JP4625590B2 - Scroll type fluid machinery - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to a scroll type fluid machine having a balance amount based on a movable scroll member and a counterweight that can be opposed to a change in the turning radius of the movable scroll member.
[0002]
[Prior art]
As a prior art, a scroll type fluid machine in which the centrifugal force of the counterweight is increased in the opposite direction relative to the centrifugal force of the movable scroll member is disclosed in Japanese Patent Application Laid-Open No. 59-215984.
[0003]
As shown in FIG. 4, the scroll type fluid machine in the prior art includes a compressor housing 10 including a front end plate 11 and a cup-shaped casing 12 installed so as to be joined to an end surface of the front end plate 11. have.
[0004]
A through hole 111 through which the main shaft 13 is inserted is formed at the center of the front end plate 11. An annular protrusion 112 concentric with the through hole 111 is formed on the back surface of the front end plate 11. The casing 12 is fixed by fitting its opening onto the annular projection 112 of the front end plate 11.
[0005]
Note that the joint surface between the front end plate 11 and the casing 12 is sealed by an O-ring 14 disposed on the annular protrusion 112. The front end plate 11 has a sleeve 15 protruding so as to surround the main shaft 13. A shaft seal assembly 16 is disposed in a space formed between the sleeve 15 and the main shaft 13.
[0006]
The sleeve 15 may be formed integrally with the front end plate 11, but in the example of FIG. 4, the sleeve 15 is formed separately and attached to the front surface of the front end plate 11 by screws (not shown). An electromagnetic clutch 17 is disposed on the outer periphery of the sleeve 15. The electromagnetic clutch 17 transmits the rotational motion of the external drive source to the main shaft 13 via a belt (not shown).
[0007]
In the casing 12 whose opening is closed by the front end plate 11, a fixed scroll member 18, a movable scroll member 19, a drive mechanism for the movable scroll member 19 and a rotation prevention mechanism 21 are arranged.
[0008]
The fixed scroll member 18 includes a side plate 181 (first plate body) and a spiral body (first spiral body) 182 fixed on one surface of the side plate 181. On the surface of the side plate 181 opposite to the surface on which the spiral body 182 is provided, a plurality of legs (not shown) are provided. Each leg portion is fixed in the casing 12 by a screw 22 screwed from the outside of the end plate portion 121 of the casing 12 at the front end surface thereof.
[0009]
In order to prevent fluid leakage along the screw 22, an O-ring (not shown) is disposed between the head of the screw 22 and the end plate portion 121. A groove is formed on the outer surface of the side plate 181. An O-ring 24 is disposed in the groove. The inside of the casing 12 is separated into a suction chamber 25 and a discharge chamber 26 by a side plate 181.
[0010]
A movable scroll member 19 is disposed in the suction chamber 25. The movable scroll member 19 includes a side plate 191 (second plate body) and a spiral body (second spiral body) 192 fixed on one surface of the side plate 191.
[0011]
The spiral body 192 of the movable scroll member 19 is engaged with the spiral body 182 of the fixed scroll member 18 with an angular shift of 180 degrees, and is superimposed so as to form a fluid pocket between the spiral bodies 182 and 192. . The movable scroll member 19 is connected to a drive mechanism and a rotation prevention mechanism 21 to be described later, and revolves on a circular orbit having a radius Ror by rotation of the main shaft 13 to compress the fluid.
[0012]
Here, the radius Ror of the circular orbit is generally given by (spiral winding pitch) −2 × (spiral winding wall thickness) / 2. Then, the spiral center of the spiral body 192 of the movable scroll member 19 is disposed so as to be separated from the spiral center of the spiral body 182 of the fixed scroll member 18 by a distance Ror.
[0013]
Therefore, the movable scroll member 19 revolves on the circular orbit having the radius Ror by the rotation of the main shaft 13. As a result, the line contact portion formed between the spiral bodies 182 and 192 and defining the fluid pocket moves toward the center along the surface of the spiral bodies 182 and 192. As a result, the fluid pocket decreases in volume. However, it moves toward the center of the spiral body 182,192. As a result, the fluid is compressed.
