JP2016223460A - Seal structure of slewing bearing and slewing bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal structure of a slewing bearing by which it can be visually confirmed whether or not a seal member is assembled while inclining to inner/outer rings, and the slewing bearing.SOLUTION: This seal structure is employed to a slewing bearing having elastic-body made seal members 7A, 7B which seal an axial end of a bearing space 6 between an inner ring 1 and an outer ring 2. Each of the seal members 7A, 7B has a base part 20 which is held to one bearing ring 2 out of the inner ring 1 and the outer ring 2, and three seal lips 21, 22 and 23 which extend from the base part 20 toward the other bearing ring 1 out of the inner ring 1 and the outer ring 2 in different orientations. The two seal lips 21, 22 which are close to at least the bearing space 6 out of the three seal lips contact with a peripheral face 1a which opposes the other bearing ring 1. The seal lip 23 which is farthest from the bearing ring 6 is formed into a shape at which it can be visually confirmed whether or not the seal member 7A is in a properly-assembled state.SELECTED DRAWING: Figure 1

Description

  The present invention is, for example, a swivel used for a swivel part of various machines used in the vicinity of the outdoors or indoors, such as a swivel seat for a yaw and a blade of a wind power generator, a deck crane, a construction machine, and a lifting machine. The present invention relates to a seal structure of a bearing and a slewing bearing.

  A swivel bearing used for a yaw of a wind power generator, a swivel seat for a blade, or the like is generally lubricated with grease. A rubber seal member is mounted on the slewing bearing in order to prevent foreign matters from entering from outside and grease leakage from the inside of the bearing (for example, Patent Documents 1 and 2). As can be seen in the examples of Patent Documents 1 and 2, a general seal member is provided with two seal lips. The seal lip located on the inner side in the axial direction is the main lip, and its main role is to prevent grease leakage from the inside of the bearing. The seal lip located on the outer side in the axial direction is a secondary lip, and its main role is to prevent foreign matters such as moisture and dust from entering the bearing from the outside.

  Since the slewing bearings for yaw and blade are not incorporated in the shaft and the housing, the rigidity of the peripheral portion of the bearing is lower than that of a general bearing. In addition, the bearing itself is small in axial and radial dimensions (cross-section) for its size, so the rigidity of the inner and outer rings is low. As described above, since the rigidity of the peripheral portion and the inner and outer rings is low, the inner and outer rings are likely to be deformed during operation.

  Many common sealing members include a metal core made of a metal ring inside a rubber material. The seal member provided with the metal core is difficult to be deformed due to the rigidity of the metal. However, in a slewing bearing for yaw and blade, since it is necessary to provide a seal member in a narrow bearing space between the inner and outer rings, it is difficult to employ a seal member having a cored bar.

  In general seal members, a garter spring is often used in order to maintain the tight force of the seal lip. However, as described above, the slewing bearing for yaw and blade has a small axial dimension and radial dimension (cross section), so the sectional thickness of the seal member is thin, and it is difficult to adopt a configuration using a garter spring. .

  Therefore, the seal member of the slewing bearing for the yaw and the blade must be composed only of a rubber material such as nitrile rubber. Such a seal member made of only a rubber material has a greater reduction in the tightening allowance between the seal lip and the bearing ring due to a change in the size of the rubber material over time than a seal member having a metal core or a seal member using a garter spring. . Therefore, in the seal member of the slewing bearing for yaw and blade, the initial tightening allowance is set in anticipation of a decrease in the tightening allowance due to the deformation of the inner and outer rings and the aging change of the rubber material.

JP 2011-27235 A JP 2012-112488 A

  However, if there is a problem with the assembly accuracy of the seal member, there is a possibility that the seal lip is insufficiently tightened and grease leakage occurs. In particular, most of the slewing bearings for yaw and blade have a diameter exceeding 1000 mm, and the assembly of the seal member is performed manually by humans, so that the assembling accuracy tends to vary. For this reason, it is important to design with sufficient consideration of variations in assembly accuracy.

  The problem in assembling accuracy is that the inclination of the seal member with respect to the race ring, that is, the shaft center of the race ring and the center of the seal member do not coincide with each other. A rubber material such as nitrile rubber has a large amount of elastic deformation as compared with a metal part, and there is a possibility that a deviation from an ideal installation position and an inclination become large. Depending on the direction of deviation and inclination, grease leakage from the inside of the bearing can result.

