JPH07189930A - Scroll type fluid machine - Google Patents

Abstract

PURPOSE:To prevent an auxiliary crank from uneven abrasion, by making larger the eccentric distance of the auxiliary crank than that of the driving shaft and canceling the clearance of the rotary bearing resulting from a centrifugal force on rotation in the case of a scroll type fluid machine. CONSTITUTION:The relation of an eccentric distance epsilon in a driving shaft 2 to an eccentric distance epsilon0 in an auxiliary crank 16 is regarded as epsilon0=epsilon+delta/2, (where, delta: radial clearance of rotary bearing 8). In this way, even when the rotary scroll 4 deviates from the center, the eccentric deviation can be absorbed by delta/2 and the uneven abrasion of the auxiliary crank 16 can be prevented and hence, the life of a fluid machine can be prolonged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type fluid machine suitable for use in, for example, an air compressor and a vacuum pump, and more particularly to a scroll type fluid machine provided with an auxiliary crank as a rotation preventing mechanism.

[0002]

2. Description of the Related Art Conventionally, for example, an oil-free scroll type air compressor is provided with a casing and a drive shaft rotatably provided at one end side of the casing and having a tip end side extending into the casing to form a crank portion. And a revolving scroll rotatably provided on the crank portion of the drive shaft via a revolving bearing, and a spiral wrap portion is erected on the end plate, and on the other end side of the casing facing the revolving scroll. A fixed scroll provided on the end plate with a spiral wrap forming a plurality of compression chambers between the wrap and the wrap of the orbiting scroll, and one side shaft rotatably to the fixed scroll or the casing. The auxiliary crank is supported, and the other side shaft portion is rotatably supported by the orbiting scroll, so that the auxiliary crank prevents rotation of the orbiting scroll.

In the above scroll type air compressor, the eccentric amount of the auxiliary crank is set to be substantially the same as the eccentric amount of the drive shaft and the crank portion.

In the scroll type air compressor according to the prior art, when the drive shaft is rotationally driven by a motor or the like, the rotation of the drive shaft is transmitted from the crank portion to the orbiting scroll through the orbiting bearing, and the orbiting scroll is While being prevented from rotating by the auxiliary crank, it revolves around the axis of the drive shaft. The compression chamber formed between the scrolls is continuously reduced by this orbital motion,
As a result, the scroll air compressor is configured to sequentially compress the air sucked from the suction port in each compression chamber and discharge the compressed air from the discharge port to an external air tank or the like.

[0005]

By the way, in the above-mentioned prior art, since the eccentricity amount due to the auxiliary crank and the eccentricity amount due to the crank portion of the drive shaft are the same eccentricity amount, during the rotation of the drive shaft. , Due to centrifugal force and its moment, spread outward by the clearance of the slewing bearing,
The orbiting scroll will revolve at a position larger than the default position. Therefore, there is a problem that a load in the radial direction is applied to the auxiliary crank and a so-called galling phenomenon occurs in the auxiliary crank.

Further, due to the galling phenomenon occurring in the auxiliary crank, the auxiliary crank is worn early to deteriorate the rotational balance, and the one side shaft part and the other side shaft part of the auxiliary crank vibrate like a rubbing motion. There is a problem of causing unstable behavior in the orbiting scroll and promoting uneven wear (galling) of the auxiliary crank and the like.

Further, the auxiliary crank must have sufficient strength to withstand the load applied in the radial direction,
There is a problem that it is large and costly.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a scroll type fluid machine capable of preventing uneven wear of an auxiliary crank.

[0009]

A scroll type fluid machine according to the present invention includes a casing, a drive shaft rotatably provided at one end side of the casing, and a tip end side extending into the casing to form a crank portion. An orbiting scroll that is rotatably provided on a crank portion of the drive shaft via an orbiting bearing, and a spiral wrap portion is erected on an end plate, and is provided on the other end side of the casing facing the orbiting scroll. The
A fixed scroll in which a spiral wrap portion that forms a plurality of compression chambers between the end plate and the wrap portion of the orbiting scroll is erected, and one side shaft portion is rotatably supported by the fixed scroll or the casing. The other side shaft portion is rotatably supported by the orbiting scroll, and is configured by an auxiliary crank that prevents rotation of the orbiting scroll.

