JPS5931929Y2 - Rotating shaft end support structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a structure for supporting a shaft end of a rotating shaft, such as a rotating shaft for speed change, which is fitted and connected with the shaft ends butted together.

Generally, a rotating shaft for speed change flexes as a result of transmission with another rotating shaft via a gear mounted at an intermediate location in the axial direction, and when the rotating shaft is deflected in this way,
The axis of the bearing formed at the end of one rotating shaft is inclined with respect to the axis of the bearing formed at the end of the other rotating shaft, so that the outer peripheral surface of the bearing is in the direction of the axis of the bearing. The bearing part wears out unevenly, such as when it slides and rotates while strongly pressed against one end, and that part wears out, and rattling occurs in the bearing part at an early stage.

In order to prevent the occurrence of looseness due to such uneven wear, a hole is formed as a bearing part at the shaft end of one rotating shaft, and a support part is formed at the shaft end of the other rotating shaft. The outer peripheral surface shape of the shaft is spherical or a curved surface close to it, so that even if one of the shafts is bent, the support part and the bearing part are in continuous line contact in the circumferential direction and uneven wear does not occur. However, if the rotating shafts that are butted against each other are configured to be able to freely rotate relative to each other, such as a rotating shaft for speed change, the relative speed between the two shafts will be reduced. The difference causes sliding wear between the mating parts of both shafts,
However, although the bearing part has a curved surface, the contact area is smaller than that of a bearing part with a round shaft shape, so it wears out quickly and is inevitably prone to looseness. .

Therefore, in the shaft end support structure in which the support portion of one rotating shaft is curved and butt-fitted as described above, a ball bearing is interposed between both shafts to prevent the occurrence of wear due to the above-mentioned relative speed difference. However, in this configuration, the diameter of one shaft would have to be made larger than necessary in order to install a large ball bearing to withstand the enormous load. To solve the first drawback and to allow some relative movement of both shafts in the axial direction due to shaft deflection, a flexibility is created between the outer circumferential surface of the bearing and the inner circumferential surface of the inner race of the ball bearing. Therefore, it is impossible to completely prevent the occurrence of sliding wear due to slipping between the outer circumferential surface of the bearing and the inner circumferential surface of the inner race due to the relative rotational speed difference between the two shafts. There is a second drawback.

The first drawback can be greatly improved by using needle bearings instead of ball bearings, but simply using needle bearings instead of ball bearings will also introduce new drawbacks, including the second drawback. It cannot be resolved without inviting it.

In other words, there are two types of needle bearings: those that have both an inner race and an outer race, and those that omit the inner race and are supported at the end in the axial direction. In order to make it as small as possible,
The latter type without an inner race is effective, and since it does not include an inner race, it is also effective in that it does not cause sliding friction between the inner race and the outer peripheral surface of the support part of the other shaft. In this type, the outer peripheral surface of the bearing directly contacts the needle of the needle bearing, so the curved outer peripheral surface of the bearing comes into point contact with the three-point bearing, and the surface pressure on that contact surface is extremely high. Because of this, there is a tendency for friction to occur even when contact is caused by rolling friction, and there is a new difficulty in that durability is reduced.

Furthermore, the former type of needle bearing that includes an inner race and an outer race not only has a larger shaft diameter than the type without the inner race, but also has the disadvantage that the second drawback cannot be completely eliminated.

The technical problem to be solved by the present invention is that in order to prevent uneven wear caused by deflection of the rotating shaft between the two rotating shafts that are fitted and connected in a butt state, the shaft end of one shaft is provided with a When forming the outer circumferential surface of the support part into a curved shape to create a shaft end support structure that does not cause uneven wear even when deflection occurs, it is necessary to prevent wear at the fitting part due to the difference in relative rotational speed between the two rotating shafts. The objective is to be able to almost completely prevent this problem without increasing the shaft diameter or reducing durability.

The technical means of this invention taken to solve the above problems are as follows:
In order to mutually support the rotating shafts, each of which has a rotation transmission wheel mounted at an intermediate location in the axial direction, in a concentric manner, a hole is formed along the axial direction at the shaft end of one of the rotating shafts, A needle bearing without an inner ring is mounted on the inner circumferential surface of this hole, and a spline collar that is cylindrical and has a spline formed on its inner surface is fitted on the inner circumferential side of the needle bearing. A support portion having an outer peripheral surface formed into a spherical surface or a curved surface close to it is provided at the end of the rotating shaft, and a spline portion of the spline collar is further formed on the outer peripheral surface of the supporting portion, so that the two rotating shafts are connected to each other. They are fitted and connected to each other in a butt-like manner at the ends in the axial direction.

The effects of taking the above technical measures are as follows.