  For example, in the case of the seal structure of Patent Document 1 shown in FIG. 10, if the seal member 7 is inclined with respect to one bearing ring to which the seal member 7 is attached, for example, the outer ring 2, poor contact between the seal lips 21 and 22 occurs. Arise. That is, the axially inner seal lip 21 is separated from the outer peripheral surface 1a of the inner ring 1 as shown in FIG. 11A, or the axially outer seal lip 22 is outer peripheral surface of the inner ring 1 as shown in FIG. Leave 1a. In the case of FIG. 11 (A), grease leakage from the bearing space 6 occurs, and in the case of FIG. 11 (B), foreign matter such as moisture and dust enters the bearing space 6 from the outside.

  In particular, the seal lip 21 as the main lip is hidden behind the seal lip 22 as the sub lip and cannot be seen from the outside. Therefore, even if there is a contact failure of the seal lip 21 as shown in FIG. Is difficult. Therefore, a method for easily confirming whether or not the seal member 7 is correctly assembled is required.

  An object of the present invention is to provide a slewing bearing seal structure and a slewing bearing capable of visually confirming whether or not a seal member is incorporated with an inclination relative to inner and outer rings.

  In the seal structure of the slewing bearing according to the present invention, raceway grooves are formed on the mutually opposing peripheral surfaces of the inner ring and outer ring, which are race rings, and a plurality of rolling elements are provided between the race grooves of the inner and outer rings. A seal member made of an elastic body that seals an axial end portion of the bearing space between the base portion and a base portion held by any one of the inner and outer races, and a base portion that is different from the base portion. And three seal lips extending toward the other raceway of the inner and outer rings, and at least two seal lips of the three seal lips close to the bearing space of the other raceway The seal lip that is in contact with the opposed peripheral surfaces and is furthest from the bearing space is configured to be able to visually determine whether or not the seal member is in a correct assembled state.

According to this configuration, of the three seal lips, at least the seal lip closest to the bearing space and the seal lip second closest to the bearing space are in contact with the opposing peripheral surfaces of the other raceway ring. The seal lip closest to the bearing space prevents grease leakage from the bearing space, and the seal lip second closest to the bearing space prevents entry of foreign matters such as moisture and dust from the outside into the bearing space.
Since the seal lip farthest from the bearing space is in a form in which it can be visually determined whether or not the seal member is in the correct assembled state, by visually observing the state of this seal lip, it is visually determined whether or not the seal member is in the correct assembled state Can be confirmed.

In this invention, it is preferable that the seal lip farthest from the bearing space is not in contact with the opposed peripheral surface of the other race ring when the seal member is in a properly assembled state.
According to this configuration, when the seal member is assembled, if the seal lip farthest from the bearing space is not in contact with the opposing peripheral surface of the other race ring, it is determined that the seal member has been installed correctly, and When the farthest seal lip is in contact with the opposing circumferential surface of the other race ring, it is determined that the seal member is incorporated at an angle. This determination can be easily made visually. Further, if the seal lip farthest from the bearing space is not in contact with the opposing circumferential surface of the other raceway ring, it is not necessary to increase the torque during normal operation.

In the above-described configuration, the inner ring and the outer ring are inclined relative to each other, and the seal lip closest to the bearing space among the three seal lips is separated from the opposing circumferential surface of the other race ring; In this case, it is preferable that the seal lip farthest from the bearing space is in contact with the opposing circumferential surface of the other race.
According to this configuration, when the inner ring and the outer ring are inclined relative to each other, even if the seal lip closest to the bearing space is separated from the opposing circumferential surface of the other race ring, the seal farthest from the bearing space Grease leakage from the bearing space can be prevented by the lip coming into contact with the opposing circumferential surface of the other race ring. In this case, the torque increases when the seal lip farthest from the bearing space comes into contact with the opposing circumferential surface of the other race ring, but the seal lip closest to the bearing space moves away from the opposing circumferential surface of the other race ring. As a result, the torque decreases, so that the overall torque hardly fluctuates.

In this invention, it is preferable that the one bearing ring has a fitting recess for holding the seal member, and the base part is held by fitting a part of the seal member into the fitting recess.
This configuration is effective for attaching the seal member to the correct position of one of the race rings in the correct posture.

  In this invention, of the three seal lips, the seal lip closest to the bearing space is in an inclined posture that approaches the bearing space as it goes from the base toward the other raceway ring, and the remaining two seal lips are Further, it may be an inclined posture that moves away from the bearing space as it goes from the base to the other raceway.

