JP2002188452A - Mechanical supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mechanical supercharger allowing sure transmission of drive force, having a simple structure and preventing twisting vibration and tooth hitting sound, and being reduced in cost. SOLUTION: In the mechanical supercharger 1 which is constituted such that fluid is pressurized by a pair of rotors 7, 8, rotating in gear receiving rotational drive force obtained by an input shaft 4, the connection between the input shaft 4 and the rotor shaft 5 in the rotor 7 is made by a torsion spring 11 for transmission of the drive force. The transmission of drive force can be ensured, and variation of torque between the input shaft 4 and the rotor shaft 5 involved in the variation of the engine output, etc., are absorbed effectively by the simple elastic material of the torsion spring 11 for transmitting the drive force, arranged for winding between the shafts. Because of the tolerance for shaft deviation, and no generation of tooth hitting sound and play to be caused by a space, such as the conventional long hole, the torque variation can be absorbed in high responsiveness in the spiral direction of the torsion spring 11. Moreover, this mechanical supercharger can be manufactured easily at a reduced cost due to its simple structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical supercharger in which fluid is pressurized by a pair of rotors meshing and rotating with each other by receiving a rotational driving force obtained from an input shaft.
The type of the pressurizing section in the supercharger can be applied to a roots type, a Rischhol type, a centrifugal pump type, an axial flow compression type, and the like.

[0002]

2. Description of the Related Art A mechanical supercharger of this type, which is configured to pressurize fluid by a pair of rotors meshing and rotating with each other by receiving a rotational driving force obtained from an input shaft, is shown in FIG. Japanese Unexamined Patent Publication No. 1-137338 (Patent No. 277297)
No. 6). This is a supercharger-type mechanical supercharger that is constantly driven by the rotational driving force of the engine. The supercharger 21, which is a supercharger, is configured such that a driving force from an input shaft 24 having a pulley 23 for obtaining a driving force from an engine fixed to an end thereof is applied to the first rotor shaft 2.
5 and simultaneously transmitted to the second rotor shaft 26 via the second timing gear 30 meshing with the first timing gear 29 fixed to the first rotor shaft 25.
The fluid is pressurized by the pressurizing action of the first and second rotors 27 and 28 attached to the first and second rotor shafts and meshing with each other.

Thus, the outside air introduced from an air cleaner (not shown) is pressurized by the supercharger 21 and supplied to the engine to be subjected to high-output combustion. Since the supercharger 21 is constantly driven to rotate by the driving force of the engine crankshaft, when the engine suddenly shifts to a high output (the same applies at the time of sudden deceleration), the pressure fluctuation accompanying the sudden change of the intake flow rate of the air-fuel mixture. This causes torsional vibration, backlash and wear in the drive unit, gear rattle noise, and noise due to air noise.

In order to prevent such a torque fluctuation of the driving force in the supercharger and a pressure fluctuation caused by a sudden change in the suction flow rate of the air-fuel mixture due to the fluctuation, the aforementioned FIG.
In this case, an elastic means is provided between an input shaft 24 having a pulley 23 for obtaining a driving force from an engine fixed to an end and a first rotor shaft 25. The elastic means is the input shaft 24
Member 24A fixed to the end of the first timing gear 2
9 and a pin 32 connecting between them, and the pin 32 is
A single torsion spring is provided in one of the long holes so as to be able to move and recover within a predetermined range. With such a configuration,
The torque fluctuation between the input shaft 24 and the first rotor shaft 25 can be effectively absorbed by the elastic means.

[0005]

The input shaft 24 as described above is used.
The torque fluctuation is absorbed by the elastic means interposed between the motor and the first rotor shaft 25, and torsional vibration in the drive unit is reduced.
The generation of rattling and wear, the gear rattling noise, and the noise due to the generation of air noise are effectively suppressed. However, since the elastic means is a connection structure formed by the pin 32 inserted in the long hole and the torsion spring via the annular member 31, the structure becomes complicated and the cost is increased. However, there is still a risk that the accumulated amount in the case where each part is worn due to the movement of the member or the use thereof for a long period of time becomes large, causing play.

