JPH08333090A - Slewing device - Google Patents

Abstract

PURPOSE: To provide a slewing device having an economical simple structure to adjust a distance between the axes of a driving gear and driven gear by providing a slewing bearing moving means to move the turning bearing radially thereof. CONSTITUTION: Fixing bolts 31, 31 to fix a ring 12 at the side detecting no driven gear of inner and outer rings 11, 12 of a slewing bearing 1 are loosened. The inner peripheral surface 6c of an arcuate central part 6b of a pull plate 6 has the curvature abutting against the outer peripheral surface of the inner ring 11. The pull plate 6 is provided on both ends 6a, 6a with bolt carriers 52, 52 and pull bolt 34, 34. The pull bolts 34, 34 of a moving means composed of the bolt carriers 51, 51 and nuts 38, 38 mounted to both positions of the slewing bearing 1 of a slewing bearing mounting plate 42 are operatively turned. The pull plate 6 is drawn near the side of respective bolt carriers 51, 51 so that the turning bearing 1 is integrally moved within the dimension of a gap between a bolt hole 36 and the fixing bolt 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swivel device for supporting a swivel portion of a working machine having a swivel portion such as an aerial work vehicle and a crane truck. The present invention relates to a structure for adjusting an axial distance between a driven gear provided on a bearing side and a drive gear provided on a speed reducer side.

[0002]

2. Description of the Related Art In work machines such as aerial work vehicles and crane cars, the base end of the boom is pivotally supported on a swivel base, and
The swivel base is attached to the vehicle body side via a swivel device so as to be swivelable.

Further, this turning device is, as is well known in the art,
An inner ring and an outer ring that are concentrically fitted to each other and are rotatable relative to each other. One of these two rings is fixed to the vehicle body side, and the other is fixed to the swivel base side, and the inner ring is also fixed. And the outer ring, either one of the outer or inner peripheral surface is provided with a driven gear, and a slewing bearing is mounted via a speed reducer fixed to the vehicle body side or the swivel base side. And a drive gear that is meshed with the gear. By rotating the drive gear by an appropriate drive means through the speed reducer, the inner ring or outer ring of the slewing bearing is rotated and fixed to the inner ring or outer ring. In addition, the swivel base is driven to swivel.

In this case, since the slewing bearing is relatively large, a large number of fixing bolts can be arranged, and the fastening torque thereof is controlled, the fixing is reliable. However, since the speed reducer is relatively small, the number of fixing bolts is limited in space, and a large driving reaction force is applied when the driven gear is driven by the driving gear. It is difficult to secure reliability when fixed, and therefore the speed reducer is generally fitted with a spigot to a member on the vehicle body side or a member on the swivel base to ensure that the fixed position is maintained.

By the way, in the case of the structure in which the driven gear on the slewing bearing side is driven by the drive gear on the decelerator side, the arrangement position of the slewing bearing and the decelerator is backlashed (that is, meshed) due to the design. Even if the setting is made so as to secure an appropriate shaft-to-shaft distance that does not cause the play of the tooth surface between gears, backlash may occur between these gears due to various factors such as gear manufacturing errors and assembly errors. Although it is hard to avoid that it occurs, such backlash is directly linked to rattling between both gears, and in turn to rattling of the swivel base with respect to the vehicle body side, so from the perspective of ensuring reliability in use of the work machine. Then, it is required to make this as small as possible. Especially in the case where the boom is connected to the swivel platform such as an aerial work vehicle or a crane vehicle,
There is a high demand for backlash reduction because the rattling of the swivel platform may amplify the swing of the work platform or the hanging load hook provided at the tip of the swivel platform to give the operator excessive uneasiness.

From such a demand, a speed reducer is conventionally driven as a structure for adjusting the axial distance between the driving gear and the driven gear to suppress backlash as much as possible when the turning device is assembled. A structure that allows the gear and the driven gear to move in the axial direction has been generally adopted.

