JP2011220368A - Seal structure of turning bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal structure of a turning bearing which can prevent grease leakage of the bearing by always stably securing an interference of a seal lip, even when the deterioration in a seal construction material advances.SOLUTION: In the seal structure of the turning bearing, seal members SR and SL include a seal base part fixed to any one of inner-outer rings 1 and 2 and a seal lip 14 having the tip contacting with any other of the inner-outer rings 1 and 2 by extending from the seal base part. Annular elastic members 16 and 16A for energizing the seal lip 14 to the other side of the inner-outer rings 1 and 2, are installed in a seal lip waist part becoming a base end part of the seal lip 14.

Description

  The present invention relates to a seal structure for a slewing bearing that is used, for example, in a slewing seat for a yaw and blade of a wind power generator, a slewing seat for a construction machine, and the like, and solves grease leakage of the bearing.

  In a slewing bearing used in a construction machine or the like, a pair of seal members that seal both axial ends of the bearing space of the inner and outer rings is disclosed (Patent Document 1). Each seal member has one seal lip and is fixed to the peripheral surface of the inner ring or the outer ring. The tip of the seal lip is in contact with the upper or lower surface of the inner and outer rings. Note that it is conceivable by those skilled in the art to increase the number of sealing lips to 2 or the like for the purpose of improving the sealing performance. In addition, the material of the seal member should be selected according to temperature and other usage environments.

JP 2002-174229 A

  Synthetic rubber such as nitrile rubber and chloroprene rubber is generally selected as the material for the seal member. However, the deterioration of the material progresses due to the influence of use, aging, ozone in the air, etc., and the sealing function is lowered. May cause. In particular, it is an important issue to ensure an appropriate fastening allowance due to permanent deformation of the material of the seal member.

  An object of the present invention is to provide a seal structure for a slewing bearing that can prevent grease leakage of the bearing by always stably securing a sealing margin of the seal lip even when deterioration of the seal material or the like proceeds. That is.

  In the seal structure of the slewing bearing according to the present invention, race grooves are formed in the inner ring and the outer ring, a plurality of rolling elements are provided between the race grooves of the inner and outer rings, and both ends of the bearing space in the inner and outer rings in the axial direction are sealed. In a seal structure of a slewing bearing provided with a pair of sealing members to be stopped, the seal member includes a seal base fixed to one of the inner and outer rings, and a tip extending from the seal base to the other of the inner and outer rings. An annular elastic member that urges the seal lip toward the other side of the inner and outer rings is attached to a seal lip waist portion that is a base end portion of the seal lip.

  According to this configuration, since the annular elastic member that urges the seal lip toward the other side of the inner and outer rings is mounted on the seal lip waist, the seal lip can always be reliably urged toward the other side of the inner and outer rings. . As a result, even when the deterioration of the seal material or the like proceeds, the tightening allowance of the seal lip can be secured stably at all times, and the grease leakage of the bearing can be prevented.

  The elastic member may be a linear member curved in an annular shape. The elastic member can be easily manufactured by cutting the linear member into a desired length and curving it in an annular shape. Since the linear member is cut into a desired length, it is possible to arbitrarily adjust the tightening margin of the seal lip.

The elastic member may be one in which one end and the other end of the linear member are bonded together.
The elastic member may be made of rubber and provided in an annular shape by bonding one end and the other end of the linear member by vulcanization of the linear member.
In these cases, the production of the elastic member can be simplified. Therefore, the manufacturing cost can be reduced.

The elastic member may be made of a material in which a plasticizer or an antioxidant is saturated. In this case, the elastic member continuously supplies a plasticizer or an anti-aging agent to the seal member. Thereby, progress of deterioration of the seal lip can be suppressed.
An oil component may be applied to the tip of the seal lip. In this case, the progress of wear of the seal lip can be suppressed, and an oil film is formed at the tip of the seal lip, and the oil film can prevent grease leakage of the bearing.
The elastic member may have a circular cross section.

