JPH0749092A - Compressor - Google Patents

Abstract

PURPOSE:To provide a scroll type compressor where desired pressing force can be obtained even when a rotating speed fluctuates by eliminating centrifugal force to be exerted on a bush, and utilizing compression reaction force of a refrigerant as force generated when a movable scroll slides to depress a fixed scroll. CONSTITUTION:A driving key 100a is formed integrally at the tip of a shaft 100 rotatably supported by a front housing 400. Meanwhile, a groove 101a fitted to the driving key 100a and receiving rotating drive force is formed on a bush 101. A balance weight 102 is integrally fixed to the bush 101a. A snap ring is provided at the tip surface of the driving key 100a, abutting against the end surface of the bush 101 so as to restrict the inclination and motion thereof in the axial direction of the shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor, which is effective as a refrigerant compressor for an automobile air conditioner, for example.

[0002]

2. Description of the Related Art Such a scroll type compressor is disclosed in many patents and documents, and its operating principle is well known. In the scroll compressor, a closed space is created which is sandwiched by a plurality of contact lines formed by a fixed scroll member and a movable scroll member that are meshed with each other. Then, when the movable scroll makes an orbital motion, the contact line moves toward the center along the wall of the spiral body, and the enclosed space sandwiched therewith moves toward the center while the volume decreases and performs compression. .

By the way, since a plurality of the contact lines are formed at the same time, it is necessary to suppress the error from the predetermined shape of the spiral body to the order of several microns, and the accuracy of the relative position of both scroll members is severe. Things are required. If these errors become large, one of the contact lines will be separated, and the degree of airtightness of the space to be sealed will decrease, resulting in a decrease in discharge rate, an increase in horsepower consumption, and higher temperature operation. Causes a problem. Therefore, in the scroll compressor, it is necessary to make the working accuracy of the scroll body and the assembling accuracy of both scrolls extremely high. This is the main reason why scroll compressors have not been put to practical use for a long time. Further, even with today's processing technology and assembly technology, various difficulties are involved.

As a means for solving the problems of such scroll compressors, many patent specifications have proposed means for varying the radius of revolution of the orbiting scroll along the shape of the scroll member. For example, Japanese Patent Laid-Open No. 59-120794 discloses a movable scroll and a movable bearing that supports the movable scroll so that the movable scroll is slidable in a plane perpendicular to the axis of the shaft. Further, Japanese Patent Laid-Open No. 62-162786 discloses that
A movable scroll and an intermediate member (bush) that transmits rotation from the shaft to the movable scroll are attached so as to be slidable in a plane perpendicular to the axis of the shaft.

However, in these devices, the direction of the slide is relative to the line connecting the shaft center and the movable scroll,
Since the shaft is tilted in the same direction as the rotating direction of the shaft, the centrifugal force acting on the bush is used as the force that pushes the movable scroll against the fixed scroll by sliding, and the dynamic imbalance of the movable scroll is offset. A balancer for is attached to the shaft. Therefore, the high-low pressure difference between the adjacent compression chambers is small at the time of high rotation like an air conditioner for automobiles, and the rotation speed is high even though the sealing property between both scrolls is not so high. The force acts so much that the movable scroll is pressed against the fixed scroll with excessive force. As a result, the horsepower consumption of the compressor increases and the wear of both scroll teeth progresses, and when severe, the scroll teeth may be damaged. On the other hand, when the load is low, the high-low pressure difference between the adjacent compression chambers is large, and high sealing performance is required. There is a problem that the force to press against is insufficient, the desired sealing property cannot be obtained, and the refrigerant leaks from the high pressure side to the constant pressure side.

In view of the above problems, the inventors of the present invention minimize the centrifugal force acting on the bushes, and mainly use the compression reaction force of the refrigerant as the force for sliding the movable scroll to press it against the fixed scroll. It has been devised to provide a scroll-type compressor that can obtain a desired pressing force even if it fluctuates. (Japanese Patent Application No. 63-331307)

[0007]

However, in this case, in order to effectively utilize the compression reaction force, the influence of the centrifugal force acting on the bush must be minimized. It is common to provide a balance weight in order to reduce the influence of centrifugal force. For example, the balance weight has been used for the scroll compressor disclosed in Japanese Patent Laid-Open No. 59-120794.

