. The scroll-type fluid machine according to claim 1, wherein the elastic body is an O-ring. 7. The scroll-type fluid machine according to claim 1, wherein the elastic body is an annular band. 8 In a scroll consisting of a fixed scroll, an orbiting scroll, a rotating shaft with a crankshaft, and a casing, and a pin crank is used as a rotation prevention mechanism of the orbiting scroll, the bearing on the fixed side of the pin crank is supported by two pieces. A scroll-type fluid machine characterized by using a bearing on the orbiting scroll side that has a particularly large radial clearance with a JIS clearance symbol of over C5. 9. The scroll-type fluid machine according to claim 7, wherein a sliding bearing is used as the bearing on the orbiting scroll side of the pink crank.