The seal lip closest to the bearing space mainly serves to prevent grease leakage from the bearing space. When the seal lip is inclined so as to approach the bearing space, when it receives the internal pressure of the bearing space during operation, it is strongly pressed against the opposing circumferential surface of the other race ring, effectively preventing grease leakage. .
The seal lip that is the second closest to the bearing space mainly has a role to prevent foreign matter from entering the bearing space from the outside. When the seal lip is in an inclined posture away from the bearing space, when the external pressure is applied, the seal lip is strongly pressed against the opposing circumferential surface of the other race ring, and effectively acts to prevent the entry of foreign matter.
The seal lip farthest from the bearing space mainly serves as a material for determining whether or not the seal member is in the correct assembled state. Since the seal lip is not involved in preventing grease leakage and preventing foreign matter from entering normally, the direction of the inclination is not particularly limited with respect to the sealing performance. By making the seal lip into an inclined posture in the same direction as the seal lip that is the second closest to the bearing space, the seal member can be made compact.

In the above configuration, the tip surface of the seal lip closest to the bearing space among the three seal lips is an inward surface extending inward from a contact point that contacts the opposing circumferential surface of the other race ring, An outward surface extending outward from the contact, and an angle formed by the outward surface and the opposed peripheral surface is smaller than an angle formed by the inward surface and the opposed peripheral surface. ,
The front end surface of the seal lip that is second closest to the bearing space has an inward surface extending inward from a contact point that contacts the opposing circumferential surface of the other race ring, and an outward surface extending outwardly from the contact point. The angle formed by the inward surface and the opposed peripheral surface is smaller than the angle formed by the outward surface and the opposed peripheral surface,
The front end surface of the seal lip farthest from the bearing space has an inward surface extending inward from a contact point that contacts the opposing circumferential surface of the other race ring when the inner ring and the outer ring are inclined relative to each other. And an outward surface extending outward from the contact, and an angle formed by the outward surface and the opposed peripheral surface is larger than an angle formed by the inward surface and the opposed peripheral surface. Small is desirable.

As described above, the seal lip closest to the bearing space serves to prevent grease leakage from the bearing space. Also, the seal lip farthest from the bearing space serves as a material for determining whether or not the seal member is properly assembled, and prevents grease leakage from the bearing space when the inner and outer rings are inclined relative to each other. Also has a role to play. As described above, for the seal lip having the role of preventing grease leakage from the bearing space, the outward surface and the opposing peripheral surface are more than the angle formed by the inward surface and the opposing peripheral surface. A smaller angle is effective in preventing grease leakage.
As described above, the seal lip that is second closest to the bearing space serves to prevent foreign matter from entering the bearing space from the outside. For this seal lip, the angle formed by the inward surface and the opposed peripheral surface is smaller than the angle formed by the outward surface and the opposed peripheral surface, which is effective in preventing foreign matter from entering. It is.

  The slewing bearing according to the present invention is one in which any of the above-described seal structures is applied, and supports the blade of the wind power generator so as to be rotatable about an axis substantially perpendicular to the main axis with respect to the main axis. Alternatively, the nacelle of the wind power generator may be supported so as to be rotatable with respect to the support base.

  In the seal structure of the slewing bearing according to the present invention, raceway grooves are formed on the mutually opposing peripheral surfaces of the inner ring and outer ring, which are race rings, and a plurality of rolling elements are provided between the race grooves of the inner and outer rings. In the seal structure of the slewing bearing provided with the seal member made of an elastic body that seals the axial end of the bearing space between, the seal member is a base portion that is held by one of the inner and outer rings And three seal lips extending toward the other raceway of the inner and outer rings in different directions from the base, and at least two seal lips close to the bearing space among these three seal lips The seal lip that is in contact with the opposing circumferential surface of the other race ring and is furthest from the bearing space is capable of visually judging whether or not the seal member is in a correctly assembled state. It was therefore possible to confirm whether or not incorporated inclined seal member relative to the inner and outer races visually.

It is the figure which added the partial enlarged view to sectional drawing of the slewing bearing to which the seal structure concerning one Embodiment of this invention was applied. It is an exploded view of the seal structure of the slewing bearing. It is a figure which shows the detail of each seal lip of the sealing member of the seal structure. It is explanatory drawing 1 of the effect | action of the seal structure. It is explanatory drawing 2 of the effect | action of the seal structure. It is explanatory drawing of an effect | action of the application example from which the seal structure differs. It is explanatory drawing of an effect | action of the application example from which the seal structure differs further. It is the perspective view which notched and represented a part of example of the wind power generator. It is a fracture side view of the wind power generator. It is sectional drawing of the seal structure of the conventional slewing bearing. It is explanatory drawing of an effect | action of the seal structure of the turning bearing.

An embodiment of the present invention will be described with reference to FIGS.
This slewing bearing is, for example, a bearing that supports a blade of a wind power generator so as to be rotatable about an axis substantially perpendicular to the main shaft axis with respect to the main shaft, or a nacelle of the wind power generator is supported so as to be rotatable with respect to a support base. Used as a bearing.

