JP2008025788A - Sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing device 1 having a main seal 2 sealing a sealing object, and an auxiliary seal 12 arranged in a sealing object side of the main seal 2 to remove foreign matter, wherein the auxiliary seal 12 can be provided side by side even when a sufficient fitting space is not secured in the main seal 2. <P>SOLUTION: The auxiliary seal 12 is provided side by side in an axial direction in a structure abutting axial end faces with the main seal 2, and a co-rotation preventing structure 21 suppressing co-rotation of the auxiliary seal 12 with respect to an axis 34 is provided in the auxiliary seal 12 and the main seal 2. For example, the co-rotation preventing structure comprises a protrusion 22 provided on either one axial end face of the auxiliary seal 12 or the main seal 2, and a groove-like recessed part 23 provided on an axial end face of the other, and it is structured to engage the protrusion 22 with the groove-like recessed part 23. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sealing device according to a sealing technique. The sealing device of the present invention is used as, for example, a sealing device for a robot or a speed reducer.

  Conventionally, oil seals for robots and reducers have gears inside the device, so when the lubricant is grease, many internal foreign matters such as gear wear powder are generated in the grease to be sealed. A seal may be damaged by a foreign object and leak may occur in a short period of time.

  For this reason, as shown in FIG. 9, an assembly seal 51 in which an auxiliary seal 53 for removing foreign matter is combined with the sealing target side A of the main seal 52 for sealing the sealed target has been developed as a countermeasure against foreign matters (see the following patent). According to this assembly seal 51, the auxiliary seal 53 removes the internal foreign matter, so that the main seal 52 can be prevented from being damaged by the internal foreign matter. The main seal 52 is integrally formed with a seal lip portion 52b slidably in close contact with the peripheral surface of the shaft 55 on the inner peripheral side of a cylindrical mounting portion 52a fixed (fitted) to the inner periphery of the shaft hole 54a of the housing 54. The auxiliary seal 53 is molded and slidable on the peripheral surface of the shaft 55 on the inner peripheral side of the cylindrical mounting portion 53a fixed (fitted) to the inner periphery of the mounting portion 52a of the main seal 52. The intimate foreign matter removal lip 53a is integrally formed.

  However, the assembly seal 51 of FIG. 9 has a structure in which the attachment portion 53a of the auxiliary seal 53 is fixed (fitted) to the inner periphery of the attachment portion 52a of the main seal 52 as described above. It is necessary to secure a fitting space (a space in the axial direction) of a certain size or more on the inner periphery of the mounting portion 52a. If the fitting space is not secured, the auxiliary seal 53 is assembled to the main seal 52. There is an inconvenience that cannot be done.

  As disclosed in Patent Document 3 below, the applicant of the present application first seals an annular gap between two members assembled so as to be movable relative to each other, and is provided integrally with a metal ring. The seal is fitted between the main seal and the seal lip that slides with other members, and the seal is sandwiched between the main seal and the bearing located on the sealing fluid side, and the seal tip slides on the bearing inner ring. A sealing device characterized by comprising a foreign matter removing member in contact therewith has been proposed, but this prior invention is different from the present invention because it does not have a co-rotation preventing structure or projection in the present invention. It is a content.

JP 2001-99330 A JP 2000-110946 A JP 2005-265078 A

  In view of the above points, the present invention can provide an auxiliary seal even when a sufficient fitting space is not ensured in the main seal, thereby removing foreign matters by the auxiliary seal and improving the durability of the main seal. It is an object of the present invention to provide a sealing device that can be used.

  In order to achieve the above object, a sealing device according to claim 1 of the present invention is a sealing device having a main seal that seals an object to be sealed, and an auxiliary seal that is disposed on the sealing object side of the main seal to remove foreign matter. The auxiliary seal is provided in the axial direction with a structure in which axial end faces are brought into contact with the main seal, and the auxiliary seal and the main seal are rotated together with the shaft. It is characterized in that a co-rotation preventing structure for suppressing the above is provided.

