JPS6116421Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a double-row tapered roller bearing with a large gear, in which a large gear is integrally formed on either the inner or outer ring.

Conventionally, crossed roller type swivel seat bearings have been used for the main shaft of tunnel excavators, but recently, due to severe load conditions, there has been a trend to switch to double-row tapered roller bearings, which have a larger load capacity. There has been a growing demand for bearings that have the performance of tapered roller bearings and the convenience of swivel seat bearings.

Fig. 1 is a diagram showing a typical structure of a cross roller type swivel seat bearing, in which an inner ring 1 is provided with a gear portion 2 and a screw hole 3 for mounting a rotating body, and an outer ring 4 divided into two parts has mounting bolt holes. A roller 8a with an end face facing upward to the right and a roller 8a with an end face facing upward to the left and rollers 8a having diameters and lengths that are approximately equal in diameter and length between the V-shaped raceway surfaces 6 and 7 formed on the inner and outer rings. 8b are incorporated alternately. 9 is a retainer. This type of bearing has the advantage of being light in weight and easy to handle, but since it is only possible to use rollers whose diameter and length are approximately equal, the load capacity can be increased by using long rollers. It is not possible to apply measures such as increasing Also, because it is structured to receive all the loads of thrust load, radial load, and moment load in one row of rollers, its load capacity is considerably lower than that of double-row tapered roller bearings. Furthermore, due to the structure of the bearing, the raceway surfaces of both the inner and outer rings are hardened by induction hardening.

It is extremely difficult to harden the raceway surface of a large bearing to a uniform roughness over the entire surface by induction hardening, and generally the hardening start point on the circumference and the hardening end point where the ring body goes around once. A non-hardened portion that has not been quenched is left between the two, that is, at one location on the circumference. Therefore, there are unhardened parts on each of the inner and outer rings, and wear and seizure are particularly likely to occur on the sliding surfaces where the end surfaces of the rollers make sliding contact. The reality is that it is considerably inferior.

Therefore, as shown in FIG. 2, it is conceivable to support the rotating body 11 (for example, a cutter head in an excavator) with a double-row tapered roller bearing 10, but this is because the gear 12 and the bearing 10 are separated. , a part 13 is required to connect the two, which makes the structure complicated and the handling considerably complicated. 1 in the diagram
4 is a drive motor, and 15 is a pinion.

This idea eliminates the above-mentioned conventional drawbacks,
The present invention provides a highly reliable bearing with a much larger load capacity than general swivel seat bearings.

Thirdly, gear cutting is performed on the outer periphery of the outer ring 21 of a bearing equipped with double rows of tapered rollers 20 to integrally form the gear portion 22, and the surface of the raceway surface 23 is hardened by induction hardening or the like. . 24 is a mounting screw hole. The inner ring 25 is provided with a flange 26 for guiding the rollers on which the end surfaces of the rollers 20 slide, and the entire surface of the inner ring 25 is quenched and hardened by a normal quenching method (for example, quenching performed by immersion in oil) or carburizing quenching. . That is, the inner ring 25 has its raceway surface 27,
Not only the guide surface of the flange 26 but also its entire surface is hardened to an even thickness. 28 is a retainer, 29
is an intercalary spacer.

In the embodiment shown in FIG. 4, a double row tapered roller 30
A gear portion 32 is integrally formed by gear cutting on the inner periphery of an inner ring 31 of a bearing equipped with the bearing, and a raceway surface 33 portion thereof is surface hardened by induction hardening or the like.
34 is a mounting screw hole.

The outer ring 35 is provided with a collar 36 for guiding the rollers on which the end surfaces of the rollers 30 slide, and is completely quenched and hardened by a normal quenching method, carburizing, or the like.

Guide surface 37 of roller guide collar 36 and outer ring raceway surface 3
One or more oil holes 39 for oil supply or oil drainage, or for both, penetrating through the outer diameter surface of the outer ring from the intersection of 8.
Furthermore, one or more oil holes 41 similar to those described above are provided in the outer ring spacer 40 interposed between the outer ring 35 divided into two left and right parts in the radial direction. 42 is a retainer.

When a large double-row tapered roller bearing and a gear are integrated and both the inner and outer rings are induction hardened,
As mentioned above, a soft zone is formed in a part of the circumference, and therefore a soft zone also exists on the roller guiding flange surface which makes sliding contact with the roller. That is, contact with the raceway surface is basically rolling contact, but if there is a soft zone on the only sliding contact surface, the wear of this area becomes large and becomes a major cause of bearing damage such as seizure.

On the other hand, if the entire ring is hardened using a general hardening method after gear cutting is performed on either the inner or outer ring, dimensional changes (distortion) will occur due to baking distortion of the teeth, reducing the performance of the gear. However, in some cases, the brittleness of the gear portion may increase, leading to breakage due to vibration, etc., or a decrease in impact resistance.

Furthermore, it is extremely inconvenient in practice to carry out gear cutting after the whole body is hardened, as it is impossible to machine with general processing methods, and requires the adoption of expensive special processing methods such as electrical discharge machining. .