  As shown in FIG. 1, the slewing bearings are formed on the inner ring 1 and the outer ring 2 that are race rings and the outer circumferential surface 1 a and the inner circumferential surface 2 a that are circumferential surfaces of the inner and outer rings 1 and 2 that face each other. A ball 3 as a plurality of rolling elements is provided between the grooves 1b and 2b so as to freely roll. A spacer or a cage is interposed between the balls 3 and 3 adjacent in the circumferential direction (not shown).

  Each of the raceway grooves 1b and 2b of the inner and outer rings 1 and 2 is composed of two curved surfaces. The two curved surfaces constituting each raceway groove 1b, 2b are Gothic arch-shaped arcs having a larger radius of curvature than that of the ball 3 and different centers of curvature. Each ball 3 is in contact with the curved surfaces of the raceway groove 1b of the inner ring 1 and the raceway groove 2b of the outer ring 2 at a contact point and makes contact at four points. That is, this slewing bearing is configured as a four-point contact ball bearing. The spacer is made of a resin material, for example. The spacer has a concave shape in which the rolling element contact surfaces on both sides form a spherical surface that is deeply recessed toward the center. The cage is manufactured from, for example, an iron plate. The cage made of this iron plate is disposed between the inner and outer rings 1 and 2 and has a pocket for the ball 3 to enter.

  A plurality of through holes 4 are provided in the inner ring 1 at regular intervals in the circumferential direction. These through holes 4 are used, for example, for connecting and fixing the inner ring 1 to a casing or the like of a nacelle described later. The outer ring 2 is also provided with a plurality of through holes 5 at regular intervals in the circumferential direction. These through-holes 5 are used, for example, for connecting and fixing the outer ring 2 to a support base described later. The through holes 4 and 5 of the inner and outer rings 1 and 2 are formed in parallel to the bearing axial direction.

The seal structure will be described.
The bearing space 6 between the inner and outer rings 1 and 2 is filled with grease, and both axial ends, that is, upper and lower ends of the bearing space 6 are sealed by seal members 7A and 7B, respectively. Since the seal structure at the upper end and the seal structure at the lower end of the bearing space 6 are the same structure, the seal structure at the upper end will be described as a representative.

  FIG. 2 is an exploded view of the seal structure at the upper end of the bearing space 6. As shown in the figure, an annular notch 10 for attaching a seal member 7A is provided at the upper end portion of the inner peripheral surface 2a of the outer ring 2. The annular notch 10 includes a main portion 11 having a substantially rectangular cross-sectional shape from the inner peripheral surface 2a to the upper end surface 2c of the outer ring 2 and a fitting recess 12 extending downward from a radial intermediate portion of the main portion 11. Is done. The height of the upper surface of the outer ring 2 serving as the bottom surface of the main portion 11 is different on both sides of the fitting recess 12, and the inner diameter side upper surface 13 is formed lower than the outer diameter side upper surface 14. The inner diameter side upper surface 13 is a horizontal plane, and the outer diameter side upper surface 14 is an inclined surface that becomes lower as it goes to the outer diameter side. An annular groove 15 as a press-fitting allowance is formed on the outer peripheral wall surface of the fitting recess 12. In the case of this example, the annular groove 15 is positioned slightly above the intermediate portion in the axial direction of the fitting recess 12 and has a circular arc cross-sectional shape.

  The seal member 7A is made of an elastic material such as nitrile or acrylic, and has a base 20 attached to the annular notch 10 and three seal lips 21, 22, 23 extending from the base 20 to the inner diameter side in different directions. It consists of. The seal lip 21 closest to the bearing space 6 extends inward in the axial direction of the outer ring 2, and the remaining two seal lips 22, 23 extend outward in the axial direction. The “inner side” and “outer side” in the axial direction indicate whether they are inside or outside the bearing space 6.

  Of the three seal lips, the two seal lips 21 and 22 close to the bearing space 6 are in contact with the outer peripheral surface 1a of the inner ring 1 when the seal member 7A shown in FIG. The seal lip 21 closest to the bearing space 6 is a main lip that mainly prevents grease leakage from the bearing space 6, and the seal lip 22 closest to the bearing space 6 is mainly a foreign matter such as moisture or dust from the outside. This is a secondary lip that prevents intrusion into the bearing space 6. The seal lip 23 farthest from the bearing space 6 is not in contact with the outer peripheral surface 1a of the inner ring 1 when the seal member 7A shown in FIG. The seal lip 23 is an inclination detection lip for determining whether or not the seal member 7A is correctly assembled.