  The seal lip may have a lip portion that is integrally connected to the tip end of the seal lip waist portion and bifurcated in and out of the axial direction. In this case, the axially inner lip portion is inclined inward in the axial direction of the bearing space toward the tip of the lip portion. For this reason, the lip portion on the inner side in the axial direction is pressed against the other race ring by the pressure inside the bearing by filling the bearing space with grease and the elastic restoring force of the elastic member. The lip portion on the outer side in the axial direction is pressed against the other race ring by the elastic restoring force of the elastic member. Therefore, the margin for tightening the seal lip can be secured stably at all times, and the grease leakage of the bearing can be prevented. Grease may be held in an annular space surrounded by the axially inner and outer lip portions and the other raceway ring. In this case, an oil film is formed on the tip portion of the seal lip by the grease held in the annular space. Therefore, wear of the seal lip can be suppressed and grease leakage of the bearing can be prevented by the oil film.

The seal base of the seal member may be fixed to the outer ring, and the seal lip extending from the seal base may have a seal structure in contact with the inner ring.
The seal base of the seal member may be fixed to the inner ring, and the seal lip extending from the seal base may have a seal structure in contact with the outer ring.
Of the pair of seal members that seal both axial ends of the bearing space in the inner and outer rings, the seal base of one of the seal members is fixed to the outer ring, and the seal lip extending from the seal base contacts the inner ring, The seal base of the seal member may be fixed to the inner ring, and the seal lip extending from the seal base may be in contact with the outer ring.
The slewing bearing of the present invention is one in which any of the above-described seal structures is applied.
According to this configuration, grease leakage of the bearing can be prevented, the replacement period of the seal member can be extended, and maintenance-free can be achieved. Therefore, it is possible to reduce the maintenance cost.

  In the seal structure of the slewing bearing according to the present invention, race grooves are formed in the inner ring and the outer ring, a plurality of rolling elements are provided between the race grooves of the inner and outer rings, and both ends of the bearing space in the inner and outer rings in the axial direction are sealed. In a seal structure of a slewing bearing provided with a pair of sealing members to be stopped, the seal member includes a seal base fixed to one of the inner and outer rings, and a tip extending from the seal base to the other of the inner and outer rings. Since the ring-shaped elastic member that urges the seal lip toward the other side of the inner and outer rings is mounted on the seal lip waist portion, which is the base end portion of the seal lip, the seal material is deteriorated. Even in the case of progress, the grease leakage of the bearing can be prevented by always ensuring the tightening margin of the seal lip stably.

It is sectional drawing of the slewing bearing which concerns on one Embodiment of this invention. (A) is the schematic plan view which a part fracture | ruptured of the slewing bearing, (B) is the AA line end view of FIG. 2 (A). (A) is sectional drawing which expands and shows the right side principal part of the seal structure of the slewing bearing, (B) is sectional drawing which expands and shows the left side principal part of the sealing structure of the slewing bearing. 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.

  An embodiment of the present invention will be described with reference to FIGS. This slewing bearing is, for example, a bearing that supports the blade of a wind turbine for wind power generation so that it can pivot about an axis substantially perpendicular to the main shaft axis or a nacelle of the wind turbine relative to a support base. It is used as a bearing to be supported or a bearing for a swivel seat such as a deck crane.

  As shown in FIG. 1, the slewing bearing includes an inner ring 1, an outer ring 2, and a plurality of rows of rolling grooves interposed between the double row raceway grooves 1a, 1b, 2a and 2b of the inner and outer rings 1 and 2, respectively. A ball 3 that is a rolling element, a spacer 4 interposed between the balls 3 in each row, and a pair of seal members SR and SL that seal both ends in the axial direction of the bearing space in the inner and outer rings 1 and 2. Prepare. Each of the raceway grooves 1a, 1b, 2a, 2b of the inner and outer rings 1, 2 is composed of two curved surfaces 1aa, 1ab, 1ba, 1bb, 2aa, 2ab, 2ba, 2bb.