[0014]
The compressor housing 10 is provided with a suction port 29 and a discharge port 30 for connecting the casing 12 to an external fluid circuit. Here, the fluid introduced from the suction port 29 into the suction chamber 25 in the casing 12 is taken into a fluid pocket formed between the scroll members 18 and 19 and is compressed by the circular orbital motion of the movable scroll member 19. , Move to the center of the spiral body 182,192. The compressed fluid is discharged from the central chamber of the fluid pocket to the discharge chamber 26 through the discharge hole 218 drilled in the side plate 181 of the fixed scroll member 18, and flows out to the fluid circuit through the discharge port 30.
[0015]
Next, the drive mechanism of the movable scroll member 19 will be described with reference to FIGS. The main shaft 13 is rotatably supported by a ball bearing 31 disposed in the sleeve 15 of the front end plate 11. A disk rotor portion 131 is formed at the inner end of the main shaft 13. The disk rotor 131 is rotatably supported by a ball bearing 32 disposed in the through hole 111 of the front end plate 11. A drive pin 132 is provided at the tip of the disk rotor portion 131 so as to protrude in the axial direction at a position shifted from the center.
[0016]
On the other hand, an annular boss 193 is formed on the side plate 191 of the movable scroll member 19 on the surface opposite to the spiral body 192. A thick disc-shaped or short shaft-shaped bush 33 is fitted in the boss 193 so as to be rotatably supported via a needle bearing 34. The bush 33 includes an arc plate-shaped counterweight 331 that is integral with the bush 33 and extends in the radial direction.
[0017]
Further, the bush 33 is provided with an eccentric hole 332 at a position shifted from the center. A drive pin 132 is fitted in the eccentric hole 332. For this reason, the bush 33 is rotatably supported on the drive pin 132.
[0018]
The rotation preventing mechanism 21, the ball bearings 31, 32, and the needle bearing 34 constitute a spiral drive bearing component.
[0019]
As shown in FIGS. 5 and 6, the positional relationship between the center S of the main shaft 13, the center B of the bush 33, and the center D of the drive pin 132 following the eccentric hole 332 of the bush 33 is the distance between the center S and the center B. Is the aforementioned orbital radius Ror, and is opposite to the center S of the main shaft 13 with respect to a line orthogonal to the line connecting the center B of the bush 33 and the center S of the main shaft 13 through the center B of the bush 33 through the center D of the bush 33 The main shaft 13 is positioned so as to be on the side that is advanced in the rotation direction of the main shaft 13 (indicated by an arrow A in FIG. 6) from the line connecting the center S of the main shaft 13 and the center B of the bush 33.
[0020]
In such a configuration of the drive mechanism, the center B of the bush 33 can move on an arc having radii B to D with the center D of the drive pin 132 as the center. That is, when the main shaft 13 rotates, the bush 33 is pulled by the drive pin 132 and a force is applied to the center D of the bush 33 away from the center S of the main shaft 13, and the spiral body 192 of the movable scroll member 19 is fixed to the fixed scroll. It contacts the side wall 191 of the spiral body 182 of the member 18.
[0021]
Accordingly, the center of the movable scroll member 19 orbits around the center S of the main shaft 13 with the radius Ror. At this time, since the movable scroll member 19 is prevented from rotating by the rotation preventing mechanism 21, only the orbital motion is performed, and the movable scroll member 19 does not rotate.
[0022]
FIG. 7 shows the spiral of the fixed scroll member 18 and the fixed scroll member 19 when the drive pin is positioned on the X axis with the basic circle coordinates of the spiral body 182 of the fixed scroll member 18 as the reference coordinates. The combination state with the wound body 192 is shown.
[0023]
First, in FIG. 7, the gas compression force Fx generated in the X-axis direction is swirled because the seal points S1, S2, S3, and S4 of the side walls of the spiral bodies 182 and 192 are not collinear. If the base radius of the wound body 192 is rg, this shift width 2 · rg is added to the area (2 · rg · H) of the scroll member with the spiral wall height H.
