Revolving device

The present invention relates to a swivel device for rotatably connecting an upper swivel body to a lower traveling body, such as a construction machine.

For example, a hydraulic excavator is composed of a lower traveling body provided with a crawler-type traveling means and an upper swivel body provided with a working means or the like mounted so as to be swivelable. The swivel device has a swivel ring composed of an inner ring and an outer ring, and a plurality of rolling elements are interposed between the inner ring and the outer ring over the entire circumference, and a swivel gear is formed on the inner peripheral surface of the inner ring. A swivel pinion connected to a swivel hydraulic motor is engaged with this swivel gear.

The inner ring and the outer ring are fixed to the lower traveling body and the upper turning body, respectively. Normally, the inner ring is fixed to the lower traveling body, and the outer ring is fixed to the upper rotating body. The swivel hydraulic motor is installed on the frame of the upper swivel body, and the swivel pinion is connected to the output shaft of the swivel motor. As a result, when the swivel hydraulic motor is driven, the swivel gear that meshes with the swivel gear of the inner ring rotates, whereby the upper swivel body turns with respect to the lower traveling body.

The rolling element interposed between the inner ring and the outer ring is generally made of a steel ball, and the opposing surfaces of the inner ring and the outer ring form a rolling surface on which the rolling element rolls. Further, a predetermined number of rolling elements and spacers are alternately provided on the rolling surface. Then, in order to smoothly slide between the rolling element and the inner ring and the outer ring and between the rolling element and the spacer, a lubricating material made of grease or the like is filled between the inner ring and the outer ring. This lubricant wraps around the entire circumference of the rolling element, which causes the swivel hydraulic motor to be driven with a light load. Since the inner ring and the outer ring are in a non-contact state, a certain amount of gap is formed between them, so that the lubricant may leak from the gap or foreign matter such as dust may be mixed into the lubricant from the outside. It is necessary to seal the top and bottom of this gap to prevent it from happening. For this reason, the seal member is mounted between the inner ring and the outer ring at the upper and lower positions of the rolling element mounting portion.

In general, the facing surfaces of the inner ring and the outer ring are shifted to some extent in the vertical direction to expose the upper portion on the inner peripheral surface of the outer ring and the lower portion on the outer peripheral surface of the inner ring. An annular seal groove is formed in each of the exposed portions, and a seal member is attached to these seal grooves. Therefore, the seal member is configured to be fixedly held in the seal groove formed on one of the inner ring and the outer ring and to be slidably contacted with the upper surface or the lower surface of the other. The seal member is made of an elastic member such as rubber formed in a band shape, and is composed of a fastening portion fitted in the seal groove and a lip portion extending from the fastening portion. Then, the fastening portion of the seal member is inserted into the seal groove, and the lip portion is attached so as to come into contact with the lower surface of the outer ring or the upper surface of the inner ring. Then, the end portion of the seal member is cut, and the start end portion and the end portion thereof are joined and fixed with an adhesive. The above configuration is disclosed in, for example, Patent Document 1.

Here, in the seal member, the inner and outer rings rotate relative to each other in a state where the lip portion constituting the tip portion thereof is in contact with the lower surface of the outer ring or the upper surface of the inner ring, so that the lip portion slides on them. As a result, a force acts in the direction in which the fastening portion of the seal member comes out of the seal groove. Therefore, if the fastening portion of the seal member is simply fitted in the seal groove and repeatedly swiveled, the seal member may deviate from the seal groove.

In consideration of the above points, in the configuration shown in Patent Document 1, the fastening portion of the sealing member is fixed to the sealing groove by using an adhesive, and a copper wire is embedded in the fastening portion. The copper wire is used to hold the fastening portion so that it does not deviate from the seal groove.<patcit num="1"><text>Japanese Unexamined Patent Publication No. 2001-254746</text></patcit>

