JPS6218651Y2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to a water pump device for a water-cooled internal combustion engine.

When installing a cooling fan at the tip of the drive pulley of a water pump driven by a V-belt in a 4-cylinder internal combustion engine, depending on the shape and weight of the cooling fan,
The secondary vibrations of the engine coincide with the vibrations of the fan and water pump system, causing a resonance phenomenon and generating excessive stress on the drive shaft of the water pump. Since this resonance phenomenon causes serious problems such as damage to the cooling fan and breakage of the drive shaft, it is necessary to eliminate resonance points within the operating rotation range of the engine.

To eliminate this resonance point (indicated by P in Figure 4), it is necessary to increase the rigidity of the water pump to some extent, and for this reason, conventionally the pump drive system has been increased in size due to a chain reaction of larger shaft diameter → larger bearing → larger housing. However, there were drawbacks such as increased cost and weight.

The present invention has been made in consideration of the above circumstances, and its object is to provide a water pump device for an internal combustion engine which can produce the same shaft diameter effect as when the drive shaft is made thicker, thereby preventing the occurrence of resonance points and improving the pump rigidity without enlarging the pump drive system.

Hereinafter, the present invention will be explained with reference to the drawings. In the drawing, reference numeral 1 denotes a housing of a water pump, and a drive shaft 4 is supported on shaft support portions 2 and 3 of this housing 1 via bearings 5 and 6. A cooling fan 7 and a drive pulley 8 are fixedly attached to one side of the drive shaft 4, and a water pump impeller 9 is attached to the other side of the drive shaft 4.
is permanently installed.

A spacer 10 is provided on the drive shaft 4 between the bearings 5 and 6. This spacer 10 is press-fitted onto the drive shaft 4 with a margin.

The drive shaft 4 is rotated by the rotational force input from the drive pulley 8, and the cooling fan 7 and the water pump impeller 9 are rotationally driven. At this time, the spacer 10 is press-fitted into the drive shaft 4. Since it has the same effect as when the shaft is made thicker, there is no resonance point P that occurs in the conventional case.
Draw the stress curve shown in Figure 4.

The curve shown in FIG. 4 corresponds to the case where the spacer is fitted to the drive shaft with a loose fit, and in this case there is a resonance point P.

If the outer circumferential surface of the spacer 10 is made into an arc shape as shown in FIG. 3, there is a further effect of eliminating resonance points.

As described above, the present invention is arranged between the bearings 5 and 6 on the drive shaft 4 which is supported by the shaft support parts 2 and 3 of the housing 1 via the bearings 5 and 6 and which rotationally drives the cooling fan 7 and the water pump impeller 9. This is a water pump device for an internal combustion engine, characterized in that an interposed spacer 10 is press-fitted.

In this way, since the spacer 10 is press-fitted into the drive shaft 4, even though the shaft diameter of the drive shaft 4 is d, the strength (rigidity) as if the shaft diameter were 1.2d can be obtained (see Figure 2). ). As a result, as shown in Fig. 5, the resonance point p within the engine speed range is moved to the engine speed non-use range as shown by the dotted line and removed, and the stress amplitude of the drive shaft 4 is greatly increased. reduced and reliability improved. Furthermore, whereas the drive shaft diameter is made thicker (1.2d) in conventional products, the effect of the equivalent shaft diameter by press-fitting the spacer 10 allows the shaft diameter to remain small and have the same effect as when the shaft diameter is made thicker. This helps in downsizing water pumps.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of one embodiment of the present invention, Fig. 2 is a front view of the drive shaft, Fig. 3 is an explanatory diagram of another embodiment of the spacer, and Figs. 4 and 5 are stress on the drive shaft. It is a line diagram. 1 is a housing, 2 and 3 are shaft support parts, 4 is a drive shaft, and 10 is a spacer.

Claims (1)

[Scope of utility model registration request] A spacer 10 interposed between bearings 5 and 6 is press-fitted into a drive shaft 4 which is supported by bearings 5 and 6 in shaft support parts 2 and 3 of a housing 1 and rotationally drives a cooling fan 7 and a water pump impeller 9. A water pump device for an internal combustion engine, characterized by: