Device with a sealing mechanism

Abstract

To provide a device having a seal mechanism which can suppress eccentricity of a slinger after assembling.SOLUTION: A device 100 comprises a shaft member 2, a case 3 for accommodating at least a part of the shaft member 2, and a seal mechanism 4 for sealing a clearance between the shaft member 2 and the case 3. The seal mechanism 4 comprises a slinger 5 arranged at an external peripheral face of the shaft member 2, and a seal member 6 arranged between the case 3 and the slinger 5. The slinger 5 comprises a cylindrical part 51 and a flange part 52 protruding toward the shaft member 2 from the cylindrical member 51. An elastic member 56 which is smaller than the flange part 52 in an elasticity coefficient is arranged between the cylindrical part 51 and the shaft part 2, and the flange part 52 abuts on the shaft member 2 in a radial direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an apparatus provided with a sealing mechanism.

Background Art

[0002] An apparatus provided with a sealing mechanism for sealing between a shaft member and a case is known. For example, Patent Document 1 describes an apparatus provided with a seal having a sealing member and a slinger surrounded by the sealing member. This sealing mechanism includes a slinger provided on the outer peripheral surface of the shaft member and a sealing member provided between the case and the slinger. The slinger has a flange portion located inside the shaft member from the cylindrical portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present inventor has obtained the following recognition regarding an apparatus provided with a sealing mechanism. In the sealing mechanism, uneven wear of the oil seal lip is considered as a factor in the deterioration of the sealing function for suppressing leakage of the lubricant. In order to suppress uneven wear of the lip, it is important to improve the press-fitting accuracy and reduce the eccentricity of the slinger after assembly. However, in the sealing mechanism described in Patent Document 1, the inside of the slinger is an elastic body and the gap between the metal portion of the slinger and the shaft member is large. In this structure, the seal is assembled in a tilted state, and the eccentricity of the slinger after assembly becomes large.

[0005] In view of such circumstances, one object of the present invention is to provide an apparatus provided with a sealing mechanism capable of suppressing the eccentricity of the slinger after assembly.

Means for Solving the Problems

[0006] In order to solve the above problems, an apparatus according to an aspect of the present invention includes a shaft member, a case that houses at least a part of the shaft member, and a sealing mechanism that seals between the shaft member and the case. The sealing mechanism includes a slinger provided on an outer peripheral surface of the shaft member and a sealing member provided between the case and the slinger. The slinger includes a cylindrical portion and a flange portion that protrudes from the cylindrical portion toward the shaft member. An elastic member having an elastic coefficient smaller than that of the flange portion is provided between the cylindrical portion and the shaft member, and the flange portion abuts against the shaft member in the radial direction.

Effects of the Invention

[0007] According to the present invention, it is possible to provide an apparatus including a sealing mechanism capable of suppressing eccentricity of the slinger after assembly.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

[0009] Hereinafter, the present invention will be described with reference to the drawings based on preferred embodiments. In the embodiments and modification examples, the same or equivalent components and members are denoted by the same reference numerals, and redundant descriptions are appropriately omitted. In addition, the dimensions of the members in each drawing are appropriately enlarged or reduced for easy understanding. In addition, a part of the members that are not important for explaining the embodiments in each drawing is omitted and shown.

[0010] Also, terms including ordinal numbers such as first and second are used to describe various components, but this term is used only for the purpose of distinguishing one component from another, and the components are not limited by this term.

[0011] [First Embodiment] Hereinafter, with reference to the drawings, the configuration of the seal mechanism 4 according to the first embodiment will be described. FIG. 1 is a side sectional view showing an apparatus 100 to which the seal mechanism 4 according to the first embodiment of the present invention is applied. The apparatus 100 includes a shaft member 2, a case 3, a seal mechanism 4, and a bearing 8. The case 3 houses at least a part of the shaft member 2. The case 3 may be formed substantially coaxially with the shaft member 2.

[0012] The seal mechanism 4 seals between the shaft member 2 and the case 3. The seal mechanism 4 includes a slinger 5 provided on the outer peripheral surface 22 of the shaft member 2, and a seal member 6 provided between the case 3 and the slinger 5. As an example, the apparatus 100 may be a speed reducer or an eccentric swing type speed reducer. In this case, the shaft member 2 corresponds to a carrier, the case 3 corresponds to a cylindrical casing that covers the outer periphery of the carrier, and the bearing 8 corresponds to a main bearing.