[0024]
The spiral body wall height H refers to the height dimension of the spiral body 192 extending from the side plate 191 of the movable scroll member 19. Here, the pressure of each fluid pocket formed by the seal points S1, S2, S3, S4 is P2 and P1 outward from the center of the spiral bodies 182 and 192, and the outer periphery of the spiral bodies 182 and 192. When the pressure of the portion is Po, the gas pressure Fx can be expressed as Fx = 2.rg.H. (P2-P1) + 2.rgH. (P1-P0) = 2.rg.H. (P2-P0). .
[0025]
Further, since the gas compression reaction force Fy generated in the Y-axis direction is orthogonal to the line connecting the center of the bush 33 and the center of the main shaft 13, assuming that the axial torque is T and the orbit radius is ro, T = ro -It is expressed as Fy and is equal to the force as a compression load. Therefore, Fy = T / ro. Here, the gas compression reaction force means that the gas taken in by the fixed scroll member 18 and the movable scroll member 19 shown in FIG. 7 is compressed and is closed by the walls of the fixed / movable scroll members 18 and 19. The force generated by the pressure difference (P2> P1).
[0026]
On the other hand, when the fluid is compressed by the orbital movement of the movable scroll member 19, it is considered that the reaction of the gas compression reaction force Fy described above acts on the center B of the bush 33 as indicated by Fy in FIG. it can. By the way, since the bush 33 is rotatable on the drive pin 132, the bush 33 receives a moment rotating around the center D of the drive pin 132 by the gas compression reaction force Fy. This moment can be expressed as Fy · L · sin α where the angle α between the direction of the gas compression reaction force Fy and the line connecting the centers D and B is the angle α shown in FIG. However, L is a distance between the center D and the center B.
[0027]
As a result, the movable scroll member 19 supported on the bush 33 receives a moment that rotates around the center D of the drive pin 132. As a result, the spiral body 192 of the movable scroll member 19 is pressed against the side wall 181 of the spiral body 182 of the fixed scroll member 18. When this pressing force is fx, fx = Fy · tan α is given.
[0028]
By the way, the rotation prevention of the movable crawl member 19 is performed by the couple formed by the centrifugal force Fs of the movable scroll member 19 applied to the rotation prevention mechanism 21 and the force -FB acting in the crank direction as shown in FIG. Is called. Here, assuming that the rotational moment of the movable crawl member 19 is Ms, it is considered that the gas compression reaction force Fy acts on an intermediate point of a line connecting the center of the base circle of the spiral member 192 of the fixed scroll member 18 and the movable scroll member 19. For this reason, the deviation between this action and the driving point generates the rotational moment Ms. When center driving is performed, the driving point is made to coincide with the center of the base circle of the spiral body 192 of the movable scroll member 19, so that the deviation from the operating point of the gas compression reaction force Fy is 1/2 · ro. Therefore, since the moment Ms is Ms = ro / 2 · Fy, Ms = 1/2 · T.
[0029]
When this rotation moment Ms is received by the rotation prevention mechanism 21 using a ball element, if the distance from the rotation prevention point of the rotation prevention mechanism 21 to the bush 33 is L, Fs = Ms / L = 1/2 · T This reaction force -FB is applied in the X-axis direction of the bush 33.
[0030]
In addition to the above-described force, the bush 33 includes a centrifugal force Fs generated by the circular orbital motion of the movable scroll member 19 and the bush 33 and a centrifugal force Fc generated by the motion of the counterweight 331 provided on the bush 33. It adds as shown in FIG.
[0031]
The relationship between the forces acting on the bush 33 has been described above, but the sum ΣXF of the forces applied in the X-axis direction becomes the force acting on the spiral body 192 of the movable scroll member 19, and when ΣXF> 0, the movable scroll The spiral body 192 of the member 19 is pressed against the side wall of the spiral body 182 of the fixed scroll member 192. Here, the wall pressing force ΣXF, which is the sum in the X-axis direction, can be expressed as ΣXF = fx−Fa + Fs−Fc−Fx. In the conventional apparatus, ΣXF> 0 was set.
