JP2522213B2 - Compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a compressor, and is effectively used as, for example, a refrigerant compressor for an automobile air conditioner.

[Conventional technology and its problems]

Such a scroll 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 of the shape of the spiral body to the order of a few microns from the predetermined shape, and also the accuracy of the relative position of both scroll members must be strict. To be done. 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 the orbital movement of the orbiting scroll along the shape of the scroll member.

For example, in Japanese Examined Patent Publication No. 58-19875, a cylindrical drive pin is provided at the end of a shaft, a bush is provided for orbiting a movable scroll, and a hole is bored in the bush, and the drive pin is rotatably fitted into the hole. It is configured to do. Further, it is proposed that the drive pin position is set apart from the center of the shaft by a distance larger than the radius of the orbital motion, and is displaced from the line connecting the center of the bush and the center of the shaft in the rotational direction. There is. According to this structure, the bush receives a compression reaction force from the orbiting movable scroll.
This reaction force causes the bush to swing around the drive pin. Due to the swing, the distance between the center of the bush and the center of the shaft, that is, the radius of the revolution movement becomes larger than that before the swing due to the above positional relationship. This means that during orbiting the orbiting scroll, a force always acts so that the orbiting radius becomes larger, and even if there is some error in the shape of the scroll member, the orbiting scroll will make contact while adjusting the orbiting radius according to that shape. A line will be formed.

However, with the above structure, the drive pin must be installed larger than the revolution radius from the center of the shaft, and therefore the end of the shaft must be twice or more larger than the other parts of the shaft. In addition, when the bush reversely swings at the time of stopping due to the above-mentioned swing, scrolls may collide with each other and may be damaged, and in order to prevent this, a swing amount regulation mechanism must be newly added. There is.

Further, JP-A-59-120794 discloses a movable scroll and a movable bearing for supporting the movable scroll, which are slidably mounted in a plane perpendicular to the axis of the shaft. Further, Japanese Patent Laid-Open No. 62-162786 discloses a movable scroll and an intermediate member for transmitting the rotation from the shaft to the movable scroll so as to be slidable in a plane perpendicular to the axis of the shaft. . However, in these devices, the sliding direction pushes the movable scroll against the fixed scroll by sliding because it is inclined in the same direction as the shaft rotation direction with respect to the line connecting the shaft center and the movable scroll. It is configured to use centrifugal force as force. Therefore, for example, in the case of an air conditioner for automobiles, the high-low pressure difference between the adjacent compression chambers is small at the time of high rotation, and although the sealing property between both scrolls is not required so much, the above-mentioned centrifugal speed is high. The force is used 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 wear of both scroll teeth progresses.
On the other hand, when the rotation speed is low, the high-low pressure difference between the adjacent compression chambers is large, and high sealing performance is required.However, since the rotation speed is low, the centrifugal force does not act so much, and the movable scroll is fixed scroll. 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.

[Problems to be Solved by the Invention]

The present invention has been devised in view of the above-mentioned problems, and makes a seal between a movable scroll and a fixed scroll that forms a sealed space with a small and simple structure to be performed with an appropriate pressing force, and at the same time, scrolls when stopped. The purpose is to propose means for preventing a violent collision between them.

(Means for Solving the Problem) A key and a fitting groove into which the key is fitted are provided in the rotation transmitting mechanism portion of the shaft and the bush with a predetermined gap in the moving direction so that the key can move along the groove. In particular, the key is arranged such that the rotation transmitting surface between the key and the groove is inclined by a certain angle θ in the direction opposite to the rotation direction of the shaft with respect to the line connecting the center of the shaft and the center of the bush.

When the key is fitted into the fitting groove, the shaft and the bush are assembled with their centers separated by an eccentric amount RI. The bush is attached to the movable scroll via a bearing. When the shaft rotates, the orbiting scroll, which is prevented from rotating, revolves around the radius RI. At this time, the compression reaction force F acts on the bush in the tangential direction of the revolution movement locus toward the center of the bush, and the component force F · sin θ becomes a force for pushing up the bush.

Since the fitting groove is larger than the key by a predetermined gap, the bush moves along the groove by F · sin θ. As a result, 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.

Further, by appropriately selecting the inclination angle θ, it is possible to set the pressing force to an optimum value and 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 in the above-described predetermined amount of gap, but before the movable scroll violently collides with the fixed scroll, the key comes into contact with the bush at the end of the groove. Movement is regulated.

Thus, it is possible to realize a driven crank mechanism having a function of adjusting the revolution radius by an appropriate pressing force and a stopper function of preventing the scroll teeth from colliding with each other, by using only the key and the groove.

〔Example〕

Hereinafter, an embodiment in which the present invention is applied to a compressor of a refrigeration cycle of a vehicle air conditioner will be described in detail 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 that 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 in the center,
A bearing 700 is installed in it, and rotatably supports the shaft 100. Further, the front housing 400 has a cylindrical boss portion 401, and the shaft seal 8
00 is incorporated. 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 the high pressure chamber 501 and the low pressure chamber 501 are separated.
It has a discharge port and a suction port (not shown), which are in communication with each other.

