JPS621474Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a gear mounting structure for an automobile transmission equipped with an overdrive gear.

[Conventional technology]

Generally, in order to fix the overdrive gear to the main shaft of the transmission, a spline hole is formed in the shaft center of the overdrive gear, and the overdrive gear is then carburized and hardened. As a result, distortion occurs due to hardening, but if the machining accuracy of the spline hole is not maintained, it will not be possible to fit the spline shaft, so as a result of prioritizing the accuracy of the spline hole, the accuracy of the teeth of the overdrive gear may be sacrificed. I have no choice but to.

This is because a normal speed change gear is supported so that it can freely rotate around the main shaft, so it is sufficient to grind the fitting hole for the main shaft according to the accuracy of the gear, but when providing a spline hole in an overdrive gear,
Polishing to remove distortion after carburizing and quenching is impossible.

[Problem that the invention attempts to solve]

In view of these problems, the purpose of the present invention is to provide a gear mounting structure for an automobile transmission that eliminates spline hole machining for the overdrive gear and fixes it to the main shaft, thereby improving the accuracy of the teeth. It is about providing.

[Means to solve the problem]

In order to achieve the above object, the present invention has a configuration in which an overdrive gear is rotatably supported at the end of the main shaft of an automobile transmission, and a running speed detection gear is mounted on a spline shaft formed at the end of the main shaft. A running speed detection gear is supported on the spline shaft portion by spline fitting, and a groove extending in a diametrical direction is engaged with one of the end face of the overdrive gear and the end face of the running speed detection gear, and the groove is engaged with the groove on the other end face. Protrusions are respectively provided to rotationally couple the overdrive gear to the main shaft via the traveling speed detection gear.

[Effect]

Since the overdrive gear 17 is simply provided with a shaft hole, the machining accuracy of the teeth can be maintained like other general speed change gears supported by the main shaft 4. And overdrive gear 17
By engaging the end face of the traveling speed detection gear 40, which does not require very strict machining accuracy of the teeth and is spline-fitted to the main shaft 4, with each other through radial grooves and protrusions, An overdrive gear 17 is rotationally coupled to the main shaft 4 .

[Example of idea]

To explain the present invention in terms of an embodiment, FIG. 1 shows an example in which a general five-speed transmission is equipped with an overdrive gear mechanism. is supported, and the rotation of the engine is transmitted to this via the clutch 2. A gear 6 is fixedly supported on the input shaft 3, and the left end of the main shaft 4 is supported with a bearing 34 in the inner hollow part, and the gear box 3 is on the right end side.
The bearing 35 is attached to the right end wall of the cover 3.
2 with bearings 36, respectively.

The main shaft 4 includes a fourth gear 12, a third gear
A speed gear 13, a second speed gear 14, a reverse gear 15, and a first speed gear 16 are supported for free rotation, and these are connected by synchronized mesh clutch mechanisms 8, 9, and 10.
It is adapted to be selectively rotationally coupled to the main shaft 4, and in particular the synchronized clutch mechanism 8 also provides a rotational coupling between the input shaft 3 and the main shaft 4.

On the other hand, the subshaft 5 is supported by bearings 37 and 38 on both end walls of the gear box 31, and the gears 7, 22,
23, 24, 26 are fixedly supported, and the gear 6 of the input shaft 3 and the aforementioned gears 12, 13, 14, 16 are fixedly supported.
and always mesh with each other. In addition, gear 2 is attached to countershaft 5.
5 is fixedly supported and always meshed with the reverse gear 15 of the main shaft 4 via the idle gear 30.

A gear 27 serving as a speed increasing mechanism is freely rotatably supported on the right end of the subshaft 5, and the synchronous mesh clutch mechanism 1
1, and this gear 27 is always meshed with the overdrive gear 17 of the main shaft 4. Such a speed increasing mechanism is generally attached to the outside of the gear box 31 and is closed with a cover 32.

As is clear from FIG. 2, which specifically shows the right half of FIG. Spline shaft portion 4 of main shaft 4
However, when induction hardening or carburizing hardening is performed on the spline hole of the overdrive gear 17 to achieve such a fit with the spline shaft portion 44b, the teeth of the overdrive gear 17 are As described above, the overdrive gear 17 is also hardened at the same time, causing distortion in the tooth surface of the overdrive gear 17, which adversely affects the meshing with the gear 27.

