JPH0610209Y2 - Rotating bearing device for construction machinery - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to a slewing bearing device including an outer ring portion provided on an upper slewing body of a construction machine such as a hydraulic excavator and an inner ring portion provided on a lower traveling body, and more particularly to an improvement of a slewing bearing device having a divided inner ring portion. .

[Prior art]

In a conventional slewing bearing device for a construction machine such as a hydraulic excavator, as shown in FIG. 4, an upper slewing body 1 is allowed to freely slew in a circumferential direction around a vertical axis on a lower traveling body 2 via a slewing bearing 3. Are linked to. That is, as shown more clearly in FIG.
Is a bearing structure in which a ball 13 is provided inside an annular outer ring portion 3a provided in a lower portion of the upper revolving structure 1 and an annular inner ring portion 3b provided in an upper portion of the lower traveling body 2 is fitted therein. . Further, in the figure, 14 is a seal member for vertically oil-sealing the gap between the outer ring portion 3a and the inner ring portion 3b in which the balls 13 are provided, and 15A is a bolt for fastening the outer ring portion 3a to the base of the upper swing body 1. 15B for the inner ring 3
It is a bolt mounting hole for fastening b to the base of the lower traveling body 2 with a mounting bolt. Then, the inner teeth 3c formed on the inner peripheral surface of the inner ring portion 3b mesh with the gears of the slewing reducer 16, and the upper slewing body 1 can freely swivel around the vertical axis of the slewing bearing 3. Here, the inner ring portion 3b of the conventional slewing bearing 3 has its outer peripheral surface in contact with the inner peripheral surface of the outer ring portion 3a via the ball 13, and the inner peripheral surface integrally formed has inner teeth 3c. Since it meshes with the gear of the swing reducer 16, it has a function as a bearing between the upper swing body 1 and the lower swing body 2 and a function as a power transmission gear (internal teeth) for swing at the same time. It is integrated in the structure. As described above, in the slewing bearing 3, since the inner ring as the bearing and the inner teeth are integrated, when the inner teeth 3c are damaged,
Although it is necessary to replace the entire inner ring portion 3b, when replacing the inner ring portion 3b, a new inner ring portion 3b and an outer ring portion 3 to be continuously used are used.
There is a feeling that the ball does not fit well with a and the ball 13 and cannot sufficiently function as a bearing. Further, replacing the entire slewing bearing 3 every time the inner ring portion 3b is damaged increases the cost. Further, in construction machines such as hydraulic excavators that are made into a series, even if the same model is used, the internal gear 3 that meshes with the rotary reducer 16 has different specifications (especially the gear specifications).
When the specifications of c are different, it is necessary to prepare separate slewing bearings 3.

[Problems to be solved by the device]

The present invention was created as a result of earnest research in view of the above circumstances, and its main problem is to divide the inner ring portion of the slewing bearing into an inner ring base portion and an inner tooth portion inside thereof, and to bolt them together. Thus, there is provided a slewing bearing device for a construction machine, which is detachably fastened to facilitate replacement of the internal teeth.

[Means for solving problems]

In order to solve the above problems, the present invention is free to rotate by inserting a ball inside an annular outer ring portion provided in the lower portion of an upper revolving structure and inserting an annular inner ring portion provided in the upper portion of a lower traveling structure. In a slewing bearing device for construction machinery bearing on (a). The inner ring portion is concentrically divided into two parts, and an inner ring base part that serves as an inner ring part side bearing outside the two parts and an inner tooth part provided with inner teeth for power transmission inside the two parts are provided. ). An outer mounting hole forming portion penetrating from the outer peripheral surface of the inner ring base portion in a radial direction, and an inner mounting which is bored to an intermediate position of an inner tooth portion on an extension line of the outer mounting hole forming portion and is capable of communicating with the outer mounting hole forming portion. Provide a bolt mounting hole consisting of the hole forming part, (c). A technical measure is taken such that a bolt is inserted into the bolt mounting hole so that the tip does not protrude from the outer peripheral surface of the inner ring base portion, and the inner ring base portion and the inner tooth portion are detachably fastened.

