JP2707296B2 - Scroll type fluid machine - Google Patents

Description

The present invention relates to an improvement in a scroll fluid machine used as a scroll compressor, a scroll vacuum pump, or the like.

[Conventional technology]

FIGS. 2 and 3 show a scroll compressor as a scroll fluid machine according to the prior art.

In the figure, 1 is a casing, 2 is a casing main body of the casing 1, and the casing main body 2 has a cylindrical peripheral wall 2A and a pair of disk-like side walls 2B, 2C opposed to each other via the peripheral wall 2A. Thereby, it is formed in the shape of a hollow container in which the inside becomes the scroll chamber 3. 4 is the casing body 2
A cylindrical one-side bearing portion formed so as to protrude outward from the one-side sidewall portion 2A, and the axis O ₁ -O ₁ of the one-side bearing portion 4 is aligned with the one-side sidewall portion 2A.
Located in the center of. On the other hand, 5 is a cylindrical other-side bearing portion formed so as to protrude outward from the other side wall portion 2B of the casing body 2, and the axis O ₂ -O ₂ of the other-side bearing portion 5 is It is provided at a position eccentric with respect to the axis O ₁ -O ₁ .

A drive shaft 6 is located on the same axis O ₁ -O ₁ as the one-side bearing portion 4 and is rotatably supported by the bearing portion 4 via bearings 7 and 8. One end of the drive shaft 6 is a casing. 1 and is connected to a motor (not shown), and the other end protrudes into the scroll chamber 3 of the casing 1.

Reference numeral 9 denotes a one-side scroll member rotatably provided in the scroll chamber 3 via the drive shaft 6. The one-side scroll member 9 has a rear-side center integrally fixed to the other end of the drive shaft 6. and end plate 9A, erected on spiral near the involute or involute on the front surface of the end plate 9A, a pair of wrap portion 9B facing the axis O ₁ -O ₁ in the radial direction about the drive shaft 6, and 9B It is composed of

On the other hand, 10 is the same axis O _{2 as the} bearing 5 on the other side of the casing 1.
Located in -O _2, a support shaft rotatably supported via a bearing 11, 12 to the bearing portion 5, the axis O ₂ -O ₂ of the support shaft 10 the axis O ₁ -O drive shaft 6 It is eccentric with respect to ₁ by the distance δ.

Reference numeral 13 denotes another scroll member rotatably provided in the scroll chamber 3 via the support shaft 10, and the other scroll member 13 is integrally fixed to the shaft end of the support shaft 10 at the center on the back side, End plate 13 facing end plate 9A of one-side scroll member 9
A, an involute or a spiral near the involute is erected on the front surface of the end plate 13A, and the axis O ₂ −O _{2 of the} support shaft 10 is provided.
A pair of wrap portions 13B, 13B radially facing each other
It is composed of When the one-side scroll member 9 is rotated in a state where the respective wrap portions 13B overlap with the respective wrap portions 9B of the one-side scroll member 9, the two wrap portions
The other scroll portion 13 also rotates due to the friction force of 9B, 13B,
A plurality of compression chambers 14, 14,... Are sequentially formed while the scroll members 9, 13 perform a relative rotational movement.

Reference numeral 15 denotes a suction port, which is formed in the peripheral wall 2A of the casing body 2 so as to communicate with the compression chamber 14 on the outermost peripheral side. On the other hand, reference numeral 16 denotes a discharge port, which is formed in the axial direction from the end plate 13A of the other scroll member 13 to the support shaft 10 so as to communicate with the compression chamber 14 on the most central side.

The prior art is configured as described above, and when the one-side scroll member 9 is rotated by the motor via the drive shaft 6, the other-side scroll member 13 also slides in the same direction, but the rotation centers are eccentric to each other. As a result of the relative rotation of the two scroll members 9, 13, each compression chamber 14 repeatedly expands and contracts, and during this time, air sucked from the suction port 15 is supplied to each compression chamber 14
And is discharged from the discharge port 16.

[Problems to be solved by the invention]

By the way, as described above, the one-side and the other-side scroll members 9 and 13 are rotatably provided with respect to the casing 1, and the other-side scroll member is rotated by the rotation of the one-side scroll member 9 by the frictional force of the wrap portions 9B and 13B. In the case of a scroll compressor in which the rotating part 13 is rotated,
In order to reduce the frictional stress between B and 13B and reduce the wear of each wrap portion 9B and 13B, it is necessary to increase the number of wrap portions 9B and 13B to reduce the pressure angle.

Therefore, as shown in the prior art, two end plates 9A, 13A of the scroll members 9, 13 are provided with a wrap angle pitch of 180 °, and two identical wrap portions 9B, 9B and 13B, 13B are respectively set upright. Further, when the overlapping lap portions 9B, 13B are disposed so as to be located at a position of a half of the lap angle pitch, that is, 90 ° apart in the circumferential direction, the overlapping lap portions 9B, 1B are disposed.
The volumes of the four compression chambers 14, 14,... Formed by 3B are all equal. However, since the four compression chambers 14, 14,... Are repeatedly opened and closed sequentially by the relative rotational movement of the scroll members 9, 13, the center point P of the relative rotational movement of the scroll members 9, 13 is located between them. The volumes of the opposing compression chambers 14, 14 will be different.