The feature of the structure adopted by the present invention to solve the above-mentioned problems is that the eccentric amount of the auxiliary crank is formed to be larger than the eccentric amount of the drive shaft and the crank portion. It has a feature.

Further, the eccentric amount by the auxiliary crank is
It is desirable that the total amount of eccentricity between the drive shaft and the crank portion and approximately half of the radial clearance of the orbiting bearing be added.

[0012]

When the drive shaft rotates, the orbiting scroll eccentrically moves outward by about half the clearance of the orbiting bearing, and the auxiliary crank acts on the auxiliary crank by setting the eccentric amount as described above. The centrifugal force and its moment can be reduced.

Further, the eccentricity of the auxiliary crank is set to a value obtained by adding approximately half the clearance of the slewing bearing to the eccentricity of the drive shaft to more reliably reduce the load applied in the radial direction to the auxiliary crank. be able to.

[0014]

Embodiments of the present invention will be described below with reference to FIGS.

In the figure, reference numeral 1 denotes a casing of a scroll type air compressor formed in a stepped cylindrical shape.
Is a large-diameter tubular portion 1A and a bearing tubular portion 1 formed so that one end side of the large-diameter tubular portion 1A is reduced in diameter and protrudes outward.
B and a reduced diameter portion 1C which is located at an axially intermediate portion of the large diameter tubular portion 1A and is formed so as to reduce in diameter inward, and the other surface side of the reduced diameter portion 1C will be described later. Each auxiliary crank 16
A plurality of (for example, three) accommodating portions 1D, 1D, 1D (only one is shown) in which the fixed side shaft portion 16A and the like are accommodated via the auxiliary crank bearing 17 are formed at predetermined intervals in the circumferential direction. There is.

Reference numeral 2 denotes a drive shaft rotatably provided in the bearing cylinder portion 1B of the casing 1 via a bearing 3, and the drive shaft 2 has its tip end side extended into the large diameter cylinder portion 1A of the casing 1. The crank portion 2A is arranged such that its axis O2-O2 is eccentric with respect to the axis O1-O1 of the drive shaft 2 by an eccentric amount ε. It is held by the orbiting scroll 4 via 8. The base end side of the drive shaft 2 projects outward from the bearing tubular portion 1B, and the projecting end serves as a drive source via a pulley or the like (both not shown).
And is driven to rotate by the electric motor.

Reference numeral 4 denotes an orbiting scroll rotatably provided on the other end side of the casing 1, and the orbiting scroll 4 is generally composed of an orbiting scroll body 5 and a holding plate 6 fixed to the orbiting scroll body 5. Has been done. here,
The orbiting scroll main body 5 is a disk-shaped orbiting side end plate 5A, and a spiral wrap portion 5 is erected on the end plate 5A with the center side as the winding start end and the outer peripheral side as the winding end end.
It consists of B and. Further, the holding plate 6 is fixed to the rear surface side of the end plate 5A by bolts 7, 7, ... (Only one is shown), and a boss portion 6A for holding a slewing bearing 8 in the center and a slewing side shaft of an auxiliary crank 16 described later. The portion 16B is composed of accommodating portions 6B, 6B, 6B which are accommodated via the auxiliary crank bearing 18, and each accommodating portion 6B is formed with an annular ring accommodating groove 6B1 in which an elastic ring 21 is disposed. . Further, between the orbiting scroll body 5 and the holding plate 6,
A plurality of heat dissipating portions 9, 9, ... Are projected from the end plate 5A of the scroll body 5 toward the holding plate 6. Also,
Each of the accommodating portions 6B is located on the outer peripheral side of the boss portion 6A, and is formed, for example, three in the circumferential direction with a predetermined distance therebetween.