This invention is a bearing in which the gear part is integrally formed on either the inner or outer ring as described above, but the bearing ring without the gear part is subjected to ordinary hardening (hardening method other than induction hardening) or carburizing hardening. The bearing ring is quenched and hardened so that the entire surface becomes uniformly flattened.Therefore, the bearing ring does not have a non-hardened part, the so-called soft zone, unlike those that have been induction hardened. Since a collar is provided for guiding the rollers, even if a soft zone is formed on a part of the raceway surface by induction hardening of the raceway ring on which the gear part is formed, the rollers will not touch the soft zone. There is no soft zone on the flange surface, which is the only sliding contact part of a tapered roller bearing, and it is possible to maintain an even roughness over the entire surface, so wear and seizure are extremely unlikely to occur. This is a tapered roller bearing with a gear, and its reliability can be significantly improved.

In addition, there are no particular restrictions on the length of the rolling elements, that is, the number of tapered rollers, and because the tapered rollers are arranged in double rows, the radial direction The bearing has a significantly high load capacity for both loads in the thrust direction, and the raceway ring with the gear part is hardened only on the raceway surface, hardening the gear part more than necessary and increasing its brittleness. Alternatively, there is no possibility that a large dimensional change due to distortion will occur in the gear portion, and there is no risk of deterioration of gear performance.

Furthermore, a structure in which a roller guide rib is provided on the outer ring, when used with a horizontal shaft, has good lubrication performance because lubricant is retained between the rib and the raceway. If an oil hole is provided through the outer diameter surface of the outer ring at the intersection of the rib surface and the raceway surface, oil can be supplied directly to the roller guide rib surface, greatly improving its lubrication performance, and it can also be effectively used as an oil drain hole to discharge wear powder, dust, etc. contained in the oil.

As described above, the present invention is equipped with a double row of tapered rollers, a gear part is integrally formed on either the outer ring or the inner ring, and the raceway ring on which the gear part is formed has a flange for guiding the rollers. A bearing ring without a gear part is formed with a flange for roller guidance, and a bearing ring with a gear part is quenched and hardened only on its raceway surface to form a gear part. Since the entire surface of the bearing ring is hardened by quenching, it has a large load capacity, is easy to process, and has excellent wear resistance, and is suitable as a main shaft bearing for a tunnel excavator, for example.

In other words, since the tapered rollers are arranged in double rows, the bearing has a high load capacity for both thrust loads and radial loads, and has a large overall load capacity. Since the gear part is integrally formed on one of the bearing rings, there is no need for any parts to attach the bearing ring and the gear part, and that process is also eliminated, making manufacturing easier. The ring is
Since only the raceway surface portion is quenched and hardened, there is no need to perform gear cutting after quenching, which requires expensive special processing methods, and there is a risk that the brittleness of the gear portion may increase or dimensional changes may occur due to distortion. Moreover, since the bearing ring on which the gear part is formed does not have a flange for guiding the rollers, there is only rolling contact between the bearing ring and the raceway surface, and in the unlikely event that the bearing ring has a soft zone. Even if this occurs, there is no risk of wear or seizure. Furthermore, since a collar for guiding the rollers is formed on the bearing ring on which no gear part is formed, the rollers are held between the bearing rings, and the entire surface of the bearing ring on which no gear part is formed is hardened. Since it is hardened, a low-cost hardening method can be used for hardening.
In addition, there is no risk of a soft zone forming in the roller guiding collar, and there is no risk of wear or seizure between the rollers and the bearing ring, resulting in excellent wear resistance.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of the main parts of a conventional cross roller type bearing, Fig. 2 is a longitudinal sectional view of the main parts of a tunnel excavator, and Fig. 3 is a longitudinal sectional view of the main parts of an embodiment of this invention. , FIG. 4 is a vertical sectional view of a main part of another embodiment. 20, 30... Tapered roller, 21, 35... Outer ring, 22, 32... Gear portion, 23, 33... Raceway surface, 25, 31... Inner ring, 26, 36... Roller guide collar, 27, 38... Raceway surface, 37... Guide surface, 39, 41... Oil hole, 40... Outer ring spacer.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) Equipped with double rows of tapered rollers, a gear part is integrally formed on either the outer ring or the inner ring, and the bearing ring on which the gear part is formed has rollers. A bearing ring without a guiding flange and a gear part is formed with a roller guiding flange part, and a bearing ring with a gear part is quenched and hardened only on its raceway surface. A double-row tapered roller bearing with a large gear, characterized in that the entire surface of the raceway ring without a section is quenched and hardened. (2) A double-row tapered roller bearing with a large gear as set forth in claim 1 of the utility model registration claim, in which a gear portion is formed on the inner ring and a collar for guiding rollers is provided on the outer ring. (3) A large gear-equipped compound according to claim 2 of the utility model registration claim, which has one or more oil supply and drainage holes penetrating the outer diameter surface from the intersection of the guide surface and raceway surface of the roller guide collar. Row tapered roller bearings. (4) Utility model registration claim 2 or 3, in which an outer ring spacer inserted between a plurality of divided outer rings is provided with one or more oil supply and drain holes penetrating in a radial direction. Double-row tapered roller bearing with large gear as described in item 3.