However, if ΣXF> 0 is set, the following drawbacks occur.
[0032]
That is, in the scroll type fluid machine, it is limited between the line contact portions of the spiral wound bodies 182 and 192 that mesh with each other. The line contact portion moves toward the center of the spiral bodies 182 and 192 along the surface of the spiral bodies 182 and 192 by the relative circular orbital movement of the scroll member, while reducing the volume thereof, and compresses the fluid. Therefore, it is necessary to ensure a sufficient sealing force at the line contact portion.
[0033]
However, if the contact force is increased to ensure the sealing force, the spiral bodies 182 and 192 will be worn. In particular, when the scroll type fluid machine is used at high speed rotation, the spiral body 192 of the movable scroll member 19 being driven is strongly pressed against the spiral body 192 of the fixed scroll member 18. Therefore, the driving force of the scroll type fluid machine is increased, and a large amount of wear powder is generated due to wear of the spiral wound bodies 182 and 192, which only adversely affects the scroll type fluid machine or the system including the scroll type fluid machine. Or mechanical efficiency will fall.
[0034]
Therefore, as shown in FIG. 10, the centrifugal force Fc of the counterweight 331 is set so that ΣXF = 0 or ΣXF <0 at the upper limit of the number of rotations used in the scroll type fluid machine.
[0035]
Further, the scroll type fluid machine includes a rotatable angle range regulating mechanism as shown in FIGS. 5 and 9. That is, a concave portion 133 is formed on the end surface of the main shaft 13 facing the bush 33 of the disk rotor portion 131, and a protruding portion 333 is formed on the end surface of the bush 33 facing the concave portion 133 of the disk rotor portion 131. It is provided. The protruding portion 333 is inserted and disposed in the recessed portion 133 with a gap. Here, the range in which the projecting portion 333 can move in the recessed portion 133 is the rotatable angle range of the bush 33, and the maximum gap between the spiral bodies 182 and 192 is determined thereby.
[0036]
FIG. 11 shows an example of static / dynamic balance. The unbalance amount of the movable scroll member 19 can be adjusted by the counterweight 331 and the balance weight 36 of the clutch armature. In FIG. 10, Us is an unbalance amount of the movable scroll member 19, Uc is an unbalance amount of the counterweight 331, Ub is an unbalance amount of the balance weight 35, and Ua is an armature. L1, L2, and L3 are distances between the balances in the longitudinal direction with respect to the main shaft 13.
[0037]
In this way, the counterweight 331 provided in the bush 33 is set so that the centrifugal force Fc is greater than the centrifugal force Fs generated by the circular orbital motion of the movable scroll member 19 and the bush 33. The excessive contact between the two spiral bodies 182 and 192 is prevented, and the wear between the spiral bodies 182 and 192 is kept small.
[0038]
However, since the centrifugal force Fs generated by the orbital motion of the movable scroll member 19 and the like and the centrifugal force Fc of the counterweight 331 satisfy Fc> Fs, unbalance is generated and vibration is generated. For this reason, it is necessary to maintain the dynamic balance of the entire scroll type fluid machine.
[0039]
Further, in the example of FIG. 4, balance weights 35 and 36 for generating centrifugal forces Fa and Fb are provided on the main shaft 13. That is, in FIG. 1, a balance weight 35 that generates centrifugal force in the same direction as the counterweight 331 is disposed on the main shaft 13 at a position close to the counterweight 331, and with respect to the balance weight 35, what is the counterweight 331? An armature balance weight 36 of the electromagnetic clutch 17 is disposed at an opposite position in the axial direction.
[0040]
The balance weight 35 is attached to the disk rotor portion 131 of the main shaft 13 by an appropriate fixing means, and the armature balance weight 36 is provided integrally with a part of the electromagnetic clutch.
[0041]
As described above, in the conventional scroll type fluid machine, as shown in FIG. 10, the load applied to the bush 33 is the gas compression reaction force Fy, the wall pressing force ΣXF (the total ΣXF in the X-axis direction, and the movable scroll member). The resultant force F1 of the centrifugal force Fc of the counterweight 331 that generates a centrifugal force in the opposite direction to balance the centrifugal force generated by the 19 circular orbital motions.
