JPH0642473A - Scroll type fluid machinery - Google Patents

Abstract

PURPOSE:To suppress the rotation of a movable scroll member with high precision by the simple structure and reduce the power loss, abrasion, etc., due to the sliding friction of an Oldham's coupling. CONSTITUTION:As for a rotation preventing mechanism such as Oldham's coupling which is used fur allowing only revolution by suppressing the rotation of the movable scroll member of the scroll type fluid machinery such as scroll compressor, when the dynamic loss due to friction and the abrasion are reduced by removing a slidable part, a key 12c formed on a retainer ring 12 is engaged with the groove part 11a of a movable race 11 installed on the movable scroll member, and a recess 11b is formed at the engagement part, and a ball 14 which rolls inside is interposed, and the direct side contact between the key 12c and the groove part 11a is prevented, and the friction is reduced, and also the slip-off of the ball 14 is prevented.

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 such as a scroll compressor or a scroll expander, and more particularly to a rotation preventing mechanism which allows the movable scroll member of the scroll type fluid machine to revolve and prevent rotation thereof. Regarding

[0002]

2. Description of the Related Art In a scroll type fluid machine such as a scroll compressor, a rotation preventing mechanism for preventing rotation of a movable scroll member has a highly accurate rotation preventing function and power loss due to sliding friction. Is desired to be small.

As a typical one of the conventional rotation preventing mechanisms used for this purpose, the Oldham coupling as used in Japanese Patent Laid-Open No. 55-81296 is well known. Since it has a sliding friction portion between flat surfaces, it is indispensable to lubricate the sliding surface by a method such as supplying lubricating oil. Further, since the sliding surface is formed on the fitting surface of the groove and the key, when they are relatively inclined, sliding friction is greatly increased, power loss is increased, and wear of the sliding portion is increased. Increase.

In order to reduce the friction of the sliding surface of the Oldham coupling, in the scroll type fluid machine described in JP-A-1-262392, a rotation preventing mechanism using a sliding pin has been proposed. However, even in this mechanism, a considerable amount of sliding friction is generated in the sliding portion of the pin, and the structure is considerably complicated as compared with an ordinary Oldham coupling. Therefore, not only the cost problem and the production technology problem occur, but also another problem that the mass of the moving part increases due to the size increase of the mechanism occurs.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above problems of the prior art, prevents rotation of the movable scroll member with high accuracy, and eliminates the sliding portion, thereby eliminating the conventional Oldham coupling. It is an object of the present invention to reduce power loss due to sliding friction and wear of a sliding portion, which are found in a rotation preventing mechanism such as.

[0006]

As a means for solving the above-mentioned problems, the present invention provides a fixed scroll member having a spiral blade and fixed in a housing, and the fixed scroll member having the spiral shape. A movable scroll member that has a spiral blade that meshes with the blade and that is driven so as to only revolve, and a rotation prevention mechanism that prevents rotation of the movable scroll member and allows only revolution.
The rotation preventing mechanism includes a movable race integrated with the movable scroll member, a fixed race fixed in the housing, and a retainer ring interposed between the movable race and the fixed race. The engaging portion between the retainer ring and the movable race and / or the fixed race has a structure in which a key axially protruding from one of them is inserted into a groove formed in the other. Moreover, the key and the groove are not in direct sliding contact with each other, the rolling member is interposed between them, and a means for preventing the rolling member from escaping from the groove is also provided. A scroll type fluid machine characterized by being provided.

[0007]

In the conventional rotation preventing mechanism of the scroll type fluid machine, sliding friction occurs between the key and the groove portion receiving the key like the Oldham coupling. However, in the rotation preventing mechanism of the scroll type fluid machine of the present invention, Since the rolling member is interposed in this portion, friction is much smaller than that in the case of sliding, so that power loss and wear can be reduced. Moreover, since the rolling member is held by the escape prevention means, troubles due to the escape of the rolling member can be avoided. Accurate operation of the rotation prevention mechanism causes the scroll-shaped blades of the scroll member to come into contact with each other and wear, or an excessive gap is generated between them to cause compressed fluid to leak from the gap to the low pressure side. It is also possible to prevent the efficiency of the scroll type fluid machine from being lowered.

