JP3569044B2 - Fluid machinery - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fluid machine used for, for example, a supercharger of a vehicle.
[0002]
[Prior art]
Published practical application JP-A-63-198401 discloses a rotor 201 as shown in FIG. 5, and JP-A-4-31694 discloses a screw compressor 203 as shown in FIG.
[0003]
A rotor 201 in FIG. 5 is a male screw rotor for a screw compressor, and is configured by fixing a rotor shaft 207 to a rotor main body 205. 6 includes male and female screw rotors 209 and 211 meshing with each other, and the rotors 209 and 211 fix rotor shafts 217 and 219 to rotor bodies 213 and 215, respectively. It is configured.
[0004]
Since the male screw rotor of the screw compressor used conventionally has a large tooth thickness, if it is solid, the moment of inertia is large. When a screw type compressor having a large moment of inertia of the rotor is used for a supercharger, the driving energy loss of the engine is large, the response at the time of acceleration is deteriorated, and the clutch for intermittently connecting with the engine needs to be large.
[0005]
Therefore, the rotors 201 and 209 are provided with hollow portions 225 and 227 in the teeth 221 and 223 of the rotor bodies 205 and 213, respectively, to reduce the weight and reduce the moment of inertia.
[0006]
[Problems to be solved by the invention]
When the rotor main body is cast in a solid-structured rotor having no hollow portion in the toothed portion, the rotor shaft is fixed with a cast-in when the rotor main body is cast. Also, when cutting the rotor body, a shaft hole is provided in a round bar having a diameter larger than that of the finished rotor, and the rotor shaft is fixed to the shaft hole. . In all of these solid rotors, there is little misalignment between the rotation center of the rotor body and the rotor shaft.
[0007]
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 to the shaft hole.
[0008]
When machining the shaft hole, an appropriate place for chucking the rotor body is necessary. However, in the hollow rotor, there is no place that can be chucked other than chucking the hollow portion of each tooth or the outer periphery of the rotor body. However, there is no place to be chucked in the hollow portion 225 of the rotor 201, and in the case of the rotor 209, the inner peripheral portion 229 of the hollow portion 227 is curved and an accurate surface for chucking is not prepared. When the shaft hole is formed by chucking such a curved inner peripheral portion 229, misalignment between the rotor body and the rotor shaft is likely to occur.
[0009]
Further, when the outer periphery of the hollow rotor is chucked, the hollow tooth streaks are deformed by the clamping force at the time of chucking, and this deformation causes misalignment of the shaft hole. Furthermore, if the hollow rotor at the time of chucking is before the processing of forming the tooth traces, in addition to the misalignment due to the deformation, the center deviation of the shaft hole due to the forming processing of the tooth traces is added, resulting in a large center deviation.
[0010]
Further, when the rotor body is cast and the hollow portion is formed by the core, the misalignment between the core and the shaft hole greatly degrades the rotational balance, and therefore, a large cost is required for correcting the balance.
[0011]
Therefore, an object of the present invention is to provide a fluid machine capable of precisely aligning the rotor main body with the rotor shaft while reducing the moment of inertia by making the rotor main body hollow.
[0012]
[Means for Solving the Problems]
2. The fluid machine according to claim 1, further comprising: a hollow rotor having a hollow portion having an opening formed in a toothed portion and having a rotor shaft fixed to a shaft hole of a rotor main body. A straight line portion is formed.
[0013]
As described above, in the fluid machine according to the first aspect, since the linear portions for chuck are formed on the inner peripheral side of the opening of the hollow portion, if the linear portions are chucked and the hole for the rotor shaft is formed, the rotor body is formed. And the rotor shaft can be precisely aligned. In addition, the forming process of the tooth lead portion (tooth mold) may be performed simultaneously with the processing of the shaft hole, or, if the rotor shaft is fixed to the shaft hole thus processed and the rotor shaft is used as a reference, the core may be formed. A hollow rotor having no rotation and having a well-balanced rotation can be obtained.
[0014]
In this way, a hollow rotor having a good rotational balance without a misalignment between the rotor main body and the rotor shaft can be obtained while the rotor has a hollow structure, is lightweight and has a small moment of inertia. Accordingly, no rotor balance correction is required, or if necessary, only a very small amount of correction and correction cost.
[0015]
A fluid machine according to a second aspect is the fluid machine according to the first aspect, wherein the hollow rotor is a screw rotor having a screw-shaped tooth portion. And a hollow rotor having good rotational balance can be obtained.
[0016]
In addition to this, in general, a screw-type fluid machine that is used at a higher speed than a roots-type fluid machine using a cocoon-shaped cross-section rotor and is likely to have a large adverse effect such as vibration due to a loss of rotational balance has a good rotational balance. The effect of the present invention in which a hollow rotor is obtained is great.