<p> In the swivel wheels constituting the swivel device, a seal member is generally attached to the inner ring on the lower side, and a seal member is generally attached to the outer ring on the upper side. Therefore, an annular seal groove is formed on the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring, respectively. However, when the seal member is attached to the seal groove formed on the outer peripheral surface of the inner ring, a certain amount of seal groove is formed. By applying tension, the fastening portion of the seal member can apply a force in the direction of pressure contact to the groove bottom portion of the seal groove. Therefore, the seal groove of the inner ring can be sufficiently stably held with a small amount of adhesive without applying an adhesive, and even if it is applied.</p><p> On the other hand, when the seal member is attached to the seal groove formed on the outer ring, the above-mentioned tension cannot be applied. Therefore, the seal member must be held by the action of the adhesive applied to the seal groove and the function of the copper wire. In addition, the copper wire embedded in the seal member exerts a certain shape-retaining function so that the seal member has an annular shape, but it has to be deformed into an annular shape when the seal member is attached, so that the rigidity is very high. You can't use anything. For this reason, there is a limit to the shape retention ability of the copper wire.</p><p> Further, the adhesive in the seal groove is one that adheres between the wall surface in the depth direction above and below the groove and the upper and lower surfaces of the fastening portion, and when the seal member slides on the upper surface of the inner ring, the adhesive is used. The force in the direction in which the fastening portion escapes from the seal groove is the force in the direction in which the adhesive is sheared. Therefore, if the adhesion is not performed extremely strongly, the adhesive may peel off during repeated swirling. For this purpose, it is necessary for the fastening portion of the sealing member to exert a large pressure contact force on the inner wall of the sealing groove, and the thickness dimension of the fastening portion of the sealing member is to some extent larger than the width dimension of the sealing groove. It must be enlarged and inserted into the seal groove in a compressed state, that is, press-fitted. Then, it is necessary to strictly control the dimensions of the seal groove and the seal member, which may cause troublesome processing of the seal groove and the like, and may make it difficult to attach the seal member. Then, when the fastening portion of the sealing member is press-fitted into the sealing groove, the adhesive applied to the sealing groove is scraped off, and excess adhesive is generated in the process of inserting the fastening portion into the sealing groove. It cannot be said that there is a possibility that it will be offset and partially flow out of the seal groove and adhere to the rolling elements. In addition, the adhesive layer may change in the circumferential direction, and as a result, the adhesive force of the sealing member changes in the circumferential direction, resulting in the adhesive strength of the sealing member at the sliding portion on the inner ring. There is a possibility that variations will occur and stress will be concentrated on the portion where the adhesive strength is weak, causing partial peeling and deformation of the sealing member due to peeling.</p><p> The present invention has been made in view of the above points, and an object of the present invention is that the seal member can be easily attached, and in the attached state, the state of being fixed to the seal groove is stable for a long period of time. It is to be able to hold it in.</p>

