JPH0953580A - Fluid machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of misalignment between the rotor body and the rotor shaft of a hollow rotor and to adjust a rotation balance. SOLUTION: A shaft hole 69 is formed in a cast rotor body 67 wherein a hollow part 67 and an opening 79 are formed in a tooth trace part 73 by means of a core and a rotor shaft 47 is fixed in the shaft hole 69 to constitute a hollow screw rotor 35. A linear part 81 chucked during machining work is formed on the inner peripheral side of the opening 79.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A rotor 201 as shown in FIG.
The screw type compressor 203 as shown in FIG. 6 is described in the publication No. 311694.

A rotor 201 shown in FIG. 5 is a male screw rotor for a screw compressor, and has a rotor body 2
The rotor shaft 207 is fixed to 05. or,
The screw type compressor 203 of FIG. 6 includes male and female screw rotors 209 and 211 meshing with each other, and the rotors 209 and 211 respectively fix rotor shafts 217 and 219 to rotor bodies 213 and 215, respectively. It is configured.

Since the male type screw rotor of the screw type compressor which has been used conventionally has a large tooth thickness, when it is solid, the moment of inertia is large. When a screw type compressor with a large rotor inertia moment is used for a supercharger, the drive energy loss of the engine is large, the response at the time of acceleration is deteriorated, and it is necessary to increase the size of the clutch that engages and disconnects with the engine.

Therefore, the rotors 201 and 209 are provided with hollow portions 225 and 227 in the tooth lines 221 and 223 of the rotor bodies 205 and 213, respectively, to reduce the weight and reduce the moment of inertia.

[0006]

In a solid rotor having no hollow portion in the tooth trace portion, when the rotor main body is cast, the rotor shaft is fixed by the cast groove when the rotor main body is cast. When cutting the rotor body,
A shaft hole is provided in a round bar having a diameter larger than that of the finished rotor, the rotor shaft is fixed to the shaft hole, and then a rotor tooth line is formed on the outer circumference of the round bar. In all of these solid rotors, there is little misalignment between the center of rotation of the rotor body and the rotor shaft.

On the other hand, in the case of a hollow rotor such as the rotors 201 and 209, a shaft hole is formed in the rotor body, and the rotor shaft is fixed in this shaft hole.

In machining the shaft hole, an appropriate place for chucking to the rotor body is required, but in the hollow rotor, a place where chucking is possible in addition to chucking the hollow portion of each tooth line or the outer periphery of the rotor body. There is no. But,
In the hollow portion 225 of the rotor 201, there is no place to be chucked, and in the case of the rotor 209, the inner peripheral portion 22 of the hollow portion 227.
Reference numeral 9 is a curved surface, and an accurate surface for chucking is not prepared.
When 9 is chucked to form the shaft hole, misalignment between the rotor body and the rotor shaft is likely to occur.

When the outer periphery of the hollow rotor is chucked,
The hollow tooth line is deformed by the clamping force at the time of chucking, and this deformation causes misalignment of the shaft hole. Further, if the hollow rotor during chucking is before the tooth line forming process, in addition to the center line displacement due to the deformation, the shaft hole center line displacement due to the tooth line forming process is added, and a large center line displacement occurs.

Further, when the rotor main body is cast and the hollow portion is formed by the core, the misalignment between the core and the shaft hole largely breaks the rotational balance, and thus the cost for correcting the balance is great.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a fluid machine capable of precisely aligning the rotor body with the rotor shaft while making the rotor body a hollow structure to reduce the moment of inertia.

[0012]

A fluid machine according to claim 1 is
A hollow rotor having a hollow portion having an opening and a rotor shaft fixed to a shaft hole of a rotor body provided in a toothed portion is provided, and a straight portion for chucking at the time of machining is formed on an inner peripheral side of the opening. It is characterized by

As described above, in the fluid machine according to the first aspect, since the linear portion for the chuck is formed on the inner peripheral side of the opening of the hollow portion,
If these straight portions are chucked to form holes for the rotor shaft, the rotor body and the rotor shaft can be precisely aligned. In addition, the forming process of the tooth line portion (tooth shape) is performed at the same time as the processing of the shaft hole, or if the rotor shaft is fixed to the shaft hole thus processed and then the rotor shaft is used as a reference, It is possible to obtain a hollow rotor having a well-balanced rotational balance and no deviation.