  According to a second aspect of the present invention, there is provided the sealing device according to the first aspect, wherein the co-rotation preventing structure includes a protrusion provided on an axial end surface of one of the auxiliary seal and the main seal, and the other. It is characterized by having a structure in which the projection and the groove-like recess are engaged with each other.

  According to a third aspect of the present invention, there is provided the sealing device according to the first aspect, wherein the co-rotation preventing structure is formed by a protrusion provided on the auxiliary seal, and the protrusion is arranged on the inner periphery of the mounting portion of the main seal. It has the structure fitted to the side.

  According to a fourth aspect of the present invention, there is provided a sealing device comprising: a main seal that seals an object to be sealed; and an auxiliary seal that is disposed on the sealing target side of the main seal and removes foreign matter. In order to prevent co-rotation due to the above, a structure is provided in which a projection is provided on the main seal side of the auxiliary seal and assembled to the main seal.

  The sealing device according to claim 5 of the present invention is the sealing device according to any one of claims 1 to 4, wherein the auxiliary seal includes an axial end surface of the main seal and an axial end surface provided on the housing. It has the structure hold | maintained in the state pinched | interposed between these.

  Furthermore, a sealing device according to claim 6 of the present invention is the sealing device according to any one of claims 1 to 5, wherein the sealing device is used as an oil seal for a robot or a speed reducer, and is to be sealed. It is characterized in that the auxiliary seal removes the gear wear powder mixed into the grease as foreign matter.

  Rather than fitting the auxiliary seal to the inner peripheral side of the main seal mounting portion, if the axial end surfaces of both seals are abutted against each other in the axial direction, the main seal mounting portion Even when a sufficient fitting space is not secured on the inner peripheral side, it is possible to provide an auxiliary seal. However, simply placing the auxiliary seals in the axial direction may cause the auxiliary seals to rotate around the shaft due to insufficient fitting load. It was decided to provide a co-rotation prevention structure that restrains the seal from co-rotating with respect to the shaft.

  As an aspect of the co-rotation prevention structure, there is a structure in which a protrusion provided on one axial end face of the auxiliary seal or the main seal is engaged with a groove-like recess provided on the other axial end face, or an auxiliary seal. A structure that fits the provided protrusion to the inner peripheral side of the main seal mounting part is suitable, or a protrusion is provided on the main seal side of the auxiliary seal and assembled to the main seal to prevent co-rotation due to a small fitting load. A structure may be used, and in any case, it is possible to effectively prevent the auxiliary seal from co-rotating. If the auxiliary seal is held between the axial end surface of the main seal and the axial end surface provided on the housing, the auxiliary seal is pressed against the axial end surface of the housing by the main seal. Thus, this also suppresses the co-rotation of the auxiliary seal.

  The sealing device of the present invention having the above contents is used as, for example, an oil seal for a robot or a speed reducer. In this case, the auxiliary seal removes gear wear powder mixed in the grease to be sealed as a foreign matter.

  The present invention has the following effects.

  That is, in each of the sealing devices according to claims 1 to 3 of the present invention, the auxiliary seals are not fitted to the inner peripheral side of the main seal mounting portion, but are structured such that the axial end surfaces of both seals are abutted against each other. Since it is provided in the axial direction, it is possible to provide an auxiliary seal even when a sufficiently large fitting space is not ensured on the inner peripheral side of the mounting portion of the main seal. Therefore, as the intended purpose of the present invention, even when a sufficient fitting space cannot be secured for the main seal, an auxiliary seal can be provided, so that the auxiliary seal can remove foreign matter and improve the durability of the main seal. it can. In addition, since the auxiliary seal and the main seal are provided with the co-rotation preventing structure, it is possible to effectively prevent the auxiliary seal from co-rotating with respect to the shaft.

  Further, in the sealing device according to claim 4 of the present invention, in order to prevent co-rotation due to a small fitting load, a projection is provided on the main seal side of the auxiliary seal and assembled to the main seal. Similarly, a structure in which an auxiliary seal is provided in the axial direction with respect to the main seal is realized. Further, since the protrusion is assembled to the main seal, the auxiliary seal is prevented from rotating together.

