JPH1047270A - Fluid machinery and work method of its rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce weight of rotors, and reduce the moment of inertia by forming hollow holes having an opening on the shaft directional one side in tooth trace parts in a pair of rotating rotors, and arranging a balance weight part to keep a rotational balance of the rotors on the inside in the radial direction of these hollow holes. SOLUTION: A screw rotor 35 whose rotor shaft is fixed to a shaft hole 67 is formed by arranging three tooth trace parts 71 in a rotor main body 65. Hollow holes 75 are arranged in the respective tooth trace parts 71 of such a screw rotor 35, and a wall part 77 is formed on the right side of the respective hollow holes 75, and an opening part 79 is formed on the left side. A balance weight part 81 is formed on the inside in the radial direction of the hollow holes 75 in the opening part 79. Machine work of a rotor main body 65 is performed with this balance weight part 81 as a work reference, and cutting work is performed on the balance weight part 81, and a rotational balance of the rotor main body 65 is kept. Therefore, since centrifugal force of the balance weight part 81 is not applied to the tooth trace 71 side, the formation of reinforcing ribs into the hollow holes 75 can be obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a fluid machine used for a supercharger of a vehicle and a method of machining a rotor used for the fluid machine.

[0002]

2. Description of the Related Art Conventionally, when such a fluid machine as described above is used in applications in which the rotational speed changes rapidly, such as a supercharger for an automobile engine, if the rotor is heavy and the inertia moment is large, The efficiency of the turbocharger, the fuel consumption of the engine, the response at the time of supercharging, etc., are reduced, and the rotors collide with each other, resulting in problems such as reduced durability.

[0003] Therefore, the gingival portion of the rotor is cut out along the tooth traces, a hollow hole is provided to reduce the weight of the rotor, and an inertia motor is provided.
There is a fluid machine that reduces the number of components.

Conventional fluid machines of this type include those described in, for example, JP-A-4-12189 and JP-A-4-31694.

The former is a roots blower. As shown in FIGS. 4 and 5, the roots blower 101 has a rotor housing 103 in which a suction port 105 and a discharge port 107 face each other. The suction port 105 and the discharge port 107 are provided.
Is formed with a rotor chamber 109 communicating with the rotor.

The rotor housing 109 contains a rotor housing 1.
03, a first rotor shaft 111 and a second rotor shaft 113 rotatably supported by the suction port 105 and the discharge port 1.
07 and at right angles to the line connecting the lines. A first rotor 115 and a second rotor 117 are mounted on the first rotor shaft 111 and the second rotor shaft 113, respectively, with a phase difference of 90 ° from each other. Has been fixed.

The convex gingival portion 115a of the first rotor 115
The convex gingival portion 117a of the second rotor 117 has hollow holes 119 and 121 formed in the meat portion along the axial direction, respectively, so that the weight of the rotors 115 and 117 is reduced and the moment of inertia is increased. Is reduced.

One end of each of the rotor shafts 111 and 113 is inserted into a gear chamber 123 provided adjacent to the rotor chamber 109, and the gear chamber 123 is interlocked by a gear transmission mechanism 125. . A driving pulley 127 is attached to the other end of the first rotor shaft 111.

When a rotational force is input to the driving pulley 127, the rotational force is transmitted to the first rotor 115 via the first rotor shaft 111, and is transmitted to the first rotor 115. From the rotor shaft 111 to the gear transmission mechanism 125 and the second rotor shaft 11
3 and is transmitted to the second rotor 117 in a synchronized manner. The first and second rotors 115 and 117 rotate while meshing with each other in a non-contact state, and the fluid sucked from the suction port 105 is discharged by the two rotors 115 and 117 to the discharge port 10.
7 to discharge.

The latter is a screw compressor 129, and as shown in FIGS. 6 and 7, a male rotor 1 having a plurality of convex gingiva portions 133a inside a casing 131.
33 and a female rotor 135 having a concave portion 135a meshing with the gingival portion 133a are arranged so as to be engaged with each other.
The male rotor shaft 137 and the female rotor rotatably supported by 31
And are fixed to the shaft 139 respectively.