[0013] Hereinafter, the direction along the central axis line La of the shaft member 2 of the apparatus 100 is referred to as the "axial direction", and the circumferential direction and the radial direction of a circle centered on the central axis line La are referred to as the "circumferential direction" and the "radial direction", respectively. The central axis line La in this example coincides with the rotation axis line of the shaft member 2. A bearing 8 is provided between the case 3 and the shaft member 2. The shaft member 2 is disposed in the case 3 and is supported so as to be relatively rotatable with respect to the case 3.

[0014] In the present embodiment, at least one of the shaft member 2 and the case 3 rotates around the rotation axis line La. For example, the case 3 may be fixed and the shaft member 2 may rotate, or the shaft member 2 may be fixed and the case 3 may rotate.

[0015] In this embodiment, the case 3 forms an internal space that houses part or all of the shaft member 2. In the internal space of the case 3, various components used in a part of the apparatus 100 may be housed together with the shaft member 2. As an example, in the internal space of the case 3, a gear component or the like that can be connected to the shaft member 2 may be arranged, but it is not limited thereto.

[0016] The bearings 8 are arranged on one axial side and the other axial side of the case 3 and the shaft member 2. The bearing 8 has a plurality of rolling elements 82 arranged at intervals in the circumferential direction. In the example of FIG. 1, the inner ring side rolling surface 83 of the bearing 8 is formed on the outer peripheral surface of the shaft member 2, and the outer ring side rolling surface 842 is formed on the outer ring 84 fitted into the inner peripheral surface of the case 3. That is, the outer ring 84 of the bearing 8 is formed separately from the case 3. A lubricant (not shown) is held in the bearing 8.

[0017] In the space between the case 3 and the shaft member 2, the region where the bearing 8 that holds the lubricant is arranged and sealed by the seal mechanism 4 is referred to as the "lubricant holding space J". Also, in the axial direction, the direction away from the lubricant holding space J is referred to as "outer side", and the opposite direction is referred to as "inner side". Also, the inner and outer ends of the member are referred to as "inner end" and "outer end". Also, in the ventilation path from the lubricant holding space J to the external space of the apparatus 100, the side closer to the lubricant holding space J is referred to as "inner side", and the opposite side is referred to as "outer side".

[0018] FIG. 2 is an enlarged view of the seal mechanism 4 of this embodiment. This figure shows a cross-section cut along the radial direction. The seal mechanism 4 includes a seal member 6 that seals the gap formed between the shaft member 2 and the case 3, and a slinger 5. In particular, in the seal mechanism 4, the seal member 6 contacts the slinger 5, thereby sealing the gap between the case 3 and the shaft member 2. The slinger 5 may be adhered to the shaft member 2.

[0019] The slinger 5 is positioned between the shaft member 2 and the case 3. The slinger 5 of the present embodiment is inserted into the shaft member 2. The slinger 5 is an annular member located radially outward from the shaft member 2. The slinger 5 will be described later.

[0020] The seal member 6 has a lip portion 62 and a lip support portion 63. By contacting the slinger 5, the lip portion 62 forms a seal between the case 3 and the slinger 5. The lip support portion 63 is an annular portion that fits onto the inner peripheral surface 32 of the case 3 and supports the lip portion 62 on the inner peripheral side of the lip support portion 63. The lip portion 62 extends radially from the lip support portion 63 toward the outer peripheral surface 512 of the slinger 5. In this example, the seal member 6 is detachably attached to the case 3 on the outer side in the axial direction of the slinger 5.

[0021] The lip portion 62 may include a plurality of elastically deformable lips. In this example, the lip portion 62 includes a main lip 623 and a dust lip 624 for contacting the outer peripheral surface 512 of the slinger 5. The main lip 623 functions as a main lip capable of suppressing the leakage of the lubricant in the lubricant holding space J to the outside. The dust lip 624 functions as a dust lip that suppresses the leakage of the lubricant in the lubricant holding space J to the outside and also suppresses the intrusion of foreign matter from the outside into the lubricant holding space J.

[0022] The lip portion 62 has a spring ring 625. The spring ring 625 is an annular member provided on the outer periphery of the main lip 623. The spring ring 625 surrounds the main lip 623 and applies a force toward the center of the shaft member 2 to the main lip 623. With this configuration, the main lip 623 adheres closely to the outer peripheral surface 512 of the cylindrical portion 51, and a sealing function is generated between the main lip 623 and the cylindrical portion 51. The dust lip 624 abuts against the outer peripheral surface 512 of the cylindrical portion 51 of the slinger 5.

