JP2000130565A - Support device for splitter gear in transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support device which can dispense with adjustment of gap between bearings which rotatably support a splitter gear. SOLUTION: A splitter gear 6 is rotatably supported by a bearing 20 attached onto a first shaft. A double row tapered roller bearing with vertex of contact angles outside of bearing is adopted to the bearing 20, in which a spacer 25 is assembled for setting a bearing gap between inner gins 22a and 22b of the double row. It is thus unnecessary to adjust the bearing gap at the time of assembling, and possible to reduce the number of assembling manhour.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for supporting a splitter gear in a primary reduction section of a transmission.

[0002]

2. Description of the Related Art A transmission shown in FIG. 2 is conventionally known as a transmission for a truck. In this transmission, a first shaft 2 that is rotatable relative to the input shaft 1 is disposed coaxially with the input shaft 1, and a drive gear 3 is provided at an axial end of the input shaft 1.
A rotatable low gear 5 provided on the input shaft 1 by a synchromesh 4
And to one of the rotatable splitter gears 6 provided on the first shaft 2, and the rotation is transmitted from the gear 5 or 6 to the gear 7 or 8 meshing therewith.

Here, the synchromesh 4 has a coupling sleeve 8 slidable along the teeth 3a of the drive gear 3, and this coupling sleeve 8 is attached to the low gear 5
Alternatively, it is shifted to the splitter gear 6 side, and the synchronizer ring 9 and each gear 5,
The clutch gear 10 is engaged with teeth on the outer periphery of the clutch gear 10 so as to transmit the rotation of the drive gear 3 to the low gear 5 or the splitter gear 6.

As the splitter gear 6 in the above transmission, a helical gear is generally used in order to suppress generation of noise. Since the splitter gear 6 composed of the helical gear generates a thrust force during its rotation, the bearing that supports the splitter gear 6 must be able to support both the radial load and the thrust load.

Therefore, conventionally, as shown in FIG.
Two single row tapered roller bearings 11a, 11 on shaft 2
b are mounted in a back-to-back combination, and the splitter gear 6 is supported by the single-row tapered roller bearings 11a and 11b.

[0006]

In a splitter gear 6 supporting apparatus using two single-row tapered roller bearings 11a and 11b, each single-row tapered roller bearing 11
It is necessary to keep the bearing clearances of a and 11b at appropriate clearances.

Therefore, conventionally, single-row tapered roller bearings 11
The spacer 13 is incorporated between the inner rings 12a and 11b to adjust the bearing clearance. At this time, several kinds of spacers for adjusting the clearance are prepared, and the spacers 13 are temporarily assembled to determine whether the bearing clearances of the single-row tapered roller bearings 11a and 11b are appropriate. Is replaced with another spacer 13, so that it takes a lot of time and effort to adjust the clearance of the bearing, and it takes time to assemble the gear supporting device.

Here, the outer race 14 of the single-row tapered roller bearings 11a and 11b in FIG.
There is also a splitter gear support device in which double-row raceways are formed on the inner diameter surface of the splitter and the tapered rollers are rolled along the raceway surface.In this case, too, the clearance between the bearings is selected by selecting the spacer. Adjustment is required, and equipment for forming a raceway surface on the splitter gear is required, which causes a problem that equipment cost is high.

It is an object of the present invention to provide a splitter gear support device capable of reducing the number of assembly steps by eliminating the need to adjust the bearing clearance.

[0010]

In order to solve the above-mentioned problems, according to the present invention, there is provided a drive gear provided on a first shaft arranged coaxially with an input shaft, at a shaft end of the input shaft. In a transmission splitter gear supporting device in a transmission in which the rotation of the transmission is provided via a synchromesh for primary deceleration, and the splitter gear is rotatably supported by a bearing attached to the first shaft, An outer ring press-fit into the inner diameter surface of the splitter gear, a double-row inner ring incorporated in the outer ring, a tapered roller incorporated between the outer ring and each inner ring, a retainer for holding the tapered roller, and the inner ring It employs a configuration using a tapered roller bearing having a spacer incorporated therein to set an appropriate bearing clearance.

As described above, by using a plurality of rows of outwardly tapered roller bearings in which the bearing clearance is set in advance,
Adjustment of the bearing clearance at the time of assembling the splitter gear can be made unnecessary.

Here, an annular groove is formed in the inner diameter surface of the spacer of the tapered roller bearing, and a radial oil hole penetrating from the outer diameter surface to the annular groove is provided. Since it is not necessary to form an annular groove,
A decrease in axial strength of the first shaft can be suppressed.

[0013] Fretting of the raceway surface is prevented by arranging the tapered rollers at an irregular pitch, or by applying a phosphate coating to the raceway surfaces of the outer ring and the inner ring.
The durability of the tapered roller bearing can be improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, only the support for the splitter gear is different from the transmission shown in FIG. 2, and only the support for the splitter gear is shown, and the others are omitted.