In this way, it is possible to obtain a hollow rotor which has a hollow structure, is light in weight, has a small moment of inertia, and is free from misalignment between the rotor body and the rotor shaft and has a good rotational balance. Therefore, the balance correction of the rotor is unnecessary, or even if it is necessary, the correction amount and the correction cost are extremely small.

A fluid machine according to a second aspect is the fluid machine according to the first aspect, in which the hollow rotor is a screw rotor having a screw-shaped tooth line portion, and the rotor body is the same as the fluid machine according to the first aspect. There is no misalignment between the rotor shaft and the rotor shaft, and a hollow rotor with good rotation balance can be obtained.

In addition to this, generally, it is used at a higher speed than a roots type fluid machine using a rotor having a cocoon section.
The effect of the present invention is large in that a hollow rotor having a well-balanced rotation balance can be obtained in a screw-type fluid machine in which a bad influence such as vibration due to the breakdown of the rotation balance is likely to occur.

A fluid machine according to a third aspect is the fluid machine according to the first or second aspect, in which the hollow rotor is cast, and a hollow portion, an opening and a straight portion are formed by using a core having a straight portion on the inner peripheral side. It was formed. The cores (hollow parts), which are arranged in the tooth traces provided at equal intervals in the rotation direction, are in a position where rotation is balanced on the rotor body, and the linear parts formed in these hollow parts are chucked during processing. Claim 1 due to the location
Alternatively, similarly to the fluid machine of No. 2, there can be obtained a hollow rotor having a good rotational balance without any misalignment between the rotor body and the rotor shaft.

In addition to this, the casting process makes it easy to process a hollow rotor having a complicated shape, and the hollow rotor can be manufactured at a lower cost than other processing methods. Further, in a cast hollow rotor in which the misalignment between the position of the core (hollow portion) and the rotor shaft significantly deteriorates the rotational balance, a hollow rotor having a good rotational balance can be obtained, and the balance correction cost is greatly reduced. Is especially effective.

Further, since the linear portion for the chuck is formed over the entire axial direction of the hollow portion by the linear portion of the core, even if the end portion of the rotor main body is cut as necessary, the linear portion and the rotor shaft are The core of the will not go mad.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. This embodiment has the features of claims 1, 2 and 3, and FIG. 1 shows a supercharger 1 using this embodiment. The left and right directions are the left and right directions in FIGS. 1 and 2, and members and the like without reference numerals are not shown.

As shown in FIG. 1, the supercharger 1 is
The input pulley 3, the speed increasing gear set 5, the timing gear set 7, the screw compressor 9 (the fluid machine of the embodiment), and the like are included.

The input pulley 3 is supported by the compressor casing 13 by bearings 11 and is spline-connected to the input shaft 15, and the bolt 17 and the washer 1 are connected.
9 and fixed. The input pulley 3 is connected to a pulley on the crankshaft side via a belt. An electromagnetic clutch is arranged on the crankshaft side pulley to connect and disconnect the engine and the supercharger 1. The input pulley 3 is rotationally driven by the driving force of the engine via this electromagnetic clutch.

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

The speed-increasing gear set 5 is composed of large-diameter and small-diameter speed-increasing gears 27 and 29 meshing with each other, and the timing gear set 7 has a large-diameter and small-diameter timing gear 3 meshing with each other.
1, 33. Also, the air compressor 9
Has male and female screw rotors 35, 37.

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

The taper ring fixing mechanism 45 engages the timing gear 33 with the timing gear 31 in a state where the screw rotors 35 and 37 are not in contact with each other, and then tightens and locks the nut 49 to lock the screw rotors 35 and 37. Positioning of 37 in the rotational direction is performed.