[Action]

A bolt mounting hole is formed by aligning an outer mounting hole forming portion and an inner mounting hole forming portion provided on the inner ring base portion and the inner tooth portion, respectively, and inserting a bolt into the bolt mounting hole to insert the bolt into the inner ring base portion and the inner tooth portion. And the inner ring part is assembled. The inner ring portion is fitted into the outer ring portion via balls to form a slewing bearing. When the inner tooth portion or the inner ring base portion is damaged, the bolt may be removed from the bolt mounting hole, and the inner ring base portion and the inner tooth portion may be separated and replaced. Also, even if the gear specifications of the swing reducer are different,
Since the inner ring part shares the inner ring base part, it is possible to deal with it by exchanging only the inner tooth part.

【Example】

A preferred embodiment in the case where the slewing bearing device for a construction machine according to the present invention is used in a hydraulic excavator will be described below with reference to FIGS. 1 to 3. The same parts as those of the conventional structure of the slewing bearing of the hydraulic excavator shown in FIGS. 4 and 5 are designated by the same reference numerals. The upper revolving structure 1 is mounted on the lower traveling structure 2 via the revolving bearing 3.
The slewing bearing 3 is connected so that it can freely rotate in the circumferential direction around the vertical axis at the center of the slewing bearing 3. The slewing bearing 3 is fixed to the lower part of the upper slewing body 1 and has an annular outer ring portion 3a similar to the conventional structure. The slewing bearing 3 is provided above the lower traveling body 2 and has a ball 13 inside the outer ring portion 3a. And an annular inner ring portion 5 that is rotatably fitted in through. The inner ring portion 5 is concentrically divided into two, and the divided outer annular portion serves as the inner ring base portion 6 and the inner annular portion serves as the inner tooth portion 7. That is, the inner ring base 6 has an outer peripheral surface in contact with the outer ring 3 a through the balls 13 and functions as an inner ring side bearing. Further, the inner tooth portion 7 has inner teeth 7a formed on the inner peripheral surface thereof, and meshes with the gear of the turning reduction gear 16 to function as a power transmission gear (inner tooth). The inner ring base portion 6 and the inner tooth portion 7 are fitted with bolts 4 into bolt mounting holes 8 formed by a combination of an outer mounting hole forming portion 9 of the inner ring base portion 6 and an inner mounting hole forming portion 10 of the inner tooth portion 7. It can be detachably fastened with screws. The outer mounting hole forming portion 9 is a through hole that radially extends from the outer peripheral surface of the inner ring base portion 6. Further, in the present embodiment, the bolt insertion end side of the outer mounting hole forming portion 9 is bored in a step portion having a diameter larger than that of the insertion side hole portion, and the head portion of the bolt 4 is attached to the step portion. The bolt 4 is formed so as to be locked so that the tip of the head of the bolt 4 does not project outward from the outer peripheral surface of the inner ring base 6. Further, the inner mounting hole forming portion 10 is provided with a counterbore-like hole up to a midway position of the inner tooth portion 7 on an extension line of the outer mounting hole forming portion 9 and a screw is formed on the inner peripheral surface thereof. The inner mounting hole forming portion 10 is the outer mounting hole forming portion 9
The bolt mounting hole 8 is assembled in alignment with. The outer mounting hole forming portion 9 is preferably formed slightly larger than the outer circumference of the bolt 4 so that the outer mounting hole forming portion 9 can function as a bolt mounting hole even if misalignment occurs during positioning by a knock pin 12 described later. At the time of this assembly, in this embodiment, as clearly shown in FIG. 3, a knock pin fitting hole 11 is provided in the inner ring base portion 6 and the inner tooth portion 7 and a knock pin 12 is driven in for positioning the connection. The knock pin fitting hole 11 has a combination of an outer fitting hole forming portion 11a formed in the inner ring base portion 6 and an inner fitting hole forming portion 11b formed in the inner tooth portion 7. Here, the outer fitting hole forming portion 11a is a through hole radially penetrating from the outer peripheral surface of the inner ring base portion 6, and the inner mounting hole forming portion 11b is an inner portion on an extension line of the outer fitting hole forming portion 11a. The tooth portion 7 is drilled up to an intermediate position. The inner fitting hole forming portion 11b is formed of a hole having the same diameter as the outer fitting hole forming portion 11a, and the knock pin fitting hole 11 is assembled by aligning the two, and the knock pin 12 is attached to the tip from the outside. The inner ring base portion 6 and the inner tooth portion 7 are positioned by driving the inner ring base portion 6 so as not to project from the outer peripheral surface of the inner ring base portion 6. Then, as described above, the bolt mounting holes 8 are aligned and the inner ring portion 5 is assembled by fastening the bolts 4. The outer peripheral surface of the inner ring base 6 which has become a part of the inner ring 5 is fitted into the outer ring via balls 13 to form the slewing bearing 3. Similarly, the inner teeth 7a formed on the inner periphery of the inner tooth portion 7 which is a part of the inner ring portion 5 meshes with the gear of the turning reduction gear 16 to transmit the turning power. If the inner tooth portion 7 or the inner ring base portion 6 is damaged,
The bolt for fastening the base of the upper revolving structure 1 and the outer ring portion 3a is removed from the mounting hole 15A to separate the outer ring portion 3a, and the bolt for fastening the lower traveling body 2 and the inner ring portion 5 is mounted in the mounting hole 15.
The inner ring portion 5 is removed from B, and the slewing bearing 3 is removed from the machine body. Next, when the ball 13 is extracted from the orbiting bearing 3, the outer ring portion 3a and the inner ring portion 5 are separated. Since the inner ring portion 5 is formed by integrally connecting the inner ring base portion 6 and the inner tooth portion 7, the bolt 4 is removed from the bolt mounting hole 8, and then the knock pin 12 is fitted into the knock pin fitting hole 11.
It is possible to replace the damaged parts by detaching the inner ring base portion 6 and the inner tooth portion 7 from each other. Further, the slewing bearing 3 can be assembled by the reverse procedure. Further, since the inner ring portion 5 has the inner ring base portion 6 in common, it is possible to prepare various kinds of inner tooth portions 7 provided with inner teeth having different pitches even if the specifications of the swing reduction gear 16 are different. It can be used only by exchanging the part 7, and has excellent versatility.