  The base portion 20 of the seal member 7A includes a base portion main body 20a disposed in the main portion 11 of the annular notch 10, and a fitting convex portion that protrudes inward in the axial direction from the base portion main body 20a and fits into the fitting concave portion 12. 20b. The protruding length in the axial direction of the fitting convex portion 20 b is shorter than the axial depth of the fitting concave portion 12. Further, the radial width of the fitting convex portion 20 b is slightly narrower than the radial width of the fitting concave portion 12.

  A first annular protrusion 25 that press fits into the annular groove 15 of the fitting recess 12 protrudes from the outer diameter side surface of the fitting protrusion 20b. The first annular protrusion 25 is located at an axial position corresponding to the annular groove 15 and has a circular cross section. Further, a second annular protrusion 26 having a smaller radial dimension and smaller axial dimension than the first annular protrusion 25 protrudes from the inner diameter side surface of the fitting convex portion 20b.

  In assembling the seal member 7A into the annular notch 10 of the outer ring 2, as shown in FIG. 1, the base body 20a is disposed on the main portion 11 (FIG. 2) of the annular notch 10 (FIG. 2), and the fitting protrusion The portion 20b is fitted into the fitting recess 12 of the annular notch 10 by press fitting. In a state where the fitting convex portion 20 b is fitted into the fitting concave portion 12, the end surface 29 of the base body 20 a of the seal member 7 </ b> A contacts the peripheral surface 16 of the main portion 11 of the annular notch 10. The inner diameter side upper surface 13 of the annular notch 10 and the inner diameter side lower surface 27 of the base body 20a of the seal member 7A are separated from each other. The outer diameter side upper surface 14 of the annular notch 10 and the outer diameter side lower surface 28 of the base body 20a of the seal member 7A are also separated from each other. Further, the bottom surface 17 of the fitting recess 12 and the lower surface 30 of the fitting projection 20b are also separated from each other.

  In the assembled state of the seal member 7A, the base 20 of the seal member 7A is held in the annular notch 10 of the outer ring 2 by fitting the fitting convex portion 20b into the fitting concave portion 12. At this time, since the first annular protrusion 25 is engaged with the annular groove 15, the fitting convex portion 20 b is prevented from coming off from the fitting concave portion 12. Further, the second annular protrusion 26 is pushed and deformed by the inner peripheral wall surface of the fitting recess 12 and functions as a press-fitting allowance. Accordingly, the fitting convex portion 20b of the seal member 7A is completely fixed to the outer ring 2 in the circumferential direction, the radial direction, and the axial direction. If the fitting concave portion 12 is fixed to the bottom surface and the wall surface of the fitting convex portion 20b with an adhesive, the fixing force of the fitting convex portion 20b is further increased.

  In the case of this embodiment, the peripheral surface 16 of the main part 11 of the annular notch 10 serves as a reference surface for maintaining the seal member 7A in an appropriate posture in the assembled state. The peripheral surface 16 is a surface along the axial direction. The contact surface of the seal member 7A that is in contact with the reference surface is the end surface 29 of the base body 20a. In the example of the figure, the reference surface is only the peripheral surface 16, but the reference surface may be two or more. In that case, the reference plane may be a plane along the axial direction or a plane perpendicular to the axial direction.

FIG. 3 is a diagram showing details of the reel lips 21, 22, and 23. As shown in FIG.
A seal lip 21 as a main lip closest to the bearing space 6 extends obliquely from the base portion 20 to the inner side in the axial direction of the outer ring 2. That is, the inclined posture approaches the bearing space 6 as it goes to the tip side. The front end surface of the seal lip 21 includes an inward surface 21a that extends inward from a contact P1 that contacts the outer peripheral surface 1a of the inner ring 1, and an outward surface 21b that extends outward. When the angle formed by the inward surface 21a and the outer peripheral surface 1a of the inner ring 1 is θ1a, and the angle formed by the outer surface 21b and the outer peripheral surface 1a of the inner ring 1 is θ1b, the relationship θ1a> θ1b is established. .

  The seal lip 21 as the main lip has a role of preventing grease leakage from the bearing space 6 as described above. When the seal lip 22 is inclined so as to approach the center of the bearing space 6, it is strongly pressed against the outer peripheral surface 1 a of the inner ring 1 when it receives the internal pressure of the bearing space 6 during operation, and effectively acts to prevent grease leakage. To do. Further, if the angle θ1b formed by the outward surface 21b and the outer peripheral surface 1a of the inner ring 1 is smaller than the angle θ1a formed by the inward surface 21a and the outer peripheral surface 1a of the inner ring 1, it is advantageous for preventing grease leakage. is there.

