JPS6230610Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an assembly structure of an idle gear 2 to a countershaft 1 of a transmission.

Conventionally, in non-synchronized transmissions used in agricultural machinery, construction machinery, etc.
Since the idle gear 2 has a structure in which it directly meshes with the dock gear 3 as illustrated in FIG. 1, the spline 4 of the countershaft 1 is carved up to the fitting position of the idle gear 2 in order to secure its effective part. Therefore, the idle gear 2 is configured to be loosely fitted onto the spline 4 and rotated.

However, in this case, the lubrication of the sliding surface A on the inner surface of the idle gear 2 is insufficient, and seizure is likely to occur.In addition, since the area in which the idle gear 2 comes into contact with the snap spring 5 that fixes the idle gear 2 is small, the thrust There was a drawback that the shear stress caused by the load on the top surface of the spline, the idle gear 2, and the bearing 10 caused the teeth of the snap spring 5 to slide or deform.

Furthermore, in Japanese Utility Model Application Publication No. 53-32281, a spline is carved on the inner circumferential wall of a bush, the bush is engaged with a spline shaft, and both ends of the bush are fixed to the spline shaft via a snap spring. A bushing in which an idle gear is loosely fitted onto the outer peripheral surface of the bushing is disclosed.

Further, Japanese Patent Application Laid-Open No. 47-506 simply discloses a bushing having a flange on the mouth edge.

However, when a bevel pinion is formed or fitted on one end of a spline shaft and meshed with a spiral bevel gear, the spline shaft is subjected to the following thrust load.

That is, during power running (hereinafter referred to as forward drive), a thrust (hereinafter referred to as positive thrust) is applied to the countershaft from the bevel pinion side toward the base end of the shaft, and this positive thrust is
It is supported by an angular contact ball bearing fitted to the same shaft base.

By the way, at first glance it appears that the thrust in the opposite direction to the above-mentioned positive thrust (hereinafter referred to as negative thrust) does not act on the countershaft, but in reality, it is used in the same way as a bevel gear to ensure quiet operation and improve gear strength. If the speed ratio of the pinion and the spiral angle of the bevel gear are set large and the pressure angle is set small, when the engine brake is activated (hereinafter referred to as reverse drive), a negative thrust will act,
It is known that the bevel pinion is drawn towards the same gear. Note that this negative thrust is even more pronounced in the case of hypoid bevel gears and phase gears.

Therefore, unless the negative thrust is properly supported, the backlash between the bevel gear and the pinion will be lost, resulting in problems such as whining noise and poor lubrication of the tooth surfaces.

As mentioned above, the spline shaft is subjected to negative thrust from the bevel pinion, and this negative thrust is supported by the snap spring, but in order to support both negative thrusts, the bush must be constructed Bearing materials have low rigidity and cannot sufficiently resist negative thrust. During reverse drive, the bevel gear and pinion operate with too little backlash, causing whining noise and lowering the Poisson's ratio. Due to this, the oil clearance of the bushing becomes too small, which tends to lead to poor lubrication.

Further, the structure of this part needs to be reduced in size in relation to other structural members, and the strength of this part cannot be increased by increasing its size.

The present invention is designed to make it possible to use a sufficiently hard material for the collar to support the above-mentioned negative thrust, and at the same time to smooth the idle fit state of the idle gear loosely fitted to the countershaft. By interposing the same collar between the bearing on the distal end side of the countershaft and the snap spring fitted in a groove carved on the outer peripheral surface of the same shaft on the proximal end side of the idle gear,
This makes it possible to support the above-mentioned negative thrust with the above-mentioned bearing.

Therefore, in the case of the instep, even if a negative thrust occurs during reverse drive, the accurate position of the bevel pinion is maintained, and the bevel gear and pinion operate under appropriate backlash. This prevents harmful effects such as whining noise and poor lubrication. Further, the negative thrust applied to the idle gear is supported by the flange of the collar.

As mentioned above, the present invention can reliably support the negative thrust of the bevel gear and the same pinion, so it is possible to improve the quietness of gear operation and the strength of the gear, or to improve the mechanical strength. Due to necessity, we increased the speed ratio of the bevel gear and the same pinion,
Even when the torsion angle of the idle gear and the spiral angle of the spiral bevel gear are increased, the pressure angle is decreased to increase the number of teeth in simultaneous engagement, and even when a hypoid bevel gear or a face gear is adopted as a variation of the spiral bevel gear, negative Separating the thrust support member and the idle gear shaft support member opens up the possibility of using a hard member for the collar, which allows for sufficient negative thrust support and a simple structure. However, the above-mentioned problems are solved.