In the rear housing 500, the movable scroll member 200 is arranged so that the scroll bodies mesh with each other at an angle with respect to the fixed scroll member 300. Movable scroll member 20
0 is connected 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 the scroll members, the movable scroll 200 is arranged such that the centers of the scrolls are separated by the radius R.

In other words, the rotation of the shaft 100 causes the bush 1
Through 01, the movable scroll member 200 makes an orbital motion with a radius R. As a result, 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. 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. In addition, the discharged refrigerant gas is
Discharge valve that prevents backflow from the air into the enclosed space of the spiral body
504 and stopper 505 that regulates the lift amount of the discharge valve 504
Is also installed.

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 face of the shaft 100, the drive key 100a is integrated with this.
Are formed. The drive key 100a is shown in FIGS.
As shown in the figure, it is formed so as to be inclined 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. On the other hand, as shown in FIG. 5, the bush 101 is provided with a groove 101a which is fitted to the drive key 100a and receives the rotational driving force. The groove 101a is installed so 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 drive key so that the bush 101 can be smoothly slid in the longitudinal direction while being in contact with the drive key 100a. To ensure smoother sliding movement, drive key 100a and groove
The surface roughness of the double-width surface of 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 due to the revolution movement of the movable scroll member 200. The balance weight 102 is the shaft 100.
May be integrally attached to.

The shaft 100, the drive key 100a, and the bush 1 described above.
The positional relationship and action of 01 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 when all the components are assembled and the compressor is completed. Shaft center 100b and bush center
The distance between 101b is RI, which is substantially equal to the revolution radius R described above. The drive key 100a is a shaft whose longitudinal direction is relative to a line passing through the shaft center 100b and the bush center 101b.
It is installed so that it is tilted at an angle θ opposite to the direction of rotation of 100. In this state, when the shaft 100 rotates in the direction indicated by 100c, the bush 101 receives the 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 bush 101
The rotation of the movable scroll member 200 makes an orbital motion and starts compression. At this time, the movable scroll member 200
A compression reaction force due to compression is applied to the bushes, and as a result, a compression reaction force as shown by F in FIG. 8 acts on the center 101b of the bush.

The reaction force is supported by the drive key 100a via the groove 101a, but since the drive key 100a is installed at an angle of θ as described above, push up the bush 101 along the drive key 100a. A component force F · sin θ of the compression reaction force is generated. Due to the component force F · sin θ, the bush 101, that is, the movable scroll member 200 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 reliably formed, the degree of sealing of the sealed space is increased, and the performance of the compressor is improved.

A description of the relative position movement of the bush 101 due to the component force F · sin θ is given in FIG. 9, and a diagram showing the increase of the revolution radius by the bush movement is given in FIG.

The component force for pushing up the bush 101, that is, the force for pressing 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 if θ is set between 30 ° and 60 °, 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 suqur, the pressure P inside the compressor is high under operating conditions where 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. In this way, 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 should be set to an appropriate value. As long as this is done, the mechanism is highly rational in that the sealing force also increases or decreases depending on the operating and pressure conditions.

The angle θ and compression reaction force F are used to determine the sealing force.
In addition, there is also a centrifugal force due to the orbital motion of the movable scroll member 200 itself, but this is canceled by the balance weight 102 if the balance weight 102 is integrally attached to the bush 101 as in this embodiment. The force prevents the movable scroll member from being excessively pressed against the fixed scroll member.

FIG. 11 shows the positional relationship among the above-described drive mechanism, the scroll members, the pressure P in the closed space, the compression reaction force F, and the sealing force.

Next, the regulation of the movement amount of the bush 101 will be described with reference to FIGS. 8 and 9.

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 the two scrolls will be generated as a strange 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. 8th
In the example shown in the figure, the longitudinal dimension of the groove 101a is made larger than the longitudinal dimension of the drive key 100a, but if this dimension is selected appropriately, when the bush 101 is lowered back, the scroll member Drive key 100a before the spirals collide with each other
The arcuate portions of the groove 101a are combined with each other, the movement of the bush 101, that is, the movable scroll member 200 is restricted, and the collision of the scroll members of the scroll member can be prevented.

In addition, if the longitudinal dimension of the groove is made sufficiently large within the range where collision between the spiral bodies does not occur, both spiral bodies 200 and 300 will rotate without contact due to liquid compression at the time of startup that sometimes occurs. It is possible to eliminate the need for a relief valve or the like for special liquid compression.

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.

It should be noted that the same operation is performed 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 shaft axial direction.

As described above, in the compressor of this example, the shaft 10
A bush 101 having a groove 101a having a size larger than the longitudinal dimension of the drive key is used, which is fitted to the drive key 100a with a drive key 100a inclined at an angle θ in the direction opposite to the rotation direction at the end of 0. Then, the position of the scroll is adjusted to drive the movable scroll member 200. As a result, the compressive reaction force of the refrigerant gas requires and sufficiently automatically obtains the pressing force at the contact line portions of both spirals, so that the contact line is reliably formed and sealing is performed reliably. In order to ensure the position adjustment of the movable spiral body, in this embodiment, a gap between the groove 101a and the drive key 100a (a gap formed below the drive key 100a in FIG. 8-a gap).
It is desirable to secure at least several tens of microns at all times.