<p> In order to solve the above-mentioned problems, the present invention connects the inner ring and the outer ring so as to be relatively rotatable via a plurality of rolling elements, and between these rolling elements and the rolling surfaces formed on the inner ring and the outer ring. A swivel device in which a lubricant is sealed and a seal member is interposed between the inner ring and the outer ring in order to prevent the lubricant from leaking from the gap between the inner ring and the outer ring. The seal member is composed of a fastening portion having a predetermined thickness and a lip portion extending from the fastening portion, and the sealing member is stopped on at least one of the outer surface of the inner ring and the inner surface of the outer ring. An annular seal groove for accommodating the attachment portion is formed, and the width dimension of the seal groove is larger than the thickness of the fastening portion of the sealing member, and the depth dimension is larger than the insertion length of the fastening portion. It is formed so as to be large, and the fastening portion of the sealing member<u style="single">To</u>Fixed with an adhesive inside the seal groove<u style="single">It is composed of the adhesive elastic adhesive, and the hardness in the cured state is 30% to 100% of the hardness of the sealing member, and the elastic modulus is 80% to 80% of the elastic modulus of the sealing member. 150%</u>That is the feature.</p><p> Here, generally, the thickness dimension of the fastening portion in the seal member is about 5 mm. On the other hand, it is desirable that the width dimension of the seal groove is 0.1 mm to 1 mm larger than the thickness of the fastening portion. Therefore, the adhesive is held between the upper and lower surfaces of the fastening portion of the seal member and the upper and lower wall surfaces of the seal groove. In this case, if the dimensional difference between the fastening portion of the seal member and the seal groove is 0.1 mm or less, the seal member will be press-fitted when the seal member is mounted, considering that there is a dimensional tolerance between the seal groove and the seal member. This causes a problem that it may be difficult to install the product. On the other hand, if the dimensional difference exceeds 1 mm, the adhesive strength to the seal member is lowered, and the holding of the seal member is not stable.</p><p> The dimensional difference between the upper and lower sides of the sealing portion of the sealing member and the upper and lower wall surfaces of the sealing groove is as described above, but the end surface of the fastening portion is also maintained in a non-contact state with respect to the groove bottom of the sealing groove. To do. As a result, the adhesive can be smoothly wrapped between the end surface of the fastening portion and the groove bottom portion of the seal groove, so that the adhesive surface can be increased. The separation distance in this case is also preferably about 0.1 mm to 1 mm, similar to the difference in width dimension. In order to accurately control the insertion depth of the fastening portion with respect to the seal groove, an index indicating the insertion depth can be provided in the vicinity of the transition portion from the fastening portion to the lip portion. This index portion is therefore provided at a portion that is not inserted into the seal groove. The index portion can be formed by, for example, drawing a line, but a convex portion protruding from the surface thereof can be used as the index portion in order to integrally form the seal member at the time of manufacturing. Further, a lead-in portion can be formed at the end portion of the fastening portion in order to facilitate insertion into the seal groove. In this case, the calling portion is formed by diagonally cutting the corner portion at the end portion of the fastening portion, and this attracting portion facilitates insertion of the fastening portion into the seal groove.</p><p> By inserting the fastening portion of the sealing member into the sealing groove, fixing the entire surface of the sealing groove and the fastening portion with an adhesive, and curing the adhesive, the adhesive function is exhibited between them. , Hold the seal member so that it does not deviate from the seal groove. After the adhesive is cured, its hardness is equal to or less than the hardness of the sealing member. Further, the elastic modulus is assumed to have a characteristic close to the elastic modulus of the sealing member. The seal groove to which the seal member is mounted is formed on the inner ring or the outer ring, and these outer rings and inner rings are made of steel because high strength is required due to their nature. Therefore, the hardness difference between the seal member, which is an elastic member, and the seal groove is extremely large. When the swivel device is swiveled, the lip portion of the seal member is in sliding contact with the upper surface of the inner ring or the lower surface of the outer ring, so that stress in the direction of escape from the seal groove and other directions acts on the lip portion. Therefore, the adhesive will partially peel off for a long period of time, and if peeling occurs even in a part of the adhesive, the peeled part will expand, deform the seal member, and seal leakage will occur. become.</p><p> From the above points, it is desirable that the adhesive interposed between the seal member and the seal groove exerts a stress relaxation function. That is, an adhesive layer having a predetermined thickness is interposed between the seal member and the seal groove, and when an external force acts on the seal member, the stress does not act directly on the joint with the seal groove. Stress will act on the adhesive. As a result, the adhesive is elastically deformed to absorb the stress, and the stress acting on the joint surface between the fastening portion of the sealing member and the adhesive and the joint surface between the adhesive and the seal groove is relaxed. As a result, it is possible to prevent the seal member from peeling off and deviating from the seal groove.</p><p><u style="single">As the adhesive, an elastic adhesive described later is used, and this elastic adhesive</u>The hardness in the cured state is 30% to 100% of the hardness of the sealing member, and the elastic modulus is 80% to 150% of the elastic modulus of the sealing member.<u style="single">To</u>。 </p><p><u style="single">The hardness of the adhesive</u>If it is 30% or less, when a force is applied in the direction in which the seal member escapes from the seal groove, sufficient resistance cannot be generated against it. Further, if it exceeds 100%, that is, if the adhesive has a higher hardness, the function as a cushioning member is impaired, and peeling between the sealing member and the adhesive occurs. Further, if the elastic modulus is 80% or less, when a force in the direction of pulling out from the seal groove acts on the seal member, the adhesive partially extends and delamination occurs between the seal member and the seal groove. Further, if the elastic modulus of the adhesive is 150% or more with respect to the elastic modulus of the sealing member, the stability of the sealing member is lost.</p><p> Specifically, as the material of the sealing member, for example, NBR (acrylic nitrile-butadiene rubber), chloroprene rubber, SBR (styrene-butadiene rubber), natural rubber, EPDM (ethylene-propylene rubber), urethane rubber, silicon Rubber, fluororubber, etc. are used. Further, as the adhesive, for example, an elastic adhesive such as a silyl group-containing special polymer adhesive, a modified silicone adhesive, an epoxy-modified silicone adhesive, a special urethane adhesive, or a synthetic rubber adhesive is preferably used.</p><p> When the above-mentioned elastic adhesive is used, it takes several minutes to several tens of minutes for the adhesive to cure and exhibit a stable adhesive function. Therefore, in order to stably hold the seal member in the seal groove by utilizing the elasticity of the seal member until the adhesive is cured, it is necessary to connect the seal member to the lip portion of the sealing portion and seal the seal. It is possible to form a locking portion in which the portion to be inserted into the inlet portion of the groove is thicker than the groove width of the seal groove. Further, when inserting the seal member into the seal groove to which the adhesive is applied, in order to prevent excess adhesive from leaking to the sealing space side of the lubricant, the seal groove is formed in the fastening portion of the seal member. It suffices to provide a protruding portion toward the inner peripheral surface on the side close to the rolling surface of the.</p>

