JP2002089464A - Scroll type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll type compressor wherein machinability of a movable scroll member is improved by aligning a central axis of a drive part of the movable scroll member with a central axis of an end plate part of the movable scroll member. SOLUTION: In this compressor, the central axis of a boss part that is the drive part of the movable scroll member 4 is aligned with the central axis of the end plate part 4b to form an axis O'. The axis O' is eccentric to an axis O of a shaft 2 by a revolution radius R of the movable scroll member 4. A basic circle central axis Os' of a blade part 4a is positioned apart from the axis O' by R/2 to a direction opposite to a final end part of the blade part 4a. A central axis of a rear housing 6 and a central axis of an end plate 7b of a fixed scroll member 7 are aligned with the axis O of the shaft 2 to form the axis O. A central axis Os of a basic circle of a blade part 7a is positioned apart from the axis O by R/2 to a direction of a final end part of the blade part 7a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type compressor, and is effective for use in, for example, a refrigerant compressor of a refrigeration cycle.

[0002]

2. Description of the Related Art A conventional scroll type compressor has a central axis of a housing, a central axis of a disk-shaped end plate portion of a fixed scroll member, and a spiral blade of the fixed scroll member because of its ease of design. The central axes of the base circles of the sections are designed to coincide. The center axis of the disc-shaped end plate portion of the movable scroll member and the center axis of the base circle of the spiral blade portion of the movable scroll member are positioned at a predetermined distance that is the orbital radius of the movable scroll member from these axis positions. , And the center axis of the drive unit is set to coincide. Since such a configuration is made only for ease of design, the radial dimension of the housing,
That is, no consideration is given to reducing the body diameter of the compressor.

In order to reduce the diameter of the compressor body, it has been proposed to offset the center axis of the end plate of the movable scroll member in the direction in which the spiral blade of the movable scroll member ends winding. That is, as shown in FIG. 5, in this compressor, the central axis O 'of the drive portion 24c of the movable scroll member 24 and the central axis of the base circle of the spiral blade portion 24a are aligned, and the central axis O' The center axis T of the end plate portion 24b of the movable scroll member 24 is set at a position eccentric by a predetermined amount.

[0004]

However, in the above-described compressor, since the center axis T of the end plate portion 24b of the movable scroll member 24 and the center axis O 'of the drive portion 24c are eccentric, the movable scroll member is not eccentric. When processing the end plate portion 24b and the drive portion 24c of the 24, it is necessary to set the respective axes T and O 'for cutting, and a great deal of time and labor is required for precision processing.

The present invention has been made in view of the problems existing in the prior art described above, and has as its object to provide a center axis of a driving portion of a movable scroll member and a center axis of an end plate portion of the movable scroll member. It is an object of the present invention to provide a scroll compressor capable of improving the workability of a movable scroll member by making the same.

[0006]

To achieve the above object, according to the first aspect of the present invention, a housing forming an outer frame;
A shaft rotatably supported by the housing and having a crank portion eccentric to an axis, a fixed scroll member fixed to the housing and having a spiral blade portion and an end plate portion supporting the blade portion; A movable scroll member rotatably disposed in the housing, the movable scroll member having a spiral blade portion and an end plate portion supporting the blade portion, disposed to face the fixed scroll member, and rotated. The movable scroll member is formed between the two scroll members and a movable scroll member rotatably fitted with a drive unit to the crank portion so as to perform the revolving motion while preventing the spiral movement. A scroll type compressor having a plurality of compression chambers configured so that the volume is gradually reduced from the outer peripheral side to the center side of the blade-shaped blade portion. The center axis of the drive unit of the movable scroll member is coincident with the center axis of the end plate of the movable scroll member, and the base circle center axis of the blade of the movable scroll member is aligned with the end plate of the movable scroll member. The gist is that it is deviated from the central axis of. According to the present invention, by making the center axis of the drive section of the movable scroll member coincide with the center axis of the end plate section, the drive section and the end plate section can be processed with the same axis.

According to a second aspect of the present invention, in the scroll type compressor according to the first aspect, the center axis of the base circle of the blade portion of the movable scroll member is shifted from the center axis of the end plate portion of the movable scroll member. The gist is that the movable scroll member is shifted in the opposite direction from the final end of the blade portion. According to this invention, in addition to the effect of the first aspect, the outer diameter of the end plate portion of the movable scroll member can be reduced by shifting the center axis of the base circle of the movable scroll member in a predetermined direction. The inner diameter of the housing can be reduced as the diameter of the end plate is reduced.