  The two curved surfaces constituting each raceway groove 1a, 1b, 2a, 2b are Gothic arch-shaped circular arcs having a radius of curvature larger than that of the ball 3 and different curvature centers. Between a pair of curved surfaces constituting each track groove 1a, 1b, 2a, 2b, there are groove portions 1ac, 1bc, 2ac, 2bc. Each ball 3 is in contact with the curved surfaces of the inner ring raceway grooves 1a and 1b and the outer ring raceway grooves 2a and 2b at the contact points, and contacts the four points. This slewing bearing is configured as a four-point contact double row ball bearing.

For example, a plurality of bolt holes 5 formed with female threads are provided at regular intervals in the circumferential direction on the end surface of the outer ring 2, and gears 6 are provided on the outer peripheral surface of the outer ring 2. The gear 6 is means for transmitting a turning driving force from a driving source (not shown) to the outer ring 2. The plurality of bolt holes 5 are holes for connecting and fixing the outer ring 2 to a support base or the like, for example.
The inner ring 2 includes a bearing ring main body 7, plugs 8 and 8 fitted into insertion holes 9 and 9 (described later) of the bearing ring main body 7, and annular members 10 and 10. The bearing ring body 7 and the plugs 8 and 8 are formed to have the same inner diameter and outer diameter. The raceway ring body 7 is formed with double rows of raceway grooves 1a and 1b, and the outer diameter surfaces of the plugs 8 and 8 form part of the circumferential direction of the raceway grooves 1a and 1b of each row. The distance between the raceway grooves 1a and 1b of the inner ring 1 and the distance between the raceway grooves 2a and 2b of the outer ring 2 are set to the same dimensions in design.

  The bearing ring main body 7 is provided with insertion holes 9 and 9 for inserting the ball 3 and the spacer 4 between the raceway grooves 1a and 1b and between the raceway grooves 2a and 2b. The insertion holes 9 are provided in the bearing ring main body 7 so as to penetrate in the bearing radial direction. Each through hole 9 is formed in a cylindrical hole shape (see FIG. 2B). Further, as shown in FIG. 2 (A), the insertion holes 9, 9 are arranged at positions close to the circumferential direction, that is, positions where the phase angle α is, for example, 4 degrees to 5 degrees. However, the phase angle α is not limited to 4 degrees to 5 degrees.

  The race ring main body 7 is provided with plugs 8 that are fitted into the respective insertion holes 9, and the plugs 8 are fixed to the race ring main body 7 by a connector or the like (not shown). An annular groove 8b is formed on the outer peripheral surface of the stopper 8 closer to the inner diameter side. An annular member 10 made of an elastic body is fitted into the annular groove 8b to enhance the sealing performance of the plug 8 with respect to the insertion hole 9 of the raceway ring body 7. The annular member 10 is made of rubber such as an O-ring or an elastic body made of resin.

The seal structure will be described.
The bearing spaces of the inner and outer rings 1 and 2 are filled with grease, and both ends in the axial direction of the bearing spaces are sealed with a pair of seal members SR and SL. First, the seal member on the right side of FIG. 1 will be described. As shown in FIGS. 1 and 3A, an annular fitting recess 12 for press-fitting the seal base portion 11 of the seal member SR is formed on the right end surface near the inner diameter of the outer ring of the right end portion of the outer ring 2. ing. The seal base 11 is press-fitted and fixed to the fitting recess 12. The fitting recess 12 is formed at a predetermined distance in the axial direction according to the axial dimension of the seal base 11. On the wall portion on the outer peripheral side of the fitting recess 12, annular recesses 12 a and 12 b made of two rows of recesses are provided in the axial direction. Of these annular recesses 12a and 12b, the annular recess 12a on the bottom side is formed in a circular arc shape that is recessed toward the outer diameter side, and the annular recess 12b on the opening edge side is formed in a rectangular shape that is recessed toward the outer diameter side.

  The seal member SR is made of, for example, a synthetic rubber such as nitrile rubber or chloroprene rubber, and extends from the seal base 11 and a seal base 11 that is press-fitted and fixed to the fitting recesses 12 a and 12 b of the outer ring 2. And a seal lip 14 whose tip is in contact with the outer peripheral surface 13 of the inner ring. The seal lip waist portion 14a serving as the base end portion of the seal lip 14 is formed in an annular body having a substantially rectangular cross section, and is disposed along the vicinity of the inner diameter edge forming the step portion on the right end surface of the outer ring 2.