The bearing 3 that rotatably holds the drive shaft 2 in the casing 1 is a ball bearing, and the orbiting bearing 8 that rotatably holds the orbiting scroll 4 in the drive shaft 2 is a cylindrical roller bearing. Has been done. Further, since the slewing bearing 8 is a cylindrical roller bearing, radial “rattle” is likely to occur between the inner ring and the outer ring, and the “rattle” is generated.
Is the clearance δ.

Reference numeral 10 denotes a fixed scroll fixedly provided on one end side of the casing 1, and the fixed scroll 10
Is a fixed scroll body 11 and the fixed scroll body 11
The cover 12 is fixed to the above. Here, the fixed scroll body 11 has its center aligned with the axis O1 -O1 of the drive shaft 2 and the end plate 11A disposed facing the end plate 5A of the orbiting scroll 4, and the orbiting scroll from the end plate 11A. The wrap portion 5B of No. 4 and the spiral wrap portion 11B are provided upright. Also,
Between the cover 12 and the end plate 12A, a plurality of heat dissipation portions 13, 13, ... Are formed so as to project from the end plate 12A toward the end cover 12. Further, the wrap portion 12B is disposed so as to overlap with the wrap portion 5B of the orbiting scroll 4 by being shifted by a predetermined angle, so that when the orbiting scroll 4 orbits, the wrap portion 5B is continuous with the wrap portion 5B. A plurality of compression chambers 14, 14, ... The fixed scroll 10 has bolts 15 and 1
, 5 (only two are shown) are fixed to the large-diameter cylindrical portion 1A of the casing 1.

Numerals 16, 16, 16 are located between the reduced-diameter portion 1C of the casing 1 and the orbiting scroll 4, and a plurality of auxiliary cranks (1) as a rotation preventing mechanism are arranged at predetermined intervals in the circumferential direction. As shown in FIG. 2, each auxiliary crank 16 has a large-diameter cylindrical fixed-side shaft portion 16A as one side shaft portion and the other end of the fixed-side shaft portion 16A. It is formed in a stepped columnar shape with a small diameter cylindrical columnar side shaft portion 16B as the other side shaft portion provided on the side.

Here, the amount of eccentricity ε0 due to the axis O3 -O3 of the fixed side shaft portion 16A of the auxiliary crank 16 and the axis O4 -O4 of the turning side shaft portion 16B turns more than the eccentricity amount ε of the drive shaft 2. About half the clearance δ of the bearing 8 (δ /
The value is set larger by 2), that is, ε0 = ε + δ / 2.

Further, the fixed side shaft portion 16A is rotatably fitted in the housing portion 1D of the casing 1 through an auxiliary crank bearing 17 such as a combination ball bearing, and the turning side shaft portion 16B.
Is rotatably fitted in the housing portion 6B of the orbiting scroll 4 via an auxiliary crank bearing 18 such as a combination ball bearing. When the orbiting scroll 4 is orbited by the rotational drive of the drive shaft 2, the orbiting scroll 4 is prevented from rotating on its own axis, and the orbiting scroll 4 is eccentric about the axis O1 -O1 of the drive shaft 2. It guides the robot to revolve with a revolution radius of ε0.

Reference numeral 19 is a suction port formed on the outer peripheral side of the fixed scroll 10, and 20 is an end plate 11A of the fixed scroll 10.
The discharge ports formed on the center side are shown, and the suction port 1
9 communicates with the compression chamber 14 on the outermost peripheral side (the lowest pressure side), and the discharge port 20 communicates with the compression chamber 14 on the most central side (the highest pressure side).

Reference numeral 21 designates a turning side shaft portion 1 of each auxiliary crank 16.
6B shows an elastic ring disposed on the outer peripheral side of the auxiliary crank bearing 18 fitted in 6B and in the ring accommodation groove 6B1 of the accommodation portion 6B. The elastic ring 21 is made of elastic rubber and accommodates the auxiliary crank bearing 18 It is designed to absorb the displacement of the portion 6D in the radial direction.