According to a third aspect of the present invention, in the scroll compressor according to the second aspect, the axis of the crank portion is shifted from the axis of the shaft by the distance of the orbital radius of the revolving motion, and the blade of the movable scroll member is moved. The base circle center axis of the movable scroll member from the center axis of the end plate portion of the movable scroll member in a direction opposite to the final end of the blade portion of the movable scroll member by a distance of 1/2 of the orbital radius. Stagger,
The center axis of the end plate portion of the fixed scroll member and the center axis of the housing coincide with the axis of the shaft, and the base circle center axis of the blade portion of the fixed scroll member is aligned with the end plate portion of the fixed scroll member. From the central axis,
The gist of the invention is that the fixed scroll member is shifted toward the final end of the blade by a distance of 1/2 of the orbital radius. According to the present invention, the outer diameter of the end plate portion of the movable scroll member can be minimized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, bearings 101 and 102 are fixed to a front housing 1 made of, for example, an aluminum alloy. A shaft 2 made of hardened steel or the like is rotatably supported by the bearings 101 and 102, and the shaft 2 is rotated by power from an engine via a belt, an electromagnetic clutch, and the like (not shown).

The front housing 1 has a sealing member 1 for sealing a refrigerant that is leaking along the shaft 2.
03 is fitted. A concave crank portion 2a is formed on the shaft 2 at a position eccentric with respect to its axis by a predetermined amount, and the bearing 3 is fixed. The movable scroll member 4 is formed on the spiral blade 4a, the end plate 4b supporting the blade 4a, and the end plate 4b on the side opposite to the blade 4a, and is formed on the axis of the base circle of the blade 4a. On the other hand, a boss portion 4c as a drive portion which is eccentric by a predetermined amount is provided. Then, the movable scroll member 4 is fitted to the bearing 3 by fitting the boss portion 4 c to the bearing 3.
And can revolve as the shaft 2 rotates.

Between the front housing 1 and the movable scroll member 4, there is provided, for example, a ball-coupling-type rotation preventing mechanism 5 for preventing the movable scroll member 4 from rotating. A rear housing 6 fixed to the front housing 1 by bolts or the like includes a spiral blade 7a having the same or substantially the same shape as the blade 4a of the movable scroll member 4, and an end plate 7b supporting the blade 7a. Is fixed by bolts or the like in a posture facing the movable scroll member 4.

The end plate 7 of the fixed scroll member 7
b, the movable scroll member 4 and the fixed scroll member 7
The refrigerant compressed in the compression chamber 8 formed by the discharge port 71 b is discharged into the discharge chamber 9 formed by the end plate portion 7 b of the fixed scroll member 7 and the rear housing 6.
Is open. The discharged refrigerant is discharged from the discharge port 71b.
A check valve 10 is provided to prevent the gas from flowing back into the compression chamber 8 through the air passage.

The rear housing 6 has a suction port 6a communicating with a suction chamber 11 formed by the front housing 1, the rear housing 6, and an end plate 7b of the fixed scroll member 7, and a discharge port communicating with the discharge chamber 9. 6b are respectively opened so that refrigerant can be sucked and discharged. Next, the main configuration of the compressor having the above configuration will be described.

Generally, in a scroll compressor, in order to reduce the body diameter of the compressor, the center axis of the end plate portion 4b of the movable scroll member 4 is set with respect to the center axis of the base circle of the spiral blade portion 4a. Thus, the blade 4a drifts in the direction of the final end of the spiral. However, in this type of compressor, the end plate 4
Since the central axis of b does not coincide with the central axis of the boss 4c, the workability of the movable scroll member 4 is sacrificed. Therefore, the present invention employs the following configuration.

The axis of the crank 2a is eccentric from the axis O of the shaft 2 by R. The orbital radius R of the movable scroll member 4 is determined by the pitch P and the thickness t of the blades 4a and 7a, and R = (P / 2) so as to seal the line contact portion between the blades 4a and 7a. −t. Note that the crank portion 2a described in the present embodiment
Is the axis of the crank 2 in which the boss 4c is inserted.
The axis of the recessed part a is shown.

First, the movable scroll member 4 will be described with reference to FIGS. Since the axis of the crank portion 2a coincides with the center axis O ′ of the boss 4c as the driving portion of the movable scroll member 4, the center axis O ′ of the boss 4c of the movable scroll member 4 is the axis of the shaft 2. O
, The eccentric position of the movable scroll member 4 is R. Also, the central axis O 'of the boss 4c.
Are formed so as to coincide with the center axis of the end plate portion 4b. That is, the axis of the crank 2a, the center axis of the boss 4c, and the center axis of the end plate 4b are on the same axis O '. The base circle center axis Os' of the blade portion 4a of the movable scroll member 4 is defined by the center axis line O 'of the end plate portion 4b of the movable scroll member 4, that is, the center axis line O' of the boss portion 4c. It is located R / 2 away from the last end in the opposite direction. That is, as shown in FIG. 2, the center axis O 'of the boss 4c, the axis O of the shaft 2 and the blade 4
In the state where the base circle center axis Os' of a is aligned, the axis Os' is located exactly halfway between the axis O 'and the axis O.