Accordingly, the present invention solves the above-mentioned problems of the conventional mechanical supercharger, enables a reliable transmission of the driving force, and has a simple structure that prevents torsional vibration and rattle. It is an object to provide an inexpensive mechanical supercharger.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention relates to a mechanical supercharger wherein a fluid is pressurized by a pair of rotors meshing and rotating with each other by receiving a rotational driving force obtained from an input shaft. The shaft and the rotor shaft of the rotor are connected by a torsion spring for transmitting driving force. Further, the invention is characterized in that the winding direction of the torsion spring is made to coincide with the driving direction. Further, the present invention is characterized in that a predetermined number of turns of the torsion spring is wound around the input shaft and the rotor shaft during driving. Further, the present invention is characterized in that a gap exists between the torsion spring and at least one of the input shaft and the rotor shaft surfaces until the rotational driving force reaches a predetermined value. These are the means for solving the problems.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a mechanical supercharger according to the present invention will be described below with reference to the drawings. FIG. 1 is an overall sectional view showing a first embodiment of the mechanical supercharger of the present invention. The present invention relates to a mechanical supercharger configured to pressurize a fluid by a pair of rotors 7 and 8 meshing and rotating with each other by receiving the rotational driving force obtained by the input shaft 4.
And a rotor shaft 5 is connected by a torsion spring 11 for transmitting driving force. The mechanical supercharger 1 which is a supercharger is supported by a pair of rotors 7 and 8 which are rotatably supported in such a manner that the outer circumference thereof is in sliding contact with the inner wall of the casing 2 and mesh with each other to form a pressurizing portion. By the rotational meshing, air introduced from a suction port (not shown, for example, on the near side in the drawing) is discharged from a discharge port (for example, in the upper part of the drawing) and pressurized.

The casing 2 is divided into three parts in the axial direction, and from the left side, a pressure casing 2A in which first and second rotors 7, 8 are accommodated, a bearing casing 2B, first and second timing gears 9, 10 And an input casing 2C accommodating the input shaft 4 are arranged and integrated by a fixing bolt. One end of the first and second rotor shafts 5 and 6 to which the first and second rotors 7 and 8 are fixed are respectively supported by the side surfaces of the pressure casing 2A, and the other end is connected to the bearing casing 2B. Each is supported.
The first rotor shaft 5 and the second rotor shaft 6 rotate synchronously via first and second timing gears 9, 10 fixed respectively. Between the first rotor shaft 5 and the input shaft 4 arranged on the same shaft, only the torsion spring 11 for power transmission is disposed in a form in which both ends are locked to each shaft. The winding direction of the torsion spring 11 is configured to coincide with the driving direction. A pulley 3 is fixed to an end of the input shaft 4 so as to obtain a driving force from a driving belt stretched between the input shaft 4 and an engine crankshaft.

With such a structure, the torsion spring 11 for power transmission is tightened in the winding direction at the time of driving, and the power transmission torsion spring 11 reliably transmits the power while absorbing the impact of the torque fluctuation. The torsion spring 11 expands to absorb the impact of the torque fluctuation. Thus, the torque fluctuation between the input shaft 4 and the first rotor shaft 5 due to the engine output fluctuation is effectively absorbed by a simple elastic member in which a torsion spring for power transmission is wound and disposed between these shafts. In addition, there is tolerance for shaft deviation, no rattling noise and no rattling due to gaps such as long holes as in conventional ones, and it absorbs torque fluctuations with high responsiveness in the helical direction of the torsion spring. It becomes possible. Moreover, it is easy to manufacture and has a low cost due to its simple structure.