[0042]
[Problems to be solved by the invention]
However, in the scroll-type fluid machine of the prior art, the urging force that seals the spiral body 192 of the movable scroll member 19 and the spiral body 182 of the fixed scroll member 18 is reduced at high speed, so that the spiral bodies 182 and 192 Wear is reduced. In this case, the gas compression reaction force (eccentric bush driving force) Fy, the urging force for sealing the spiral body 192 of the movable scroll member 19 and the spiral body 182 of the fixed scroll member 18, and the centrifugal force Fc of the counterweight 331 The resultant force is applied to the bush 33, and this load shortens the life of the drive bearing 34 fitted to the bush 33.
[0043]
Further, this load is applied as moment load to the other bearings 31 and 32 supporting the main shaft 13, and a bearing having a large load capacity must be used.
[0044]
Therefore, an object of the present invention is to reduce the load applied to the drive bearing 34 fitted to the bush, further reduce the load applied to the other bearings 3 and 32 supporting the main shaft, and a bearing having a small load capacity. It is an object of the present invention to provide a scroll type fluid machine that can be used in a reduced amount of parts.
[0045]
In particular, since the load is reduced when the number of rotations is high, it is possible to operate at a high speed, and another object of the present invention is to apply the load applied to the bush without changing the wall pressing force and the static / dynamic balance. It is an object of the present invention to provide a scroll type fluid machine that can be reduced and can use a bearing having a small load capacity.
[0046]
[Means for Solving the Problems]
According to the present invention, the rotation of the main shaft is caused by the large diameter portion of the main shaft, A drive pin provided in the large diameter portion and an eccentric hole into which the drive pin is fitted bush, Coupled to the bush The counterweight and the spiral drive bearing component change the revolving motion of the movable scroll member that is eccentrically combined with the fixed scroll member by a predetermined distance, and compress the fluid while moving from the outer periphery to the inner periphery of the movable scroll member. Is done, By the counterweight , Against the centrifugal force generated by the revolving motion of the movable scroll member Anti In a scroll type fluid machine that generates centrifugal force in the opposite direction, When the direction of the centrifugal force acting on the movable scroll member is the X axis, the counterweight is made asymmetrical with respect to the X axis, so that the centrifugal force of the movable scroll member is opposite to the counterweight. The amount of unbalance that acts In a direction to reduce the gas compression reaction force applied to the bush Act Unbalance amount When A scroll type fluid machine characterized in that is added can be obtained.
[0047]
[Action]
According to the present invention, centrifugal force is generated by adding an unbalance amount of the counterweight in the direction opposite to the gas compression reaction force. The unbalance amount is obtained by multiplying the distance from the center of the rotation axis of the solid having the mass attached to the rotation axis to the center of gravity and the weight of the solid.
[0048]
Further, the centrifugal force is generated by adding the direction of the unbalance amount and the angle of the drive pin position of the main shaft from the center of the bush to the direction of the centrifugal force. These resultant forces can reduce the load applied to the bush by increasing the rotational speed of the main shaft.
[0049]
Further, an increase in the wall pressing force (wall pressing force (sum)) due to the centrifugal force can be canceled by the centrifugal force due to the unbalance amount in the direction of the centrifugal force.
[0050]
Further, since the load applied to the bush is reduced, the moment load applied to the bearing fitted to the bush and other bearings supporting the main shaft is also reduced.
[0051]
Furthermore, the imbalance between the static and dynamic balance caused by adding the counterweight unbalance amount can be adjusted by the balance weight of the counterweight and the clutch armature.
[0052]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a scroll type fluid machine according to the present invention will be described with reference to the drawings. FIG. 1 shows the load applied to the eccentric bush. FIG. 2 shows an example of static / dynamic balance. FIG. 3 shows the load / vector and resultant force applied to the eccentric bush.