The scroll type air compressor according to this embodiment has the above-mentioned structure. When the drive shaft 2 is rotationally driven by an electric motor via a pulley or the like, the drive shaft 2 rotates from the crank portion 2A. It is transmitted to the orbiting scroll 4 via the orbiting bearing 8, and the orbiting scroll 4 revolves around the axis O1 -O1 of the drive shaft 2 while preventing rotation by the auxiliary cranks 16.
Then, by this revolution movement, each lap portion 5B, 11B
The compression chambers 14, 14, ... Defined between and are continuously reduced, whereby the scroll air compressor sequentially compresses the air sucked from the suction port 19 in each of the compression chambers 14. At the same time, the compressed air is discharged from the discharge port 20 to an external air tank (not shown) or the like.

Next, the features of the scroll type fluid machine according to this embodiment will be described with reference to FIGS. 3 and 4.

First, FIG. 3 shows the direction of the centrifugal force F associated with the rotation of the crank portion 2A of the drive shaft 2 and the variation of the clearance of the slewing bearing 8. When the drive shaft 2 is stopped, the axis O1 Although the center of the drive shaft 2 is at the position, when the drive shaft 2 is rotated in the direction of arrow A, for example, the centrifugal force F causes the outer circumference of the slewing bearing 8 to be in the direction of the centrifugal force F by a half of the clearance (δ / 2). To the position of the slewing bearing 8 '. As a result, the center of rotation of the drive shaft 2 is apparently the axis O.
It is the same as moving to the 1'position (the position moved by δ / 2). Further, since the centrifugal force F sequentially moves in the radial direction as the drive shaft 2 rotates, the center of rotation when the drive shaft 2 rotates has a radius δ / 2 around the axis O1.
A circular orbit C of (axis O1 ') comes to be drawn. As a result, the orbiting scroll 4 revolves in a state of being eccentrically outward in the radial direction by δ / 2.

FIG. 4 shows the fixed side shaft portion 16A, the turning side shaft portion 16B and the elastic ring 21 of the auxiliary crank 16. Here, the amount of eccentricity ε in the auxiliary crank 16
0 is set to be larger than the eccentricity amount ε of the drive shaft 2 by about δ / 2. Here, when the drive shaft 2 is stopped, the auxiliary crank 16 also does not rotate, and the rotation center of the auxiliary crank 16 is on the axis O3. On the other hand, by rotating the drive shaft 2, the auxiliary crank 16 also rotates in the direction of arrow B, and is eccentric by half the clearance δ of the drive shaft 2, and the eccentric portion is assisted via the orbiting scroll 4 and the auxiliary crank bearing 18. It is transmitted to the turning side shaft portion 16B of the crank 16. And
In the auxiliary crank 16, this eccentricity δ / 2 tends to act on the auxiliary crank 16 as a load in the radial direction, but in the auxiliary crank 16, the eccentricity amount ε0 is set large in advance by the clearance δ / 2 minutes. From
It is possible to absorb half the eccentricity of the clearance δ, and it is possible to reduce the load in the radial direction applied to the auxiliary crank 16.

Further, the elastic ring 21 provided on the outer periphery of the auxiliary crank bearing 18 can absorb the difference in the amount of eccentricity by elastically deforming by the clearance δ / 2 when the drive shaft 2 is stopped, and at the time of start-up. Is also appropriately elastically deformed to reduce the load applied to the auxiliary crank 16.

However, in the scroll type air compressor according to the present embodiment, when the drive shaft 2 rotates, the orbiting scroll 4 is caused by the centrifugal force and its moment to cause the orbiting bearing 8 to rotate.
It expands outward by a clearance of δ. However, in the auxiliary crank 16 according to the present embodiment, the eccentricity amount ε0 between the fixed side shaft portion 16A and the turning side shaft portion 16B is set to be larger than the eccentricity amount ε of the drive shaft 2 by δ / 2.
It is possible to surely reduce the load applied to 6 in the radial direction,
The galling phenomenon of the auxiliary crank 16 can be reduced.

