JPH09144548A - Screw type supercharger - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To reduce the inertia acting on the press-fitting portion, to reduce the burden driving torque, and to install the timing gear which does not require the precision of the strict press-fitting tolerance. A simple screw type turbocharger. SOLUTION: Male and female rotor timing gears 7 and 8 composed of helical teeth pressed into rotor shafts 2A and 3A of a pair of screw type male and female rotors 2 and 3 meshing with each other.
Of the pair of screw type male and female rotors 2 and 3
In the screw type supercharger that rotates and rotates to engage the teeth thereof, the input shaft 6 connected to the input pulley 4 side and one of the male and female timing gears 7 and 8
And are directly connected by fitting the spline 13 or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw type supercharger for obtaining a high output by supplying compressed air to an engine or the like by a pair of screw type male and female rotors meshing with each other.

[0002]

2. Description of the Related Art Conventionally, various types of screw type superchargers installed in an intake system of an internal combustion engine have been used. One of these is shown in FIG.
The one described in Japanese Patent No. 11695 is exemplified. FIG.
As shown in (A), the screw type supercharger is provided with rotors 22 and 23 each having a plurality of spiral teeth that mesh with each other in opposite directions in a casing 21. The supplied air is compressed by the compression part formed by the meshing parts of the plurality of spiral teeth, is discharged from the other side in the axial direction, and is used for high-power combustion of the internal combustion engine. Such a screw type supercharger is rotationally driven by a driving force transmitted from a crankshaft (not shown) via a V-belt and an input pulley. Normally, the input pulley and the input shaft are used to reduce mechanical loss. An electromagnetic clutch is installed between the
The electromagnetic clutch is engaged and disengaged under computer control by analyzing engine speed, intake air amount, and the like.

As shown in FIG. 2B, a screw rotor 22 is fixed to a rotor shaft 22A connected to an input shaft 26 which is rotationally driven by obtaining power by connecting the electromagnetic clutch. The screw rotor 23 is fixed to a rotor shaft 23A arranged in parallel with the rotor 22A. On the other hand, a taper press-fitting portion 32 is formed on the input shaft 26 side of the rotor shaft 22A, and a rotor timing gear 27 is press-fitted into the taper press-fitting portion 32 and tightened by a tightening nut 31. A rotor timing gear 28 is fixed to the shaft end of the rotor shaft 23A.
28 is meshed with each other, and the screw rotors 22, 2
Rotate 3 in the opposite direction. Normally, the timing gears 27 and 28 are helically meshed with each other, and the rotational direction and axial position of the timing gear 27 with respect to the rotor shaft 22A, that is, the press-fitting amount is selected, whereby the spiral of the rotor 22 of the timing gear 27 is selected. It is configured to be able to properly adjust the phase of the toothed tooth and the meshing phase of the timing gear 27 with the timing gear 28.

[0004]

However, in the supercharger provided with the screw type rotor of this type, the timing gear 27 is adjusted with respect to the phase of the spiral teeth of the rotor 22 and the timing gear 27 has a timing gear. In order to properly adjust the meshing phase with 28, not only high precision is required for assembling the timing gear 27 to the taper press-fitting portion 32 of the rotor 22, but also the press-fitting portion 32.
Since an inertia for strongly rotating each member after the timing gear 28 acts on the component via the timing gear 27 by the driving force from the input shaft 26, the driving force that the taper press-fitting portion 32 bears is extremely large. Therefore, the press-fitting tolerance is further narrowed and the tightening nut 31 is strongly tightened, and the timing gear 27 with respect to the rotor shaft 2A is tightened.
Therefore, it is necessary to prevent the position deviation from occurring, resulting in an increase in processing cost.