  In addition to the above, in claim 5 of the present invention, the auxiliary seal is held in a state of being sandwiched between the axial end surface of the main seal and the axial end surface provided in the housing. Therefore, the auxiliary seal can be prevented from rotating together.

  Furthermore, in the sixth aspect of the present invention, the effects of the present invention according to the first to fifth aspects can be obtained in the field of oil seals for robots or speed reducers.

  Next, embodiments of the present invention will be described with reference to the drawings.

First embodiment ...
FIG. 1 shows a cross section of a main part of a sealing device 1 according to a first embodiment of the present invention.

  The sealing device 1 according to this embodiment is used as an oil seal for a robot or an oil seal for a speed reducer, and is mounted for the purpose of sealing lubricating grease filled in the device of the robot or the speed reducer. Another object of the present invention is to seal the gear wear powder so that it does not reach the main seal 2 because the gear wear powder is generated in the mechanism.

  The sealing device 1 includes a main seal 2 that seals the lubricating grease that is to be sealed, and an auxiliary seal 12 that is disposed on the sealing target side A of the main seal 2 and seals the gear wear powder that is foreign matter. The auxiliary seal 12 is provided in the axial direction in a structure in which the end faces in the axial direction are abutted against the main seal 2. The auxiliary seal 12 and the main seal 2 are provided with a co-rotation prevention structure 21 for suppressing the auxiliary seal 12 from co-rotating with respect to the shaft 34. The co-rotation prevention structure 21 is a combination of a protrusion 22 provided on the axial end face of the auxiliary seal 12 and a groove-like recess 23 provided on the axial end face of the main seal 2. The structure is engaged. The sealing device 1 has a structure in which a protrusion 22 is provided on the main seal 2 side of the auxiliary seal 12 and is assembled to the main seal 2 to prevent co-rotation due to a small fitting load. It is configured to be held in a state of being sandwiched between an axial end surface of the main seal 2 and an axial end surface portion 33 provided in the housing 31.

  Details of each part or each part are set as follows.

  That is, first, the main seal 2 has a cylindrical (annular) attachment portion 3 for attaching the main seal 2 to the inner periphery of the shaft hole 32 of the housing 31. An annular seal lip portion 5 that is slidably in close contact with the peripheral surface (outer peripheral surface) of the shaft (rotary shaft) 34 is provided via the connecting portion (lip holding portion) 4. As viewed from the connecting portion 4, the mounting portion 3 is provided toward one side in the axial direction (inner side, that is, the sealing target side A), and the seal lip portion 5 is also provided toward one side in the axial direction. As a result, the main seal 2 Is formed in a substantially U-shaped cross section. The main seal 2 is fitted as a component to a metal ring 6, a rubber-like elastic body 7 attached to the metal ring 6, and a seal lip 5 a that is a part of the rubber-like elastic body 7. The garter spring 8 is provided.

  The metal ring 6 is radially inward at the end of the cylindrical portion 6a fitted to the inner periphery of the shaft hole 32 of the housing 31 and the other axial end of the cylindrical portion 6a (the outside of the machine, that is, the atmosphere side B). It has integrally the flange part 6b integrally molded toward. The rubber-like elastic body 7 is attached to the outer peripheral surface of the cylindrical portion 6 a of the metal ring 6 and seals between the metal ring 6 and the housing 31, and an outer peripheral surface attached portion (outer peripheral seal portion) 7 a and the cylindrical portion 6 a. A tip end surface adhering portion 7b attached to the tip end surface, an inner peripheral surface adhering portion 7c attached to the inner peripheral surface of the tubular portion 6a, and one axial end surface (inner end surface) of the flange portion 6b. ) Applied to the inner end face attached portion 7d attached to the inner peripheral end of the flange portion 6b, and the other end face (outer end face) in the axial direction of the flange portion 6b. A seal lip (main lip) 5a for sealing grease is integrally provided in the axial direction as the seal lip portion 5 so as to integrally remove external dust. A dust lip (second lip) 5b to be sealed is integrally provided toward the other side in the axial direction.