[0007]

However, in such a structure in which the axial distance between the driving gear and the driven gear is adjusted by a method in which the speed reducer can be moved in the axial direction of both gears. As described above, since the speed reducer is fixed to the vehicle body side member or the swivel base side member by the spigot fitting, in order to make the speed reducer movable in the direction between the shafts of both gears, It is necessary to adopt a structure in which the spigot fitting hole is made to be an elongated hole in the axial direction, or the speed reducer mounting base in which the speed reducer is spigot fitted can be moved with respect to the vehicle body side member or the swivel side member. However, in the case of the former, there is a problem that the number of processing man-hours increases and the manufacturing cost increases because it is necessary to manufacture the slotted spigot fitting hole with high processing accuracy, and in the case of the latter. Increase the number of parts and Similar to the former, there is a problem that the manufacturing cost increases due to the complication, and both of them have a drive reaction applied to the reducer side at the spigot fitting part or the fixed part of the reducer mount after adjusting the inter-axis distance. Since it is necessary to support the force, there is also a problem that the structure of these parts becomes complicated and large, and in conclusion, it is difficult to say that any of these methods is a suitable method.

Therefore, the present invention makes it possible to adjust the axial distance between the drive gear and the driven gear in the turning device with a simple and inexpensive structure, and the backlash between the fixed side member and the turning side member due to backlash. The purpose of this is to suppress as much as possible and to secure a highly reliable turning operation.

[0009]

In the present invention, as a concrete means for solving such a problem, as shown in FIGS. 1 to 4, an inner member fitted concentrically and capable of relative rotation. A ring 11 and an outer ring 12, and one of the inner ring 11 and the outer ring 12 is attached to the stationary member 42 and the other ring 12 is attached.
Fixing bolts 31, 31 ...
., 32, 32, ..
The inner peripheral surface of the inner ring 11 or the outer ring 1
The revolving bearing 1 having a driven gear 4 formed on one of the outer peripheral surfaces of the reciprocating member 2 and the speed reducer 2 fixed to the fixed member 42 or the revolving member 45 by a spigot fitting. The driven gear 4 of the slewing bearing 1 which is axially mounted
And a drive gear 5 meshed with the drive gear 5, and the drive means 3 rotates the drive gear 5 via the speed reducer 2 so as to integrally drive the orbiting side member 45 with the other ring 12. In the swivel device, the fixing bolts 31, 31, ... for fixing the inner ring 11 and the outer ring 12 of the swivel bearing 1 on the side where the driven gear 4 is not formed are loosened. In order to increase or decrease the axial distance between the driven gear 4 and the driving gear 5, the orbiting bearing moving means (6, 6) for moving the orbiting bearing 1 in its radial direction.
34) and (35).

[0010]

According to the present invention, the following actions and effects can be obtained with such a configuration.

That is, in the turning device of the present invention, of the inner ring 11 and the outer ring 12 of the turning bearing 1, the ring 1 on the side on which the driven gear 4 is not formed.
In order to increase or decrease the axial distance between the driven gear 4 on the side of the slewing bearing 1 and the drive gear 5 on the side of the speed reducer 2 in a state in which the fixing bolts 31, 31 ,. Since the slewing bearing moving means (6, 34), (35) for moving 1 in the radial direction is provided, the speed reducer 2 is fixed to the fixed side member or the slewing side member by a spigot fitting. Also, with the speed reducer 2 fixed in its fixed position, the slewing bearing moving means (6, 34), (35) move the slewing bearing 1 in the axial direction between the driven gear 4 and the drive gear 5. By adjusting the axial distance between the gears, it is possible to minimize backlash and suppress rattling between the fixed-side member and the turning-side member.

In this case, after adjusting the distance between the shafts, the driven gear 4 in the inner ring 11 or the outer ring 12 of the slewing bearing 1 is adjusted.
By tightening the fixing bolts 31 and 31 for fixing the ring 12 on the side not formed with a predetermined tightening torque, the inner ring 11 or the outer ring 12 is fixed to the corresponding fixed side member or swivel side member. It is firmly fixed. Therefore, in combination with the fact that the speed reducer 2 secures its fixed position by the spigot fitting, the axial distance between the driven gear 4 and the drive gear 5 adjusted by the above operation is long-term. It is maintained stably, and rattling between the fixed side member and the swivel side member due to backlash is reliably prevented.In particular, the rattling of the swivel side member is amplified by the boom, and the workbench or the suspended hook on the boom tip side In a work machine with a boom, such as an aerial work vehicle or a crane car, which is transmitted to the vehicle, the operational reliability is significantly improved.