Therefore, the present invention solves the various problems in the conventional screw type turbocharger, reduces the inertia acting on the press-fitting portion, reduces the driving torque required, and requires a precise press-fitting tolerance. A low-cost, simple screw-type turbocharger with a simple structure that enables the installation of timing gears that do not

[0006]

Therefore, according to the present invention, the pair of screw-type male and female is formed by the meshing of the male and female rotor timing gears, each of which has helical teeth press-fitted to the rotor shafts of the pair of screw-type male and female rotors meshing with each other. In a screw type supercharger that rotates a rotor and meshes those teeth to perform a pumping action, the input shaft connected to the input pulley side and one of the male and female rotor timing gears are directly connected by spline fitting or the like. It is characterized by the fact that it has been done, and this is used as a means for solving the problems.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an essential part of one embodiment of a screw type supercharger of the present invention. In FIG. 1, most of the air suction portion and the male and female rotors in the screw type supercharger of the present invention are omitted. A screw type supercharger installed in an intake system of an engine of an internal combustion engine includes a plurality of spiral teeth arranged in parallel in a casing 1 and rotationally meshing in opposite directions (not shown in FIG. 2A). Of 2
(Corresponding to 2, 23) and a screw type male rotor 3 and a female rotor 2. These screw type male and female rotors 2 and 3 are connected to an input pulley 4 via a V-belt from a crankshaft (not shown).
Where the air that is rotatably driven by the driving force transmitted to the electromagnetic clutch 5 through the connection of the electromagnetic clutch 5 and that is supplied from one of the axial directions (the suction portion on the right side) is formed by the meshing portions of the plurality of spiral teeth. Is compressed by the compression chamber 15 and is discharged from the other discharge port 16 in the axial direction (in a direction perpendicular to the paper surface) for high-power combustion of the internal combustion engine.

The screw type male and female rotors 2 and 3 are fixed to the male and female rotor shafts 2A and 3A, respectively, which are rotatably supported by bearings in the casing. One female rotor shaft 2A is provided with an input pulley via the electromagnetic clutch 5. 4 and an input shaft 6 which can be freely connected and disconnected. In the present invention, in order to connect the female rotor shaft 2A and the input shaft 6, a boss portion of the female rotor timing gear 7 having helical teeth is externally fitted to the input shaft side end portion of the female rotor shaft 2A. The female rotor timing gear 7 is press-fitted to form a press-fitted portion 12, and the boss portion of the female rotor timing gear 7 is extended along the axial center of the input pulley 4 to form a tubular portion 7A, and the boss portion of the input shaft 6 is formed. Is extended to the outer peripheral side of the rotor timing gear cylinder portion 7A to form the input shaft cylinder portion 6A, and splines engraved on the outer circumference of the timing gear cylinder portion 7A and the inner circumference of the input shaft cylinder portion 6A are fitted. The spline portion 13 is formed by fitting the tightening bolt 11 into the timing gear cylinder portion 7A with a collar or the like interposed between the tip end of the tightening bolt 11 and the end portion on the input shaft side of the female rotor shaft 2A. , The tightening bolt 11 is the axis Fill force the pulley 4, the electromagnetic clutch 5, the female rotor shaft 2A including the input shaft 6 and the female rotor timing gear 7 will be rotatably supported by a bearing 14 or the like with respect to the casing 1. On the other hand, a male rotor timing gear 8 composed of helical teeth is fixed to the shaft end of the male rotor shaft 3A by a tightening nut 10 with a taper ring 9 interposed therebetween, and the male rotor timing gear 8 is attached to the female rotor timing gear 7. The screw type rotors 2 and 3 of the male and female are engaged and rotated in the opposite direction at a predetermined rotational speed ratio. The connection and disconnection of the electromagnetic clutch 5 arranged between the input pulley 4 and the input shaft 6 is
It is computer-controlled by analyzing the throttle opening, engine speed, intake air amount, etc.