[0008]

FIG. 1 shows an embodiment in which the scroll type fluid machine of the present invention is applied to a non-lubricated scroll compressor 1 for air compression of an air suspension device for an automobile. Scroll compressors have the characteristics of smooth rotation and low operating noise, but on the other hand, when the rotation prevention mechanism and scroll members are low in accuracy, the spiral blades of the two scroll members are radial or axial. Since the blade surface of the two scroll members and the end surface of the blade are worn by contact with the blades, if a large radial or axial gap is provided between the scroll members in order to avoid contact between the blades of the two scroll members. However, there is also a drawback that the fluid compressed in the crescent-shaped space formed between them leaks to the low pressure side, and the efficiency of the entire compressor is likely to decrease. Therefore, it is required that the rotation preventing mechanism has high manufacturing accuracy and operation accuracy.

The scroll compressor 1 shown in FIG. 1 mainly includes a fixed scroll member 3 fixed to the housing body 2 and forming a part of the housing, and a prime mover such as an electric motor 4 (even in a hydraulic motor, an internal combustion engine or the like). Eccentric wheel 6 provided with a balance weight attached to the shaft end of the drive shaft 5 to rotate, a movable scroll member 7 driven by the eccentric wheel 6, and an orbit of the movable scroll member 7 when driven. It is composed of a rotation preventing mechanism 8 which allows only the rotation and prevents the rotation.

The fixed scroll member 3 and the movable scroll member 7 are provided with spiral-shaped blades 3a and 7a having substantially the same shape, and they have the same length (height) in the axial direction. . And, by supporting them in such a manner that they are relatively out of phase and eccentrically engaged with each other, the crescent-shaped space for compressing the fluid between the blades is at least one.
Form more than one.

In the illustrated embodiment, the movable scroll member 7
Is integrally provided with a short driven shaft 7c projecting in the axial direction at the center behind the disk-shaped side plate 7b to which the spiral blades 7a are attached, and the driven shaft 7c includes the eccentric wheel 6c. Is inserted into a circular eccentric opening 6a, which is open in the axial direction at a position eccentric to the drive shaft 5, inside, to be relatively rotatable via, for example, a needle bearing 9 or the like. However, the structure of this portion is such that a crankshaft portion is formed at the shaft end of the drive shaft 5, and the crankshaft portion is formed in the opening of the driven sleeve formed by projecting the crankshaft portion in the axial direction at the center behind the side plate 7b of the movable scroll member 7. Needless to say, they may be replaced by an equivalent structure such as being rotatably inserted via a needle bearing or the like.

The rotation preventing mechanism 8 includes a fixed race 10 which is integrally attached to the housing body 2, and a movable race 11 which is integrally attached to an annular step portion formed on the back surface of the side plate 7b of the movable scroll member 7. The retainer ring 12 interposed between the two races is provided in a position parallel to each other. The fixed race 10 and the movable race 11 are made of a hard material such as bearing steel, and sandwich a plurality of thrust balls 13 between the surfaces facing each other. As shown in FIG. 3, the retainer ring 12 has a hole 12a having an inner diameter slightly larger than the diameter of the thrust ball 13, in which the thrust ball 13 can roll, but The thrust ball 13 holds the races 10 and 11 so as not to fall out of a predetermined range on the surfaces thereof. With this structure, the movable race 11 can maintain a fixed distance with respect to the fixed race 10 even when an axial force is applied, and the parallelism of the movable scroll member 7 with respect to the fixed scroll member 3 is maintained.

The retainer ring 12 faces a pair of keys 12b, which are radial projections projecting axially toward the fixed race 10 from the surface facing the fixed race 10, and the movable race 11 which is the back surface thereof. A pair of keys 12c that are ridges in the radial direction that project in the axial direction toward the movable race 11 from the surface. The keys 12b and 12c are provided in directions perpendicular to each other,
Each has a constant width in the circumferential direction.

As clearly shown in FIG. 2, a groove 11a in the radial direction is cut on the surface of the movable race 11 facing the retainer ring 12 so as to receive the key 12c of the retainer ring 12, and the groove 11a is formed. Grooves are also formed in the both side walls of the to form groove-shaped depressions 11b in the radial direction. The recess 11b has inner and outer end walls in the radial direction, and accommodates one or two small balls 14 therein, thereby holding the key 12c of the retainer ring 12. Ball 1
4 is for reducing the friction between the groove 11a or the depression 11b and the key 12c, but since the depression 11b has end walls radially inside and outside, the ball 14 is within the range of the narrow depression 11b. Although it can roll with, it cannot escape from the recess 11b.

