JPH034794Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an improvement of a mechanical supercharger for supercharging a mixer in an internal combustion engine of an automobile or the like.

[Conventional technology]

A conventional mechanical supercharger is shown in FIGS. 4 and 5. In the figure, 1 is a trunk-shaped housing, and an intake port 1A is provided on one side of the housing 1.
An exhaust port 1B is provided on the other side. A pair of rotors 2 and 3 are housed in the housing 1, and the pair of rotors 2 and 3 are connected to shafts 2A and 3.
The outer surfaces of the rotors 2 and 3 are connected to the housing 1 by being pivotally supported at the front and rear by the bearings 4A, 4B, 5A, and 5B of the bearing housings 4 and 5 via A.
It is now possible to rotate while being in close contact with the inner surface. Rotating shafts 2A and 3A of the pair of rotors 2 and 3
are fitted with gears 6, 7 which mesh with each other on the outside of the rear bearing housing 5. Further, a rear cover 8 is attached to cover the rear bearing housing 5 and the gears 6, 7, and a space 9 formed between the rear cover 8 and the rear bearing housing 5 is filled with an appropriate amount of lubricating oil 10. ing.

In the above configuration, when the rotation of the internal combustion engine is transmitted to the rotor 2, the rotor 2 rotates, and as a result, the rotor 3 rotates synchronously via the gears 6 and 7, and the air-fuel mixture sucked into the housing 1 from the intake port 1A is It is compressed between the rotors 2 and 3 and the housing 1 and between the rotors 2 and 3, and is supercharged from the exhaust port 1B to the internal combustion engine side.

[Problem that the invention attempts to solve]

In the conventional configuration described above, when the rotation of the rotor 2 is transmitted to the rotor 3 via the gears 6 and 7, frictional heat of the gears 6 and 7 is generated, and the lubricating oil in the space 9 of the rear cover 8 is heated. The temperature of the rear bearing housing 5 is higher than that of the front bearing housing 4 (usually about 20° C.).

When the mechanical supercharger is operating, the rotor 2,
3 is heated by the heat of compression of the air-fuel mixture, and the rotor 2,
The front and rear bearing housings 3 and 3 undergo thermal expansion to the same extent, while the front and rear bearing housings 4 and 5 also undergo thermal expansion due to the heat of compression. Thermal expansion of the rotors 2 and 3 acts to reduce the distance between the rotors 2 and 3, and the thermal expansion of the front and rear bearing housings 4 and 5 acts to increase the distance between the rotors 2 and 3. Since the thermal expansion of the rotors 2 and 3 is larger than that of the front and rear bearing housings 4 and 5, the distance between the rotors 2 and 3 becomes smaller overall due to the compression heat. As mentioned above, since the temperature of the rear bearing housing 5 is higher than that of the front bearing housing 4, the rate of thermal expansion of the front bearing housing 4 is smaller than that of the rear bearing housing 5, so that the rotor 2,
Between 3 and 3, the front part is smaller than the rear part. Therefore, in order to increase the compression ratio of the air-fuel mixture and obtain a high discharge pressure, if the distance between the rotors 2 and 3 is made smaller, the distance between the front parts of the rotors 2 and 3 becomes almost zero during operation of the mechanical supercharger. This causes the rotors 2 and 3 to come into contact with each other, leading to damage. On the other hand, if the distance between the rotors 2 and 3 is increased to prevent such damage, high discharge pressure cannot be obtained.

[Means for solving problems]

The present invention provides a housing 1 having an intake port 1A and an exhaust port 1B, a pair of rotors 2 and 3 rotatably housed in the housing 1, and a pair of rotors 2 and 3 rotatably housed in the housing 1. It consists of a pair of gears 6, 7 that are attached to one end of the rotating shafts 2A, 3A of the rotors 2, 3, respectively, and mesh with each other,
To provide a mechanical supercharger in which the distance between the pair of rotors 2 and 3 is made larger on the side where the gears 6 and 7 are not attached than on the side where the gears 6 and 7 are attached.

[Effect]

The function of the present invention is as follows.