The rotor shafts 47 and 39 of the screw rotors 35 and 37 are supported by the casing 13 at the left end by a ball bearing 51 and at the right end by a collar 53 and a roller bearing 55, respectively. or,
A seal 59 is arranged between the collar 57 attached to the left end portions of the rotor shafts 39 and 47 and the casing 13, and a seal 61 is arranged between the collar 53 at the right end portion and the casing 13.
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 rotationally drives the screw rotors 35 and 37 via the timing gear set 7. The driven compressor 9 pumps the intake air sucked from the suction port 63 leftward in the axial direction between the screw rotors 35 and 37,
It is discharged from the discharge port 65 and supplied to the engine.

The screw rotor 35 includes a rotor body 67.
The rotor shaft 47 is fixed to the shaft hole 69 of
Similarly, the screw rotor 37 is also constructed by fixing the rotor shaft 39 to the shaft hole of the rotor body 71.

As shown in FIGS. 3 and 4, the rotor body 67 of the male screw rotor 35 is provided with three screw-shaped tooth traces 73. Also, the female screw rotor 3
The rotor main body 71 of No. 7 has four screw-shaped tooth line portions. These rotor bodies 67, 71 are castings made of aluminum alloy.

Each tooth line portion 7 of the male screw rotor 35
3, a hollow portion 75 is formed. As shown in FIGS. 1 and 2, the wall portion 77 is provided on the left side of the hollow portion 75, and the opening 79 is provided on the right side. As shown in FIGS. 3 and 4, a linear portion 81, a rib 83, and a balancer portion 85 are formed in each opening 79. The hollow portion 75, the opening 79 and the like are formed at the time of casting by using a core having a straight portion on the inner peripheral side.

The left wall portion 77 closes the hollow portion 75 to prevent pressure leakage between the discharge side and the suction side of the compressor 9. Further, the ribs 83 reinforce the opening 79, and prevent the bulging of the tooth line portion 73 due to the centrifugal force and the contact between the screw rotors 35 and 37 and the contact between the screw rotor 35 and the casing 13 due to the bulging. Further, the balancer portion 85 balances with the left wall portion 77 during rotation to prevent vibration.

The straight line portion 81 is formed on the inner peripheral side of each tooth line portion 73, and is provided for a chuck of a cutting machine. As shown in FIG. 3, the tooth traces 73 are separated from each other by 12
The hollow portions 75 are arranged at equal intervals at an angle of 0 °, and the hollow portions 75 are located on the rotor body 67 in a rotationally balanced position.
Therefore, when the rotor body 67 is rotated as indicated by the arrow 87 in FIG. 4, the linear portion 8 of each tooth line portion 73 is rotated by the three plate-shaped chuck tools 89 arranged at an angle of 120 °.
1 can be chucked with a uniform hit.

The shaft hole 69 of the rotor body 67 and the tooth line portion 73
The machining is performed in the state where the linear portion 81 is chucked as described above. Therefore, the tooth line portion 73 (tooth shape and hollow portion 7
Since 5) and the shaft hole 69 are accurately aligned with each other, the rotation balance of the screw rotor 35 is basically adjusted only by fixing the rotor shaft 47 to the shaft hole 69.

Thus, the supercharger 1 is constructed.

Since the supercharger 1 has no imbalance of the screw rotor 35, vibration is reduced and durability of each bearing 51, 55 is greatly improved.
The contact between the screw rotors 35 and 37 and the contact between the screw rotor 35 and the casing 13 are prevented, so that the function and performance are kept normal.

Further, since the hollow screw rotor 35 is lightweight and has a very small moment of inertia and has a good rotational balance as described above, the vehicle equipped with the supercharger 1 has improved fuel efficiency of the engine and response at the time of acceleration. At the same time, the screw rotors 35 and 37 are prevented from coming into contact with each other during rapid acceleration / deceleration (when the supercharger 1 is started and stopped). In addition, the electromagnetic clutch that connects and disconnects the engine and the supercharger 1 can be downsized.

As described above, the screw rotor 35 basically maintains the rotational balance by chucking the linear portion 81 at the time of cutting. Therefore, it is unnecessary or necessary to correct the balance. Also requires a very small amount of modification and modification cost.

In addition to this, in a cast hollow rotor in which the hollow portion 75 is formed by a core like the screw rotor 35, the misalignment between the core position and the rotor shaft 47 has a great influence on the rotational balance. According to the present invention, by preventing these misalignment, the balance correction cost is significantly reduced.

