JPH04102747A - Rotary shaft of transmission and gear cutting of rotary shaft thereof - Google Patents

Abstract

PURPOSE:To prevent the deterioration of meshing between gears, suppress noise, and secure the sufficient strength of the gear by increasing the diameter of a between-gear shaft part arranged between two gears, larger than the diameter of the bottom circle of one gear. CONSTITUTION:A between-gear shaft part 8d between two close gears 8b and 8c has the diameter d1 equal to the addendum curved surface 8c1 of the small diameter gear 8c between two gears 8b and 8c, and a smooth tapered curved surface part 8c3 is formed at the edge part in the axial direction on the between-gear shaft 8d side of the small diameter gear 8c, and the diameter dimension of the terminal edge is equal to the diameter dimension of the addendum curved surface 8c1. With this constitution, the strength of the shaft part 8d becomes larger than the strength of a rotary shaft part where the small diameter gear 8c is arranged, and the deflection quantity becomes large because of the shortage of strength of the between-gear shaft part, different from the conventional rotary shaft, and the generation of large noise due to the meshing trouble between gear trains, and the increase of abrasion of gears can be suppressed.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a rotating shaft of a transmission and a method for cutting gears on the rotating shaft. The present invention relates to a rotating shaft and a gear cutting method for a gear integrated with the rotating shaft.

[Conventional technology]

2. Description of the Related Art Among transmissions for vehicles and the like, there is known a type of transmission in which gears formed integrally with a single rotation shaft are arranged side by side on the shaft.

FIG. 5 shows a conventional transmission of the above type. In the figure, a drive shaft 1 and a wave shaft 6 are rotatably supported by bearings, respectively, and are arranged in the internal spaces of a front case 2 and a rear case 3. A plurality of gear pairs constituting each gear stage are rotatably supported on a drive shaft 1 and a driven shaft 6, respectively. On the drive shaft 1, a first gear 1a, a second gear 1b, and a third gear IC are formed integrally with the drive shaft and arranged in parallel in the axial direction. Further, on the driven shaft 6, a plurality of driven gears 6a are provided.

5b and 5c are rotatably supported on the driven shaft 6.

Drive gears 1a, lb on corresponding drive shafts 1, respectively.

It constitutes a gear pair that meshes with the IC and becomes each gear stage.

With the above configuration, for example, when selecting the second gear, the second gear pair consisting of the second gear 1b on the drive shaft 1 and the second gear driven gear 6b on the driven shaft 6 is selected by the synchronizer 61. , the vehicle is operated through power transmission by the second gear pair.

[Problem to be solved by the invention]

When power is transmitted through the meshing of gears in a conventional transmission, a meshing reaction force is generated in a direction perpendicular to the shaft between the pair of gears during power transmission, and this meshing reaction force is As a result, both the drive shaft 1 and the driven shaft 6 are bent. FIG. 3 shows a state in which the drive shaft 1 is bent.

As shown in the figure, due to the meshing reaction force P between the gears generated by the meshing of the second gear 1b, the drive shaft 1, which is supported at the bearing support points A and B, is deflected by a deflection me.

In conventional transmissions, if the amount of deflection e becomes too large, the meshing state of the gear pair during power transmission deteriorates.
Generate noise between pairs of gears.

This poses a problem in that the gear itself is more likely to wear out, and the bearing has an inclination angle, which impairs the durability of the bearing.

The present invention prevents large deflection of the rotating shaft of a transmission equipped with gears formed integrally with the shaft, thereby causing large noise due to deterioration of the meshing condition and wear of the gears. To provide a rotating shaft of a transmission that does not become large and does not cause a large inclination angle in a bearing part.

It is also an object of the present invention to provide a method for cutting gears of such a rotating shaft.