<p> With the above configuration, the seal member can be easily attached to the seal groove provided on the outer ring or the inner ring, and in the attached state, the fixed state to the seal groove can be stably maintained for a long period of time. Therefore, peeling of the seal member can be prevented.</p>

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, Fig. 1 shows a hydraulic excavator as a typical example of a machine equipped with a swivel device. In the figure, 1 is a lower traveling body and 2 is an upper swivel body, and the lower traveling body 1 and the upper swivel body 2 are connected via a swivel device 3. The upper swivel body 2 is provided with a working means 4 including a boom 4a, an arm 4b, and a bucket 4c as an attachment for excavating earth and sand, and a driver's cab 5 is provided at a position alongside the working means 4. is set up. Further, a machine room building 6 is installed behind the driver's cab 5, and a counterweight 7 is installed behind the machine room building 6.

The upper swivel body 2 provided with the working means 4 can be swiveled with respect to the lower traveling body 1 by the swivel device 3. Therefore, the work means 4 is operated to excavate the earth and sand, the upper swivel body 2 is swiveled by a predetermined angle, and the excavated soil is loaded on the dump truck.

The configuration of the swivel device 3 is shown in FIG. In the figure, 10 is a main frame in the lower traveling body 1, 11 is a track frame provided by winding the track 12, and 13 is an upper frame constituting the upper swivel body 2. The swivel device 3 is provided between the main frame 10 of the lower traveling body 1 and the upper frame 13 of the upper swivel body 2. A round body 14 is connected to the main frame 10, and an inner ring 16 constituting the swivel wheel 15 is fixedly provided on the round body 14 by bolts 17. A swivel gear 18 is provided on the inner peripheral surface of the inner ring 16 over the entire circumference thereof. On the other hand, an outer ring 19 is fixedly provided on the lower surface of the upper frame 13 by bolts 20, and a steel ball 21 as a rolling element extends the entire circumference in the circumferential direction between the outer ring 19 and the inner ring 16. Many are intervened. Further, a swivel pinion 23 provided connected to the output shaft of the swivel hydraulic motor 22 mounted on the upper frame 13 of the upper swivel body 2 meshes with the swivel gear 18 of the inner ring 16. Therefore, by operating the swivel hydraulic motor 22 to rotate the swivel pinion 23, the entire upper swivel body 2 including the outer ring 19 can swivel 360 ° with respect to the inner ring 16.