Therefore, in the present invention, by rotationally coupling the overdrive gear 17 to the traveling speed detection gear 40 spline-fitted to the terminal end of the main shaft 4, it is possible to eliminate the need for providing a spline hole in the overdrive gear 17. This is what I did. That is, the third
As shown in the figure, the overdrive gear 17 is provided with a shaft hole 43 that fits into the main shaft 4, and a plurality of protrusions extending in the radial direction, for example, are provided on the right end surface of the overdrive gear 17 at predetermined intervals in the circumferential direction. Form 41.

On the other hand, a traveling speed detection gear 40 spline-fitted to the main shaft 4 adjacent to the overdrive gear 17
A spline hole 44a is formed in this axis, and of course induction hardening or carburizing is performed.
Furthermore, a plurality of grooves 42 are provided on the left end surface of the traveling speed detection gear 40, and extend in the radial direction at predetermined intervals in the circumferential direction. In this way, the overdrive gear 17 and the traveling speed detection gear 40 are supported on the main shaft 4 adjacent to each other, and the protrusion 41 is engaged with the groove 42.

As described above, in the present invention, the overdrive gear 17 is simply hole-fitted to the terminal end of the main shaft 4 without using spline fitting, and the spline hole 44a of the traveling speed detection gear 40 is connected to the spline shaft portion 44b of the main shaft 4.
The overdrive gear 1 is fitted and supported by the overdrive gear 1.
Since the protrusion 41 of No. 7 is engaged with the groove 42 of the travel speed detection gear 40, the rotational force of the overdrive gear 17 is transmitted to the main shaft 4 via the travel speed detection gear 40.

Conventionally, a spline hole was formed in the shaft center of the overdrive gear 17 and induction hardening or carburizing was performed, but instead of such a spline hole, a shaft hole 43 was simply formed and induction hardening was performed. Alternatively, after carburizing and quenching, the shaft hole 43 can be polished and corrected to match the distortion of the teeth of the gear, so finishing is easier than in the case of a spline hole, and the machining accuracy of the teeth of the overdrive gear 17 can be improved. can be improved.

On the other hand, the traveling speed detection gear 40 has a spline hole 4
4a is subjected to induction hardening or carburizing hardening as in the past, but even if the tooth of the running speed detection gear 40 is distorted, it is not for transmitting power but for detecting the running speed. Therefore, such distortion is not a problem.

[Effect of idea]

As described above, in the present invention, the overdrive gear 17 is shaft-fitted and supported on the main shaft, and the traveling speed detection gear 40 is spline-fitted to the main shaft, and a protrusion is provided on one side of the mutually opposing end surfaces of the two, and a protrusion is provided on the other side. Since grooves are provided on the sides and these grooves engage with each other, the structure is simple and easy to finish, and it is also possible to eliminate the negative effects of meshing caused by distortion caused by heat treatment of conventional overdrive gears. This excellent effect can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of an automobile transmission equipped with a speed increasing mechanism, Fig. 2 is a sectional view showing a specific configuration of the gear mounting structure of an automobile transmission according to the present invention, and Fig. 3 is the same. FIG. 3 is a cross-sectional view of an overdrive gear and a traveling speed detection gear that constitute a gear mounting structure. 3: input shaft, 4: main shaft, 5: subshaft, 6, 7: gears, 8 to 11: synchronous mesh clutch mechanism, 12: 4th speed gear, 13: 3rd speed gear, 14: 2nd speed gear, 15: Reverse gear, 16: 1st speed gear, 17:
Overdrive gear, 40: Traveling speed detection gear,
41: Projection, 42: Groove, 43: Shaft hole, 44a: Spline hole, 44b: Spline shaft.

Claims (1)

[Scope of utility model registration request] An overdrive gear is rotatably supported at the end of the main shaft of an automobile transmission, and a travel speed detection gear is supported by spline fitting on a spline shaft formed at the end of the main shaft, and the end face of the overdrive gear is supported by spline fitting. and a groove extending in the diametrical direction on one end face of the running speed detection gear, and a protrusion that engages with the groove on the other end surface, and the overdrive gear is connected to the main shaft via the running speed detection gear. A gear mounting structure for an automobile transmission characterized by rotational coupling.