Further, since the slewing bearing moving means (6, 34) and (35) are provided on the slewing bearing 1 side to adjust the distance between the shafts, the reduction gear 2 fitted with the spigot fitting is provided.
There is no need to add a special moving structure to the side, and, for example, by facilitating the machining of the spigot fitting hole or preventing the structure of the mounting portion of the reduction gear 2 from becoming complicated, the overall cost of the turning device can be reduced. Can be achieved.

Further, after the axial distance is adjusted by the slewing bearing moving means (6, 34), (35), a fixed member is provided on the ring 12 on the side where the driven gear 4 is not formed. Since the slewing bearing 1 is fixedly held by the bolts 31, 31, ..., The slewing bearing moving means (6, 34), (35) simply generate a force capable of moving the slewing bearing 1 in its radial direction. It is sufficient if it is possible, and it is not necessary to have a force for fixing and holding the slewing bearing 1. Therefore, the structure of the speed reducer 2 side does not become unnecessarily complicated and large as in the conventional case, and the slewing apparatus as a whole does not The structure can be simplified and downsized.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The turning device of the present invention will be specifically described below based on embodiments.

First Embodiment FIGS. 1 and 2 show the essential parts of a turning device Z _{1 according to} a first embodiment of the present invention. The swivel device Z ₁ is a swivel bearing mounting plate 42 which is fixed to a vehicle body side member 41 and corresponds to a “fixed side member” in a working machine such as an aerial work vehicle or a crane vehicle. It is arranged between a swivel bearing mounting plate 46 fixed to a swivel base 45 corresponding to the "swing side member" in the claims, and the swivel base 45 is supported so as to be swivelable with respect to the vehicle body side member 41. And has a slewing bearing 1 described below.

The slewing bearing 1 has a small diameter inner ring 11 and a large diameter outer ring 12 and a plurality of balls 1.
The inner ring 11 and the outer ring 12 are configured to be relatively rotatable on the same core so that the inner ring 11 and the outer ring 12 are fitted and arranged so as to be superposed in the radial direction via 3, 13 ,. In the embodiment, the outer ring 1 out of the inner ring 11 and the outer ring 12 is
A driven gear 4 is formed on the outer peripheral surface of the device 2.

Of the inner ring 11 and the outer ring 12 of the slewing bearing 1, the inner ring 11 is a slewing bearing mounting plate 42 attached to the vehicle body side member 41 side, and the outer ring 12 is the swivel base 45.
It is fixed to the slewing bearing mounting plate 46 mounted on each side. That is, the inner ring 11 has a plurality of bolt holes 36, 36, provided in the inner ring 11 with the lower surface thereof abutting against the slewing bearing mounting plate 42.
..A plurality of fixing bolts 31, 3 respectively inserted into
It is firmly tightened and fixed by 1, ... Further, the outer ring 12 has a plurality of fixing bolts inserted into the plurality of bolt holes 37, 37, ... Provided in the outer ring 12 in a state where the upper surface of the outer ring 12 abuts against the orbiting bearing mounting plate 46. 32, 32, ... are firmly fixed and fixed. In the fitted state of the inner ring 11 and the outer ring 12, the respective rings 11, 1
Since the inner ring 11 and the outer ring 12 are slightly offset in the axial direction because it is necessary to fix 2 to the vehicle body-side member 41 and the swivel base 45, respectively, the swivel bearing mounting plate 42 and the outer ring 12 are separated from each other. An annular gap having a predetermined width is formed between the lower surface and the lower surface.

On the other hand, a reduction gear fitting hole 43 having a predetermined diameter is formed at a position radially outside the inner ring 11 of the slewing bearing mounting plate 42 to which the inner ring 11 is fixed. The spigot fitting portion 2a of the speed reducer 2 is fitted into the speed reducer fitting hole 43 from the lower surface side thereof, and the speed reducer 2 has four fixing bolts 3
3, 33, ... by the slewing bearing mounting plate 42
It is fastened and fixed to the side. A small-diameter drive gear 5 is fixed to an output shaft (not shown) of the speed reducer 2 protruding upward from the slewing bearing mounting plate 42, and the drive gear 5 is meshed with the driven gear 4. There is. Reference numeral 3 is a hydraulic motor (corresponding to "driving means" in claims) connected to the input side of the speed reducer 2.

Therefore, as the hydraulic motor 3 rotates, the drive gear 5 is decelerated and rotated, and the outer ring 12 is rotationally driven via the driven gear 4 meshing with the drive gear 5, and the swivel base 45 is rotated. Will turn with respect to the vehicle body side member 41.