[0017]
A fluid machine according to a third aspect is the fluid machine according to the first or second aspect, wherein the hollow rotor is formed by casting, and the hollow portion, the opening, and the straight portion are formed using a core having a straight portion on the inner peripheral side. It is. The cores (hollow portions) arranged at the toothed portions provided at equal intervals in the rotational direction are located at positions where the rotation is balanced on the rotor body, and the linear portions formed in these hollow portions are chucked during processing. Therefore, a hollow rotor having a good rotational balance without a misalignment between the rotor body and the rotor shaft can be obtained as in the fluid machine according to the first or second aspect.
[0018]
In addition, according to the casting process, even a hollow rotor having a complicated shape can be easily processed, and the hollow rotor can be manufactured at low cost as compared with 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 greatly deteriorates the rotational balance, a hollow rotor having a good rotational balance can be obtained, and the cost of correcting the balance is greatly reduced. The effect is particularly great.
[0019]
In addition, since the linear portion for the chuck is formed in the entire axial direction of the hollow portion by the linear portion of the core, the core between the linear portion and the rotor shaft can be formed even if the end of the rotor body is cut as necessary. Don't go crazy.
[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.
[0021]
As shown in FIG. 1, the supercharger 1 includes an input pulley 3, a speed increasing gear set 5, a timing gear set 7, a screw compressor 9 (the fluid machine of the embodiment), and the like.
[0022]
The input pulley 3 is supported by a bearing 11 on a compressor casing 13, is spline-connected to an input shaft 15, and is fixed by bolts 17 and washers 19. The input pulley 3 is connected to a pulley on the crankshaft side via a belt. An electromagnetic clutch is disposed on the crankshaft-side pulley, and connects and disconnects the engine and the supercharger 1. The input pulley 3 is driven to rotate via this electromagnetic clutch by the driving force of the engine.
[0023]
The input shaft 15 is supported inside the casing 13 by a ball bearing 21, and a seal 25 is arranged between the collar 23 mounted on the input shaft 15 and the casing 13 to prevent oil leakage.
[0024]
The speed increasing gear set 5 includes large-diameter and small-diameter speed increasing gears 27 and 29 that mesh with each other, and the timing gear set 7 includes large-diameter and small-diameter timing gears 31 and 33 that mesh with each other. The air compressor 9 includes male and female screw rotors 35 and 37.
[0025]
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 attached to the rotor shaft 39 of the female screw rotor 37 by a key 41. It is connected and the nut 43 prevents it from falling off. 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.
[0026]
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 tightens and locks the nut 49 to rotate the respective screw rotors 35 and 37. Direction positioning.
[0027]
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. A seal 59 is arranged between the collar 57 attached to the left end 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 and the casing 13. Prevents air leakage.
[0028]
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 to the left in the axial direction between the screw rotors 35 and 37, discharges the suction air from the discharge port 65, and supplies the engine.
[0029]
The screw rotor 35 is configured such that the rotor shaft 47 is fixed to the shaft hole 69 of the rotor body 67, and the screw rotor 37 is also configured such that the rotor shaft 39 is fixed to the shaft hole of the rotor body 71.
[0030]
As shown in FIGS. 3 and 4, the rotor main body 67 of the male screw rotor 35 has three screw-shaped toothed portions 73. The rotor main body 71 of the female screw rotor 37 has four screw-shaped toothed portions. These rotor bodies 67 and 71 are castings made of an aluminum alloy.
[0031]
A hollow portion 75 is formed in each tooth portion 73 of the male screw rotor 35. As shown in FIGS. 1 and 2, a wall portion 77 is provided on the left side of the hollow portion 75, and an opening 79 is provided on the right side. As shown in FIGS. 3 and 4, each opening 79 is formed with a straight portion 81, a rib 83, and a balancer portion 85. Such a hollow portion 75 and an opening 79 are formed at the time of casting using a core having a straight portion on the inner peripheral side.
[0032]
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 rib 83 reinforces the opening 79 to prevent the bulge of the toothed 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 bulge. Further, the balancer section 85 balances with the left wall section 77 during rotation to prevent vibration.
[0033]
The straight portion 81 is formed on the inner peripheral side of each toothed portion 73 and is provided for a chuck of a cutting machine. As shown in FIG. 3, the tooth traces 73 are disposed at equal intervals at an angle of 120 ° to each other, and the respective hollow portions 75 are located on the rotor main body 67 at a position where the rotation is balanced. Therefore, when the rotor main body 67 is rotated as indicated by an arrow 87 in FIG. 4, the linear portions 81 of the tooth traces 73 are uniformly formed by the three plate-like chuck tools 89 arranged at an angle of 120 °. It can be chucked at a hit.
[0034]
The processing of the shaft hole 69 and the toothed portion 73 of the rotor body 67 is performed in a state where the straight portion 81 is chucked in this manner. Accordingly, since the alignment between the toothed portion 73 (the tooth shape and the hollow portion 75) and the shaft hole 69 is precisely performed, the rotational balance of the screw rotor 35 is basically maintained only by fixing the rotor shaft 47 to the shaft hole 69. Get ready.
[0035]
Thus, the supercharger 1 is configured.