Although not shown in the drawings because of the similar structure, grooves and depressions are formed on the surface of the fixed race 10 facing the retainer ring 12 in the same manner as described above. That is, the fixed race 10 also has a radial groove portion similar to the groove portion 11a for receiving the key 12b protruding in the axial direction from the retainer ring 12, and a radial groove shape similar to the recess portion 11b formed by further engraving the groove portion. And the depressions are formed. However, it is needless to say that the grooves and the depressions support the key 12b, so that they are formed in the direction perpendicular to the grooves 11a and the depressions 11b. In addition, a small ball that is rollable like the ball 14 is inserted between the recess and the key 12b,
It reduces the friction between them.

The space 15 in the housing shown in FIG.
Is a suction chamber of the scroll compressor 1, and a fluid to be compressed such as air is sucked into the suction chamber 15 through a suction port and a suction valve (not shown). A discharge port 16 that communicates with the outside is formed in the center of the spiral blade 3a of the fixed scroll member 3, and a discharge valve 17 that automatically opens and closes the discharge port 16 is provided. In addition,
In the above description, rolling antifriction means such as balls 14 are provided on both surfaces of the keys 12b and 12c, but in some cases, only one surface in the rotational direction of the keys 12b and 12c is provided. Even if the ball 14 is provided, a sufficient effect may be obtained in some cases.

Since the embodiment of the scroll compressor 1 shown in FIGS. 1 to 3 has the structure as described above, when the drive shaft 5 and the eccentric wheel 6 are rotationally driven by the rotation of the electric motor 4,
The driven shaft 7c of the movable scroll member 7, which is eccentric to the drive shaft 5, tends to rotate via the needle bearing 9, but the movable scroll member 7 is prevented from rotating by the rotation preventing mechanism 8. It will only revolve around the drive shaft 5. Thereby, as long as the rotation direction of the drive shaft 5 is selected so as to be adapted to the scroll compressor 1, between the spiral blade 3a of the fixed scroll member 3 and the spiral blade 7a of the movable scroll member 7. The crescent-shaped space that is formed is defined by both scroll members 3,
It will gradually move from the outer peripheral portion of 7 toward the center.

A crescent-shaped space is formed on both scroll members 3, 7.
When it was opened in the suction chamber 15 at the outer peripheral part of
The low-pressure fluid such as air taken into the crescent-shaped space from the suction chamber 15 closes the crescent-shaped space and gradually moves toward the center from the outer peripheral portions of both scroll members 3 and 7 when the volume of the space is increased. Is compressed by being continuously reduced, so that the fluid compressed from the central portions of the scroll members 3, 7 pushes the discharge valve 17 open and is discharged to the outside through the discharge port 16.

On the contrary, when the fluid pressurized from the outside through the discharge port 16 is supplied to the central portions of the scroll members 3 and 7, the fluid expands the crescent-shaped space and the scroll members 3 , 7, the scroll compressor 1 operates as an expander and becomes a kind of prime mover although the rotation directions are opposite. The basic operation of such a scroll type fluid machine is the same as that of the prior art in each of the embodiments of the present invention, and the present invention is not characterized in this respect.

In the above-mentioned operation, the movable scroll member 7 is driven so as to accurately revolve with respect to the stationary fixed scroll member 3, and unless the movable scroll member 7 is completely prevented from rotating. The spiral blade 3a of the fixed scroll member 3 and the spiral blade 7a of the movable scroll member 7 are pressed against each other with a strength that causes wear, or vice versa, compressed from between them. There will be a gap enough to cause fluid leakage. Therefore, the spiral blade 3a and the spiral blade 7a
In order for and to always maintain proper relative positions, it is absolutely necessary that the rotation preventing mechanism 8 operates accurately. Further, if the rotation preventing mechanism 8 slides and generates friction during operation, not only power loss but also wear in the sliding portion may cause inaccurate operation.
It also causes wear of the spiral blades of the scroll member.