[0053]
Note that the scroll type fluid machine according to the present embodiment has the same configuration as that of the scroll type fluid machine described in FIG. Description of the part is omitted.
[0054]
Referring to FIG. 3 together with FIG. 1 and FIG. 2, the bush 33 has a centrifugal force (movable scroll member 19 in the opposite direction) in order to balance the centrifugal force Fs generated by the circular orbital motion of the movable scroll member 19. Counterweight 331 for generating a reaction force Fc) of the centrifugal force Fs.
[0055]
The counterweight 331 adds an unbalance amount Fc1-Fc so as to be larger than the centrifugal force Fs of the movable scroll member 19, and unbalances the counterweight 331 in the direction of decreasing the gas compression reaction force Fy applied to the bush 33. A balance amount Uc2 is added.
[0056]
Next, referring to FIG. 2, the unbalance amount Vc1 of the counterweight 331 is the unbalance amount Uc and the bush 33 for balancing the centrifugal force Us of the spiral body 192 of the movable scroll member 19. If the direction of the gas compression reaction force Fy and the angle of the drive pin 132 position of the main shaft 13 from the center of the bush 33 are α, and the unbalance amount added in the direction of decreasing the gas compression reaction force Fy is Uc2, the movable scroll member 19 The unbalance amount Uc1 of the counterweight 331 in the direction opposite to the centrifugal force Fs generated in the equation is Uc1 = Uc + Uc2 × tan α.
[0057]
That is, the centrifugal force Fc2 is generated by adding the unbalance amount Uc2 of the counterweight 331 in the direction opposite to the gas compression reaction force Fy shown in FIG.
[0058]
Further, the unbalance amount Uc2 × tan α (α is the direction of the gas compression reaction force Fy applied to the bush 33 and the angle of the drive pin 132 position of the main shaft 13 from the center of the bush 33 is also added to the direction of the centrifugal force Fc1. A centrifugal force Fc1 is generated.
[0059]
Further, the imbalance between the static and dynamic balance caused by adding the unbalance amount Uc1-Uc of the counterweight 331 can be adjusted by the counterweight 331 and the balance weight 36 of the clutch armature.
[0060]
As shown in FIG. 2, in order to maintain the overall dynamic balance, the following unbalance amount may be set.
[0061]
Us: Unbalance amount of the spiral body 192 of the movable scroll member 19.
Uc1: Unbalance amount of the counterweight 331.
Ub1: Unbalance amount of the balance weight 35.
Ua1: the unbalance amount of the armature balance weight 36.
Ub2: an unbalance amount of the balance weight 35 for adjusting the static / dynamic balance imbalance caused by the unbalance amount Uc2 added to the counterweight 331.
Uc2: Unbalance amount of the balance weight 35 added in the opposite direction of the gas compression reaction force Fy.
Ua2: an unbalance amount of the balance weight 36 of the clutch armature that adjusts the imbalance between the static and dynamic balance generated by the unbalance amount Uc2 added to the counterweight 331.
[0062]
Where L1, L2, L3; distances between balances in the longitudinal direction with respect to the main axis,
Us-Uc1 -Ub1 + Ua1 = 0
Uc2 -Ub2 + Ua2 = 0
Ub1. + Uc1. (L2 + L3) -Us (L1 + L2 + L3) = 0
Ub 2 · L 3 −Uc 2 · (L 2 + L 3) = 0
[0063]
Referring to FIG. 3, the resultant force F2 of the gas compression reaction force Fy, the centrifugal force Fc2, the centrifugal force Fc1, and the wall pressing force ΣXF increases the load applied to the bush 33 as the rotational speed of the main shaft 13 increases. It becomes possible to decrease.
[0064]
Further, the increase in the wall pressing force ΣXF due to the centrifugal force Fc2 can be canceled by the centrifugal force (Fc1−Fc) due to the unbalance amount Uc2 × tanα in the direction of the centrifugal force Fc2.
[0065]
Further, since the load applied to the bush 33 is reduced, the moment load applied to the bearing 34 fitted to the bush 33 and the other bearings 31 and 32 supporting the main shaft 13 is also reduced.