[Effect of device]

Since the present invention is constructed as described above, the following special effects can be obtained. (1). If the inner tooth portion of the slewing bearing is damaged, the outer ring portion and the inner ring base portion can be used as they are, and only the inner tooth portion needs to be replaced, so the labor and cost required for repair can be reduced. (2). Further, when only the inner tooth portion is replaced, the bearing structure does not change, and there is no fear that the bearing function will be familiar to the balls and the outer ring portion and the bearing function will not be impaired. (3). If the specifications of the internal teeth are different for models of the same shovel capacity, the outer ring part and the inner ring base of the slewing bearing can have the same specifications, increasing versatility.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view showing a preferred embodiment of a slewing bearing device for a construction machine according to the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is III of FIG. -III line sectional view, FIG. 4 is an explanatory view showing a connected state of an upper revolving structure and a lower revolving structure of a conventional hydraulic excavator, and FIG. 5 is a vertical sectional view of a conventional slewing bearing. 1 ... Upper revolving structure 2 ... Lower revolving structure 3 ... Revolving bearing 4 ... Bolt 5 ... Inner ring part 6 ... Inner ring base 7 ... Inner tooth part 8 ... Bolt mounting hole 9 ... Outer mounting hole configuration Part 10 …… Inner mounting hole configuration part 11 …… Knock pin fitting hole 12 …… Knock pin 13 …… Ball 16 …… Swing reduction gear

Claims (3)

[Scope of utility model registration request] 1. A swing of a construction machine in which a ball is provided inside an annular outer ring portion provided in a lower portion of an upper revolving structure and an annular inner ring portion provided in an upper portion of a lower traveling structure is fitted therein to rotatably bear a bearing. In the bearing device, the inner ring part is divided into two concentric circles on the outer side to serve as the inner ring part side bearing, the inner tooth part provided with inner teeth for power transmission on the inner side of the two parts, and the outer peripheral surface of the inner ring part. From the outer mounting hole forming portion that penetrates in the radial direction from the inner mounting hole forming portion that is formed on the extension line of the outer mounting hole forming portion up to the middle position of the inner tooth portion and is capable of communicating with the outer mounting hole forming portion. A swivel of a construction machine, comprising: a bolt mounting hole, and a bolt that is inserted into the bolt mounting hole so that the tip does not protrude from the outer periphery of the inner ring base portion and detachably fastens the inner ring base portion and the inner tooth portion. Bearing device. 2. A utility model registration claim according to claim 1, wherein the bolt insertion end side of the outer mounting hole forming portion of the inner ring base is a large diameter step portion for locking the head portion of the bolt. Slewing bearing device for construction machinery. 3. A slewing bearing device for a construction machine according to claim 1, wherein the inner ring base portion and the inner tooth portion are positioned by a knock pin fitted from the outside in a radial direction. .