  A seal lip 22 as a secondary lip closest to the bearing space 6 extends from the base portion 20 to the outer side in the axial direction of the outer ring 2. That is, it is an inclined posture that moves away from the center of the bearing space 6 as it goes to the tip side. The front end surface of the seal lip 22 includes an inward surface 22a that extends inward from a contact P2 that contacts the outer peripheral surface 1a of the inner ring 1, and an outward surface 22b that extends outward. When the angle formed by the inward surface 22a and the outer peripheral surface 1a of the inner ring 1 is θ2a and the angle formed by the outer surface 22b and the outer peripheral surface 1a of the inner ring 1 is θ2b, the relationship θ2a <θ2b is established. .

  As described above, the seal lip 22 which is a sub lip has a role of preventing foreign matter from entering the bearing space 6 from the outside. When the seal lip 22 is in an inclined posture away from the center of the bearing space 6, it is strongly pressed against the outer peripheral surface 1 a of the inner ring 1 when it receives an external force, and effectively acts to prevent foreign matter from entering. Further, if the angle θ2a formed by the inward surface 22a and the outer peripheral surface 1a of the inner ring 1 is smaller than the angle θ2b formed by the outer surface 22b and the outer peripheral surface 1a of the inner ring 1, it is advantageous for preventing foreign matter from entering. is there.

  Similarly to the seal lip 22, the seal lip 23 as the tilt detection lip farthest from the bearing space also extends outward from the base portion 20 in the axial direction of the outer ring 2. That is, it is an inclined posture that moves away from the center of the bearing space 6 as it goes to the tip side. The front end surface of the seal lip 23 includes an inward surface 23a that extends inward from the contact P3 when it contacts the outer peripheral surface 1a of the inner ring 1, and an outward surface 23b that extends outward. When the angle formed by the inward surface 23a and the outer peripheral surface 1a of the inner ring 1 is θ3a and the angle formed by the outer surface 23b and the outer peripheral surface 1a of the inner ring 1 is θ3b, the relationship θ3a> θ3b is established. .

  The seal lip 23 that is an inclination detection lip has a role of determining whether or not the seal member 7A is in a correct assembled state, and in addition, when the inner ring 1 and the outer ring 2 are inclined relative to each other as described later. In addition, it has a role of preventing leakage of grease from the bearing space 6. However, normally, the seal lip 23 is not involved in preventing grease leakage. Therefore, although it is disadvantageous for prevention of grease leakage, the inclined posture is away from the center of the bearing space 6, which is the same as the seal lip 22, so that the seal member 7 </ b> A can be made compact. On the other hand, in order to prevent grease leakage, the angle θ3b formed by the outward surface 23b and the outer peripheral surface 1a of the inner ring 1 is more than the angle θ3a formed by the inward surface 23a and the outer peripheral surface 1a of the inner ring 1. Is made smaller.

The operation of this seal structure will be described with reference to FIGS.
In the correct assembled state of the seal member 7A, as shown in FIG. 4A, the end surface 29, which is the contact surface of the seal member 7A, contacts the peripheral surface 16, which is the reference surface of the outer ring 2, so The portion of the seal member 7A excluding the joint convex portion 20b is prevented from floating outward. That is, the elastic deformation of the seal lips 21, 22, 23 to be displaced outwards due to the increase in the internal pressure of the bearing space 6 is restricted. As a result, the seal lip 21 as the main lip is kept in contact with the outer peripheral surface 1a of the inner ring 1, and grease leakage from the bearing space 6 is prevented. Thus, during operation with the seal member 7A correctly assembled, the seal lip 23 is not in contact with the outer peripheral surface 1a of the inner ring 1, so that torque is not increased.

  When an external force is applied during assembly, the seal member 7A may fall into the bearing space 6 as shown in FIG. In that case, the seal lip 23 which is an inclination detection lip contacts the outer peripheral surface 1 a of the inner ring 1. Thus, when the seal lip 23 contacts the outer peripheral surface 1a of the inner ring 1, it is determined that the seal member 7A is not properly assembled. On the other hand, when the seal lip 23 is not in contact with the outer peripheral surface 1a of the inner ring 1, it is determined that the seal member 7A has been correctly assembled. Thus, since it is only necessary to observe whether the seal lip 23 is in contact with the outer peripheral surface 1a of the inner ring 1 or not, this determination can be easily made by visual observation.

  Further, as shown in FIG. 5, the inner ring 1 and the outer ring 2 may be inclined relative to each other during operation. In that case, the seal lip 21 as the main lip is in a state of being separated from the outer peripheral surface 1 a of the inner ring 1. However, grease leakage from the bearing space 6 can be prevented when the seal lip 23, which is an inclination detection lip, contacts the outer peripheral surface 1 a of the inner ring 1. In this case, the torque increases as the seal lip 23 comes into contact with the outer peripheral surface 1a of the inner ring 1. However, the torque decreases as the seal lip 21 moves away from the outer peripheral surface 1a of the inner ring 1, so that the overall torque is Almost no change.