  The auxiliary seal 12 has a flat plate-like attachment portion 13 for attaching the auxiliary seal 12, and an annular foreign substance that is slidably in close contact with the peripheral surface of the shaft 34 on the inner peripheral side of the attachment portion 13. A removal lip 15 is provided. The foreign matter removal lip 15 is provided radially inward from the inner peripheral end of the mounting portion 13, and the inner peripheral end thereof is directed in one axial direction like the seal lip 5 a. The auxiliary seal 12 has a metal ring 16 and a rubber-like elastic body 17 attached to the metal ring 16 as its component parts.

  The metal ring 16 is formed as a flat annular body. The rubber-like elastic body 17 includes an outer peripheral end attached portion 17a attached to the outer peripheral end of the metal ring 16, and an inner end face attached portion 17b attached to one end surface (inner end surface) in the axial direction of the metal ring 16. And an inner peripheral end attached portion 17c attached to the inner peripheral end of the metal ring 16 and an outer end face attached portion 17d attached to the other axial end surface (outer end surface) of the metal ring 16. Further, the foreign matter removing lip 15 is integrally provided.

  The auxiliary seal 12 is provided side by side in the axial direction on one side of the main seal 2 in the axial direction so that the end faces in the axial direction abut against the main seal 2 as illustrated. Axial end faces against each other are end faces of the attachment portion 3 on the main seal 2 side, and more specifically, end faces of the rubber-like elastic body 7 in the attachment portion 3, and tips of the rubber-like elastic body 7. It is an end surface of the surface adherent portion 7b. On the other hand, on the auxiliary seal 12 side, it is an end surface of the attachment portion 13, and more specifically, an end surface of the rubber-like elastic body 17 in the attachment portion 13, and an end surface of the outer end face attached portion 17d in the rubber-like elastic body 17. It is. Thus, since the auxiliary seal 12 is provided along the axial direction with respect to the main seal 2, the auxiliary seal 12 is provided even if there is no sufficient fitting space on the inner peripheral side of the mounting portion 3 of the main seal 2. Is possible.

  The sealing device 1 is provided with a co-rotation preventing structure 21 between the auxiliary seal 12 and the main seal 2 so that the auxiliary seal 12 does not co-rotate with respect to the shaft 34.

  As shown in an enlarged view in FIG. 2, the co-rotation preventing structure 21 includes a combination of a protrusion 22 provided on the axial end surface of the auxiliary seal 12 and a groove-shaped recess 23 provided on the axial end surface of the main seal 2. Therefore, both 22 and 23 are engaged. As described above, on the auxiliary seal 12 side, the end face of the mounting portion 13 is abutted against each other, more specifically, the end surface of the rubber-like elastic body 17 in the mounting portion 13 and the outer end face coverage of the rubber-like elastic body 17. Since it is the end face of the attaching portion 17d, the protrusion 22 is the end face of the attaching portion 13, more specifically, the end face of the rubber-like elastic body 17 in the attaching portion 13, and the outer end face attaching portion 17d in the rubber-like elastic body 17. Projecting toward the other end in the axial direction. Further, on the main seal 2 side, the end surface of the mounting portion 3 is abutted against each other, more specifically, the end surface of the rubber-like elastic body 7 in the mounting portion 3 and the tip-face-attached portion of the rubber-like elastic body 7. 7b, the recess 23 is the end surface of the attachment portion 3, more specifically, the end surface of the rubber-like elastic body 7 in the attachment portion 3, and the end surface of the tip-surface-attached portion 7b in the rubber-like elastic body 7. Are provided so as to open toward one side in the axial direction. Therefore, the structure 21 is such that a protrusion 22 made of rubber engages with a recess 23 that is also formed of rubber.