Next, the fixed scroll member 7 will be described with reference to FIG.
Since b is fitted along the inner peripheral wall of the rear housing 6, the center axis of the rear housing 6 and the center axis of the end plate portion 7b coincide with each other. The center axis Os of the base circle of the blade 7a is located at a distance of R / 2 from the center axis of the end plate 7b toward the final end of the blade 7a.

The axis O of the shaft 2 coincides with the center axis of the end plate 7b of the fixed scroll member 7.
That is, the axis of the shaft 2, the center axis of the rear housing 6, and the center axis of the end plate 7b are on the same axis O. Also,
The axis O of the shaft 2 coincides not only with the center axis of the rear housing 6 but also with the center axis of the front housing 1. More specifically, the axis O is the axis of the peripheral surface of the front housing 1 with which the bearings 101 and 102 and the seal member 103 fitted to the main shaft 2 are in contact, and the end plate portion 4b.
The inner peripheral wall of the rear housing 6 into which the end plate portion 7b is fitted and the axis of the peripheral surface of the rear housing 6 which slides or opposes coincide with each other.

Further, the end plate portion 7b of the fixed scroll member 7
Is (m + R) obtained by adding the orbital radius R of the movable scroll member 4 when the radius of the end plate portion 4b of the movable scroll member 4 is m. That is, the diameter of the end plate portion 7b of the fixed scroll member 7 is (2m + 2R). As described above, since the end plate portion 7b of the fixed scroll member 7 is fitted along the inner peripheral wall of the rear housing 6, the inner diameter of the rear housing 6 is equal to that of the end plate portion 7b of the fixed scroll member 7. It is the same as the diameter (2m + 2R).

As described above, the positional relationship between the end plate portion 4b of the movable scroll member 4 and the blade portion 4a is formed in consideration of the body diameter of the compressor in the same manner as in the prior art, and the end plate portion 4b of the movable scroll member 4 is formed. By aligning the center axis with the center axis O ′ of the boss 4c, the inner diameter of the housing of the scroll compressor, that is, the body diameter of the compressor is kept small as before, and the workability of the movable scroll member 4 is improved. be able to.

In the scroll compressor, a compression chamber 8 formed between the fixed scroll member 7 and the movable scroll member 4 based on the revolution of the movable scroll member 4.
Of the fluid in the compression chamber 8 acts on the movable scroll member 4. Due to the compression reaction force, a moment is generated around the central axis O ′ of the boss 4c, and the movable scroll member 4 tends to rotate around the central axis O ′ of the boss 4c.

Further, the centrifugal force generated by the revolution of the movable scroll member 4 is always applied to the shaft 2 which is the center of the orbit.
Acts in the centrifugal direction from the axis O of Due to the setting of the center of gravity of the movable scroll member 4, a moment due to centrifugal force is generated around the central axis O 'of the boss 4c, and the movable scroll member 4 tends to rotate around the central axis O' of the boss 4c.

As a method for canceling the moment due to the centrifugal force and the moment due to the compression reaction force, for example, a method disclosed in Japanese Patent Application Laid-Open No. Hei 8-247051 is generally used. In the present embodiment, the movable scroll member 4
And the central axis O 'of the boss 4c.
And the center axis Os 'of the end plate portion 4b is shifted by R / 2 with respect to the axis O', so that the movable scroll member 4 is heavily biased.
Therefore, as shown in FIG. 3, a movable scroll member is formed by forming a cutout 4d on the boss 4c side of the end plate portion 4b so that the moment due to the compression reaction force is offset as much as possible by the moment due to the centrifugal force. 4, the center of gravity is set.

The present embodiment having the above configuration has the following effects.

(1) End plate 4b of movable scroll member 4
And the central axis O ′ of the boss 4c coincides. The end plate portion 4b and the boss portion 4c have a perfect circular cross section when viewed from the axial direction, so that the processing can be easily performed when the axial lines coincide with each other.

(2) Due to the position of each axis of the movable scroll member 4 and the fixed scroll member 7 described in the embodiment, the inner diameter of the housing is reduced to the diameter of 2 m of the movable scroll member 4 and the movable scroll member 4 as in the prior art. (2m + 2R), which is the small diameter.