In the upper end seal structure described above, the annular notch 10 for attaching the seal member 7A is provided in the outer ring 2, and the seal lips 21, 22 of the seal member 7A are in contact with the outer peripheral surface 1a of the inner ring 1. That is, the outer ring 2 is one of the bearing rings referred to in the claims, and the inner ring 1 is the other bearing ring referred to in the claims.
On the other hand, in the seal structure at the lower end, an annular notch 10 for attaching the seal member 7B is provided in the inner ring 1, and the seal lips 21, 22 of the seal member 7B are in contact with the inner peripheral surface of the outer ring 2. That is, the inner ring 1 is one of the bearing rings referred to in the claims, and the outer ring 2 is the other bearing ring referred to in the claims.
However, this is limited to this embodiment. One of the race rings may be either the inner ring 1 or the outer ring 2, and the other race ring may be either the outer ring 2 or the inner ring 1. .

  As described above, in this seal structure, it is determined whether or not the seal member 7A is properly assembled by providing the inclination detection lip (23) outside the main lip (21) and the sub lip (22). In addition, grease leakage from the bearing space 6 when the inner ring 1 and the outer ring 2 are inclined relative to each other can be prevented. The seal members 7A and 7B used in this seal structure require more material for the inclination detection lip (23) than the seal member consisting only of the main lip (21) and the sub lip (22). Since the manufacturing process does not change, there is only a slight increase in cost.

  FIG. 6 shows different application examples of the seal structure. In this application example, the height of the upper end of the inner ring 1 is lower than the height of the tip of the seal lip 23 that is the lip for detecting the inclination of the seal member 7A. Therefore, as shown in FIG. 6B, the tip of the seal lip 23 does not come into contact with the outer peripheral surface 1 a of the inner ring 1 even if the seal member 7 </ b> A is incorporated with an inclination. Therefore, in the case of this application example, the radial position of the tip of the seal lip 23 is directly measured, and this measured value φxxx is compared with the radial position of the outer peripheral surface 1a of the inner ring 1 that is known in advance. It is determined whether or not the seal member 7A is inclined.

  As described above, instead of directly measuring the radial position of the tip of the seal lip 23, an inclination detection jig 40 may be used as shown in FIG. The tilt detection jig 40 is, for example, a circular body having the same diameter as the inner ring 1, and is used by being placed on the inner ring 1 with the inner ring 1 aligned with the axis. In this case, when the seal member 7 </ b> A is inclined, the tip of the seal lip 23 comes into contact with the outer peripheral surface 40 a of the inclination detection jig 40. That is, by using the tilt detection jig 40, it is possible to visually determine whether or not the seal member 7A is tilted, as in the application example shown in FIG.

  8 and 9 show an example of a wind power generator. This wind power generator 51 is provided with a nacelle 53 on a support base 52 so as to be able to turn horizontally, and a main shaft 55 is rotatably supported in a casing 54 of the nacelle 53, and at one end of the main shaft 55 protruding outside the casing 54. The blade 56 which is a swirl wing is attached. The other end of the main shaft 55 is connected to a speed increaser 57, and the output shaft 58 of the speed increaser 57 is coupled to the rotor shaft of the generator 59.

  The nacelle 53 is rotatably supported by the slewing bearing BR1. In the slewing bearing to which any one of the seal structures of the above embodiments is applied, for example, a slewing bearing BR1 for the nacelle 53 having a gear or the like provided on the outer peripheral surface of the outer ring 2 is used. As shown in FIG. 8, a plurality of drive sources 60 are installed in the casing 54, and pinion gears are fixed to the drive sources 60 via reduction gears (not shown). It arrange | positions so that the said gear of the outer ring | wheel 2 (FIG. 1) may mesh | engage with the said pinion gear. For example, the outer ring 2 is connected and fixed to the support base 52 through the plurality of through holes 5, and the inner ring 1 (FIG. 1) is fixed to the casing 54. The plurality of drive sources 60 are driven in synchronization, and this turning driving force is transmitted to the outer ring 2. Therefore, the nacelle 53 can turn relative to the support base 52.

  The blade 56 is rotatably supported by the swing bearing BR2. This slewing bearing BR2 is a slewing bearing to which any one of the seal structures of the above-described embodiments is applied. For example, a bearing provided with a gear on the inner circumferential surface of the inner ring 1 is applied. A driving source for rotating the blade 56 is provided at the protruding end portion 55 a of the main shaft 55. The outer ring 2 of the slewing bearing is connected and fixed to the distal end portion 55a, and a gear provided on the inner peripheral surface of the inner ring 1 meshes with the pinion gear of the drive shaft. By driving this drive source and transmitting this turning drive force to the inner ring 1, the blade 56 can turn. Therefore, the slewing bearing BR2 supports the blade 56 of the wind power generator with respect to the main shaft 55 so as to be rotatable about an axis L2 substantially perpendicular to the main shaft axis L1. In this way, the angle of the blade 56 and the direction of the nacelle 53 are changed at any time according to the wind state.