However, conventional balance weights have been designed to reduce the dynamic unbalance of the movable scroll member in order to reduce the vibration of the entire compressor. Therefore, no special consideration is given to the positional relationship between the balance weight and the bush, and the balance weight is attached to the shaft in the above-described conventional example. Therefore, the centrifugal force acting on the bush cannot be sufficiently canceled out, and the compression reaction force cannot be effectively utilized even when applied to the scroll compressor devised by the present inventors.

The present invention is to further improve the invention of the inventors of the present invention in which the sealing reaction property is enhanced by utilizing the compression reaction force. In order to effectively utilize the compression reaction force, the influence of the centrifugal force acting on the bush is taken into consideration. The aim is to make it as small as possible.

[0010]

In order to achieve the above object, the present invention has a fixed scroll member having a spiral body formed on an end plate, and a spiral body formed on the end plate. A movable scroll member incorporated so as to shift the center of the scroll member and engage with each other, a shaft that rotates by receiving a driving force, and the shaft end portion is arranged eccentrically from the center of the shaft by the revolution radius of the movable scroll member, The movable scroll member is provided with a bush for revolving and a rotation transmission mechanism for transmitting the rotation of the shaft to the bush, and has a rotation stopping mechanism that allows only the revolution of the movable scroll member and prevents rotation thereof. However, the orbital movement of the movable scroll member reduces the volume of the sealed space between the movable scroll member and the fixed scroll member. To move toward the center of the reluctant spiral body,
In a scroll compressor in which the fluid in the closed space is compressed, an end portion of the movable scroll member is formed with an engaging portion with the bush for receiving the revolution driving force while allowing the rotation of the bush. The rotation transmission mechanism includes a groove having a rotation transmission surface and at least one rotation transmission surface fitted into the groove so that the bush can move along the rotation transmission surface. A drive key having a holding shape, and the rotation transmission surface of the drive key is installed so as to incline in a direction opposite to the rotation direction of the shaft with respect to a line passing through the center of the bush and the center of the shaft. And a balance wheel that is provided integrally with the bush and that cancels the dynamic unbalance due to the orbital movement of the movable scroll member and the centrifugal force that acts on the bush. To adopt the technology means that it has the over door.

[0011]

[Operation and effect] A drive key and a fitting groove into which the key is fitted are provided in the rotation transmission mechanism portion between the shaft and the bush, and when the drive key is fitted into the groove, a line connecting the center of the shaft and the center of the bush is formed. On the other hand, the drive key is arranged so as to be inclined by a certain angle θ in the direction opposite to the rotation direction of the shaft.

When the drive key is inserted into the fitting groove, the shaft and the bush are assembled with their centers separated by the eccentricity RI. The bush is attached to the movable scroll via a bearing. When the shaft rotates, the movable scroll, which is prevented from rotating, revolves with a radius RI. At this time, a compression reaction force F acts on the bush in the tangential direction of the orbit of locus toward the center of the bush, and the component force F · si
n θ is the force that pushes up the bush. Here, a centrifugal force due to the orbital motion of the movable scroll member and a centrifugal force due to the rotation of the bush itself act on the bush, but in the compressor of the present invention, since the bush is integrally provided with the balance weight as described above, The influence of centrifugal force can be made extremely small, and the compression reaction force of the refrigerant is mainly used as the force that slides the movable scroll member and presses it against the fixed scroll member, and the desired pressing force can be obtained even if the rotation speed changes. To be

When the bush-side fitting groove is provided larger than the drive key by a predetermined amount, the bush moves along the groove in a direction in which the revolution radius of the movable scroll member is increased. That is, the revolution radius becomes larger than the initial RI, the movable scroll abuts and slides along the fixed scroll shape, and reliably seals the scroll teeth. Also,
By appropriately selecting the inclination angle θ, it is possible to prevent an excessive pressing force from being generated. Furthermore, when the shaft reverses due to a stop or the like, the bush moves in the opposite direction, but the movement of the bush is restricted before the movable key violently collides with the fixed scroll due to the drive key abutting at the end of the groove. .