By the way, the position where the reduction gear fitting hole 43 is formed is the center position of the reduction gear fitting hole 43 and the center position of the outer ring 12 (that is, the bolt holes 36, 36,
The distance between the driven gear 4 and the drive gear 5 is set so as to correspond to the pitch circle diameter of the driven gear 4 and the pitch circle diameter of the drive gear 5. It is set by design so as to match the axial distance between and. Therefore, if the formation positions of the bolt holes 36, 36, ..., the formation positions of the speed reducer fitting holes 43, and the manufacturing dimensions of the gears 4 and 5 are as designed, theoretically, Almost no backlash is possible. However, in actuality, due to factors such as processing errors and manufacturing errors of these respective parts, backlash occurs when the orbiting bearing 1 and the speed reducer 2 are assembled and the driven gear 4 and the driving gear 5 are meshed with each other. Occurs. Therefore, it is necessary to reduce this backlash as much as possible to suppress rattling between the vehicle body side member 41 and the swivel base 45. Therefore,
In the turning device Z ₁ of this embodiment, a backlash is normally adjusted between the bolt holes 36, 36, ... Of the inner ring 11 and the fixing bolts 31, 31 ,. Paying attention to the fact that there is a gap of a sufficient size for applying the present invention, the pulling plate 6 described below is arranged in the gap portion on the lower surface side of the outer ring 12 described above.

The pulling plate 6 constitutes the "slewing bearing moving means" in the claims together with the pulling bolt 34 which will be described later, and is constituted by a plate body integrally formed in an arc shape. The inner peripheral surface 6c of the arc-shaped central portion 6a of the pulling plate 6 has a curvature such that it can contact the outer peripheral surface of the inner ring 11. In addition, on both ends 6b, 6b of the pulling plate 6,
Bolt receivers 52 and 52 are provided, and pull bolts 34 and 34 are provided to the bolt receivers 52 and 52, respectively.

On the other hand, bolt receivers 51, 51 are attached to both sides of the slewing bearing 1 of the slewing bearing mounting plate 42, and are attached to the bolt receivers 52, 52 at both ends of the pulling plate 6. The drawn pulling bolts 34, 34 are respectively screwed into the nuts 38 via the bolt receivers 51, 51.

Therefore, prior to fixing the swivel base 45 to the outer ring 12 of the swivel bearing 1, the inner ring 11 is placed on the swivel bearing mounting plate 42 and the driven gear on the outer ring 12 side is mounted. 4 is engaged with the drive gear 5 on the speed reducer 2 side fixed to the slewing bearing mounting plate 42 by spigot fitting, and through the bolt holes 36, 36, ...
.. are screwed onto the slewing bearing mounting plate 42 side in a loose state. Then, in this state, the pulling plate 6 is placed in the gap portion on the lower surface side of the outer ring 12,
Moreover, the inner peripheral surface 6c is arranged along the outer peripheral surface of the inner ring 11, and the pulling bolts 34, 34 are appropriately screwed to move the pulling plate 6 to the bolt receiving portions 51, 51 side. When the slewing bearing 1 is pulled toward the drive gear 5 by the pull plate 6, the slewing bearing 1 is integrally pulled within the clearance between the bolt hole 36 and the fixing bolt 31 to the drive gear 5 side. The gear 4 and the gear 4 are engaged with each other with a proper distance between the shafts with almost no backlash. This completes the work of adjusting the axial distance between the driven gear 4 and the drive gear 5, that is, the work of preventing backlash.

After the adjustment work of the axial distance between the driven gear 4 and the driving gear 5 is completed, the fixing bolts 31, 31, ..., which have been loosened in advance, are fastened with a predetermined fastening torque. , The inner ring 11 is firmly fixed to the slewing bearing mounting plate 42.

Thereafter, the revolving bearing mounting plate 46 on the revolving base 45 side is placed on the outer ring 12 and is firmly fixed by the respective fixing bolts 32, 32, .... Thus, the revolving bearing 1 is attached, the distance between the driven gear 4 and the drive gear 5 is adjusted, and the revolving base 45 is moved to the vehicle body side member 41 side through the revolving bearing 1. All installation work will be completed.