When the rotation of the internal combustion engine is transmitted to the rotor 2, the rotor 2 rotates, and as the rotor 2 rotates, a gear 6 is attached to one end of the rotating shaft 2A, and a gear meshing with the gear 6 is attached to one end of the rotating shaft 3A. The rotor 3 rotates synchronously through 7, and the intake port 1A
The air-fuel mixture sucked into the housing 1 is compressed between the rotors 2 and 3 and the housing 1 and between the rotors 2 and 3, and is supercharged from the exhaust port 1B to the internal combustion engine side. At this time, frictional heat is generated in the gears 6 and 7, and the temperature of the mechanical supercharger becomes higher on the side where the gears 6 and 7 are attached. Therefore, rotor 2,
3 is narrowed more on the side where the gears 6 and 7 are not attached than on the side where the gears 6 and 7 are attached. However, the distance between the rotors 2 and 3 is set larger on the side where the gears 6 and 7 are not attached than on the side where the gears 6 and 7 are attached, so in a mechanical supercharger, the distance between the rotors 2 and 3 is set larger at high temperatures.
3 is substantially uniform between the side where the gears 6 and 7 are attached and the side where the gears 6 and 7 are not attached.

[Effect of idea]

Therefore, in the present invention, even if the space between the rotors 2 and 3 is made as small as possible to obtain a high discharge pressure, damage to the rotors 2 and 3 and the housing 1 can be reliably prevented.

〔Example〕

The present invention will be explained below based on an embodiment shown in FIGS. 1 to 3.

In the figure, reference numeral 1 denotes a trunk-shaped housing, and one side of the housing 1 is provided with an intake port 1A, and the other side is provided with an exhaust port 1B. A pair of rotors 2 and 3 are housed in the housing 1, and the pair of rotors 2 and 3 are connected to rotating shafts 2A and 2A.
The rotors 2 and 3 are rotatably supported by the bearings 4A, 4B, 5A, and 5B of the bearing housings 4 and 5 at the front and rear via the rotors 3A, making it possible to rotate the rotors 2 and 3 while keeping the outer surfaces of the rotors 2 and 3 in close contact with the inner surface of the housing 1. . Rotating shafts 2A, 3 of the pair of rotors 2, 3
Attached to A are gears 6 and 7 that mesh with each other on the outside of the rear bearing housing 5. Further, a rear cover 8 is attached to cover the rear bearing housing 5 and the gears 6 and 7.
A space 9 formed between the rear bearing housing 5 and the rear bearing housing 5 is filled with a suitable amount of lubricating oil 10.

The pair of rotors 2, 3 has a small diameter so that the distance 11 gradually increases linearly from the side where the gears 6, 7 are attached to the side where the gears 6, 7 are not attached, as shown in FIGS. 2 and 3. The outer surface of the side has been removed in a straight line compared to the conventional outer surface shown in dotted lines.

In the above configuration, when the rotation of the internal combustion engine is transmitted to the rotor 2, the rotor 2 rotates, and as a result, the rotor 3 rotates synchronously via the gears 6 and 7, and the air-fuel mixture sucked into the housing 1 from the intake port 1A is It is compressed between the rotors 2 and 3 and the housing 1 and between the rotors 2 and 3, and is supercharged from the exhaust port 1B to the internal combustion engine side.

At low loads, the temperature on the side where gears 6 and 7 are installed (rear side) and the side where gears 6 and 7 are not installed (front side) is approximately the same, and the rotors 2 and 3 are as shown in Figures 2 and 3. In the solid line state in the figure, the distance 11 is larger on the front side than on the rear side. When the load is high, the rear side becomes higher in temperature than the front side due to the frictional heat of the gears 6 and 7, and the rotors 2 and 3 are in the state shown by the dotted lines in Figures 2 and 3, and the gap 11 is between the front and rear sides. become virtually identical.

Other than this embodiment, the distance 11 between the rotors 2 and 3 may be gradually increased from the rear side to the front side along a predetermined curve. Further, as a means to gradually increase the distance 11 between the rotors 2 and 3, the entire circumference of only one rotor 2 or 3 may be removed along a predetermined straight line or curve, or the pitch between the rear bearings 5A and 5B may be removed. The pitch of the front bearings 4A, 4B may be increased.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention, in which FIG. 1 is a side sectional view, FIG. 2 is a rotor side view, and FIG. 3 is an AA sectional view in FIG. 4 and 5 show a conventional example, where FIG. 4 is a side sectional view and FIG.
FIG. In the diagram, 1...housing, 1A...intake port, 1
B...Exhaust port, 2, 3...Rotor, 2A, 3A
...rotating axis, 6, 7...gear, 11...between.

Claims (1)

[Scope of utility model registration request] It consists of a housing having an intake port and an exhaust port, a pair of rotors rotatably housed within the housing, and a pair of gears that are respectively attached to one end of the rotating shaft of the pair of rotors and mesh with each other. , a mechanical supercharger characterized in that the distance between the pair of rotors is larger on the side where the gear is not attached than on the side where the gear is attached.