As described above, it is possible to obtain the scroll type compressor having the function of adjusting the revolution radius by the appropriate pressing force mainly utilizing the compression reaction force of the refrigerant.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a compressor of a refrigerating cycle of an automobile air conditioner will be described in detail below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. The present compressor has a housing formed by a rear housing 500 and a front housing 400 which is fastened by bolts (not shown) so as to close an opening of the rear housing 500. The front housing 400 has a holding hole at the center, and the bearing 700 is mounted in the holding hole.
The shaft 100 is rotatably supported. Further, the front housing 400 has a cylindrical boss portion 401, and the shaft seal 800 is incorporated therein.
A magnet clutch (not shown) is attached on the outer periphery of the boss portion 401, and the rotational force of the vehicle running engine is transmitted to the shaft 100 via the magnet clutch. The fixed scroll member 300 is fitted and inserted into the inside of the rear housing 500, and is fixed to the bottom portion of the rear housing 500 by a bolt (not shown). The rear housing 500 is separated into a high pressure chamber 501 and a low pressure chamber 502 by the fixed scroll member 300 and the O-ring 801, and a discharge port and a suction port (not shown) that communicate with the high pressure chamber 501 and the low pressure chamber 502, respectively. Have a mouth

In the rear housing 500, the movable scroll member 200 is arranged so that the scroll bodies mesh with each other at a different angle with respect to the fixed scroll member 300. The movable scroll member 200 is linked to the rotation stopping mechanism, and its rotation is restricted. Further, the movable scroll member 200 is connected to a bush 101 according to the present invention, which will be described later, and revolves to compress the refrigerant gas.

Since the radius R of the revolution movement is determined by the shapes of both scroll members, the movable scroll 200 is arranged so that the centers of both scrolls are separated by the radius R. That is, when the shaft 100 rotates, the movable scroll member 200 is moved through the bush 101.
Will make an orbital motion of radius R. by this,
The contact line formed between both scrolls moves toward the center along the spiral shape, and the sealed space moves toward the center while reducing the volume. In this way, the refrigerant is compressed. Further, a discharge port 503 for discharging the compressed refrigerant gas into the high pressure chamber 501 is formed in the center of the fixed scroll member 500. Further, the discharge valve 504 and the discharge valve 50 which prevent the discharged refrigerant gas from flowing back from the high-pressure chamber 501 to the closed space of the swirl.
A stopper 505 that regulates the lift amount of No. 4 is also attached.

Next, the drive mechanism of the movable scroll member 200 will be described with reference to the drawings. FIG. 2 shows the structure of the drive mechanism. On the end surface of the shaft 100. The drive key 100a is formed integrally with this. The drive key 100a
Is formed so as to incline by a certain angle θ in the direction opposite to the rotation direction with respect to a line passing through the center of the shaft, as shown in FIGS. On the other hand, as shown in FIG. 5, the bush 101 is provided with a groove 101a that fits into the drive key 100a and receives a rotational driving force. The groove 101a
Is installed such that the longitudinal dimension of the groove in this embodiment is longer than that of the drive key 100a. The width of the groove is set to be larger than the width of several tens μ of the driving key so that the bush 101 can be smoothly slid in the longitudinal direction while being in contact with the driving key 100a. In order to ensure a smoother sliding movement, the surface roughness of the double-width surface of the drive key 100a and the groove 101a is suppressed to several μ by polishing. Further, a balance weight 102 is integrally attached to the bush 101 so as to cancel the centrifugal force caused by the revolution movement of the movable scroll member 200 and the centrifugal force caused by the rotation movement of the bush 101 itself.