[0036]
Since the supercharger 1 has no unbalance of the screw rotor 35, the vibration is reduced, the durability of the bearings 51 and 55 is greatly improved, the contact between the screw rotors 35 and 37, and the Is prevented, and the function and performance are maintained normally.
[0037]
Further, the screw rotor 35 having a hollow structure is lightweight, has an extremely small moment of inertia, and has a good rotational balance as described above. Therefore, a vehicle equipped with the supercharger 1 has improved engine fuel efficiency and acceleration response, The contact between the screw rotors 35 and 37 during rapid acceleration and deceleration (when the supercharger 1 starts and stops) is prevented. Further, the size of the electromagnetic clutch for intermittently connecting the engine and the supercharger 1 can be reduced.
[0038]
As described above, the screw rotor 35 is basically balanced in rotation by chucking the linear portion 81 at the time of cutting, so that it is not necessary to correct the balance, or if necessary, very little. A large amount of modification and modification cost are required.
[0039]
In addition, in the case of a cast hollow rotor in which the hollow portion 75 is formed by the core, such as the screw rotor 35, the misalignment between the core position and the rotor shaft 47 greatly affects the rotational balance. According to the present invention, these misalignments are prevented, so that the cost of correcting the balance is greatly reduced.
[0040]
Furthermore, according to the casting process, even a hollow screw rotor 35 having a complicated shape can be easily processed, and can be manufactured at a lower cost than other processing methods.
[0041]
Since the chuck linear portion 81 is formed in the entire axial direction of the hollow portion 75 by the core linear portion, even if the end of the rotor main body 67 is cut as necessary, the linear portion 81 and the rotor shaft 47 are not cut. The core does not go out of order.
[0042]
In general, a screw type compressor 9 which is used at a higher speed than a roots type fluid machine using a cocoon-shaped cross-section rotor and in which vibrations due to unbalance and the like are apt to be large is also provided according to the present invention. Advantageously, 35 is obtained.
[0043]
In this way, a screw rotor 35 having a hollow structure and having no misalignment can be obtained.
[0044]
In the present invention, the hollow rotor may be manufactured by plastic working such as drawing or extrusion in addition to casting.
[0045]
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]
【The invention's effect】
In the fluid machine according to the first aspect, when a shaft hole is formed or a tooth is formed in the rotor body, a straight portion formed in the opening of the hollow portion is chucked, so that the center of the rotor body and the rotor shaft are precisely aligned. Thus, a hollow rotor having a good rotational balance can be obtained.
[0047]
As described above, a hollow rotor having a hollow structure without a misalignment between the rotor main body and the rotor shaft can be obtained while reducing the weight of the rotor and the inertia moment by making the rotor hollow. Therefore, it is not necessary to correct the balance of the rotor, or even if necessary, it can be performed with a very small correction amount and correction cost.
[0048]
The fluid machine according to claim 2 uses a hollow screw rotor in the fluid machine according to claim 1 to obtain the same effect as that of the fluid machine according to claim 1, and is generally used at high speed rotation, and has a rotational balance. In a screw-type fluid machine, which is liable to be adversely affected by collapse, a hollow rotor with basically good rotational balance can be obtained, and the effect of the present invention is great.
[0049]
The fluid machine according to claim 3 is the fluid machine according to claim 1 or 2, wherein the hollow rotor is cast and the hollow portion, the opening, and the straight portion are formed by a core. The same effect as that of the fluid machine is obtained, and the hollow rotor having a complicated shape can be easily processed by casting, 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 greatly deteriorates the rotational balance, the effect of the present invention which can prevent the misalignment and obtain a hollow rotor having a well-balanced rotational balance is obtained. Particularly large, the balance correction cost can be significantly reduced.
[0050]
Further, since the straight portion for the chuck is formed entirely in the axial direction of the hollow portion by the straight portion of the core, the core between the straight portion and the rotor shaft can be formed even if the end of the rotor body is cut as necessary. Don't go crazy.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an embodiment of the present invention.
FIG. 2 is a sectional view taken along line AA of FIG. 3, showing a male screw rotor 35;
FIG. 3 is a view taken in the direction of arrow B in FIG. 2 and shows an end of the male screw rotor 35;
FIG. 4 is a perspective view showing a male screw rotor 35 whose end is chucked.
FIG. 5 is a side view showing a conventional screw rotor.
FIG. 6 is a sectional view showing another conventional screw type compressor.
[Explanation of symbols]
9 Screw compressor (fluid machinery)
35 Male screw rotor (hollow rotor)
47 Rotor shaft 67 Rotor body 69 Shaft hole 73 Toothed part 75 Hollow part 79 Opening 81 Straight part

Claims (3)

A hollow portion having a hollow portion having an opening and having 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. A fluid machine characterized by: The fluid machine according to claim 1, wherein the hollow rotor is a screw rotor having a screw-shaped tooth portion. 3. The fluid machine according to claim 1, wherein the hollow rotor is formed by casting, and the hollow portion, the opening, and the linear portion are formed by a core having a linear portion on the inner peripheral side.

Images