FIG. 2 is an overall sectional view showing a second embodiment of the mechanical supercharger according to the present invention. The basic structure is the first
This embodiment is the same as the embodiment, except that the power transmission torsion spring 11 disposed between the input shaft 4 and the first rotor shaft 5 is driven by the torsion spring 11 during driving. It is characterized in that a predetermined number of turns of the spring 11 is wound around the input shaft 4 and the first rotor shaft 5. In other words, the torsion spring 11 for power transmission of the first embodiment is configured by arranging a slightly thicker at least one turn, whereas the torsion spring 11 of the present embodiment has 7 to 7 turns. A torsion spring 11 for power transmission of about 10 turns is employed, and both ends thereof are locked and fixed to the input shaft 4 and the first rotor shaft 5, respectively.

With such a configuration, similarly to the above-described embodiment, at the time of driving, it is tightened in the winding direction, and the torsion spring 11 for power transmission reliably transmits power and absorbs the impact of torque fluctuation. At the coast, the torsion spring 11 for power transmission expands and absorbs the impact of the torque fluctuation. However, in the present embodiment, the torsion spring 11 for power transmission is particularly enhanced during driving. A predetermined number of turns is wound around the input shaft 4 and the first rotor shaft 5 to generate a predetermined frictional force, which is backed up by the frictional force to more reliably transmit power. A spiral groove having a cross section that matches the cross section of the torsion spring 11 may be formed on the outer peripheral surfaces of the input shaft 4 and the first rotor shaft 5 around which a predetermined number of the torsion springs 11 are wound. With this configuration, the frictional contact area between the torsion spring 11 and the helical groove on each shaft can be increased, and more reliable power transmission with a larger frictional force can be achieved.

FIG. 3 is a sectional view of a main part of a mechanical supercharger according to a third embodiment of the present invention. In this embodiment,
Until the rotational driving force between the input shaft 4 and the first rotor shaft 5 reaches a predetermined value, a gap is formed between the torsion spring 11 and at least one of the surfaces of the input shaft 4 and the first rotor shaft 5. It is characterized by having been constituted. In the present embodiment, the helical diameter of the torsion spring 11 is formed at a connection portion between the input shaft 4 and the first rotor shaft 5 to be somewhat larger, and is wound. With such a configuration, a predetermined number of turns of the torsion spring 11 for power transmission is applied to the input shaft 4 and the first rotor shaft 5 during driving with respect to a rotational driving force, that is, torque fluctuation up to a practical level. Winding produces a predetermined frictional force, which is backed up by the frictional force to ensure power transmission. In the event that excessive torque fluctuations occur due to any cause, the surfaces of the shafts 4 and 5 are The torsion spring 11 is further wrapped around the gap between the two to form a damper capable of absorbing the torque fluctuation, and the torque fluctuation absorbing ability can have a margin.

FIG. 4 is a sectional view of a main part of a mechanical supercharger according to a fourth embodiment of the present invention. In this embodiment,
Until the rotational driving force between the input shaft 4 and the first rotor shaft 5 reaches a predetermined value, a gap is formed between the torsion spring 11 and at least one of the surfaces of the input shaft 4 and the first rotor shaft 5. As a configuration that exists, a tapered surface 4A is formed at one shaft, for example, at an end of the input shaft 4. That is, in the present embodiment, a straight spiral torsion spring 11 for power transmission similar to that of the second embodiment in FIG. 2 is employed, but the end of the input shaft 4 is tapered. By being formed on the surface 4 </ b> A, a clearance between the input shaft 4 and the torsion spring 11 can be provided at this portion, so that there is a margin. With such a configuration, the predetermined number of turns of the torsion spring 11 is applied to the straight outer peripheral surface of the input shaft 4 and the first rotor shaft 5 during driving with respect to rotational driving force, that is, torque fluctuation up to a practical level. Winding produces a predetermined frictional force, which is backed up by the frictional force to ensure power transmission. If an excessive torque fluctuation occurs for any reason, the input shaft 4
The torsion spring 11 is further wound around the gap between the surface and the torque fluctuation, so that the torque fluctuation can be absorbed, and the torque fluctuation absorbing ability can have a margin.