The upper swivel body 2 swivels as described above, but in order to enable smooth swivel and reduce the load of the swivel hydraulic motor 22, the swivel pinion 23 and the swivel gear 18 formed on the inner ring 16 Lubricating material is similarly supplied to the meshing portion of the above. Further, the outer peripheral surface of the inner ring 16 and the inner peripheral surface of the outer ring 19 are kept in a non-contact state, and a steel ball 21 constituting a bearing for turning is interposed between the steel balls 21. And, in order to minimize the sliding friction between the outer surface of the inner ring 16 and the accommodating portion of the steel ball 21 on the inner surface of the outer ring 19, that is, the rolling surfaces 16a and 19a (see FIG. 3) of the steel ball 21. In the meantime, a lubricant made of grease or the like is filled.

As described above, the inner ring 16 and the outer ring 19 are in a non-contact state, and a liquid lubricant is filled between them, although the inner ring 16 and the outer ring 19 are viscous including the periphery of the steel ball 21. Therefore, in order to keep the lubricating material from leaking and to protect the lubricating material from foreign matter such as dust entering from the outside, the upper and lower parts of the lubricating material filling portion are sealed.

That is, as shown in FIG. 3, the inner ring 16 and the outer ring 19 do not completely overlap in the vertical direction, but the lower end of the inner ring 16 connected to the round body 14 is below the lower end of the outer ring 19. The outer ring 19 which is extended and attached to the upper frame 13 is located above the upper end of the inner ring 16. Therefore, a seal groove 24 is formed in an annular shape on the outer peripheral surface of the inner ring 16 below the lower end surface 19b of the outer ring 19, and the seal member 25 is mounted on the seal groove 24. Further, on the inner peripheral surface of the outer ring 19, an annular seal groove 26 is also formed in a portion above the inner ring 16, and the seal member 27 is mounted on the seal groove 26. Then, the sealing member 25 provided on the inner ring 16 side is brought into contact with the lower end surface 19b of the outer ring 19, and the sealing member 27 provided on the outer ring 19 side is brought into contact with the upper end surface 16b of the inner ring 16 to fill the lubricant. The top and bottom of the part are sealed.

The sealing members 25 and 27 are composed of the fastening portions 25a and 27a and the lip portions 25b and 27b, and are usually formed of an elongated strip, and the fastening portions 25a and 27a are inserted into the sealing grooves 24 and 26, respectively. After joining both end faces, the end faces are fixed with an adhesive so that they are assembled in an annular shape. The lip portions 25b and 27b of the sealing members 25 and 27 are brought into contact with the lower end surface 19b of the outer ring 19 and the upper end surface 16b of the inner ring 16, respectively, so that a predetermined pressing force acts on them. When the swivel device 3 is swiveled in this state, the lip portions 25b and 27b of the seal members 25 and 27 slide in a pressure contact state with respect to the lower end surface 19b of the outer ring 19 and the upper end surface 16b of the inner ring 16, respectively, and the inner ring 16 Since the outer ring 19 vibrates during the previous operation and the like, stress acts on the seal members 25 and 27 in various directions. Even if a force in the direction of pushing the seal members 25 and 27 into the seal grooves 24 and 26 acts, it does not cause a special problem, but when a force in the direction of pulling out the seal members 25 and 27 from the seal grooves 24 and 26 acts. In addition, the sealing members 25 and 27 may deviate from the sealing grooves 24 and 26.

If the seal member 25 is attached to the seal groove 24 in a state where tension is applied, the seal member 25 does not deviate from the seal groove 24. On the other hand, since the seal member 27 is inserted into the seal groove 26 formed on the inner peripheral surface of the outer ring 19, pressurization cannot be generated in the direction of insertion into the seal groove 26. Therefore, at least the attachment portion of the seal member 27 to the seal groove 26 formed in the outer ring 19 is fixed by using an adhesive. However, it is not very desirable for the seal member 25 to be attached to the seal groove 24 in a state where tension is applied in advance because a problem may occur in durability. Further, when the seal member 25 receives a force in a direction parallel to the seal groove 24, the lip portion 25b is deformed and the pressure contact force of the outer ring 19 with respect to the lower end surface 19b is reduced. It is desirable that the seal member 25 is also fixed to the seal groove 24 by using an adhesive from the viewpoint that the seal member 25 may also be fixed to the seal groove 24.