  The seal base 11 extends in the axial direction and is provided so as to be press-fit into the aforementioned fitting recesses 12a and 12b. On the outer peripheral surface of the seal base 11, annular convex portions 11a and 11b that are press-fitted and fitted into the fitting concave portions 12a and 12b are provided. These outer peripheral annular convex portions 11a and 11b are surface protruding portions of the seal base portion 11, and are formed so as to correspond to the cross-sectional arc shape and the rectangular cross-sectional shape of the fitting concave portions 12a and 12b. On the inner peripheral surface of the seal base 11, an annular convex portion 11 c is provided as a press-fitting allowance consisting of a protrusion that protrudes from the surface of the seal base 11 and elastically deforms by press-fitting. The radially press-fitting allowance dimension of the inner peripheral annular protrusion 11c is smaller than the radially press-fitting allowance dimension of the fitting recesses 12a and 12b. Further, the annular protrusion 11c on the inner peripheral side is formed so as to be positioned on the inner side in the axial direction than the annular protrusions 11a and 11b on the outer peripheral side.

  The seal lip 14 includes the seal lip waist portion 14a and a lip portion 14b that is integrally connected to the tip on the inner peripheral side of the seal lip waist portion 14a. The seal member SR is a contact type in which the lip portion 14b is in contact with the outer peripheral surface 13 of the inner ring. The lip portion 14b has first and second lip portions 14ba and 14bb that are bifurcated inward in the axial direction. The first lip portion 14ba is inclined inward in the axial direction of the bearing space toward the tip. The second lip portion 14bb is inclined outward in the axial direction of the bearing space toward the tip. In this embodiment, oil such as grease is applied to the tips of the first and second lip portions 14ba and 14bb. An annular space 15 surrounded by the first and second lip portions 14ba and 14bb and the inner ring outer peripheral surface 13 is formed. In addition to the grease sealed in the bearing space, the annular space 15 may be held with grease.

  An annular elastic member 16 that urges the seal lip 14 toward the inner ring 1 is attached to the seal lip waist portion 14a. In this example, the elastic member 16 is made of rubber, and one end portion and the other end portion of a linear member having a circular cross section are joined by adhesion. The elastic member 16 is attached to the annular dent 14aa connected to the second lip portion 14bb of the seal lip waist portion 14a after the diameter of the elastic member 16 is determined from the natural state. The first and second lip portions 14ba and 14bb are always urged toward the inner ring 1 by the elastic return force of the elastic member 16 toward the inner diameter side. Thereby, the fastening margin of the seal lip 14 is secured stably. In this case, the annular space 15 surrounded by the first and second lip portions 14ba and 14bb and the inner ring outer peripheral surface 13 is smaller than the state before the elastic member is mounted.

The seal base portion of the seal member SL on the left side of FIG. 1 is press-fitted and fixed to the fitting recess 12 on the left end surface of the inner ring 1. With respect to the structure of the seal member SL, portions having the same operational effects as those of the seal member SR on the right side of FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. The structure is the same as that of the member SR.
As shown in FIGS. 1 and 3B, an elastic member 16A for urging the seal lip 14 toward the outer ring 2 is attached to the seal lip waist portion 14a of the seal member SL. In this example, the elastic member 16A is made of a substantially C-shaped metal as viewed from the axial direction, and the natural state of the elastic member 16A is formed in the annular recess 14aa connected to the second lip portion 14bb of the seal lip waist portion 14a. It will be installed after the diameter is reduced. The first and second lip portions 14ba and 14bb are always urged toward the outer ring 2 by the elastic return force of the elastic member 16A toward the outer diameter side. Thereby, the fastening margin of the seal lip 14 is secured stably. In this case, the annular space 15 surrounded by the first and second lip portions 14ba, 14bb and the outer ring inner peripheral surface 17 is smaller than the state before the elastic member is mounted.