In addition, the bush 101 is provided along the longitudinal direction of the drive key 100a.
Is movable, the revolution radius is automatically adjusted in response to changes in the pitch and wall thickness of the spiral due to dimensional errors in the shape of the spiral, and this also reliably forms the contact line, It is possible to secure a seal and to perform accurate movement.

Without adding another mechanism, it is possible to prevent the scrolls from colliding with each other due to the descending return of the movable scroll member 200 when the compressor is stopped, and to prevent the damage. It also has a relief mechanism that prevents the generation of high pressure during liquid compression.

In the above embodiment, the drive key 100a is configured to be eccentric with respect to the central axis of the shaft 100, but the fitting groove 101a of the bush 101 is eccentric with respect to the central axis of the bush 101. Needless to say, the same action and effect can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the compressor of the present invention.
FIG. 2 is a perspective view showing the shaft and bush shown in FIG. FIG. 3 is a front view of the drive portion of the shaft in the embodiment of FIG. FIG. 4 is a side view of the shaft shown in FIG. FIG. 5 is a front view of the bush in the embodiment of FIG. FIG. 6 is a front view seen from the right in FIG. FIG. 7 is a sectional view taken along line VII-VII in FIG.
FIG. 8 is a mechanical explanatory view of the 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 for explaining an increase in the revolution radius after the bush moves as shown in FIG. FIG. 11 is a view for explaining the mechanical and relative positional relationship between the contact line and the internal pressure between the bush and the movable scroll in the embodiment of FIG. 100 ... Shaft, 100a ... Drive key, 101 ... Bush, 101a
... Groove, 102 ... Balance weight, 200 ... Movable scroll member, 300 ... Fixed scroll member, 400 ... Front housing, 500 ... Rear housing, 600 ... Rotation stop mechanism, 700 ...
Bearing, 800 ... shaft seal.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-59-120794 (JP, A) JP-A-62-282186 (JP, A) JP-A-62-162786 (JP, A) JP-B-58- 19875 (JP, B2)

Claims (3)

(57) [Claims] 1. A housing having an inlet and an outlet, a scroll body formed on an end plate, and a fixed scroll member provided in the housing, and a scroll body formed on the end plate. A movable scroll member having a fixed scroll member and a center of the movable scroll member engaged with the fixed scroll member, a shaft rotatably supported by the housing, and an eccentrically arranged shaft end portion. 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 the rotation of the bush is formed, and the bush has two parallel surfaces. And a drive key having a shape having two parallel surfaces is provided at the end of the shaft, and the groove is formed by the bush along the two parallel surfaces of the drive key. Is fitted in the drive key with a predetermined gap in the moving direction so as to be movable, and the center of the bush is eccentric from the center of the shaft by the radius of the revolution motion, and is parallel to the drive key. A compressor, wherein two surfaces are installed so as to be inclined in a direction opposite to a rotation direction of the shaft with respect to a line passing through a center of the bush and a center of the shaft. 2. A housing having an intake port and a discharge port, a shaft rotatably supported by the housing, and a shaft having a drive key having at least one rotation transmitting surface at an end thereof, and a rotation of the drive key. A bush having a groove having a rotation transmission surface that fits the drive key with a predetermined gap in the moving direction so as to be movable along the transmission surface; and a bush rotatably engaged with the bush. A movable scroll member that revolves in the housing, and a fixed scroll member that engages with the movable scroll member and forms a sealed space between the movable scroll member and the rotation of the drive key of the shaft. The transmission surface is inclined at a predetermined angle in a direction opposite to the rotation direction of the shaft with respect to a line connecting the center of the bush and the center of the shaft. Compressor that have been made. 3. A movable scroll member having a fixed scroll member having a spiral body formed on an end plate and a spiral member formed on the end plate, the movable scroll member being incorporated so as to be engaged with the fixed scroll member while shifting the center thereof. A scroll member, a shaft that rotates by receiving a driving force, a bush that is eccentrically arranged at the shaft end portion and that orbits the movable scroll member, and a rotation transmission mechanism that transmits the rotation of the shaft to the bush. A rotation preventing mechanism that allows only the revolution of the movable scroll member and prevents rotation of the movable scroll member, and 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. Meanwhile, in the scroll compressor in which the fluid in the closed space is compressed by moving toward the center of the spiral body, The end plate of the crawl member is formed with an engaging portion with the bush for receiving the revolution driving force while allowing the rotation of the bush, and the rotation transmission mechanism has a groove having a rotation transmission surface. When,
And a key having a shape having at least one rotation transmitting surface fitted in the groove with a predetermined gap in the moving direction so that the bush can move along the rotation transmitting surface. The center of the bush is eccentric from the center of the shaft by a radius of revolution, and the rotation transmitting surface of the key is inclined 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 characterized by being installed.