The shaft 100 and the drive key 1 described above
The positional relationship and operation of the 00a, the bush 101, and the groove 101a will be described with reference to FIGS. 6 to 9. FIG. 6 shows the relative positional relationship between the shaft 100 and the bush 101 in a state where all the components are assembled and the compressor is completed. The distance between the shaft center 100b and the bush center 101b is RI, which is substantially equal to the revolution radius R described above. The drive key 100a is installed such that its longitudinal direction is inclined by an angle θ which is opposite to the rotation direction of the shaft 100 with respect to a line passing through the shaft center 100b and the bush center 101b. In this state, when the shaft 100 rotates in the direction indicated by 100c, the bush 101 receives a rotational driving force via the drive key 100a and similarly starts rotating in the 100c direction. here,
Since the movable scroll member 200 is engaged with the bush 101 via a bearing or the like, the rotation of the bush 101 causes the movable scroll member 200 to revolve and start compression. At this time, the movable scroll member 20
A compression reaction force due to compression acts on 0, and as a result, a compression reaction force as shown in FIG. 8F acts on the center 101b of the bush.

The reaction force is transmitted through the groove 101a to the drive key 1
00a, but as described above, the drive key 100
Since a is installed at an angle of θ, drive key 1
A component force F · sin θ of the compression reaction force that pushes up the bush 101 along 00a is generated. This component force F ・ sin θ
By the bush 101, that is, the movable scroll member 2
00 tries to revolve with a radius larger than the initial revolution radius RI. As a result, even if there are some errors in the shapes of the scrolls of the movable scroll member 200 and the fixed scroll member 300, the revolution radius is automatically adjusted until the scroll of the movable scroll member 200 abuts the scroll of the fixed scroll member 300. The orbital motion will be performed while making it larger. Therefore, the contact line between the scroll members 200 and 300 can be surely formed, the degree of sealing of the sealed space is increased, and the performance of the compressor is improved. In addition, the movable scroll member 20
The centrifugal force f 0 due to the revolution movement of 0 and the centrifugal force f ₁ due to the rotation movement of the bush 101 itself act on the bush 101, but the balance weight 1 integrally provided on the bush 101.
Since most of them are canceled by the centrifugal force f ₂ acting on 02, the compression reaction force F can be mainly used as the force for sliding the movable scroll member 200 toward the fixed scroll member 300 and pressing it.

Bush 101 due to the component force F · sin θ
FIG. 9 shows the relative position movement of FIG. 9 and FIG. 10 shows the increase of the revolution radius by the bush movement. Bush 1
01, that is, the force that pushes the scroll body of the movable scroll member 200 against the scroll body of the fixed scroll member 300, sets the magnitude of θ appropriately as can be seen from the formula of F · sin θ. By doing so, the optimum one can be obtained. That is, when θ is increased in the range of 0 ° to 90 °, the component force, that is, the sealing force between the spiral bodies can be increased. However, if the sealing force becomes excessively large, the mechanical loss of the compressor increases and the horsepower consumption becomes large. As a result of experiments and examinations conducted by the present inventors,
It has been found that when θ is set between 30 ° and 60 °, a sufficient sealing force can be obtained even under various operating conditions.

Further, as is clear from the formula F · sin θ, the sealing force also depends on the magnitude of the compression reaction force F. Then, the compression reaction force F is determined by the operating state of the compressor.
Since there is a monotonically increasing function relationship with the pressure P in the enclosed space between both scrolls, the pressure P inside the compressor is equal to the pressure P under operating conditions in which the heat load is large and the rotation speed of the compressor is low. As a result, the compression reaction force F also becomes large, and as a result, the sealing force F · sin θ also increases. As described above, the sealing force F · sin θ increases as the pressure P inside the compressor increases, that is, when the pressure difference between the sealed spaces increases, so the above θ is set to an appropriate value. If this is done, the mechanism is highly rational in that the sealing force will also increase or decrease according to operating and pressure conditions.

In addition to the angle θ and the compression reaction force F, the movable scroll member 2 determines the sealing force F · sin θ.
There is also a centrifugal force due to the orbital movement of 00 itself, but this can be ignored because it is canceled by the balance weight 102 integrally attached to the bush 101 described above. FIG. 11 shows the positional relationship among the drive mechanism having the above operations, the scroll members, the pressure P in the closed space, the compression reaction force F, and the sealing force.