(3) Center axis of housing and shaft 2
And the axis O coincides. Therefore, in processing the inner peripheral surface of the housing, the inner peripheral surface of the housing where the end plate portion 4b slides or opposes, and the inner peripheral surface of the housing where the bearings 101 and 102 and the sealing material 103 abut are aligned with the same axis. It can be worked with. As described above, since the peripheral surfaces at a plurality of locations inside the housing are constituted by one axis, precision machining of the peripheral surface inside the housing can be performed quickly and easily.

(4) By forming a cutout 4d on the boss 4c side of the movable scroll member 4, the center of gravity of the movable scroll member 4 is set so that the moment due to the compression reaction force is offset as much as possible by the moment due to the centrifugal force. Has been set. This makes it difficult for the movable scroll member 4 to rotate around the central axis O ′ of the boss 4c, which is the drive center, when the compressor moves.

The present invention can be carried out in the following manner without departing from the spirit of the present invention.

A motor or the like may be used instead of the engine as the drive source.

The blades 4a, 7a in this specification
Is not strictly limited to the tips of the blades 4a, 7a. For example, as shown in FIG.
In the compressor in which the wall thickness near the outermost peripheral ends of the b and 7b is gradually reduced, the final ends of the blades 4a and 7a are the outermost peripheral ends of the end plates 4b and 7b. A portion where the wall thickness in the vicinity is gradually reduced, in other words, the blade portion 4
The outer walls near the outermost distal end of the end plates 4b, 7b
And a portion constituting the same peripheral surface as that of the outer peripheral surface. In FIG. 4, in order to clarify the distinction between the blade portions 4a and 7a, the blade portion 4a is indicated by a dashed line, and the blade portion 7a is indicated by a dotted line.

[0033]

According to the present invention having the above structure, the workability of the movable scroll member can be improved.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a scroll compressor according to an embodiment.

FIG. 2 is a schematic diagram showing a center or an axis of each part of a movable scroll member and a fixed scroll member.

FIG. 3 is a perspective view of a movable scroll member of the compressor.

FIG. 4 is a schematic diagram showing a movable scroll member and a fixed scroll member of a compressor according to another embodiment.

FIG. 5 is a perspective view of a movable scroll member of a conventional compressor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Front housing, 2 ... Shaft, 2a ... Crank part, 4 ... Movable scroll member, 4a ... Blade part, 4b ...
End plate portion, 4c: Boss portion as drive portion, 4d: Notch portion, 6: Rear housing, 7: Fixed scroll member, 7
a: blade, 7b: end plate, 8: compression chamber, O: axis of shaft, Os: center axis of base circle of blade of fixed scroll member, O ': center axis of drive unit of movable scroll member, Os '... the center axis of the base circle of the blade portion of the movable scroll member, R ... the radius of revolution.

Claims (3)

[Claims] 1. A housing forming an outer frame, a shaft rotatably supported by the housing and having a crank portion eccentric with respect to an axis, a spiral blade fixed to the housing, and the spiral blade and the blade A fixed scroll member having an end plate portion for supporting the portion, a movable scroll member rotatably disposed in the housing, comprising a spiral blade portion and an end plate portion for supporting the blade portion, A movable scroll member disposed opposite to the fixed scroll member and having a drive unit rotatably fitted to the crank unit so as to perform a revolving motion while preventing rotation;
And a plurality of compression chambers formed between the two scroll members and configured such that the volume gradually decreases from the outer peripheral side to the center side of the spiral blade portion by the revolving motion of the movable scroll member. In the scroll compressor, the center axis of the drive unit of the movable scroll member is
The center axis of the end plate portion of the movable scroll member coincides with the center axis of the blade portion of the movable scroll member, and the center axis of the base circle of the movable scroll member is offset from the center axis of the end plate portion of the movable scroll member. Scroll compressor. 2. A base circle center axis of a blade portion of the movable scroll member is directed in a direction opposite to a final axis of a blade portion of the movable scroll member from a center axis of an end plate portion of the movable scroll member. The scroll compressor according to claim 1, wherein the scroll compressor is shifted. 3. An axis of the crank portion is shifted from an axis of the shaft by a distance of an orbital radius of the revolving motion,
The base circle center axis of the blade portion of the movable scroll member is shifted from the center axis line of the end plate portion of the movable scroll member in a direction opposite to the final end portion of the blade portion of the movable scroll member. The center axis of the end plate portion of the fixed scroll member and the center axis of the housing coincide with the axis of the shaft, and the center axis of the base circle of the blade portion of the fixed scroll member is 3. The fixed scroll member according to claim 2, wherein the end of the fixed scroll member is displaced from the center axis of the fixed scroll member toward the final end of the blade of the fixed scroll member by a distance equal to a half of the orbital radius. Scroll type compressor.