JPS5920050B2 - Power transmission mechanism using helical gear - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power transmission mechanism using a helical gear.

More specifically, the present invention relates to a power transmission mechanism consisting of a pair of single helical gears in which a thrust bearing provided on the shaft can be omitted.

In a power transmission mechanism configured by meshing a pair of single helical gears, the meshing of both helical gears generates a thrust that moves away from each other and acts on the shaft.

Therefore, a thrust bearing is attached to the shaft to receive such thrust.

However, installing this thrust bearing not only requires installation space on the shaft for the thrust bearing, but also requires thread machining, making it more complicated than a mechanism with a bearing without thrust. This is an unavoidable drawback.

The purpose of the present invention is to solve the above-mentioned problems, and to eliminate the need to consider installing a thrust bearing that receives thrust regardless of whether it is on the driving side or the driven side. The present invention aims to provide a power transmission mechanism consisting of a helical gear.

A power transmission mechanism comprising a helical gear according to the present invention which achieves the above object is a power transmission mechanism consisting of a pair of single helical gears in mesh with each other. In addition to fixing the side plate with a large diameter, a chamfering is provided on the outer periphery of the side surface of the other single helical gear tooth, which includes the bottom portion of the tooth and has a tapered surface with an angle α of 5° to 10° with respect to the side surface of the tooth. This is characterized in that an oil film is interposed in the gap between the side surface of the tooth having chamfering and the side plate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to embodiments shown in the drawings.

In Figures 1 and 2, 1 is a single helical gear on the driving side, and 2 is a single helical gear on the driven side that meshes with the single helical gear on the driving side, and is fixed to the power transmission shafts 3 and 4, respectively. ing.

Among these, side plates 5a and 5b are fixed to both sides of the single helical gear 20 on the driven side with bolts 6, respectively.

The outer peripheries of the side plates 5a and 5b cover the side surfaces of the teeth 2a of the single helical gear 2, and have a diameter extending to the outside larger than the addendum.

With this configuration, when the pair of single helical gears 1 and 2 are engaged, the side plates 5 a t 5 b cover the entire side surface of the teeth 1 a of the single helical gear 1 on the driving side.

On the other hand, as shown in FIG. 3, in the single helical gear 1 on the drive side, the outer periphery of the side surface of the tooth 1a is chamfered into a tapered shape by a chamfering C, and this chamfering C extends to the bottom of the tooth. It has been processed to include.

When power is transmitted by the above-mentioned power transmission mechanism, thrusts as shown by arrows S1 and S2 act on the power transmission shafts 3 and 4 due to the meshing of the pair of single helical gears 1 and 2, respectively.

Therefore, the teeth 1a of the single helical gear 1 and the side plate 5
By contacting with S1.b, the above-mentioned thrust S1. S2 are supported so as to cancel each other out.

That is, in the part indicated by hatching A in FIG.
The inner wall surface of b and the side surface of the tooth 1a of the single helical gear 1 support thrust while opposing each other.

In the part receiving the thrust shown by hatching A in Fig. 4, that is, in the contact part between the side plate 5b and the tooth 1a, the helical gears 1 and 2 move in substantially the same direction and at the same speed, as shown in Fig. 5. Since they are in a moving relationship, the relative slip between them is extremely small.

In addition, in order to prevent slight slippage that occurs in the direction in which the axes of both shafts 3 and 4 are connected, chamfering C is applied to the outer periphery of the side surface of the tooth 1a, including the bottom portion, so that the lubricating oil acts as a wedge. occurs, and an oil film F is always formed on the slight sliding surface between the tooth 1a and the side plate 5b, resulting in an extremely low frictional resistance.

In order to facilitate the occurrence of such a wedge effect of the lubricating oil more effectively, it is necessary to set the angle α of the chamfering C to the tooth side surface to 5° to 10°.

Therefore, according to the above mechanism, there is no need to provide a thrust bearing on each of the power transmission shafts 3.4 as in the conventional mechanism, and the mechanism can be simplified.

Furthermore, by eliminating the need for installation space for the thrust bearing, it contributes to the downsizing and cost reduction of the device.

In the above-mentioned mechanism, when the power transmission shaft 3 is rotated in the opposite direction, the side plate 5a and the teeth 1a receive thrust, and the same effect as in the above case is performed.

In the above embodiment, the side plates 5a and 5b are fixed to the single helical gear 2 side, but they may be fixed to the single helical gear 1 side.

In such a case, tooth 2 on the single helical gear 2 side
It is necessary to chamfer the outer periphery of the side surface of a, including the bottom of the tooth.

As described above, the present invention provides a power transmission mechanism consisting of a pair of single helical gears in mesh with each other. , Chamfering is applied to the outer periphery of the side surface of the tooth of the other single helical gear to form a tapered surface that includes the bottom part and has an angle α of 5° to 10° with respect to the side surface of the tooth, and the side surface of the tooth with this chamfering Since an oil film is interposed in the gap between the pair of single helical gears and the side plate, the thrust generated by the meshing of the pair of single helical gears is supported by the contact between the side plate of one helical gear and the tooth side of the other helical gear. The wedge effect of the oil film between the two supports them with extremely low frictional resistance.

Therefore, the installation of a thrust bearing required in the conventional mechanism can be omitted, and as a result, it is possible to simplify the mechanism, save space, and reduce costs.

[Brief explanation of the drawing]

Fig. 1 is a front view of a power transmission mechanism according to an embodiment of the present invention, Fig. 2 is a side view of the same, Fig. 3 is a perspective view partially showing the teeth of a helical gear used in the mechanism, and Fig. 4. 5 is a side view showing the main parts of the mechanism, FIG. 5 is a schematic side view illustrating the function of the mechanism, and FIG. 6 is a schematic cross-sectional view illustrating the function of the mechanism. 1.2...Single helical gear, 1a, 2a
...Teeth, 5a, 5b...Side plate, C...
... Chamfering, F... Oil slick.

Claims (1)

[Claims] 1. In a power transmission mechanism consisting of a pair of single helical gears meshing, a side plate is fixed to both sides of one single helical gear to cover at least the side surface portions of the teeth with a diameter larger than the addendum, and side plates are fixed to both sides of one single helical gear, and Chamfering is applied to the outer periphery of the side surface to form a tapered surface that includes the bottom part of the tooth and has an angle α of 5° to 10° with respect to the side surface of the tooth, and the gap between the side surface of the tooth having this chamfering and the side plate is A power transmission mechanism using a helical gear characterized by an intervening oil film.