Although not shown, a suction port is provided at one axial end of the casing 131. A discharge port 141 is provided at the other end in the axial direction.

A hollow hole 1 is formed inside the convex gingival portion 133a of the male rotor 133 along the axial direction of each gingival portion 133a.
43 are provided to reduce the weight of the male rotor 133 and reduce the moment of inertia.

It is necessary that the male rotor 133 closes a part of the hollow hole 143. If the hollow hole penetrates from the suction side end face to the discharge side end face of the rotor, the operation of the screw compressor is started. This is because, during the middle, the fluid flows from the high pressure side end face to the low pressure side end face through this hollow hole.

One end of each of the rotor shafts 137 and 139 is linked to each other by a transmission mechanism (not shown), and one of the rotor shafts, for example, the male rotor shaft 137, has a drive shaft. A pulley 145 is attached.

When a rotational force is input to the drive pulley 145, the rotational force is transmitted to the male rotor 133 via the male rotor shaft 137, and is transmitted to the male rotor shaft 137. And transmitted in synchronism to the female rotor 135 via the transmission mechanism and the female rotor shaft 139. And the rotor 13 of both sexes
3, 135 rotate while meshing with each other in a non-contact state, and pressurize the fluid sucked from the suction port while compressing the fluid, and
Discharge from 41.

[0016]

By the way, in this type of fluid machine, a minute gap is provided between both rotors so that the pair of rotors rotate while meshing with each other while maintaining a non-contact state. It is necessary to assemble each row for this purpose.
It is necessary to balance the rotation during rotation. The rotational balance of the rotor is corrected by cutting small holes or the like on both end faces in the axial direction and adjusting the weight.

However, in the above-mentioned conventional fluid machines, a hollow hole is provided inside the gingival part of the rotor by lightening in order to reduce the weight of the rotor and reduce the moment of inertia. Therefore, in each of the conventional examples, there is no balance correcting portion for cutting a small hole or the like for keeping the rotational balance on the axial end face of the rotor, and there is a problem that the rotational balance of the rotor cannot be corrected completely. .

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a fluid machine and a rotor machining method which can reduce the weight of the rotor and reduce the moment of inertia and can easily balance the rotation.

[0019]

According to the first aspect of the present invention, there is provided a fluid machine.
Inside a casing having a fluid inlet and a fluid outlet,
What is claimed is: 1. A fluid machine in which a pair of rotors rotating while meshing with each other are arranged, wherein a hollow hole having an opening at least on one axial side is formed in said rotor. A balance weight portion for balancing the rotation of the rotor is provided radially inward of the hollow hole.

As described above, in the fluid machine of the first aspect, the centrifugal force applied to the balance weight portion is reduced by providing the balance weight portion radially inside the hollow hole, and the centrifugal force of the hollow hole is reduced. Since it does not touch the tooth ridge side, no deformation (bulging) of the tooth ridge occurs.

Therefore, it is not necessary to provide a reinforcing rib in the hollow hole to prevent the rotor from being deformed by the centrifugal force of the balance weight portion, and it is not necessary to make the wall of the hollow hole thicker. An increase in the weight of the motor and the moment of inertia are prevented.

Further, since the bulge of the tooth ridge due to centrifugal force is small, occurrence of unbalance and vibration due to the bulge, contact with the other rotor or casing, seizure and vibration due to contact, and deterioration of performance are prevented. Is done.

According to a second aspect of the present invention, there is provided the fluid machine according to the first aspect, wherein the balance weight portion is disposed on the opening side, and the same effects as those of the first aspect are obtained.

According to a third aspect of the present invention, there is provided the first or second aspect.
3. The fluid machine according to claim 1, wherein the rotor is a screw-type fluid machine having a screw-shaped toothed portion, and an effect equivalent to that of claim 1 or claim 2 is obtained.

In the screw type fluid machine, a slight increase in the inertia moment tends to greatly reduce the performance and the response, and the tooth ridge is easily expanded by centrifugal force, but the wall of the hollow hole is made thick. No need for inertia mode due to high speed rotation
This is particularly advantageous because adverse effects of an increase in the number of teeth and swelling of the tooth ridges can be extremely small.