In the following description, the seal member 27 mounted on the seal groove 26 of the outer ring 19 will be described, but the same configuration can be adopted for the seal member 25 mounted on the seal groove 24 of the inner ring 16. Further, if the seal member 25 on the inner ring 16 side has the same configuration as the seal member 27, the action and effect thereof will be the same.

Therefore, FIG. 4 shows an enlarged cross section of the seal member 27 mounted on the seal groove 26 of the outer ring 19. As is clear from the figure, the thickness dimension D1 of the fastening portion 27a in the seal member 27 is smaller than the groove width of the seal groove 26, that is, the distance D2 between the upper surface 26a and the lower surface 26b of the seal groove 26. Further, the length of the portion where the fastening portion 27a is inserted into the seal groove 26 is shorter than the depth dimension of the seal groove 26. That is, the fastening portion 27a is in a non-contact state with the groove bottom surface 26c of the seal groove 26. In order to control the insertion depth of the fastening portion 27a of the sealing member 27, an annular convex portion 28 is provided at the transition portion from the fastening portion 27a to the lip portion 27b. The convex portion 28 can be integrally provided when molding the seal member 27. The convex portion 28 is formed at a position near the entrance portion of the seal groove 26 and not entering the inside of the seal groove 26 when the fastening portion 27a of the seal member 27 is inserted into the seal groove 26. Further, diagonally cut lead-in portions 27c and 27c are formed at the end of the fastening portion 27a of the seal member 27 so that the seal member 27 can be smoothly inserted into the seal groove 26.

Then, by filling the adhesive 29 between the fastening portion 27a and each surface forming the seal groove 26, the seal member 27 is substantially held in a floating state with respect to the seal groove 26. Here, as the adhesive 29, an elastic adhesive is preferably used. This elastic adhesive has rubber-like elasticity in a cured state, and has a function of dispersing or absorbing internal stress by forming a tough and flexible elastic film.

Specifically, the sealing member 27 may be made of rubber (hardness 73 ± 3HS, elongation 250%) in which NBR and vinyl chloride are blended, and a silyl group-containing special polymer adhesive may be used as the adhesive 29. it can. The adhesive 29 has a strong adhesive force to rubber, and the adhesive force is generated about 7 minutes after application, so that the seal member 27 can be stably held inside the seal groove 26. Here, the silyl group-containing special polymer adhesive as the adhesive 29 has a hardness of about 44HS after curing, and its elongation rate is approximately 280%. The adhesive 29 has excellent weather resistance as a characteristic, and since the adhesive strength is maintained even in a high temperature and high humidity state and in a cold state, it is used for a machine operating outdoors such as a hydraulic excavator. It is extremely advantageous as an adhesive.

As described above, due to the dimensional difference (D2-D1) between the fastening portion 27a of the sealing member 27 and the sealing groove 26, the fastening portion 27a is formed in the sealing groove 26 with the entire surface of the fastening portion 27a and the sealing groove 26. A layer of adhesive 29 will be formed between the entire wall surface and the entire circumference of the wall surface. Therefore, when a force in the direction of pulling out from the seal groove 26 acts on the seal member 27 or a force acts in the direction parallel to the seal groove 26, the layer of the adhesive 29 bends. Disperses or absorbs this load. Further, not only the upper and lower surfaces of the fastening portion 27a but also the end faces are bonded, so that a wide bonding surface is secured. As a result, the adhesive surface between the fastening portion 27a and the adhesive 29 and between the adhesive 29 and the seal groove 26 does not peel off. Further, when the action of the external force on the sealing member 27 is released, the adhesive 29 is restored to the original state by the elastic restoring force.

Therefore, by repeatedly turning the upper swivel body 2, the seal member 27 slides with respect to the upper end surface 16b of the inner ring 16 and is drawn out from the seal groove 26, a direction parallel to the wall surface of the seal groove 26, and the like. Even if stresses in various directions act, the stresses are effectively dispersed or absorbed by the adhesive 29. As a result, the seal member 27 is held in a state of being fixed in the seal groove 26 extremely stably for a long period of time.