In this work completed state, the inner ring 11 and the outer ring 12 of the slewing bearing 1 are fixed to the vehicle body side member 41 by a plurality of fixing bolts 31, 31 ,. Side and the swivel base 45 side, the pull bolt 3 is firmly fixed.
Although a pulling force for pulling the swivel bearing 1 is applied to the shafts 4 and 34, a load larger than that, that is, a reaction force due to a moment load from the swivel base 45 side is not applied. Therefore, the pulling plate 6 and the pulling bolts 34, 34, etc. need only have sufficient strength performance to pull the orbiting bearing 1 toward the drive gear 5, and the pulling plate 6 etc. can be made smaller and lighter. Can be.

Further, in this work completed state, the axial distance between the driven gear 4 and the driving gear 5 is properly adjusted and the backlash is minimized. Rattling between the side member 41 and the swivel base 45 is prevented as much as possible, and in particular, work in high places where the influence of this rattling is amplified and transmitted to the workbench on the tip side or the hanging load hook via the boom. The effect is remarkable in a working machine such as a car or a crane truck, and the reliability in using the working machine is improved accordingly.

Further, since the structure is such that the axial distance between the driven gear 4 and the driving gear 5 is adjusted by moving the orbiting bearing 1 side, for example, in order to move the spigot-reduced speed reducer 2 side. In comparison with the conventional structure in which a special moving structure is added to the speed reducer 2 side, the faucet fitting hole can be easily machined or the structure of the mounting part of the speed reducer 2 can be simplified, and the turning can be performed accordingly. The cost of the device Z ₁ as a whole can be reduced.

In this embodiment, pulling bolts 34 and 3 are attached to both ends 6b and 6b of the pulling plate 6, respectively.
4 is provided, but in another embodiment, both ends 6b,
It is also possible to provide the pulling bolt 34 on only one side of the 6b and to make it a pin coupling capable of pivoting on the other side. Further, the member for pulling the pulling plate 6 toward the drive gear 5 side is not limited to the pulling bolt 34 as in this embodiment, but it may be a push bolt structure, a cam structure, or other various structures. Of course, can be adopted.

Further, the structure in which the pulling plate 6 is arranged on the outer peripheral side of the inner ring 11 and the swivel bearing 1 is moved to the drive gear 5 side by the pulling plate 6 as in this embodiment is, for example, the swivel bearing 1 described above. This is a structure suitable for the case where various auxiliary equipments are arranged on the inner peripheral side and there is no space in this portion.

Second Embodiment FIGS. 3 and 4 show the essential parts of a turning device Z _{2 according to} a second embodiment of the present invention. The basic structure of the turning device Z _{2 is} the same as that of the turning device Z ₁ of the first embodiment,
Therefore, here, the same reference numerals are respectively attached to the respective members on the side of FIGS. 3 and 4 corresponding to the respective members illustrated in FIGS. 1 and 2, and the description thereof will be omitted. And this second
The biggest difference between the swivel device Z ₂ in the embodiment and the swivel device Z ₁ in the first embodiment is the structure of the part for adjusting the axial distance between the driven gear 4 and the drive gear 5. is there. Therefore, here, only the structure for adjusting the axial distance will be described in detail.

The structure of this embodiment is suitable for use, for example, when there is a space in the inner peripheral side of the slewing bearing 1, and specifically, the slewing bearing 1 is directly pushed by a bolt. 35 (corresponding to "slewing bearing moving means" in claims) can be moved to the drive gear 5 side. That is, the bolt receiver 53 is attached to the swivel bearing mounting plate 42 at a position corresponding to the inner peripheral portion of the inner ring 11 near the drive gear 5, and the bolt receiver 53 is attached.
The push bolt 35 is screwed onto the screw 3, and the tip of the push bolt 35 can be brought into contact with the inner peripheral surface of the inner ring 11.

Therefore, when mounting the slewing bearing 1, the driven gear 4 is connected to the drive gear 5 on the speed reducer 2 side.
The inner ring 11 is placed on the slewing bearing mounting plate 42 in a state of being engaged with, and the fixing bolts 31, 31, ... Are inserted into the bolt holes 36, 36 ,. Under such a state, the bolt bearing 53 is appropriately screwed and the inner ring 11 (that is, the slewing bearing 1) is pushed toward the drive gear 5 side by its tip to move the inner ring 11 (that is, the slewing bearing 1) to move the slewing bearing 1 above. The drive gear 5 and the driven gear 4 can be arranged in the reduction gear 2 in a state in which there is an appropriate axial distance without backlash. Then, in a state where the axial distance is adjusted by the push bolt 35, the fixing bolts 31, 31, ... Are tightened to firmly fix the inner ring 11 to the slewing bearing mounting plate 42. By doing so, the distance between the axes can be reliably maintained.