A fluid machine according to a fourth aspect is the fluid machine according to the first or second aspect, wherein the rotor is a roots blower type fluid machine having a toothed portion formed along an axial direction. In this case, an effect equivalent to that of claim 1 or claim 2 is obtained.

According to a fifth aspect of the present invention, there is provided a rotor for a fluid machine in which a pair of rotors which rotate while meshing with each other at the teeth are arranged inside a casing having an inlet and an outlet for fluid. A method of machining a rotor, wherein each rotor is machined with a balance weight portion formed radially inward of a hollow hole provided in the toothed portion as a machining reference, and thereafter the balance weight portion is balanced. It is characterized in that cutting is performed to balance the rotation of the rotor.

According to this processing method, precision processing of each part of the rotor becomes possible, and the rotation balance of the rotor is adjusted to a certain degree by precisely processing each part. -The balance correction of the data is completed,
The balance correction cost can be greatly reduced.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. This embodiment is defined in claims 1, 2, 3, 5
FIG. 1 is a block diagram showing the use of this embodiment.
The charger 1 is shown. Left and right directions are Figs.
The members and the like without the reference numerals are not shown.

As shown in FIG. 1, this supercharger 1
Is composed of an input pulley 3, a speed increasing gear set 5, a timing gear set 7, a screw type compressor 9 (the fluid machine of the embodiment), and the like.

The input pulley 3 is supported by a bearing 11 on a compressor casing 13 and is spline-connected to an input shaft 15 so that a bolt 17 and a washer 1 are provided.
9 and fixed. The input pulley 3 is connected to a pulley on the crankshaft side via a belt. The pulley on the crankshaft side is connected to the engine and the
The input pulley 3 is rotatably driven by the driving force of the engine via the electromagnetic clutch.

The input shaft 15 is supported by a ball bearing 21 inside the casing 13.
A seal 25 is arranged between the collar 23 mounted on the casing and the casing 13 to prevent oil leakage.

The speed increasing gear set 5 is composed of large and small diameter speed increasing gears 27 and 29 meshed with each other, and the timing gear set 7 is a large diameter and small diameter timing gear 3 meshed with each other.
1, 33. The speed increasing gear set 5 and the timing gear set 7 are arranged in a gear chamber 34 formed in the casing 13. Further, as shown in FIG. 1, the air compressor 9 includes male and female screw rotors 35 and 37.

The large-diameter speed increasing gear 27 is formed integrally with the right end of the input shaft 15, and the small-diameter speed increasing gear 29, together with the large-diameter timing gear 31, is a female screw rotor 37.
Is connected to the rotor shaft 39 by a key 41, and the nut 43 prevents the rotor shaft 39 from falling off. Also, the small-diameter timing gear 33
Is a male screw via a tapering fixing mechanism 45.
The rotor 35 is connected to a rotor shaft 47 of the rotor 35.

The taper ring fixing mechanism 45 engages the timing gear 33 with the timing gear 31 in a state where the respective screw rotors 35 and 37 do not contact each other, and then locks the nut 49 by tightening it. Each of the screw rotors 35, 37 and the compressor casing 13 can maintain a clearance during operation.
Positioning in the rotation direction of 37 is performed.

The left and right ends of the rotor shafts 47 and 39 of the screw rotors 35 and 37 are respectively casing by a ball bearing 51 and the right end by a collar 53 and a roller bearing 55. 13 is supported. or,
A seal 59 is disposed between the casing 13 and the collar 57 mounted on the left end of the rotor shafts 39 and 47, and between the casing 53 and the collar 53 at the right end. Is a seal 61
Are arranged to prevent air leakage.

The driving force of the engine input from the pulley 3 is increased by the speed increasing gear set 5 and drives the screw rotors 35 and 37 to rotate via the timing gear set 7. The driven compressor 9 pumps the intake air sucked from the suction port 63 (inflow port) to the left in the axial direction between the screw rotors 35 and 37, discharges it from the discharge port (outflow port), and supplies it to the engine. .