  Further, if the protrusion 22 and the groove-like recess 23 are structured so that they are press-fitted together, even if both of them are annular, they exhibit the joint rotation preventing effect, but a plurality of both are provided on the circumference and engaged with each other. Since both engage in the circumferential direction, the co-rotation preventing effect can be further increased. Accordingly, in this embodiment, a plurality of protrusions 22 are equally arranged on the circumference, and the same number of groove-like recesses 23 as the protrusions 22 are equally formed on the circumference as shown in FIG. However, the illustrated six-spot arrangement is merely an example, and the number of formations is not particularly limited. In any case, when the co-rotation prevention structure 21 is provided in this way, the main seal 2 is tightly fitted to the inner periphery of the shaft hole 32 of the housing 31 and is prevented from rotating, so that the auxiliary seal 12 is interposed via the main seal 2. Is also prevented from rotating relative to the housing 31. Therefore, as a result, it is possible to effectively prevent the auxiliary seal 12 from rotating together with the shaft 34.

  Further, when the auxiliary seal 12 is assembled to the main seal 2 by engaging the protrusion 22 and the recess 23 as described above, both the seals 2 and 12 are made into an integral assembly. Accordingly, both the seals 2 and 12 can be handled as an integral assembly seal even if they are arranged side by side in the axial direction.

  The auxiliary seal 12 is assembled to the main seal 2 and attached to the housing 31 via the main seal 2. Since the auxiliary seal 12 is arranged side by side with the main seal 2 in the axial direction, the auxiliary seal 12 is fitted to the housing 31 by itself. In this case, the auxiliary seal 12 is held not only by the main seal 2 but also by the housing 31. Therefore, since it is held by both the main seal 2 and the housing 31, a larger co-rotation preventing effect can be obtained.

  Furthermore, as shown in FIG. 4, the sealing device 1 can be mounted on the inner peripheral surface of the axial hole (cylindrical surface shape) of the housing 31 in the axial direction. 1, the auxiliary seal 12 is mounted between the axial end surface of the main seal 2 and the axial end surface portion 33 provided on the housing 31. It is held in a state of being sandwiched between. Accordingly, the main seal 2 is pressed against the axial end surface portion 33 of the housing 31 and is sandwiched between the axial end surface portion of the main seal 2 and the axial end surface portion 33 of the housing 31. In addition, it is possible to obtain a greater co-rotation preventing effect.

  In the present invention, the configuration of the co-rotation prevention structure 21 is not limited to the above embodiment, and may be as follows, for example.

Second embodiment ...
That is, as shown in FIG. 5, the auxiliary seal 12 is provided with a projection 22 having a relatively large volume as a fitting portion, and this projection 22 is fitted to the inner peripheral side of the mounting portion 3 of the main seal 2 from one axial direction. The protrusion 22 is the end surface of the mounting portion 13 of the auxiliary seal 12 as in the case of the first embodiment, more specifically, the end surface of the rubber-like elastic body 17 in the mounting portion 13 and the outer end surface of the rubber-like elastic body 17. Although it protrudes toward the other end in the axial direction on the end surface of the adherend portion 17d, it is fitted on the inner peripheral side of the mounting portion 3 of the main seal 2, so that it is disposed on the inner peripheral side from the abutting surface. Yes. Since the protrusion 22 is a rubber protrusion, and the rubber-like elastic body 7 (inner peripheral surface attached portion 7c) is attached to the inner peripheral side of the mounting portion 3 of the main seal 2, the structure 21 is made of rubber materials. It becomes a fitting. In addition, the protrusions 22 are formed into an annular shape (cylindrical shape) from the viewpoint of setting the strength and fitting allowance to be large, but the protrusions 22 do not necessarily have an annular shape, and have a structure in which a plurality of them are equally formed on the circumference. May be. In any case, when the protrusion 22 is provided and fitted to the inner peripheral side of the main seal 2, the main seal 2 is tightly fitted to the inner periphery of the shaft hole 32 of the housing 31 and is prevented from rotating. The auxiliary seal 12 is also prevented from rotating with respect to the housing 31 via the seal 2. Therefore, as a result, it is possible to effectively prevent the auxiliary seal 12 from rotating together with the shaft 34.