Since the thickness of the fastening portion 27a of the sealing member 27 is smaller than the groove width of the sealing groove 26, the work of fitting the fastening portion 27a into the sealing groove 26 becomes easy. It can be done easily and quickly. Further, since the center of gravity of the seal member 27 is on the fastening portion 27a side and the fastening portion 27a is located in the seal groove 26, even after the seal member 27 is attached, the adhesive force of the adhesive 29 is applied. Is not sufficiently exhibited, the seal member 27 is stably held in the seal groove 26.

However, since it takes some time for the adhesive force 29 to generate the adhesive force due to the curing, if an external force acts on the seal member 27 during that time, the adhesive force 29 may be displaced from the seal groove 26. To prevent this, the sealing member indicated by reference numeral 127 in FIG. 5 can be used. In this seal member 127, a ridge portion 127d protruding from both upper and lower side portions of the fastening portion 127a connected to the lip portion 127b is formed, and at the portion of the ridge portion 127d in the fastening portion 127a. The thickness dimension of the seal groove 26 is larger than the width dimension of the seal groove 26, and the ridge portion 127d reaches the insertion end position when the fastening portion 127a is inserted into the seal groove 26. It is designed to be inserted in. Therefore, when the seal member 127 is mounted in the seal groove 26, it is inserted from the calling portion 127c side, so that no particular difficulty occurs. Further, when the ridge portion 127d enters the seal groove 26, the resistance increases, but this increase in resistance makes it possible to recognize the end of the insertion work as a click feeling, so that the insertion depth of the fastening portion 127a It is advantageous in making it constant.

By the way, the adhesive 29 is applied in advance into the seal groove 26, and then the fastening portion 27a of the seal member 27 is inserted into the seal groove 26, so that the excess adhesive is pushed out from the seal groove 26 at this time. May leak to. Then, when it flows out to the surface of the lip portion 27b of the sealing member 27 on the side where the lubricant is sealed, it adheres to the surface of the steel ball 21 and the rolling surfaces 16a and 19a of the inner ring 16 and the outer ring 19, and is large during turning. Resistance will occur. When the seal member 27 is inserted while being pressed against the lower surface 26b of the seal groove 26, the excess adhesive wraps around to the opposite side, so that the adhesive does not flow out to the sealing side of the lubricant.

In order to more reliably prevent the adhesive from flowing out to the sealing side of the lubricant, the sealing member can be configured as shown by reference numeral 227 in FIG. That is, in the fastening portion 227a connected to the lip portion 227b, the convex curved portion 227d is formed on the surface of the lip portion 227b on the side receiving the lubricant. The convex curved portion 227d protrudes as shown by a virtual line in the figure in the free state, and therefore slides with the lower surface 26b of the seal groove 26 when the fastening portion 227a is inserted into the seal groove 26. As a result, the excess adhesive is extruded to the upper surface 26a side and does not wrap around to the sealing side of the lubricant.

<figref num="1">It is a front view of the hydraulic excavator as an example of a machine provided with a swivel device.</figref><figref num="2">It is sectional drawing of the main part of the swivel device mounted on the hydraulic excavator of FIG.</figref><figref num="3">It is an enlarged view of the main part of FIG.</figref><figref num="4">It is an enlarged sectional view of the seal member attached to the seal groove of the outer ring.</figref><figref num="5">It is sectional drawing which shows the modification of the seal member of FIG.</figref><figref num="6">It is sectional drawing which shows the further modification of the seal member of FIG.</figref>

Code description

1 Lower running body 2 Upper turning body 3 Swivel device 15 Swivel wheel 16 Inner ring 19 Outer ring 16a, 19a Rolling surface 16b, 19b Upper end surface 21 Steel ball 22 Swing hydraulic motor 23 Swivel pinion 24,26 Seal groove 25,27,127,227 Seal member 25a, 27a, 127a, 227a Stop 25b, 27b, 127b, 227b Lip part 28 Convex 29 Adhesive