[Means to solve the problem]

The object of the present invention is to provide a first rotary shaft connected to the input shaft, a second rotary shaft attached to the first rotary shaft and connected to the output shaft, and a second rotary shaft connected to the first and second rotary shafts. a gear train disposed in the gear train;

The apparatus further includes at least two gears arranged in parallel in the axial direction of one of the first and second rotation shafts and formed integrally with the one rotation shaft.

a rotational shaft of a transmission, wherein said gear train rotationally couples said first and second rotational shafts to achieve a plurality of gears, at least in part through selective actuation of an associated synchronizer; In.

Achieved by a rotating shaft of a transmission characterized in that the diameter of the shaft portion between the two gears that is formed integrally with the rotating shaft is larger than the diameter of the tooth bottom of at least one of the gears. Ru.

The diameter of the shaft portion between the two gears that are formed integrally with the shaft and arranged in parallel is preferably the same as the tip diameter of the gear whose root diameter is smaller. According to this configuration, both the shaft portion between the gears and the gear having the smaller tooth root diameter can be machined into a cylindrical shape at the same time.

The findings of the present invention are as follows.

FIG. 4 shows the detailed shape of a conventional drive shaft. In the conventional rotating shaft, the gear 1b is formed integrally with the rotating shaft 1 and is adjacent to the rotating shaft with a small gear spacing f.

The diameter d of the shaft portion 1d between the two adjacent integral gears 1b and lc is formed to be smaller than the diameter of the bottom curved surface 1cl of the small diameter gear at least in a portion of the integral gears 1b and lc that are close to the small diameter gear 1c. It had been. The reason for this is as follows.

Conventionally, in order to process grooves on each gear, a method of cutting with a binion cutter has been used. The method using a pinion cutter is a method of cutting grooves on a gear to be cut using a pinion cutter having a cutting edge shape imaginary of a gear that meshes with the gear to be cut.As illustrated in FIG. 9 is reciprocated in the axial direction, and the gear to be cut 10 is
This is a method of creating a tooth groove in the gear to be cut 10 by rotating the pinion cutter 9a and the pinion cutter 9a in the direction of the arrow shown in the figure, and gradually decreasing the distance between the shafts during the cutting stroke g in the axial direction.

The pinion cutter 9a cuts the tooth groove portion of the gear in a cutting stroke g parallel to the axis, so that the shape of the virtual gear represented by the cutting edge 9b of the cutter and the shape of the gear to be cut 10 are suitable for meshing. The cutting process continued until the

However, in order to cut gear gears through a pinion cutter, cutter relief is required to move the cutter past the gear being cut during each axial cutting stroke. It was not possible to increase the diameter d of the part. For this reason, as mentioned above, the diameter of the shaft portion is smaller than the diameter of the curved tooth bottom surface of the adjacent small diameter gear. However, the deflection of the rotating shaft was caused by insufficient strength of the shaft portion between the gears having a small diameter.

The inventors of the present invention have come up with the above facts, and by increasing the diameter of the shaft portion between the gears and reducing the amount of deflection of the rotating shaft in this portion, the inventors of the present invention solved the problem caused by poor meshing of the gears. In other words, it has become possible to reduce noise during gear meshing and prevent wear of the gears themselves.

On the other hand, if the diameter of the shaft part between two gears formed integrally with the shaft is larger than the diameter of the bottom surface of the adjacent gears,
There are reports that when cutting the gears using a pinion cutter, it is not possible to take the cutter relief as in the conventional method. Therefore, in the gear cutting method of the rotary shaft gear of the present invention, cutting of the cutter gear integral with the rotary shaft of the cutter supported by the cutter shaft is performed using a cutting stroke parallel to both axes and a distance between both axes. a cutting stroke including an expansion movement;
This problem was solved by a configuration consisting of .

[Effect]

In the rotating shaft of the transmission of the present invention, the diameter of the shaft portion between the two gears formed integrally with the shaft is made larger than the root diameter of at least one of the adjacent gears. The weak point that caused the deflection of the gear can be eliminated, and the amount of deflection of the rotating shaft due to the meshing reaction force acting between the pair of gears can be reduced.