Next, referring to FIGS. 8 and 9, the bush 1
The regulation of the movement amount of 01 will be described. As described above, the bush 101 is movable along the longitudinal direction of the drive key 100a, but the rotation may be stopped due to disengagement of the magnet clutch during operation, for example. At this time, due to the inertial force of each part, the bush 101 moves backward along the drive key 100a so as to slide down. As a result, the scroll of the orbiting scroll member 200 violently collides with the scroll of the fixed scroll member 300, and the descending return is stopped. If this is allowed, not only the collision noise between both scrolls will be generated as an abnormal noise at the time of stop, but also the scroll member of the scroll member may be damaged. In order to prevent these, conventionally, another locking mechanism had to be provided, but if the configuration described above is adopted, it is not necessary to provide any new mechanism.
In the example shown in FIG. 8, the longitudinal dimension of the groove 101a is the drive key 1
00a is made larger than the longitudinal dimension, but if this dimension is selected appropriately, the drive key 100a and the groove 101a can be formed before the scrolls of the scroll members collide with each other when the bush 101 is lowered. The arcuate parts of the above are combined, the movement of the bush 101, that is, the movable scroll member 200 is restricted, and the collision of the scrolls of the scroll member can be prevented in advance.

Further, if the longitudinal dimension of the groove is made sufficiently large within the range in which the spiral bodies do not collide with each other, both spiral bodies 200, 3 against the liquid compression at the time of starting which sometimes occurs.
00 is allowed to rotate without coming into contact, and a relief valve or the like for special liquid compression can be dispensed with. As described above, there is an advantage that only the mechanism for adjusting the revolution radius can act as a relief mechanism for restricting the moving range of the movable scroll member and for liquid compression.

The same effect can be obtained even if a locking means such as a circlip is added to the tip of the drive key 100a in order to restrict the movement of the bush 101 in the axial direction of the shaft. As described above, in the compressor of the present example, the drive key 100a is provided at the end of the shaft 100 inclined by the angle θ in the direction opposite to the rotation direction. Groove 10 having a dimension larger than the longitudinal dimension
Since the movable scroll member 200 is driven by using the bush 101 having 1a, the compression reaction force of the refrigerant gas requires a pressing force at the contact line portions of both spirals, so that the contact force can be obtained automatically and sufficiently. The line is surely formed and the seal is surely performed.

Further, since the bush 101 is movable along the longitudinal direction of the drive key 100a, even if the pitch or the wall thickness of the spiral body changes due to the dimensional error of the spiral body shape, the bush 101 is automatically responded to this. The orbital radius can be adjusted to form a contact line with reliability, a seal can be secured, and an accurate motion can be performed. Without adding another mechanism, it is possible to prevent the scrolls from colliding with each other due to the return of the movable scroll member 200 when the compressor is stopped, and to prevent the breakage of the scrolls. It also has a relief mechanism that prevents the generation of high pressure during liquid compression.

Although the drive key 100a is eccentric with respect to the central axis of the shaft 100 in the above embodiment, the fitting groove 101a of the bush 101 is eccentric with respect to the central axis of the bush 101. It goes without saying that the same action and effect can be obtained even if this is done.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a compressor of the present invention.

FIG. 2 is a perspective view showing a shaft and a bush shown in FIG.

FIG. 3 is a front view of the drive unit of the shaft in the embodiment of FIG.

FIG. 4 is a side view of the shaft of FIG.

5 is a front view of the bush in the embodiment of FIG. 1. FIG.

FIG. 6 is a front view seen from the right side of FIG.

FIG. 7 is a sectional view taken along line VII-VII in FIG.

FIG. 8 is a mechanical explanatory view of a force acting on the bush in the embodiment of FIG.

FIG. 9 is a diagram for explaining the direction in which the bush moves due to the action of the force in FIG.

FIG. 10 is a schematic diagram illustrating an increase in the revolution radius after the bush moves as shown in FIG.

FIG. 11 is a diagram illustrating a mechanical and relative positional relationship between a contact line and an internal pressure between the bush and the movable scroll in the embodiment of FIG.