Further, the turning side shaft portion 16 of the auxiliary crank 16
Since the elastic ring 21 is provided on the outer periphery of the auxiliary crank bearing 18 that holds B to absorb the positional deviation, the difference in the eccentricity amount of δ / 2 can be absorbed when the drive shaft 2 is stopped.

Furthermore, by preventing the galling phenomenon which occurs in the auxiliary crank 16, it is possible to prevent the auxiliary crank 16 from prematurely wearing and deteriorating the rotational balance of the orbiting scroll 4, and the life of the orbiting scroll type air compressor. Can be effectively extended.

Moreover, the strength with respect to the auxiliary crank 16 can be reduced by surely preventing the galling phenomenon.

In the above embodiment, the auxiliary crank 16
The eccentricity amount ε 0 due to eccentricity due to the drive shaft 2 is set to be larger than the eccentricity amount ε due to the drive shaft 2 by a half of the radial clearance δ of the slewing bearing 8 that supports the drive shaft 2. Even if the amount ε 0 is slightly larger than the eccentric amount ε due to the drive shaft 2, it is possible to obtain substantially the same action and effect as in the embodiment, and it is preferable that the amount is within half of the radial clearance.

[0035]

As described above in detail, according to the present invention, since the eccentric amount of the auxiliary crank is formed to be larger than the eccentric amount of the drive shaft and the crank portion, when the drive shaft is rotating. In addition, it is possible to reduce the radial load applied to the auxiliary crank and reduce the galling phenomenon in the auxiliary crank.

Further, by making the eccentricity of the auxiliary crank larger than the eccentricity of the drive shaft by about half the radial clearance of the orbiting bearing connecting the orbiting scroll and the drive shaft, the auxiliary crank is rotated when the drive shaft rotates. The load in the radial direction that acts on the
The galling phenomenon of the auxiliary crank can be further reduced, and the life of the scroll fluid machine can be reliably extended.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a scroll air compressor according to this embodiment.

FIG. 2 is an enlarged vertical sectional view showing an auxiliary crank in FIG.

FIG. 3 is an explanatory diagram showing movements of a crank portion and a slewing bearing in a drive shaft.

FIG. 4 is an explanatory view showing movements of a fixed side shaft portion and a turning side shaft portion in the auxiliary crank.

[Explanation of symbols]

 1 casing 2 drive shaft 2A crank part 4 orbiting scroll 5A end plate 5B wrap part 8 orbiting bearing 10 fixed scroll 11A end plate 11B wrap part 14 compression chamber 16 auxiliary crank 16A fixed side shaft part (one side shaft part) 16B orbiting side shaft part ( 21) Elastic ring ε Eccentricity due to the drive shaft ε0 Eccentricity due to the auxiliary crank δ Radial clearance

Claims (2)

[Claims] 1. A casing, a drive shaft rotatably provided at one end side of the casing, and a tip end side extending into the casing to form a crank portion, and a crank bearing of the drive shaft through a swing bearing. An orbiting scroll that is provided so as to be rotatable, and a spiral wrap portion is erected on the end plate, and is provided on the other end side of the casing facing the orbiting scroll.
A fixed scroll in which a spiral wrap portion that forms a plurality of compression chambers between the end plate and the wrap portion of the orbiting scroll is erected, and one side shaft portion is rotatably supported by the fixed scroll or the casing. In a scroll fluid machine including an auxiliary crank that prevents the orbiting scroll from rotating on its axis, the other side shaft portion is rotatably supported by the orbiting scroll. A scroll-type fluid machine characterized in that it is formed so as to have a larger eccentricity with respect to the portion. 2. The scroll fluid according to claim 1, wherein the eccentric amount by the auxiliary crank is a value obtained by adding the eccentric amount between the drive shaft and the crank portion and substantially half of the radial clearance by the slewing bearing. machine.