Further, according to the casting process, even the hollow screw rotor 35 having a complicated shape can be easily processed and can be manufactured at a lower cost than other processing methods.

Since the linear portion 81 for chucking is formed in the entire axial direction of the hollow portion 75 by the linear portion of the core, even if the end portion of the rotor main body 67 is cut as necessary, the linear portion 8
The core of 1 and the rotor shaft 47 does not go out of order.

Further, according to the present invention, even in the screw type compressor 9 which is generally used at a higher speed than a roots type fluid machine using a rotor having a cocoon type cross section, and vibrations due to unbalance are likely to occur. Advantageously, a good screw rotor 35 is obtained.

Thus, the screw rotor 35 having a hollow structure and having no misalignment can be obtained.

In the present invention, the hollow rotor may be manufactured by plastic working such as drawing or extrusion in addition to casting.

Further, the fluid machine of the present invention may be a roots type fluid machine using a hollow rotor having a cocoon-shaped cross section.

[0046]

In the fluid machine according to the first aspect of the present invention, when the rotor body is subjected to axial hole machining or tooth molding, the linear portion formed in the opening of the hollow portion is chucked. Therefore, the core of the rotor body and the rotor shaft is A hollow rotor having a good rotational balance can be obtained because the matching can be performed precisely.

In this way, a hollow rotor having a hollow structure and a reduced weight and a small moment of inertia can be obtained while the rotor body and the rotor shaft are not misaligned. Therefore,
No rotor balance correction is necessary, or if necessary, it can be done with very little modification and cost.

A fluid machine according to a second aspect uses the hollow screw rotor in the fluid machine according to the first aspect, has the same effect as that of the fluid machine according to the first aspect, and is generally used at high speed rotation. In a screw type fluid machine, which is likely to be adversely affected by the loss of rotational balance, the effect of the present invention is large in that a hollow rotor having basically good rotational balance can be obtained.

A fluid machine according to a third aspect is the fluid machine according to the first or second aspect, wherein the hollow rotor is cast and processed, and
A hollow part, an opening, and a straight part are molded with a core,
While obtaining the same effect as the fluid machine according to claim 1 or 2,
According to the casting process, a hollow rotor having a complicated shape can be easily processed, and the hollow rotor can be manufactured at a lower cost than other processing methods. In addition, in a cast hollow rotor in which the misalignment between the position of the core (hollow portion) and the rotor shaft significantly deteriorates the rotational balance, the effect of the present invention is to obtain a hollow rotor with prevented rotational misalignment and well-balanced rotational balance. In addition to being particularly large, the balance correction cost can be significantly reduced.

Further, since the linear portion for the chuck is formed by the linear portion of the core along the entire axial direction of the hollow portion, even if the end portion of the rotor body is cut as necessary, the linear portion and the rotor shaft are not separated. The core of the will not go mad.

[Brief description of drawings]

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

2 is a cross-sectional view taken along the line AA in FIG. 3, showing a male screw rotor 35. FIG.

FIG. 3 is a view taken in the direction of arrow B in FIG. 2, showing the end of the male screw rotor 35.

FIG. 4 is a male type screw rotor 35 having a chucked end.
FIG.

FIG. 5 is a side view showing a conventional screw rotor.

FIG. 6 is a cross-sectional view showing another conventional screw compressor.

[Explanation of symbols]

 9 Screw type compressor (fluid machine) 35 Male type screw rotor (hollow rotor) 47 Rotor shaft 67 Rotor body 69 Shaft hole 73 Tooth line part 75 Hollow part 79 Opening 81 Straight part

Claims (3)

[Claims] 1. A hollow rotor having a hollow portion having an opening, wherein a rotor shaft is fixed to a shaft hole of a rotor main body provided in a toothed portion, for chucking the inner peripheral side of the opening during machining. A fluid machine having a straight portion. 2. The fluid machine according to claim 1, wherein the hollow rotor is a screw rotor having screw-shaped toothed portions. 3. The fluid machine according to claim 1, wherein the hollow rotor is cast, and the hollow portion, the opening, and the straight portion are formed by a core having a straight portion on the inner peripheral side.