JPH08232655A - Fan driving structure - Google Patents

Abstract

PURPOSE: To contrive to reduce a bending vibration generated in a fan shaft system in a cooling fan of an engine. CONSTITUTION: In this structure, it has a water pump drive shaft 3, pulley 4 fixed to the water pump drive shaft 3, spacer 5 fixed to the pulley 4, disk- shaped hub fixed to the spacer 5, bending damper 12 having an elastic unit fixed to a side of the spacer 5 in a rotary shaft direction in a peripheral part of this hub and having an inertia body fixed to a rotary shaft direction of this elastic unit and a fan 8 fixed to the bending damper 12 through a fan coupling 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive structure for a fan mounted on a drive shaft of a water pump provided in an engine.

[0002]

2. Description of the Related Art FIG. 9 shows a drive system for a cooling fan of an engine. A water pump pulley 4 is fixed to the tip of a drive shaft 3 of a water pump 2 provided in the engine 1. A fan coupling 7 is attached to the spacer 4 via spacers 5 and 6, and a cooling fan 8 is further attached to the fan coupling 7. A belt 10 loops between a pulley (not shown) mounted on the drive shaft of the auxiliary equipment such as the water pump pulley 4 and other alternators and a crank pulley 9 mounted on the tip of the crank shaft of the engine 1. Has been done. And
The drive shaft 3 of the water pump 2 is driven by the rotation of the engine 1, and accordingly the cooling fan 8 rotates to assist ventilation of the radiator during low speed running or idling.

[0003]

The conventional fan drive structure described above has a large overhang in the drive system of the water pump drive shaft 3 to the spacer 5, 6 to the fan coupling 7 to the fan 8. Bending vibration as shown by the dotted line occurs, the tip side, that is, the fan 8 vibrates greatly with respect to the center of the drive shaft 3 shown by the dashed line, and noise increases. Further, the stress of the drive shaft 3 of the water pump 2 supporting the fan 8 and the water pump case 2a becomes high.
It is necessary to increase the rigidity of each part including, which leads to an increase in weight.

As an engine noise reduction device, for example,
There is one disclosed in JP-A-3-4730. This is configured so that the mass inertia of the weight attached to the front end side of the crankshaft is not directly transmitted to the crankshaft. However, this device is designed to reduce the noise of the crankshaft, and is not for suppressing the bending vibration of the cooling fan attached to the tip of the drive shaft of the water pump.

The present invention has been made in view of the above points, and provides a fan drive structure for reducing bending vibration of a fan by providing a bending damper on the tip side of a fan shaft system having a large bending vibration amplitude. The purpose is to do.

[0006]

To achieve the above object, according to the present invention, a water pump drive shaft, a pulley fixed to the water pump drive shaft, and a spacer fixed to the pulley, A bending damper having a disk-shaped hub fixed to the spacer, an elastic body fixed to the spacer side of the outer peripheral portion of the hub in the rotation axis direction, and an inertial body fixed to the rotation axis direction of the elastic body, The structure has a fan fixed to the bending damper via a fan coupling.

According to a second aspect of the present invention, the pulley has a disk-shaped hub, an elastic body fixed to the outer peripheral portion of the hub in the rotational axis direction, and an inertial body fixed to the elastic body in the rotational axis direction. The structure is such that a damper is provided.

[0008]

The bending damper provided on the tip side of the fan shaft system (between the spacer and the fan coupling) having a large bending vibration amplitude disperses the resonance peak of the bending vibration amplitude generated in the fan shaft system. This greatly reduces the bending vibration amplitude. In the second aspect, by providing the water pump pulley with the bending damper, the space can be effectively used.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The same members as those in FIG. 9 are designated by the same reference numerals, and detailed description thereof will be omitted. In FIG. 1, a water pump pulley 4 is attached and fixed to a drive shaft 3 of a water pump 2, and a fan coupling 7 is attached to the water pump pulley 4 via spacers 5 and 6. A bending damper 12 is attached to the spacer 5. The bending damper 12 is used for the hub 1 as detailed in FIG.
3, the elastic member 14, and the inertial body 15. The hub 13 has a disk shape, and a peripheral edge portion 13b forms a step with respect to the central portion 13a and bulges toward one side to form a substantially shallow hat shape. The hub 13 has a central portion 13a.
Has an inner diameter slightly larger than the outer diameter of the spacer 5, and a hole 13c into which the tip 5a of the spacer 5 fits is formed in the center.
Has been drilled. Around the hole 13c, a bolt hole 13d is formed corresponding to each bolt hole 5b of the spacer 5.

On the outer peripheral portion 13b of the hub 13, a disk-shaped elastic member 14 is fixed so as to face the axial direction. The elastic member 14 is formed of, for example, a rubber member. The elastic member 14 has a disk-shaped inertial body 15
The one end face of is fixed. That is, the inertial body 15 is fixed to the outer peripheral portion 13b of the hub 13 via the elastic member 14 to form the bending damper 12.

As shown in FIG. 1, a hub 13 of the bending damper 12 is fitted onto the tip of a spacer 5, and the center portion 13a is fixed together with the spacer 6 to the tip of a water pump pulley 4 by a bolt. . In this state, the inertial body 15 is concentrically arranged outside the spacer 5. In this way, the bending damper 12 is mounted between the spacer 5 and the fan coupling 7. That is, the bending damper 12 is provided between the spacer 5 and the fan coupling 7) on the front end side of the fan shaft system (the front end side of the water pump drive shaft 3) having a large bending vibration amplitude. The bending natural frequency (fd1) of the bending damper 12 is, for example, about 0.7 to 0.9 times (fd1 = (0.7 to 0.9) of the bending vibration natural value (fs1) of the drive shaft 3 system of the water pump 2. ) ×
fs1).