According to the seal structure of the slewing bearing described above, the elastic members 16 and 16A for urging the seal lip 14 toward the facing race ring are mounted on the seal lip waist portion 14a. Can be energized. As a result, even when the deterioration of the seal material or the like proceeds, the tightening allowance of the seal lip 14 can always be ensured stably, and the grease leakage of the bearing can be prevented.
Since the first lip portion 14ba of the seal members SR, SL is inclined inward in the axial direction of the bearing space toward the tip, the grease is sealed in the bearing space, and the elastic restoring force of the elastic members 16, 16A. And pressed against the other race. The second lip portion 14bb is pressed against the other race ring only by the elastic restoring force of the elastic members 16, 16A. In this way, the tightening allowance of the seal lip 14 can be secured stably at all times, and the grease leakage of the bearing can be prevented. The pressure inside the bearing acts on the seal members SR and SL. However, since the seal base 11 of the seal members SR and SL is press-fitted and fixed to the fitting recess 12 with the press-fitting allowance of the concavo-convex shape, this is fixed. The sealing members SR and SL will not drop off undesirably.

  Since the elastic members 16 and 16A are formed by bending a linear member in an annular shape, the elastic members 16 and 16A are easily manufactured by cutting the linear member into a desired length and bending it in an annular shape. be able to. Since the linear member is cut to a desired length, the tightening allowance of the seal lip 14 can be arbitrarily adjusted. Since the elastic member SR is obtained by bonding one end and the other end of the linear member by bonding, the production of the elastic member SR can be simplified. Therefore, the manufacturing cost can be reduced.

  Further, when oil is applied to the tip of the seal lip 14, it is possible to suppress the progress of wear of the seal lip 14, and an oil film is formed at the tip of the seal lip 14, and this oil film prevents grease leakage of the bearing. be able to. When the grease is held in the annular space 15, the annular space 15 becomes smaller than the state before the elastic member is mounted due to the elastic restoring force of the elastic members 16 and 16A, so that a part of the grease in the annular space 15 is pushed out. Thus, an oil film is formed at the tip of the seal lip 14. In this case as well, it is possible to prevent the wear of the seal lip 14 from progressing and to prevent grease leakage of the bearing by the oil film.

As another embodiment of the present invention, the elastic member may be made of rubber, and one end portion and the other end portion of the linear member may be bonded to each other by vulcanization of the linear member and provided in an annular shape. In this case, the manufacturing of the elastic member can be simplified, and therefore the manufacturing cost can be reduced.
The elastic member may be made of a material in which a plasticizer or an anti-aging agent is saturated. For example, trioctyl trimellitic acid can be used as the plasticizer. As examples of the anti-aging agent, for example, amines can be used. In this case, the elastic member continuously supplies a plasticizer or an anti-aging agent to the seal member. Thereby, progress of deterioration of the seal lip can be suppressed.
The inner and outer rings are not limited to double-row raceway grooves. A single row raceway groove may be used.
As the slewing bearing, a deep groove ball bearing other than the four-point contact double row ball bearing may be used depending on use conditions. A roller may be used as the rolling element, and the slewing bearing may be a cross roller bearing in which the rollers are alternately arranged substantially orthogonally along the circumferential direction.

  4 and 5 show an example in which the slewing bearing having the seal structure is used in a wind turbine for wind power generation. This windmill 21 is provided with a nacelle 23 on a support base 22 so as to be able to turn horizontally, and a main shaft 25 is rotatably supported in a casing 24 of the nacelle 23. A blade 26 which is a wing is attached. The other end of the main shaft 25 is connected to the speed increaser 27, and the output shaft 28 of the speed increaser 27 is coupled to the rotor shaft of the generator 29.

  The nacelle 23 is rotatably supported by the slewing bearing BR1. In the slewing bearing of the embodiment shown in FIG. 1 of the present invention, for example, the one provided with a gear or the like on the outer peripheral surface of the outer ring 2 is used for the slewing bearing BR1 for the nacelle 23. As shown in FIG. 4, a plurality of drive sources 30 are installed in the casing 24, and a pinion gear is fixed to each drive source 30 via a speed reducer (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 22 by a plurality of through holes 2 b, and the inner ring 1 is fixed to the casing 24. The plurality of drive sources 30 are driven in synchronization, and this turning driving force is transmitted to the outer ring 2. Therefore, the nacelle 23 can turn relative to the support base 22.