[Explanation of symbols]

 100 Shaft 100a Drive Key 101 Bushing 101a Groove 102 Balance Weight 200 Movable Scroll Member 300 Fixed Scroll Member 400 Front Housing 500 Rear Housing 600 Rotation Stopper 700 Bearing 800 Shaft Seal 900 Circlip

Claims (3)

[Claims] 1. A housing having an inlet and an outlet, a scroll member formed on an end plate, and a fixed scroll member provided in the housing, and a scroll member formed on the end plate. A movable scroll member that is installed so as to be engaged with the fixed scroll member while shifting the center, a shaft that is rotatably supported by the housing, and an eccentrically arranged shaft end portion, and the movable scroll member A bush that gives an orbital motion, and a rotation stopping mechanism that allows only the orbital movement of the movable scroll member and prevents rotation of the movable scroll member. By the orbital movement of the movable scroll member, a gap between the movable scroll member and the fixed scroll member is provided. A scroll compressor in which the closed space moves toward the center of the spiral body while reducing its volume, and the fluid in the closed space is compressed. In the end plate of the movable scroll member, an engaging portion with the bush for receiving the revolution driving force while allowing rotation of the bush is formed, and the bush has two parallel surfaces. A groove having a shape is provided, a drive key having a shape having two parallel surfaces is provided at the end of the shaft, and the groove has a shape in which the bush is provided along two parallel surfaces of the drive key. It is movably fitted to the drive key, the center of the bush is eccentric from the center of the shaft by a radius of revolution, and the two parallel surfaces of the drive key are the center of the bush and the center of the shaft. It is installed so as to incline in a direction opposite to the rotation direction of the shaft with respect to the passing line, and is provided integrally with the bush to cancel out the dynamic imbalance due to the revolution movement of the movable scroll member. And a compressor, characterized in that it comprises a balance weight for canceling a centrifugal force acting on the bush. 2. A housing having an inlet and an outlet, a shaft having a drive key rotatably supported by the housing and having at least one rotation transmitting surface at an end thereof, and rotation of the drive key. A bush having a groove having a rotation transmission surface that fits with the drive key so as to be movable along the transmission surface, and a movable scroll member that is rotatably engaged with the bush and revolves in the housing. A fixed scroll member that engages with the movable scroll member and forms a closed space between the movable scroll member and the movable scroll member, cancels a dynamic imbalance due to the orbital motion of the movable scroll member, and acts on the bush. A balance weight integrally formed with the bush for canceling centrifugal force, wherein the rotation transmitting surface of the drive key of the shaft is the block. A compressor formed so as to be inclined at a predetermined angle in a direction opposite to a rotation direction of the shaft with respect to a line connecting the center of the shoe and the center of the shaft. 3. A fixed scroll member having a scroll body formed on an end plate, and a scroll body formed on the end plate, wherein the fixed scroll member is incorporated so as to engage with the fixed scroll member while shifting the center. A scroll member; a shaft that rotates when receiving a driving force; a bush that is eccentrically disposed at the end of the shaft by an orbital radius of the movable scroll member from the center of the shaft, and that imparts an orbital motion to the movable scroll member; And a rotation transmitting mechanism for transmitting the rotation of the movable scroll member to the bush, and a rotation stopping mechanism that allows only the revolution of the movable scroll member and prevents rotation of the movable scroll member. The closed space between the member and the fixed scroll member moves toward the center of the spiral body while reducing the volume, In a scroll compressor in which the fluid inside is compressed, an end portion of the movable scroll member is formed with an engaging portion with the bush for receiving the revolution driving force while allowing the rotation of the bush. The rotation transmission mechanism includes a groove having a rotation transmission surface,
And a drive key having a shape having at least one rotation transmitting surface fitted into the groove so that the bush can move along the rotation transmitting surface. It is installed so as to incline in a direction opposite to the rotation direction of the shaft with respect to a line passing through the center of the bush and the center of the shaft. A compressor having a balance weight for canceling the balance and for canceling the centrifugal force acting on the bush.