The operation will be described below. The rotation of the crankshaft of the engine 1 is transmitted from the crank pulley 9 to the water pump pulley 4 via the belt 10, and the water pump drive shaft 3 is rotationally driven. Then, as the water pump drive shaft 3 rotates, the fan 8 rotates via the fan coupling 7. The bending damper 12 rotates together with the rotation of the water pump drive shaft 3 to reduce bending vibration of the fan shaft system. That is, as shown by the curve II in FIG. 6, one resonance peak when the bending damper shown by the curve I is not used is dispersed into two peaks, and the bending vibration amplitude is greatly reduced.

FIG. 3 shows a second embodiment of the bending damper,
The inertial body 17 is provided on the other side of the outer peripheral portion 13b of the hub 13 of the bending damper 12 shown in FIG. 2 via an elastic member 16 to form a two-mass structure. As a result, as shown by the curve III in FIG. 7, one resonance peak when the bending damper shown by the curve I is not used can be dispersed into three peaks to reduce the bending vibration amplitude. Alternatively, as shown by curves IV and V in FIG. 8, the two resonance peaks when the bending dampers shown by the curves I and I ′ are not used are dispersed into two peaks by each damper to reduce the bending vibration amplitude. You can As a result, the bending vibration amplitude can be significantly reduced over a wide range of engine speeds.

FIG. 4 shows a third embodiment of the present invention in which a bending damper 20 is further provided in addition to the bending damper 12. The bending damper 12 is provided between the spacer 5 and the fan coupling 7 as in FIG. 1, and the bending damper 20 is attached to the cylindrical portion at the front end of the water pump pulley 4. In the hub 21 of the bending damper 20, one end of a cylinder is expanded to the outside at a substantially right angle to form a flange-shaped damper attachment portion, and an inertial body is axially provided on the back surface of the damper attachment portion via an elastic member 22. 23 is fixed. Then, the hub 21 is press-fitted and externally fitted and fixed to the cylindrical portion at the front end of the water pump pulley 4. The hub 21
Is formed by sheet metal working.

As a result, the bending damper 20 can be reduced in weight and size. Further, since the sheet metal hub 21 has high rigidity and a small surface area, the sound generated from the hub 21 can be suppressed to be small. Further, by mounting the bending damper 20 on the water pump pulley 4, it is advantageous in terms of space, and further size reduction and weight reduction can be achieved. The hub of the bending damper 20 mounted on the water pump pulley 4 is shown in FIG.
As described above, a simple disk-shaped hub 25 is used, an inertial member 27 is fixed to the outer peripheral portion in the axial direction via an elastic member 26, and the hub 25 is fastened together with the spacer 5 (FIG. 4) to form the water pump pulley 4 It may be fixed to the front end of the.

[0016]

As described above, according to the present invention, the bending vibration amplitude generated in the fan shaft system can be greatly reduced, and as a result, the vibration and stress of the fan shaft system can be significantly reduced. As a result, the weight of each part such as the water pump and the fan coupling can be reduced, which contributes to the weight reduction of the vehicle. Further, the bending damper has a simple structure and can be easily mounted on the drive shaft of the water pump.

According to the second aspect of the present invention, by providing the water pump pulley with the bending damper, the space in the engine room can be effectively utilized, and the bending damper can be reduced in size and weight.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing a first embodiment of a fan drive structure according to the present invention.

2 is a cross-sectional view of the bending damper of FIG.

FIG. 3 is a cross-sectional view of an essential part showing a second embodiment of the bending damper shown in FIG.

FIG. 4 is a sectional view of an essential part showing a second embodiment of the fan drive structure according to the present invention.

5 is a cross-sectional view of a main part showing another embodiment of the bending damper shown in FIG.

6 is an explanatory diagram of bending vibration characteristics by the bending damper of FIG.

FIG. 7 is an explanatory diagram of bending vibration characteristics when the bending damper of FIG. 2 is used.

FIG. 8 is an explanatory diagram of bending vibration characteristics when the bending damper of FIG. 3 is used.

FIG. 9 is an explanatory view of a main part of a conventional fan drive structure.

10 is an explanatory diagram of bending vibration of the fan shaft system in FIG.

[Explanation of symbols]

 1 Engine 2 Water Pump 3 Water Pump Drive Shaft 4 Water Pump Pulley 5, 6 Spacer 7 Fan Coupling 8 Fan 9 Crank Pulley 10 Belt 12, 20 Bending Damper 13, 21, 25 Hub 14, 16, 22, 26 Elastic Member 15 , 17, 23, 27 inertial body

Claims (2)

[Claims] 1. A water pump drive shaft, a pulley fixed to the water pump drive shaft, a spacer fixed to the pulley, a disk-shaped hub fixed to the spacer, and a rotation of an outer peripheral portion of the hub. A bending damper having an elastic body fixed to the spacer side in the axial direction and an inertia body fixed to the rotation axis direction of the elastic body, and a fan fixed to the bending damper via a fan coupling. Fan drive structure. 2. The pulley is provided with a bending damper having a disk-shaped hub, an elastic body fixed to the outer peripheral portion of the hub in the rotation axis direction, and an inertial body fixed to the rotation axis direction of the elastic body. The fan drive structure according to claim 1, wherein the fan drive structure is provided.