The male screw rotor 35 has a rotor shaft 47 fixed to a shaft hole 67 of a rotor body 65, and the female screw rotor 37 is similarly rotatable. Body 69
The rotor shaft 39 is fixed to the shaft hole.

As shown in FIG. 2, the rotor main body 65 of the screw rotor 35 has three screw-shaped toothed portions 71. The rotor body 69 of the female screw rotor 37 has four screw-shaped toothed portions 73. These rotor bodies 65 and 69 are cast from aluminum.

As shown in FIGS. 2 and 3, a hollow hole 75 is provided in each toothed portion 71 of the male screw rotor 35. Each hollow hole 75 has a wall 77 formed on the right side and an opening 79 formed on the left side. The wall 77 closes the hollow hole 75 to prevent pressure leakage between the discharge side and the suction side of the compressor 9.

Each opening 79 has a balance weight portion 81 formed radially inside the hollow hole 75. These hollow holes 75, opening portions 79, balance weight portions 81, and the like are formed using a core during casting. Rotor body 65
A hammer hole 83 for a hammer that supports the core at the time of casting is provided on the right end side.

The machining of the rotor body 65 is performed using the balance weight portion 81 as a machining reference. Thereafter, the balance weight portion 81 is subjected to a cutting process so that the rotor body 6 is machined.
Balance the rotation of 5.

Next, the processing procedure of the male screw rotor 35 will be described, including the processing method of the rotor according to the present invention. Hereinafter, the shape and dimensions of each member are different before and after processing, but the reference numerals are unified before and after.

In the first step, the rotor body 65 is cast.

In the second step, as shown in FIG.
2 is supported by a spindle 85 of a lathe. As shown in FIG. 2, the balance weight portion 81 of each hollow hole 75 is gripped by a chuck 87 to support the rotor body 65 at both ends, and the outer diameter is cut.

At this time, the rotor main body 65 is positioned in the radial direction by the outer peripheral surface 89 of the balance weight portion 81, and the rotor main body 65 is positioned in the axial direction by the axial surface 91.

In the third step, the shaft hole 67 is machined based on the cut outer diameter.

In the fourth step, rough cutting is performed on the tooth ridge 71 with reference to the shaft hole 67.

In the fifth step, a coating is applied to the rotor main body 65 (tooth ridge 71) which has been subjected to the coarse gear cutting.

In the sixth step, this coating layer is subjected to precise finishing gear cutting.

It should be noted that the coarse tooth cutting of the tooth lead portion 71 is performed by using the shaft hole 6.
In some cases, the rotor shaft 47 is fixed to 7, and the rotor shaft 47 is used as a reference.

Thus, the supercharger 1 (the screw compressor 9: the fluid machine of the embodiment) is constituted.

In this supercharger 1, as described above, a hollow hole 75 is provided in each toothed portion 71 of the screw rotor 35, and a radially inner side of the hollow hole 75 on the opening 79 side is provided. Since the balance weight portion 81 is provided in the first hole, the centrifugal force of the balance weight portion 81 is not applied to the tooth streak 71 side of the hollow hole 75.

Therefore, the screw rotor 3 by centrifugal force
It is not necessary to provide a reinforcing rib in the hollow hole 75 in order to prevent the deformation of the screw hole 5, and it is not necessary to make the wall of the hollow hole 75 thick, so that the weight of the screw rotor 35 and the inertia −
This prevents the increase in fuel consumption and improves the response during supercharging and fuel efficiency of the engine.

The bulge of the toothed portion 71 is reduced by the centrifugal force of the balance weight portion 81, so that the unbalance due to the bulge and vibration, the screw rotor 37 on the other side due to the bulge, and the like. Case 1
3, seizure due to the contact, vibration, performance degradation, and the like are prevented.

Further, since the machining of the screw rotor 35 is performed with reference to the balance weight portion 81, it is possible to machine each portion precisely. As described above, since the rotation balance is adjusted to some extent by precisely processing each part, after machining, the balance weight of the screw rotor 35 is completed only by applying a small amount of cutting to the balance weight portion 81. In addition, the cost for correcting the balance is greatly reduced.