As shown, a double-row outward tapered roller bearing 20 is mounted on the first shaft 2, and the splitter gear 6 is supported by the double-row outward tapered roller bearing 20.

The double row outward tapered roller bearing 20 includes an outer ring 21 press-fit into the inner diameter surface of the splitter gear 6, a double row inner ring 22a, 22b, an outer ring 21, and each inner ring 22a, 22b.
A tapered roller 23 is interposed between them, a retainer 24 for holding each tapered roller 23, and a spacer 25 incorporated between the inner races 22a and 22b of the double row.

The spacer 25 is provided with an annular groove 26 on the inner diameter surface and a plurality of radial oil holes 27 penetrating from the outer diameter surface to the annular groove 26.
The oil supply passage 15 is formed in communication with the oil supply passage 15.

Therefore, by supplying the lubricating oil to the oil supply passage 15, the lubricating oil flows from the annular groove 26 to the oil hole 27 to enter the inside of the bearing, and the inside of the bearing can be lubricated by the lubricating oil. .

The double row outward tapered roller bearing 20 has an appropriate clearance in advance by a spacer 25 incorporated between the inner rings 22a and 22b.

For this purpose, a double-row tapered roller bearing 20 is fitted on the first shaft 2 and one end thereof is brought into contact with a shoulder 2a provided on the first shaft 2, so that the first shaft 2 shown in FIG. By pressing the inner ring 22b against the shoulder 2a by tightening the tightening nut 16 screw-engaged with the screw shaft portion 2b, the double-row outwardly tapered roller bearing 20 has an appropriate clearance.

Therefore, there is no need to adjust the bearing clearance when assembling the splitter gear 6 into the outer ring 21 by press fitting, so that the number of assembling steps can be reduced.

The cage 2 for holding the tapered rollers 23
If the plurality of pockets 24a are made to have unequal pitch, or if the raceway surfaces of the outer race 21 and the inner races 22a and 22b are subjected to a phosphate coating treatment, fretting on the raceway surface is prevented and the durability of the tapered roller bearing is improved. Can be planned.

Further, when the annular groove 26 is formed on the inner diameter surface of the spacer 25 as in the embodiment, it is not necessary to form the annular groove for refueling on the first shaft 2.
A decrease in the shaft strength of the shaft 2 can be prevented.

[0024]

As described above, according to the present invention, since the splitter gear is supported by using the double row outward tapered roller bearing having a proper clearance, the tapered roller bearing is mounted when the splitter gear is assembled. This eliminates the need to adjust the bearing clearance, thereby reducing the number of assembly steps.

Further, since there is no need to adjust the clearance, there is no concern about excessive clearance, excessive preload, and the like, and stable rotational performance can be obtained, so that reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a support device according to the present invention.

FIG. 2 is a sectional view showing a supporting portion of a transmission splitter gear.

FIG. 3 is a cross-sectional view showing a conventional support device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input shaft 2 1st shaft 3 Drive gear 4 Synchromesh 6 Splitter gear 20 Double row outward tapered roller bearing 21 Outer ring 22a, 22b Inner ring 23 Tapered roller 24 Cage 25 Pocket

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J028 EA08 EA28 EB35 EB67 FC32 FC42 GA02 HB03 3J063 AA02 AA03 AB02 AB55 AC06 BA01 BB23 BB27 CA01 CD02 CD03 CD13 CD17 CD23 XA05 XA11 XA33 3J101 AA16 BA22 BA70 GA71 GA05 FA05

Claims (4)

[Claims] A first shaft disposed coaxially with the input shaft;
A primary deceleration splitter gear is provided on the shaft for transmitting the rotation of a drive gear provided at the shaft end of the input shaft via a synchromesh, and the splitter gear is rotatable by a bearing attached to the first shaft. In the supporting device for the splitter gear in the transmission supported by the above, the bearing is assembled between the outer race and each inner race, the outer race being press-fitted into the inner diameter surface of the splitter gear, the double-row inner race incorporated in the outer race. A device for supporting a splitter gear in a transmission, comprising: a tapered roller; a retainer that holds the tapered roller; and a spacer that is incorporated between the inner rings to set an appropriate bearing clearance. 2. The splitter according to claim 1, wherein an annular groove is formed in an inner diameter surface of the spacer, and a radial oil hole penetrating from the outer diameter surface to the annular groove is provided. Gear support device. 3. The splitter gear supporting device according to claim 1, wherein the tapered rollers are arranged at unequal pitch. 4. The splitter gear support device in a transmission according to claim 1, wherein the raceway surfaces of the outer race and the inner race are treated with a phosphate coating.