Note that this also has the effect of significantly relaxing the design limitations previously imposed by negative thrust and expanding the degree of freedom in design.

The present invention will be described in detail below with reference to an embodiment shown in the drawings.

What is shown in FIGS. 1 and 2 is one part of a countershaft of a transmission for an agricultural working machine, and shows a conventional example and an application example of the present invention, respectively. In these cases, the countershaft 1 serves as a shaft for transmitting power to the outside, and is provided with a spiral bevel gear at one end, so that the negative thrust is supported by the snap spring 4. An application example of the present invention will be described below.

The idle gear 2 is loosely fitted into a collar 6 made of a hard material, for example, via a bush 8 made of a short cylindrical bearing material, and slides and rotates on the abutting surface of the bush 8 and the collar 6. The collar 6 has a short cylindrical shape and has a flange 7 on its mouth edge, and has a spline 4' cut on its inner circumferential wall, and meshes with a spline 4 cut on the countershaft 1.

Moreover, the flange 7 of the collar 6 is brought into contact with the concave bottom of the idle gear concave surface 2-1 on the opposite side to the bearing 10 abutment surface of the countershaft 1,
The collar 6 is fixed to the countershaft 1 by a snap spring 5 disposed in contact with the outer peripheral surface of the flange 7, and its opposing side ends are brought into contact with a bearing 10 of the countershaft 1 via a thrust washer 9.

Therefore, according to the assembly structure of the idle gear 2 according to the present invention, in addition to the functions and effects described above, the following functions and effects are produced.

That is, the collar 6 having the spline 4' on the inner peripheral wall is connected to the spline 4 of the countershaft 1.
A snap spring 5 is disposed in contact with the flange 7 side of the collar 6, and the other end is brought into contact with the bearing 10 of the countershaft 1 via the thrust washer 9.
Since the collar 6 and the countershaft 1 are securely fixed to the countershaft 1, the collar 6 and the countershaft 1 rotate together.

Then, a button 8 is formed on the outer peripheral surface of the collar 6.
Since the idle gear 2 is rotatably fitted loosely through the bushing 8 and the collar 6, the idle gear 2 slides and rotates on the contact surface between the bush 8 and the collar 6. Since the lubricity caused by the surface contact with the idler 2 is maintained well for a long period of time, the smooth idle function of the idler 2 can be ensured.

Furthermore, since the snap spring 5 that fixes the collar 6 is in contact with the concave bottom of the idle gear concave surface 2-1 and is in contact with the outer surface of the flange 7, the contact area of the collar 6 with respect to the snap spring 5 is reduced. Even when the thrust load increases and is sequentially transmitted to the thrust washer 9, the idle gear 2, the collar 6, and the flange 7 of the collar 6 and acts on the snap spring 5, the shear stress on the snap spring 5 increases. Since concentration of the collar is avoided, deformation of the snap spring 5 can be prevented, and the collar fixing function of the snap spring can be reliably maintained.

As described above, according to the present invention, an appropriate backlash between the idle gear and the spiral bevel gear and the pinion is maintained to enable smooth meshing, to ensure the smooth idle function of the idle gear, and to prevent the snap spring from slipping. This has the effect of maintaining function at the same time.

In the figure, 11 indicates the main shaft.

The present invention has the above-described configuration, and can be applied to the conventional configuration without major changes.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a transmission of a conventional agricultural working machine, and FIG. 2 is a sectional view showing an example in which the present invention is applied to the transmission. 1: countershaft, 2: idle gear,
4: spline, 4': spline, 5: snap spring, 6: collar, 7: flange, 8: bush, 9: thrust washer, 10: bearing, A: sliding surface, a: spiral bevel gear.

Claims (1)

[Scope of utility model registration request] In an idle gear 2 which is loosely fitted into a countershaft 1 having a spline 4 carved therein and idles, a collar 6 having a short cylindrical shape and having a spline 4' carved in its inner circumferential wall and a flange 7 on its mouth edge is provided.
The collar 6 meshes with the spline 4 of the countershaft 1, and the idler gear 2 is rotatably fitted to the outer peripheral surface of the collar 6 via a bush 8, and the flange 7 of the collar 6 is engaged with the bearing 10 of the countershaft 1. The collar 6 is brought into contact with the concave bottom of the idle gear concave surface 2-1 on the opposite side to the contact surface, and the collar 6 is fixed to the countershaft 1 by a snap spring 5 disposed in contact with the outer surface of the flange 7, so that the collar 6 faces the countershaft 1. An assembly structure of an idle gear in a countershaft in which a thrust washer 9 is positioned at the side end and abuts against a bear link 10 of a countershaft 1.