In addition, in the method for cutting gears on a rotary shaft of the present invention, the cutter supported by the cutter shaft cuts the gear to be cut, which is integral with the rotary shaft, using a cutting stroke parallel to the shaft and an expansion of the distance between both axes. and a cutting stroke that includes an opening movement.

Despite the diameter of the adjacent shaft portion being larger than the diameter of the bottom circle of the gear, the gear can be easily cut.

〔Example〕

The invention will be further explained with reference to the drawings.

FIG. 1 shows the shape of a rotating shaft 8 of a transmission according to an embodiment of the present invention. In the same figure, the one-rotation shaft 8 has three parallel gears 8a formed integrally with the shaft, similar to the drive shaft 1 shown in the conventional transmission.

8b and 8c. Two adjacent gears 8b, 8
The inter-gear shaft portion 8d between gears c has the same diameter d1 as the tooth tip curved surface 8cl of the smaller diameter gear 8C among both gears gb and gc, and the tooth bottom curved surface 8c2 of the small diameter gear 8C has the same diameter as the tooth tip curved surface 8c2 of the small diameter gear 8C. 8C has a smooth Taper curved surface portion 111c3 at the axial end on the inter-gear shaft portion 8d side, and the diameter of the end thereof is the same as the diameter of the tip curved surface 8cl. With this configuration, the strength of the shaft portion 8d is greater than the strength of the rotating shaft portion on which the small diameter gear 8c is arranged, and unlike conventional rotating shafts, the amount of deflection due to insufficient strength in the shaft portion between the gears If e becomes large, large noise may be generated due to poor meshing between gear trains.

There is no significant wear on the gears. Furthermore, the reduction in the amount of deflection of the shaft per rotation reduces the angle of inclination that occurs in the bearing, and the durability of the bearing also improves.

The shaft portion 8 between the two gears formed integrally with the shaft as described above
The problems in gear cutting caused by increasing the diameter of d are solved by the gear cutting method of the rotary shaft gear of the present invention as follows.

In the gear cutting method of the rotating shaft gear according to the embodiment of the present invention, when machining the small diameter gear 8C of the rotating shaft 8 shown in FIG. 1, the cutting stroke of the cutter shaft relative to the rotating shaft is As shown by the symbol g' added to , the cutting stroke should consist of a cutting stroke part parallel to the axis, and a cutting stroke part following the parallel cutting stroke part, which includes movement to widen the distance between the two axes. . As a result, the direction of movement g' of the cutting blade differs from the linear cutting stroke g of the cutting blade of a conventional pinion cutter.

The cutting stroke g' in this embodiment is defined as moving the cutter shaft away from the axis of the gear to be cut at the final stage of each cutting stroke via a cam mechanism, that is, moving the distance between the shafts to expand. This can be easily done by including In this way, the escape position of the cutter is on the outside in the radial direction of the shaft portion 8d in each cutting stroke g', so unlike the conventional gear cutting method using a pinion cutter, the large diameter shaft portion 8d is There is no risk of it becoming an obstacle. Note that the cutting stroke indicated as g' may not be necessary for all cutting strokes depending on the diameter of the shaft.
It goes without saying that there are cases in which it is sufficient to only measure the cutting stroke at the final stage of cutting.

As a method for machining grooves on a gear for a rotating shaft of a transmission according to an embodiment of the present invention, an example was shown in which a small-diameter gear is machined by the stroke g' of the cutting blade as described above. The rotating shaft of the machine is not limited to the rotating shaft manufactured by this groove processing method; for example, gear 8C can be formed by rolling, and gear 8C can also be formed by rolling.
When there is no gear 8a as shown in FIG. 1 in the axial direction opposite to the adjacent large-diameter gear 8b when viewed from above, that is, the small-diameter gear 8C
If there is no gear 8a with a larger diameter, it is also possible to form the small diameter gear 8C by cold forging.