In the embodiment shown in FIGS. 1 to 3, when the movable scroll member 7 revolves without rotation by the action of the rotation preventing mechanism 8 and compresses the fluid confined in the crescent-shaped space, As a reaction of compression, the movable scroll member 7 is pressed in the axial direction, but this axial force (thrust) is supported by the fixed race 10 so that the movable scroll member 7 does not move in the axial direction and has a spiral shape. The tip of the blade 7a in the axial direction does not separate from the inner surface of the housing that also serves as the side plate of the fixed scroll member 3. Therefore, the compressed fluid is prevented from leaking from this portion. Moreover, in this embodiment, the fixed race 1
Since the thrust ball 13 is sandwiched between the 0 and the movable race 11, the thrust ball 13 rolls so that the orbit of the movable scroll member 7 is in a state in which the friction due to the axial force hardly acts as described above. Is done lightly.

Corresponding to the features of the present invention, in the embodiment shown in FIGS. 1 to 3, the keys 12b and 12c formed on both axial sides of the retainer ring 12 of the rotation preventing mechanism 8 are provided. As shown in FIG. 4 (a), it engages with the opposite fixed race 10 and the movable race 11 through the groove portions 11a, respectively, through rolling antifriction means such as balls 14. Therefore, friction is hardly generated even when the force in the rotational direction is transmitted between the retainer ring 12 and the fixed race 10 or the movable race 11. Moreover,
Since the ball 14 rolls inside the recess 11b having a limited size, the ball 14 operates stably without fear of getting out of the rolling position.

As shown in FIG. 4B, the movable scroll member 7 is temporarily tilted with respect to the fixed scroll member 3, and the retainer ring 12 is accordingly moved by the movable race 11.
Even if there is a tendency to tilt with respect to the
c can freely move in and out of the groove portion 11a of the movable race 11, and will not be twisted. Therefore, even in such an abnormal case, an unreasonable force does not act on any part, so that abnormal wear or the like is prevented. Further, since the action of an unreasonable force can be avoided by the rolling of the ball 14, it is not necessary to provide extra play between the key 12c and the groove portion 11a of the movable race 11, so that the rotation preventing mechanism 8 The accuracy of is improved.

On the other hand, in the case of the conventional Oldham coupling, as shown in an enlarged view in FIG. 5A, the key 12c 'of the retainer ring 12' is formed in the groove portion 11 of the movable race 11 '.
Since it is in direct sliding contact with the side wall of a ', friction between the surfaces occurs and lubrication cannot be absent. Also,
When the retainer ring 12 'is inclined with respect to the movable race 11' as shown in FIG. 5 (b), the key 12c 'is twisted in the groove 11a', and sliding friction is very great even if it is not locked. Not only does it increase in size and power loss, but also wear of sliding parts progresses, and durability of the mechanism is significantly reduced. To avoid this, if the width of the groove 11a 'is made sufficiently larger than the width of the key 12c', the play becomes excessively large at this time, the accuracy of the rotation preventing mechanism 8 deteriorates, and the spiral shape of the movable scroll member 7 decreases. The blades 7a of 3 contact the spiral blades 3a of the fixed scroll member 3 to cause wear. These problems are solved by the present invention.

In the embodiment shown in FIGS. 1 to 3, the scroll members 3 and 7 are spiral blades 3a and 7a, respectively.
However, the scroll member and the spiral-shaped blade may be separately manufactured and then fixed by some means to be integrated. Also, the key 12b which is a convex portion
The key 12c and the key 12c are formed in the retainer ring 12, and the groove 11a is provided with the recess 11b which is a recess for receiving them.
Etc. are formed on the side of the movable race 11 and the fixed race 10, but substantially the same action and effect can be obtained even if the relationship of these irregularities is arranged oppositely.

Further, the groove portion 11a and the recess 1 of the movable race 11 as shown in FIG. 2 for engaging with the key 12c of the retainer ring 12 through the rolling ball 14.
6 to 11 show the main parts of some other embodiments having a part replacing the structure of 1b. As described above, the same structure can be provided on the fixed race 10 side, and when the relationship of the concavities and convexities is reversed, the structure such as these groove portions can be provided on the retainer ring 12 side.

First, in the structure shown in FIG. 6, the groove portion 11a of the movable race 11 shown in FIG. 2 which is open on both inner and outer sides in the radial direction is closed to form a window-like shape together with a portion having the same function as the depression 11b. An opening 11c is formed, and the key 12c of the retainer ring 12 and the ball 14 are inserted into the opening 11c in the axial direction. The structure is simple because only the window-shaped opening 11c is formed, and the window-shaped opening 11c naturally has a function of preventing the balls 14 from coming out.