Therefore, the turning device Z ₂ of the second embodiment can obtain the same effects as those of the turning device Z ₁ of the first embodiment, but especially the turning device Z of this embodiment. _{When the} "slewing bearing moving means" is constituted by the push bolt 35 itself as shown in ₂ , the above first
Compared with the turning device Z ₁ of the embodiment, the structure can be further simplified and downsized, which is more advantageous in terms of cost and the like.

In this embodiment, the "slewing bearing moving means" is constituted by a single push bolt 35, but the present invention is not limited to this, and is the same as in the case of the first embodiment. Similarly, it goes without saying that the push bolt 35 may be constructed of various structures such as a pull bolt structure and a cam structure.

In addition, in each of the above-described embodiments, the inner ring 11 of the slewing bearing 1 is fixed to the vehicle body side member 41 side, the outer ring 12 is fixed to the swivel base 45 side, and the driven gear is attached to the outer peripheral surface of the outer ring 12. 4 is formed and the drive gear 5 meshing with the driven gear 4 is fixed to the orbiting bearing mounting plate 42 side by a spigot fitting, but the present invention is not limited to such a configuration. Of course,
For example, the inner ring 11 is fixed to the swivel base 45, the outer ring 12 is fixed to the vehicle body-side member 41, the inner ring 11 is formed with the driven gear 4, and the driven gear 4 is the inner ring 11 or the outer ring. Ring 12
Formed on the inner peripheral surface of the revolving base 4 and the speed reducer 2
The present invention can be directly applied to various aspects that can be adopted due to the structure of the slewing bearing 1, such as one fixed to the 5 side by a spigot fitting.

[Brief description of drawings]

FIG. 1 is a plan view of a turning device according to a first embodiment of the present invention.

FIG. 2 is a view taken along the line II-II in FIG.

FIG. 3 is a plan view of a turning device according to a second embodiment of the present invention.

4 is a view taken along the line IV-IV in FIG.

[Explanation of symbols]

1 is a slewing bearing, 2 is a speed reducer, 3 is a hydraulic motor, 4
Is a driven gear, 5 is a driving gear, 6 is a pulling plate, 11
Is an inner ring, 12 is an outer ring, 13 is a ball,
31 to 33 are fixing bolts, 34 is a pull bolt, 35 is a push bolt, 36 and 37 are bolt holes, 38 is a nut, 4
1 vehicle body member, 42 swing bearing mounting plate 43 is reducer fitting hole, 45 swivel base, 46 swing bearing mounting plate, the bolt receiving 51 to 53, Z ₁ and Z ₂ are the turning device .

Claims (1)

[Claims] 1. An inner ring (11) and an outer ring (12) which are concentrically fitted to each other and are rotatable relative to each other, and the inner ring (11) and the outer ring (1).
One of the rings (11) of (2) is the fixed side member (42) and the other ring (12) is the swivel side member (4).
5) fixing bolts (31, 31, ...), (3)
2, 32, ...) and a driven gear (4) is formed on either the inner peripheral surface of the inner ring (11) or the outer peripheral surface of the outer ring (12). And a slewing bearing (1) axially mounted on a speed reducer (2) fixed by a spigot fitting to the fixed side member (42) or the slewing side member (45). A drive gear (5) meshed with the driven gear (4) of the other ring, the drive means (3) rotating the drive gear (5) through the speed reducer (2) to thereby rotate the other ring. (1
A swivel device configured to swivelly drive the swivel member (45) integrally with 2), wherein the driven gear of the inner ring (11) and the outer ring (12) of the swivel bearing (1) is driven. Between the driven gear (4) and the drive gear (5) in a state where the fixing bolts (31, 31, ...) For fixing the ring (12) on which the (4) is not formed are loosened. Slewing bearing moving means (6, 34), (3) for moving the slewing bearing (1) in the radial direction to increase or decrease the distance.
A swivel device characterized by comprising 5).