With such a configuration, the input pulley 4 is rotationally driven by a belt or the like that is wound around a crank pulley of an engine (not shown), and when the electromagnetic clutch 5 is connected, the input shaft 6 The rotational driving force from the female rotor timing gear 7 is strongly transmitted from the input shaft tubular portion 6A to the tubular portion 7A of the female rotor timing gear 7 through the spline portion 13, and the driving force from the female rotor timing gear 7 is passed through the press-fitting portion 12. While being transmitted to the female rotor shaft 2A, it is transmitted to the male rotor shaft 3A via the male rotor timing gear 8 meshing with the female rotor timing gear 7. Thus, the screw type male and female rotors 2 and 3 which are interlocked and linked to each other at a predetermined rotation speed ratio to form the compression chamber 15 form the air flowing from the air cleaner (not shown) into the suction port in the axial direction in the compression chamber 15. The compression / pressurization operation is carried out during the flow down to the outside of the turbocharger, and thereafter, it is discharged at a high pressure from the discharge port 16 to the outside of the supercharger to be used for high power combustion of the internal combustion engine.

The embodiments of the present invention have been described above, but within the scope of the gist of the present invention, the material and sectional shape of the screw type male and female rotor, the spiral angle of the rotor teeth, the sectional shape and number, the suction port and the discharge. Port shape, electromagnetic clutch form, input shaft and female rotor timing gear form, spline and other connection forms, female rotor timing gear and female rotor shaft press fit form, male rotor timing gear and rotor shaft press fit form It goes without saying that any suitable form can be adopted for the input pulley, the electromagnetic clutch, the input shaft, and the form of shaft support for the casing of the female rotor timing gear. Also,
It goes without saying that the input shaft can be connected to the male rotor side.

[0011]

As described in detail above, according to the present invention, the rotational driving force from the input shaft is strongly transmitted from the input shaft directly to the female rotor timing gear through the spline portion or the like, Since it is transmitted to the female rotor shaft via the press-fitting portion and is transmitted to the male rotor shaft via the male rotor timing gear that meshes with the female rotor timing gear, the female rotor timing gear and the female rotor shaft are Inertia for rotating the respective members after the male rotor timing gear does not act on the press-fitting part of, and the press-fitting part bears driving the screw type female rotor,
Only a very small driving force is required (about 20% compared to the conventional 80%). Therefore, it is not necessary to form the tapered portion and narrow the press-fitting tolerance in the tapered portion to strongly tighten the tightening nut so as to prevent the displacement of the female rotor timing gear with respect to the female rotor shaft unlike the conventional one. Since the press-fitting tolerance is wide and the press-fitting margin is small, a simple press-fitting structure that does not require precise precision can be adopted, and the processing cost can be significantly reduced.
Moreover, the small driving force that the press-fitting portion bears means that
In a supercharger equipped with a screw type rotor having rotor timing gears of this type, each male / female rotor timing gear is properly adjusted by each press-fitting portion with respect to the phase of the spiral teeth of each screw type male / female rotor. Adjust to
At the same time, after properly adjusting the meshing phase of the female rotor timing gear with the male rotor timing gear, these press-fitting portions do not easily move and rotate relative to each other, and it is possible to prevent these proper phases from deviating inadvertently. It

[Brief description of the drawings]

FIG. 1 is a sectional view of an essential part of a screw type supercharger, showing an embodiment of a screw type supercharger of the present invention.

FIG. 2 is an overall sectional view showing a conventional screw type supercharger.

[Explanation of symbols]

 2 Screw type female rotor 2A Female rotor shaft 3 Screw type male rotor 3A Male rotor shaft 4 Input pulley 5 Electromagnetic clutch 6 Input shaft 7 Female rotor timing gear 8 Male rotor timing gear 11 Tightening bolt 12 Press fitting portion 13 Spline

Claims (1)

[Claims] 1. A pair of screw type male and female rotors are rotated by the meshing of male and female rotor timing gears, each of which has helical teeth press-fitted into rotor shafts of a pair of screw type male and female rotors meshing with each other, and the teeth are meshed with each other. In a screw type supercharger that performs pumping action by a screw, the input shaft connected to the input pulley side and one of the male and female rotor timing gears are directly connected by spline fitting or the like. Feeder.