The embodiment of the present invention has been described above. However, within the scope of the present invention, a mechanical supercharger type, for example, a pressurized compression rotor such as a supercharger of the embodiment is used. The present invention is applicable to a centrifugal pump, an axial flow pump, a blower-type vane pump, a gear pump, and the like, in addition to a reciprocal or roots pump by meshing. Also, the shape of the casing, the shape of the rotor, the shape of the bearing of the rotor shaft, the shape of the input shaft, the shape of the timing gear, and the form (even when the meshing form of the helical gear is adopted to improve quietness, the meshing surface of the rotor and The torsion spring can effectively suppress the generation of thrust force between the casing and the end face of the casing.)
And the arrangement position (the timing gear may be arranged on the side opposite to the input shaft), the shape and type of the torsion spring and the form of locking to each shaft, the clearance between the torsion spring, the input shaft and the rotor shaft The formation form and the like can be appropriately selected.

[0016]

As described above in detail, according to the present invention, a mechanical supercharger configured to pressurize fluid by a pair of rotors meshing and rotating with each other by receiving a rotational driving force obtained from an input shaft. In the machine, by connecting the input shaft and the rotor shaft of the rotor with a torsion spring for driving force transmission, while enabling reliable power transmission, the input shaft and the rotor shaft due to engine output fluctuation and the like The torque fluctuations during this period are effectively absorbed by a simple elastic member that is provided by simply arranging a torsion spring for power transmission between these shafts. It is possible to absorb torque fluctuations with high responsiveness in the spiral direction of the torsion spring without occurrence of backlash due to a gap such as a long hole such as the one described above. Moreover, it is easy to manufacture and has a low cost due to its simple structure.

Further, since the winding direction of the torsion spring coincides with the driving direction, it is possible to surely transmit power particularly in the driving direction. Further, when driving, when the predetermined number of turns of the torsion spring is wound around the input shaft and the rotor shaft, particularly during driving, the predetermined number of turns of the torsion spring for power transmission is applied to the input shaft and the rotor shaft. The wire is wound to generate a predetermined frictional force, and the power is more reliably transmitted by being backed up by the frictional force. Still further, if a gap is provided between the torsion spring and at least one of the input shaft and the rotor shaft until the rotational driving force reaches a predetermined value, some sort of error may occur. If an excessive torque fluctuation occurs due to the cause, a torsion spring is further wound around the gap between the shaft and the surface of each shaft to constitute a damper capable of absorbing the torque fluctuation, so that the torque fluctuation absorbing capacity is not sufficient. Can be provided. Thus, according to the present invention, there is provided a low-cost mechanical supercharger with a simple structure that enables reliable transmission of driving force and prevents torsional vibration and rattling noise.

[Brief description of the drawings]

FIG. 1 is an overall sectional view showing a first embodiment of a mechanical supercharger according to the present invention.

FIG. 2 is an overall sectional view showing a second embodiment of the mechanical supercharger of the present invention.

FIG. 3 is a sectional view showing a main part of a mechanical supercharger according to a third embodiment of the present invention.

FIG. 4 is a sectional view showing a main part of a mechanical supercharger according to a fourth embodiment of the present invention.

FIG. 5 is an overall sectional view of a conventional supercharger.

[Explanation of symbols]

 Reference Signs List 1 supercharger 2 casing 2A pressure casing 2B bearing casing 2C input casing 3 input pulley 4 input shaft 4A taper surface 5 first rotor shaft 6 second rotor shaft 7 first rotor 8 second rotor 9 first timing gear 10th 2 timing gear 11 torsion spring for power transmission

Claims (4)

[Claims] 1. A mechanical supercharger configured to pressurize fluid by a pair of rotors meshing and rotating with each other by receiving a rotational driving force obtained from an input shaft. And a torsion spring for transmitting a driving force. 2. The mechanical supercharger according to claim 1, wherein a winding direction of the torsion spring is made to coincide with a driving direction. 3. The mechanical supercharger according to claim 1, wherein a predetermined number of turns of the torsion spring is wound around the input shaft and the rotor shaft during driving. 4. A structure is provided in which a gap exists between the torsion spring and at least one of the input shaft and the rotor shaft until the rotational driving force reaches a predetermined value. The mechanical supercharger according to claim 1.