Further, the fluid machine of the present invention is not limited to applications such as a compressor which operates by applying a rotational force to a rotor as in the embodiment, but also provides a pressurized fluid to rotate the rotor from the rotor. May be used as a motor for extracting the

The arrangement of the balance weight portion 81 and the processing based on the processing of the portion 81 in the present embodiment are not limited to the screw type compressor 9 but can be applied to a rotor of a roots blower type fluid machine. Of course.

[0059]

According to the fluid machine of the first aspect, the balance weight portion is provided radially inside the hollow hole formed in the rotor, so that the centrifugal force of the balance weight portion is on the toothed side of the hollow hole. I can't take it.

Accordingly, it is not necessary to provide a reinforcing rib in the hollow hole in order to prevent the deformation of the rotor, and it is not necessary to make the wall of the hollow hole thick, so that the weight and inertia moment of the rotor are reduced. Is prevented from increasing.

Since the balance weight portion is provided radially inward of the hollow hole, the bulge of the tooth ridge due to centrifugal force is also reduced, and the unbalance and vibration due to the bulge, the mating rotor and the casing are reduced. Contact, seizure due to contact, performance degradation, and the like are prevented.

According to the second aspect of the invention, the same effect as that of the first aspect is obtained.

The invention of claim 3 is the invention of claim 1 or claim 2.
This is particularly advantageous because the effect equivalent to that of the above configuration is obtained, and the wall of the hollow hole does not need to be thickened, and the adverse effect of the increase in the inertial moment due to the high-speed rotation and the bulging of the tooth ridge are extremely small. is there.

A fluid machine according to a fourth aspect is a roots type fluid machine in which the tooth portions of the rotor are formed along the axial direction, and has the same effect as the first or second aspect. obtain.

According to the rotor processing method of the fifth aspect, since the rotor is machined with reference to the balance weight portion provided radially inside the hollow hole of the rotor, the rotor is machined.
Each part of the rotor is precisely machined, and the rotor balance can be corrected simply by making a small cut to the balance weight part.
Repair costs are greatly reduced.

[Brief description of the drawings]

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

FIG. 2 is a view taken in the direction of arrow A in FIG. 3 and shows a male screw rotor according to one embodiment.

FIG. 3 is a cross-sectional view taken along the line BB of FIG. 2, showing a cross section along a tooth trace.

FIG. 4 is a sectional view showing a first conventional example.

FIG. 5 is a sectional view taken along line CC of FIG. 4;

FIG. 6 is a sectional view showing a second conventional example.

FIG. 7 is a sectional view taken along line DD of FIG. 6;

[Explanation of symbols]

 9 Screw-type compressor (fluid machine) 13 Casing 35, 37 Screw rotor (Rotor) 63 Inlet (inlet) 71 Toothed line 75 Hollow hole 79 Opening 81 Balance weight

Claims (5)

[Claims] 1. A fluid machine comprising: a casing having a fluid inlet and a fluid outlet; and a pair of rotors arranged and rotated while meshing with each other in a toothed portion of the casing.
A hollow hole having an opening at least on one side in the axial direction is formed in the tooth trace portion of the rotor, and a balance weight portion for balancing the rotation of the rotor is provided radially inside the hollow hole. Fluid machine characterized by the following. 2. The fluid machine according to claim 1, wherein the balance weight portion is disposed on an opening side of the hollow hole. 3. The fluid machine according to claim 1, wherein the rotor is a screw-type fluid machine having a screw-shaped toothed portion. 4. The fluid machine according to claim 1, wherein the rotor is a roots blower type fluid machine having a toothed portion formed along an axial direction. . 5. A method for processing a rotor of a fluid machine in which a pair of rotors which rotate while meshing with each other at teeth are disposed inside a casing having an inlet and an outlet for a fluid. The balance weight portion formed on the radially inner side of the hollow hole provided in the tooth trace portion is processed using a balance weight portion as a processing reference.
A method of processing a rotor of a fluid machine, wherein each part of the rotor is processed, and thereafter, the balance weight portion is subjected to balance cutting to balance the rotation of the rotor.