In the structure shown in FIG. 7, the retainer ring 12 is placed in a wide groove portion 11d whose both ends in the radial direction are open.
The key 12c and the ball 14 are inserted, and the groove 11
As a means for preventing the ball 14 from escaping from the d, four pins 18 are driven into the groove portion 11d of the movable race 11. Further, instead of the pin 18, four keys 19 are formed in the groove portion 11d of the movable race 11, or they are axially projected from the side of the retainer ring 12 in parallel with the key 12c to prevent the balls 14 from coming out. This is shown in FIG. Further, in the structure shown in FIG. 9, the flange portions 12d are formed on both ends of the key 12c of the retainer ring 12 inside and outside in the radial direction.
Is used as a means for preventing the ball 14 from coming out of the groove 11d of the movable race 11.

Another embodiment shown in FIGS. 10 and 11 is
In other words, the ball 14 in each of the above embodiments is also provided with the function of the thrust ball 13. In this embodiment, what corresponds to the key 12c of the retainer ring 12 is a key 12e having an enlarged width, which is inserted into the wide groove portion 11e formed in the movable race 11. Therefore, since the balls 14 are distributed and arranged in a wide range of the movable race 11, it is possible to bear the axial force as a reaction force for compressing the fluid, like the thrust balls 13. The means for preventing the balls 14 from escaping may be the same as in each of the above-described embodiments, and the one shown in FIG. 10 has the same structure as that shown in FIG. In the embodiment shown in FIGS. 10 and 11, since the thrust ball 13 can be omitted, there is an advantage that the structure becomes simpler.

In the above embodiments, the case where the present invention is applied to a non-lubricated compressor has been described. However, the present invention is not limited to a non-lubricated compressor, and a compressor for a refrigerant in an air conditioner is not limited to this. The same effect can be obtained even when applied to a lubrication system such as.

[0031]

According to the present invention, it is possible to prevent rotation of the movable scroll member with high accuracy with a simple structure, and reduce power loss due to sliding friction and wear of sliding parts. it can.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a cross-sectional side view taken along the line AA of FIG.

3 is a cross-sectional side view taken along the line BB of FIG.

FIG. 4 is a partial cross-sectional view showing an enlarged main part of the embodiment of FIG. 2, (a) showing a normal state and (b) showing an inclined state.

FIG. 5 is a partial cross-sectional view showing an enlarged main part of a conventional example, in which (a) shows a normal state and (b) shows an inclined state.

FIG. 6 is a partial side view showing a main part of another embodiment.

FIG. 7 is a partial side view showing a main part of still another embodiment.

FIG. 8 is a partial side view showing a main part of still another embodiment.

FIG. 9 is a partial side view showing a main part of still another embodiment.

FIG. 10 is a partial side view showing a main part of still another embodiment.

11 is a partial cross-sectional view showing an enlarged main part of the embodiment of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Scroll compressor 3 ... Fixed scroll member 3a ... Spiral blade 5 ... Drive shaft 6 ... Eccentric ring 7 ... Movable scroll member 7a ... Spiral blade 8 ... Rotation prevention mechanism 10 ... Fixed race 11 ... Movable race 11a, 11d, 11e ... Groove portion 11b ... Recess 11c ... Window-shaped opening 12 ... Retainer ring 12a ... Hole 12b, 12c, 12e ... Key 12d ... Collar portion 13 ... Thrust ball 14 ... Ball 18 ... Pin 19 ... Key

Claims (1)

[Claims] 1. A fixed scroll member having a spiral blade and fixed in a housing, and a spiral blade that meshes with the spiral blade of the fixed scroll member so as to only revolve. The movable scroll member is driven, and a rotation preventing mechanism that prevents rotation of the movable scroll member and allows only revolving, and the rotation preventing mechanism includes a movable race that is integral with the movable scroll member and the inside of the housing. And a retainer ring interposed between the movable race and the fixed race, and the engaging portion between the retainer ring and the movable race and / or the fixed race is It has a structure in which a key protruding in the axial direction from one is inserted into a groove formed in the other, and There is no direct sliding contact with the groove, and a rolling member is interposed between them.
The scroll fluid machine further comprising means for preventing the rolling member from escaping from the groove.