Furthermore, the gear cutting method of the present invention is not limited to the method using the cutting stroke g' shown in the above embodiment, but the cutting stroke includes a cutting stroke parallel to the axis and a movement to widen the distance between the axes. It is also possible to configure each cutting stroke separately. In this case, the cutting stroke of the cutter is preferably numerically controlled by a computer.

〔Effect of the invention〕

In the configuration of the rotating shaft of the transmission of the present invention, the diameter of the inter-gear shaft portion disposed between two gears that are formed integrally with the rotating shaft and arranged in parallel in the axial direction is at least one of the teeth of the gear. By making it larger than the diameter of the bottom circle, the rigidity of the rotating shaft at the shaft portion is improved.

To provide a rotating shaft for a transmission that can reduce the deflection of the rotating shaft during power transmission, thereby preventing deterioration of the meshing condition of gears, suppressing noise generated between a pair of gears, and having sufficient gear strength. I was able to do that. Also.

By reducing the deflection of the shaft, the angle of inclination of the bearing portion that supports the shaft is reduced, and the life of the bearing can also be improved.

In the method for cutting gears of a rotating shaft according to the present invention.

Cutting of a workpiece gear by a cutter supported by a cutter shaft includes a cutting stroke parallel to the shaft and a cutting stroke that includes expanding the distance between the axes of both the cutter shaft and the rotary shaft;
Due to the structure that it consists of.

The cutting blade of the pinion cutter does not interfere with the inter-gear shaft portion, which has a diameter larger than the root diameter of the gear to be cut, making it easier to cut the gears adjacent to the large-diameter inter-gear shaft portion. Therefore, it was possible to provide a method for cutting gears of a rotating shaft, which facilitates the manufacture of a highly rigid rotating shaft.

[Brief explanation of drawings]

FIG. 1 is an axial sectional view of the rotating shaft of the transmission of the present invention. FIG. 2 is a schematic diagram showing the relationship between a gear to be cut and a cutter shaft for explaining the present invention and a conventional gear cutting method. FIG. 3 is an axial cross-sectional view for explaining the deflection of the shaft of a conventional rotating shaft. FIG. 4 is an axial cross-sectional view for explaining the structure of a conventional rotating shaft. FIG. 5 is a schematic cross-sectional view of a transmission taken along a plane passing through an axis to show the structure of a conventional transmission. It is. Explanation of symbols 1... Drive shaft 1a, 1b, IC... Drive gear 4.5... Bearing 6... Driven shaft 6a, 6b,
6cm driven gear 8...Rotating shafts 8a, 8b, 8c...Gears 8cl integrated with the rotating shaft...
・Tooth tip curved surface 8c2...Tooth bottom curved surface 9...Cutter shaft 9a...Pinion cutter g, g'...Cutting stroke

Claims (2)

[Claims] (1) A first rotating shaft connected to the input shaft, a second rotating shaft attached to the first rotating shaft and connected to the output shaft, and a second rotating shaft disposed on the first and second rotating shafts. The gear train includes two gears arranged in parallel in the axial direction of one of the first and second rotating shafts and formed integrally with the one rotating shaft. further comprising: the gear train rotationally coupling the first and second rotational shafts to achieve a plurality of gear stages, at least in part through selective actuation of an associated synchronizer; The rotating shaft of the transmission of the above type is characterized in that the diameter of the shaft portion between the two gears formed integrally with the rotating shaft is larger than the diameter of the tooth bottom of at least one of the gears. The rotating shaft of the transmission. (2) In a method for cutting gears on a rotating shaft that includes two gears formed integrally with the rotating shaft and arranged in parallel in the axial direction, the cutter supported by the cutter shaft has at least one gear on the rotating shaft. A gear on a rotary shaft, characterized in that cutting consists of a cutting stroke that moves parallel to the rotary shaft, and a cutting stroke that includes movement to widen the distance between the rotary shaft and the cutter shaft. How to cut the teeth.