In other words, since the rotating shaft on the side in which the hole is formed and the rotating shaft in which the support is formed are fitted and connected via a needle bearing, the relative rotation of the two wheels due to the difference in relative rotational speed between the two shafts is caused. The movement takes place through this bearing and therefore
Although the occurrence of large wear due to direct sliding contact between the inner circumferential surface of the hole of one shaft and the outer circumferential surface of the support portion of the other shaft is suppressed by the support structure using this bearing,
In particular, in the present invention, in order to obtain a bearing structure as described above, the bearing is a needle bearing without an inner ring, a spline collar is interposed between the needle bearing and the outer peripheral surface of the bearing part, and
Since the spline collar and the outer circumferential surface of the bearing part are spline-engaged, the diameter of the rotating shaft can be made as small as possible even though the bearing is inserted, and the outer circumferential surface of the bearing part is curved to create a needle bearing. Even though the collar is supported by the support, the existence of the collar does not cause a decrease in durability due to excessively increasing the contact pressure between the two, and furthermore, the collar and the support are integrated by spline engagement. Therefore, even if the support part is loosely fitted to the collar so that it is somewhat movable in the axial direction,
One that completely eliminates relative rotation between the two, eliminates wear due to sliding on both, and almost completely prevents the occurrence of wear caused by the relative rotation speed difference between the two rotating shafts. It is.

EMBODIMENT OF THE INVENTION Hereinafter, an embodiment of the present invention will be described based on a transmission transmission mission for a tractor.

2 has one end fitted and rotatably supported on the end of another transmission rotating shaft 3, and the other end near the transmission case 4 rotatably supported by a transmission case 4 via a bearing 5. The rotating shaft 2 has a gear 6 attached to the end of the other rotating shaft 3 at an intermediate position in the axial direction of the rotating shaft 2, and a gear 6 interlocked with the gear 6 via a speed change gear 7. A gear 1 (this is an example of a rotary transmission wheel body) which is selectively interlocked with a gear 8 which is loosely fitted onto the rotating shaft 2 via a two-position switching type shut gear 9 is attached in a transmission state. .

The other rotating shaft 3 has a transmission gear 12 serving as a rotary transmission wheel that engages and makes noise with the transmission gear 11 on the side of the cylindrical rotating shaft 10 that is linked to the engine. ... is loosely fitted, and this loosely fitted transmission gear 12...
A gear 13 for selectively switching between the interlocking state and the non-interlocking state between the rotary shaft 3 and the other rotating shaft 3 is installed.

The structure in which the end of the rotary shaft 2 is supported by the end of the other rotary shaft 3 is such that a relatively large diameter hole 3A is formed at the end of the another rotary shaft 3 along the axial direction. And this hole 3A
A spline collar having a cylindrical shape and a spline portion 15a formed on the inner surface of the needle bearing is attached via the needle bearing 14 to the inner circumferential surface of the needle bearing. 15
This spline collar 15
A support portion 2A formed at the end of the rotating shaft 2 is supported by the support portion 2A.

The supporting portion 2A has an outer circumferential surface formed into a curved surface close to a spherical surface that has the largest diameter at the axial center of the supporting portion 2A, and the spline collar 1 is formed on the outer circumferential surface.
Spline portion 2a that engages with spline portion 15a on the 5 side
It is formed.

Therefore, according to the above structure, even if the axis of the rotating shaft support part 2A is inclined with respect to the axis of the separate rotating shaft 3 due to the deflection of the rotating shaft 2 or another rotating shaft 3, the support Part 2A
The outer circumferential surface of the spline collar 15 and the inner circumferential surface of the spline collar 15 are always in contact with each other via a line contact portion that is continuous in the circumferential direction and is located in a plane perpendicular to the axis of the separate rotating shaft 3. In addition, since the spline collar 15 is in a position where its axis is aligned with the axis of the separate rotating shaft 3, the outer peripheral surface of the spline collar 15 rotating together with the rotating shaft 2 and the needle 14...
It is possible to prevent uneven wear between... and to rotate the rotating shaft 2 smoothly without wobbling.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, with FIG. 1 being a longitudinal side view showing the transmission structure of a tractor, and FIG. 2 being an enlarged longitudinal side view of the main parts. 1.12...Rotation transmission wheel body, 2,3...
・Rotating shaft, 2A...Supporting part, 2a, 15
a... Spline part, 3A... Hole part,
14... Needle bearing, 15...
・Spline color

Claims (1)

[Scope of utility model registration request] Rotation transmission wheels 1°12... are placed at intermediate locations in the axial direction.
... to support the rotating shafts 2 and 3 concentrically with each other, a hole 3A is formed along the axial direction at the shaft end of one of the rotating shafts 3, and this hole 3A A needle bearing 14 without an inner ring is installed on the inner peripheral surface of the bearing, and
A spline collar 15, which is cylindrical and has a spline portion 15a formed on the inner surface thereof, is fitted into the inner circumferential side of the needle bearing 14, and the outer circumferential surface is formed into a spherical or similar shape to the shaft end of the other rotating shaft 2. A support portion 2A having a nearly curved surface is provided, and the spline portion 2a of the spline collar 15 is formed on the outer peripheral surface of the support portion 2A, so that the rotation shafts 2 and 3 are connected to each other at the ends in the axial direction. A shaft end support structure for a rotating shaft, characterized in that the shaft ends are fitted and connected to each other in a butt-like manner.