As described above, when a plurality of wrap portions 9B and 13B are erected on each of the end plates 9A and 13A in order to reduce the pressure angle of the wrap portions 9B and 13B, the wrap portions 9B and 13B cause point symmetry of the rotation center. It is difficult to mechanically balance the pressure in the compression chambers 14, formed at the positions. As a result, the scroll member
An eccentric load is applied to the bearings 9 and 13, which causes an increase in vibration and a corresponding decrease in the life of the bearings 7, 8, 11, and 12.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described drawbacks of the related art, and provides a scroll-type fluid machine capable of mechanically balancing the pressure in a compression chamber to prevent the occurrence of vibration of a scroll member and a reduction in the life of a bearing. The purpose is to:

[Means for solving the problem]

A feature of the means of the present invention configured to solve the above-described problem is that at least three or more odd-numbered wrap portions are erected on each end plate of the pair of scroll members, and the pair of scroll members are relatively positioned. In this case, the volume of the compression chambers which oppose the center point of the relative rotation among the plurality of compression chambers formed between the wrap portions of the scroll members is made equal.

[Action]

With such a configuration, the odd number of wrap portions erected on each head plate always face the wrap portions erected on the opposing head plate, and the center of the relative rotational movement is placed in the radial direction. Since the volumes of the compression chambers formed at the symmetrical positions are equal, the forces acting on each scroll member in the radial and circumferential directions are extremely small.

〔Example〕

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. The same reference numerals are given to the same components as those of the above-described conventional technology, and the description thereof will be omitted.

In the drawing, reference numeral 21 denotes a one-side scroll member, and the one-side scroll member 21 is integrally fixed to the shaft end of the drive shaft 6 and is a mirror plate.
21A (not shown) and three spiral wrap portions 21B, 21B, 21B erected on the end plate, and the wrap angle pitch of each wrap portion 21B is set to 120 °. Have been.

On the other hand, reference numeral 22 denotes another scroll member facing the one scroll member 21 and rotatably disposed in the scroll chamber 3 of the casing 1, and the other scroll member 22 is a support shaft.
A mirror plate 22A having a back side integrally fixed to the shaft end of the shaft 10; and three spiral wrap portions 22 erected on the front surface of the mirror plate 22A.
B, 22B, 22B, and the wrap angle pitch of each wrap portion 22B is the same as the one-side scroll member 21,
It is 120 °.

Thus, each wrap portion 2 of the two scroll members 21 and 22
When 1B and 21B are overlapped, each wrap portion 21B (22B) always faces the other wrap portion 22B (21B), and a plurality of compression chambers 23 and 22 formed between both scroll members 21 and 22 are formed. Two
Of the three, the compression chambers 23, 23 opposed to each other with the center point P of the relative rotational motion therebetween always have the same volume.

The embodiment is configured as described above, and the operation itself of compressing air in each compression chamber 23 by relatively rotating the one-side scroll member 21 and the other-side scroll member 22 is substantially different from the related art. There is no place.

However, according to the embodiment, each of the scroll members 21 and 22
By forming the odd number of three wrap portions 21B, 21B, 21B and 22B, 22B, 22B on the end plates 21A, 22A of the scroll members 21, a plurality of wrap portions 21B, 22B formed between the scroll members 21, 22 are formed. Compression chamber
Among the compression chambers 23, 23, the rotation centers P of which are opposed to each other.
Since the volume of 3 is equal, the pressure in both compression chambers 23 can be balanced. Therefore, each scroll member
It is possible to prevent imbalanced load from being applied to 21, 22 and the scroll member 2
It is possible to suppress vibrations of 1,22 and improve the life of the bearing.

Further, in the embodiment, since the number of the wrap portions 21B and 22B is larger than that of the prior art, the pressure pulsation and the torque fluctuation can be reduced, and the center of gravity of the wrap portion becomes closer to the theoretical center, so that the balance of the scroll members 21 and 22 is improved. Can be improved.

In the embodiment, it is described that three odd wrap portions 21B, 21B, 21B and 22B, 22B, 22B are erected on each end plate 21A, 22A, but the number of wrap portions is three or more odd numbers. Any number is acceptable. Although the scroll members 21 and 22 of the embodiment are provided rotatably with respect to the casing 1, for example, a scroll type fluid machine in which one scroll member is fixed to the casing and only the other scroll member performs a revolving motion is also available. The present invention is applicable.

〔The invention's effect〕

The present invention is as described in detail above, and among a plurality of compression chambers formed between a pair of scroll members, compression chambers opposed to each other with a center point of relative rotation therebetween are configured to have equal volumes. Since the pressures in the respective compression chambers are balanced, it is possible to prevent the scroll member from vibrating due to an uneven load applied thereto and to prevent the bearing from being unevenly worn, thereby providing a scroll type fluid machine having excellent durability. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing a scroll compressor according to an embodiment of the present invention at the same position as FIG. 3, FIGS. 2 and 3 relate to the prior art, and FIG. 2 is a sectional view of the scroll compressor. FIG. 3 is a sectional view taken along the line III-III in FIG. 1. Casing, 21, 22 Scroll member, 21A, 22A
… End plate, 21B, 22B… Wrap, 23… Compression chamber, P…
…Center point.

Claims (1)

(57) [Claims] 1. A pair of scroll members each having a pair of spirally wrapped portions erected on an end plate facing each other with their axes eccentric, and the pair of scroll members are relatively rotated. In the scroll type fluid machine, a closed space is formed between the wrap portions of the scroll member, and at least three or more odd number wrap portions are erected on each end plate of the pair of scroll members. When the scroll member is relatively rotated, the compression chambers which oppose the center point of the relative rotation among the plurality of compression chambers formed between the wrap portions of both scroll members are configured to have the same volume. A scroll type fluid machine characterized by the above-mentioned.