  The slewing bearing of the present invention can be applied to construction machines such as hydraulic excavators and cranes other than wind power generators, rotary tables of machine tools, gun seats, parabolic antennas, and the like.

  As mentioned above, although the form for implementing this invention based on the Example was demonstrated, embodiment disclosed here is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 ... Inner ring (the other race)
1a ... outer peripheral surface (opposing peripheral surface)
1b ... raceway groove 2 ... outer ring (one raceway)
1b ... Inner peripheral surface (opposing peripheral surface)
2b ... raceway groove 3 ... ball (rolling element)
6 ... Bearing space 7A, 7B ... Seal member 12 ... Fitting recess 20 ... Base parts 21, 22, 23 ... Seal lips 21a, 22a, 23a ... Inward faces 21b, 22b, 23b ... Outward face 53 ... Nacelle 56 ... Blade BR1, BR2 ... slewing bearings P1, P2, P3 ... contacts

Claims (8)

A raceway groove is formed on each of the circumferential surfaces of the inner ring and the outer ring that are raceways opposite to each other, and a plurality of rolling elements are provided between the raceway grooves of the inner and outer rings, and an axial end portion of the bearing space between the inner and outer rings is provided. In a seal structure of a slewing bearing provided with a sealing member made of an elastic body for sealing,
The seal member includes a base portion held by any one of the inner and outer rings, and three seal lips extending from the base portion toward the other of the inner and outer rings in different directions. Of these three seal lips, at least two seal lips close to the bearing space are in contact with the opposing circumferential surfaces of the other bearing ring, and the seal lip farthest from the bearing space is the seal lip. A seal structure for a slewing bearing characterized in that it can be visually judged whether or not a member is in a correctly assembled state.   The seal structure of the slewing bearing according to claim 1, wherein the seal lip farthest from the bearing space is in non-contact with the opposing circumferential surface of the other race ring when the seal member is in a properly assembled state. Bearing seal structure.   The seal structure of the slewing bearing according to claim 2, wherein the inner ring and the outer ring are inclined relative to each other, and the seal lip closest to the bearing space among the three seal lips is the one of the other race ring. A seal structure for a slewing bearing in which a seal lip farthest from the bearing space comes into contact with the opposing peripheral surface of the other race ring when being separated from the opposing peripheral surface.   4. The seal structure for a slewing bearing according to claim 1, wherein the one bearing ring has a fitting recess for holding the seal member, and the seal member is fitted with the fitting. A seal structure of a slewing bearing in which the base is held by fitting a part into a mating recess.   5. The seal structure for a slewing bearing according to claim 1, wherein a seal lip closest to the bearing space among the three seal lips is directed from the base portion to the other raceway ring. And the remaining two seal lips are inclined to move away from the bearing space toward the other raceway from the base. 6. The seal structure for a slewing bearing according to claim 5, wherein a tip end surface of the seal lip that is closest to the bearing space among the three seal lips is from a contact point that contacts the opposing circumferential surface of the other race ring. An inward surface extending inward and an outward surface extending outward from the contact point, the outer surface and the opposing circumference more than an angle formed by the inward surface and the opposing peripheral surface The angle formed by the surface is smaller,
The front end surface of the seal lip that is second closest to the bearing space has an inward surface extending inward from a contact point that contacts the opposing circumferential surface of the other race ring, and an outward surface extending outwardly from the contact point. The angle formed by the inward surface and the opposed peripheral surface is smaller than the angle formed by the outward surface and the opposed peripheral surface,
The front end surface of the seal lip farthest from the bearing space has an inward surface extending inward from a contact point that contacts the opposing circumferential surface of the other race ring when the inner ring and the outer ring are inclined relative to each other. And an outward surface extending outward from the contact, and an angle formed by the outward surface and the opposed peripheral surface is larger than an angle formed by the inward surface and the opposed peripheral surface. small,
Slewing bearing seal structure.   A slewing bearing having the seal structure according to any one of claims 1 to 6, wherein the slewing bearing supports the blade of the wind power generator with respect to the main shaft so as to be rotatable about an axis substantially perpendicular to the main shaft axis. .   A slewing bearing having the seal structure according to any one of claims 1 to 6, wherein the slewing bearing supports the nacelle of the wind turbine generator with respect to a support base.

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