The blade 26 is rotatably supported by the swing bearing BR2. As this slewing bearing BR2, in the slewing bearing of the embodiment shown in FIG. 1, for example, a bearing provided with a gear on the inner peripheral surface of the inner ring 1 is applied. A driving source for rotating the blade 26 is provided at the protruding end portion 25 a of the main shaft 25. The outer ring 2 of the slewing bearing is connected and fixed to the distal end portion 25a, and a gear attached to the inner peripheral surface of the inner ring 1 is engaged with a pinion gear of the drive source. The blade 26 can turn by driving the driving source and transmitting the turning driving force to the inner ring. Therefore, the slewing bearing BR2 can support the wind turbine blade 26 with respect to the main shaft 25 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 26 and the direction of the nacelle 23 can be changed at any time according to the wind condition.
When the slewing bearing having the seal structure is used for a wind turbine for wind power generation, grease leakage of the bearing can be prevented, the replacement cycle of the seal member can be extended, and maintenance-free can be achieved. Therefore, it is possible to reduce the maintenance cost.

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

DESCRIPTION OF SYMBOLS 1 ... Inner ring 1a, 1b ... Track groove 2 ... Outer ring 2a, 2b ... Track groove 3 ... Ball 14 ... Seal lip 14a ... Seal lip waist part 16, 16A ... Elastic member SR, SL ... Seal member BR1, BR2 ... Slewing bearing

Claims (12)

The inner ring and the outer ring each have a raceway groove, a plurality of rolling elements are provided between the raceway grooves of the inner and outer rings, and a turn provided with a pair of seal members that respectively seal the axial ends of the bearing space in the inner and outer rings. In the bearing seal structure,
The seal member has a seal base fixed to one of the inner and outer rings, and a seal lip extending from the seal base and having a distal end contacting the other of the inner and outer rings, and a base end of the seal lip; An annular elastic member for urging the seal lip toward the other side of the inner and outer rings is mounted on the seal lip waist portion.   2. The seal structure for a slewing bearing according to claim 1, wherein the elastic member is a linear member curved in an annular shape.   3. The seal structure for a slewing bearing according to claim 2, wherein the elastic member is formed by bonding one end and the other end of the linear member by adhesion.   4. The swivel according to claim 2, wherein the elastic member is made of rubber, and is provided in an annular shape by bonding one end and the other end of the linear member by vulcanization of the linear member. Bearing seal structure.   5. The seal structure for a slewing bearing according to claim 1, wherein the elastic member is made of a material in which a plasticizer or an anti-aging agent is saturated.   6. The seal structure for a slewing bearing according to claim 1, wherein an oil component is applied to a tip of the seal lip.   7. The seal structure for a slewing bearing according to claim 1, wherein the elastic member has a circular cross section.   8. The seal structure for a slewing bearing according to claim 1, wherein the seal lip has a lip portion integrally connected to a tip end of the seal lip waist portion and bifurcated inward and outward in the axial direction.   9. The seal structure for a slewing bearing according to claim 1, wherein a seal base of the seal member is fixed to the outer ring, and a seal lip extending from the seal base has a seal structure in contact with the inner ring.   The seal structure for a slewing bearing according to any one of claims 1 to 9, wherein the seal base of the seal member is fixed to the inner ring, and the seal lip extending from the seal base has a seal structure in contact with the outer ring.   9. The seal base according to claim 1, wherein a seal base of one seal member is fixed to the outer ring, and the seal base is fixed to the outer ring. A seal structure for a slewing bearing in which a seal lip extending from a base is in contact with an inner ring, a seal base of the other seal member is fixed to the inner ring, and a seal lip extending from the seal base is in contact with an outer ring.   A slewing bearing to which the seal structure according to any one of claims 1 to 11 is applied.