Third embodiment ...
Further, in the case of fitting the protrusions 22, when the rubber material and the metal material are fitted together instead of fitting the rubber materials, as shown in FIG. The metal ring 6 is exposed on the surface by omitting the inner peripheral surface adherent portion 7c of the elastic body 7, and the protrusion 22 is fitted therein. In this case, the protrusion 22 is directly fitted to the inner peripheral surface of the cylindrical portion 6 a of the metal ring 6.

  Further, the sealing device 1 according to the second or third embodiment can also be mounted on the inner peripheral surface of the axial hole 31 of the axially straight housing 31 (see FIGS. 7 and 8).

Sectional drawing of the principal part of the sealing device which concerns on 1st Example of this invention. Illustration of co-rotation prevention structure in the same sealing device Explanatory drawing which is a C direction arrow view in FIG. 2, and shows the example of arrangement | positioning of the groove-shaped recessed part in the sealing device Sectional drawing which shows the other example of the housing structure which mounts the sealing device Sectional drawing of the principal part of the sealing device which concerns on 2nd Example of this invention. Sectional drawing of the principal part of the sealing device which concerns on 3rd Example of this invention. Sectional drawing which shows the other example of the housing structure which mounts | wears with the sealing device which concerns on 2nd Example of this invention. Sectional drawing which shows the other example of the housing structure which mounts | wears with the sealing device which concerns on 3rd Example of this invention. Sectional drawing of the principal part of the sealing device which concerns on a prior art example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sealing device 2 Main seal 3,13 Attachment part 4 Connection part 5 Seal lip part 5a Seal lip 5b Dustrip 6,16 Metal ring 6a Cylindrical part 6b Flange part 7,17 Rubber-like elastic body 7a Outer peripheral surface adherence part 7b Tip end surface adhering portion 7c Inner peripheral surface adhering portion 7d, 17b Inner end surface adhering portion 7e, 17c Inner end end adhering portion 7f, 17d Outer end surface adhering portion 8 Garter spring 12 Auxiliary seal 15 Foreign matter removing lip 17a Outer end Adhering part 21 Co-rotation prevention structure 22 Protrusion 23 Groove-shaped recess 31 Housing 32 Axle hole 33 Axial end face part 34 Axis A Sealing target side B Atmosphere side

Claims (6)

In a sealing device (1) having a main seal (2) for sealing an object to be sealed, and an auxiliary seal (12) arranged on the sealing object side (A) of the main seal (2) to remove foreign matter,
The auxiliary seal (12) is provided side by side in the axial direction in a structure in which axial end faces are abutted against the main seal (2),
The auxiliary seal (12) and the main seal (2) are provided with a co-rotation prevention structure (21) for suppressing the auxiliary seal (12) from co-rotating with respect to the shaft (34). A sealing device characterized. The sealing device according to claim 1.
The co-rotation preventing structure (21) includes a protrusion (22) provided on one axial end face of the auxiliary seal (12) and the main seal (2), and a groove-shaped recess (23 provided on the other axial end face. ), And has a structure for engaging the projection (22) with the groove-shaped recess (23). The sealing device according to claim 1.
The co-rotation prevention structure (21) includes a protrusion (22) provided on the auxiliary seal (12), and the protrusion (22) is fitted to the inner peripheral side of the mounting portion (3) of the main seal (2). A sealing device characterized by comprising: In a sealing device (1) having a main seal (2) for sealing an object to be sealed, and an auxiliary seal (12) arranged on the sealing object side (A) of the main seal (2) to remove foreign matter,
In order to prevent co-rotation due to a small fitting load, the auxiliary seal (12) is provided with a protrusion (22) on the main seal (2) side and assembled to the main seal (2). The sealing device according to any one of claims 1 to 4,
The auxiliary seal (12) has a structure that is held in a state of being sandwiched between the axial end face of the main seal (2) and the axial end face (33) provided in the housing (31). Sealing device. The sealing device according to any one of claims 1 to 5,
The sealing device (1) is used as an oil seal for a robot or a speed reducer, and has a structure in which the auxiliary seal (12) removes gear wear powder mixed in the grease to be sealed as foreign matter. Sealing device.

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