[0066]
A detailed description of the load and balance around the bush 33 and the bearing is disclosed in Japanese Patent Application Laid-Open No. 59-215984 as a prior art.
[0067]
The present invention can also utilize this technique for the above-described scroll type fluid machine for a vacuum pump or an expander.
[0068]
【The invention's effect】
According to the scroll type fluid machine of the present invention, the load applied to the drive bearing 34 fitted to the bush 33 can be reduced, and further, the load applied to the other bearings 31 and 32 supporting the main shaft can be reduced. A bearing with a small capacity can be used, and the cost of parts can be reduced.
[0069]
Further, the load applied to the bush can be reduced without changing the wall pressing force and the static / dynamic balance, and a bearing with a small load capacity can be used, thereby reducing the cost.
[0070]
In particular, according to the scroll type fluid machine of the present invention, the load is reduced when the number of revolutions is high, so that a high revolution operation is possible.
[Brief description of the drawings]
FIG. 1 is an explanatory view for explaining a load applied to an eccentric bush of a scroll type fluid machine of the present invention.
FIG. 2 is an explanatory diagram showing an example of static / dynamic balance of the scroll type fluid machine of the present invention.
FIG. 3 is an explanatory diagram illustrating a load / vector and resultant force applied to an eccentric bush of the scroll type fluid machine of the present invention.
FIG. 4 is a central sectional view of a conventional scroll type fluid machine.
FIG. 5 is an exploded perspective view of the drive mechanism used in FIG. 4;
6 is an explanatory diagram for explaining an operation of an eccentric bush of the scroll type fluid machine shown in FIG. 4; FIG.
7 is an explanatory diagram for explaining a force applied to a spiral body of a movable scroll member of the scroll type fluid machine shown in FIG. 4; FIG.
8 is an explanatory diagram for explaining a force applied to an eccentric bush of the scroll type fluid machine shown in FIG. 4; FIG.
9 is an explanatory diagram for explaining a force generated by a rotation prevention mechanism of the scroll type fluid machine shown in FIG. 4; FIG.
10 is an explanatory diagram for explaining a load / vector and resultant force applied to an eccentric bush of the scroll type fluid machine shown in FIG. 4; FIG.
11 is an explanatory diagram for explaining a static / dynamic balance of the scroll type fluid machine shown in FIG. 4; FIG.
[Explanation of symbols]
10 Compressor housing
13 Spindle
18 Fixed scroll member
19 Movable scroll member
33 Bush
35, 36 Banlance weight
132 Drive pin
331 counterweight

Claims (2)

Rotation of the main shaft includes a large-diameter portion of the main shaft, a drive pin provided in the large-diameter portion, a bush having an eccentric hole into which the drive pin is fitted , a counterweight coupled to the bush , and a spiral drive bearing configuration the elements, instead of the revolving motion of only eccentrically combined movable scroll predetermined distance with respect to the stationary scroll member, which compression is performed while moving to the inner periphery of the fluid from the outer periphery of the movable scroll member, said counter weight by, in the scroll type fluid machine for generating a centrifugal force in opposition direction to the centrifugal force generated by the revolution of the movable scroll member,
When the direction of the centrifugal force acting on the movable scroll member is defined as the X axis, the counterweight is asymmetrically formed with respect to the X axis, so that the counterweight is opposite to the centrifugal force of the movable scroll member. scroll fluid machine, characterized in that the addition of the amount of unbalance acting in the direction of reducing the gas compression reaction force acting on the bush unbalanced weight acting. The scroll fluid machine of claim 1, wherein the amount of unbalance to balance against centrifugal force before Symbol movable scroll member Uc, the direction of the gas compression reaction force applied to the bushing from the center of the bush If the angle of the drive pin position of the main shaft is α and the unbalance amount acting in the direction of decreasing the gas compression reaction force is Uc2, the unbalance amount Uc1 acting in the direction opposite to the centrifugal force of the movable scroll member is A scroll type fluid machine characterized by the following formula.
Uc1 = Uc + Uc2 x tan α

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