[0023] The lip support portion 63 has an elastic portion 632 and a rigid portion 631. The rigid portion 631 functions as a core material that maintains the shape of the elastic portion 632 within a certain range. The rigid portion 631 can be composed of a metal material such as an iron-based metal, a non-metal material such as a hard plastic, a composite material of these, etc. The rigid portion 631 is an annular member with an L-shaped cross-section cut along the radial direction. The rigid portion 631 has a hollow disk-shaped disk portion and a hollow cylindrical cylindrical portion extending axially inward from the outer periphery of the disk portion. The elastic portion 632 covers the entire rigid portion 631. The elastic portion 632 is formed of a soft resin material such as rubber. The lip portion 62 is integrally formed with the elastic portion 632 of the lip support portion 63.

[0024] (Slinger) The slinger 5 includes a cylindrical portion 51 and a flange portion 52 located radially inward of the shaft member 2 from the cylindrical portion 51. The cylindrical portion 51 of this example has a cylindrical shape with substantially coaxial outer peripheral surface 512 and inner peripheral surface 513. The cylindrical portion 51 may have an arbitrary shape.

[0025] An elastic member 56 having a smaller elastic modulus than the flange portion 52 is provided between the cylindrical portion 51 and the shaft member 2. The elastic member 56 of this example has a cylindrical shape with substantially coaxial outer peripheral surface 562 and inner peripheral surface 563. The cylindrical portion 51 may have an arbitrary shape. In a state before being inserted into the slinger 5 (hereinafter referred to as the "non-inserted state"), the outer peripheral surface 562 may have the same diameter as or be slightly larger than the inner peripheral surface 513 of the cylindrical portion 51. In a state where the slinger 5 is inserted (hereinafter referred to as the "inserted state"), the outer peripheral surface 562 may be in close contact with the inner peripheral surface 513. The elastic member 56 may be crushed in the radial direction in the inserted state. The elastic member 56 may be, for example, an adhesive with adhesiveness. In this case, in order to reduce the bleeding of the adhesive to areas other than the flange portion 52, the adhesive may be attached to a part of the region.

[0026] The flange portion 52 abuts against the shaft member 2 in the radial direction. The flange portion 52 and the shaft member 2 may be a shrink fit with an interference, a clearance fit with a slight clearance without an interference, or an intermediate fit. The clearance in the case of a clearance fit can be set according to the allowable amount of eccentricity of the slinger 5 after assembly. The flange portion 52 has an overhanging shape that projects radially inward from the inner peripheral surface 513 of the cylindrical portion 51. The radial thickness of the flange portion 52 may be smaller than the radial thickness of the elastic member 56 in the uninserted state. In this case, in the inserted state, the elastic member 56 is elastically deformed in the radial direction and has a shape conforming to the shape of the outer peripheral surface 22 of the shaft member 2.

[0027] When inserting the shaft member 2 into the slinger 5, of the both axial sides of the slinger 5, the side that first contacts the shaft member 2 is referred to as the "insertion side", and the opposite side is referred to as the "anti-insertion side". In other words, the "insertion side" can also be said to be the inner side of the device (the side closer to the space filled with the lubricant), and the "anti-insertion side" is the outer side of the device. In the example of FIG. 2, the flange portion 52 includes a first flange portion 53 disposed on the insertion side of the elastic member 56. In this case, the highly accurate flange portion 52 contacts the shaft member 2 before the elastic member 56, and when both are substantially centered, the elastic member 56 contacts the shaft member 2, so that the elastic member 56 contacts substantially evenly in the circumferential direction, and non-uniform deformation in the circumferential direction can be avoided.

[0028] Further, the flange portion 52 includes a second flange portion 54 disposed on the anti-insertion side of the elastic member 56. The flange portion 52 may be provided away from the end of the cylindrical portion 51, but in this example, the first flange portion 53 and the second flange portion 54 are provided at the end of the cylindrical portion 51. That is, the first flange portion 53 and the second flange portion 54 are disposed at both axial ends of the cylindrical portion 51. In this case, since the flange portions contact the shaft member 2 on both axial sides of the elastic member 56, the elastic member 56 contacts the shaft member 2 substantially uniformly in the axial direction, and non-uniform deformation in the axial direction can be avoided.

[0029] When inserting the shaft member 2 into the flange portion 52, it is desirable that they be inserted in a state where they are generally centered. For this reason, the flange portion 52 is provided with a guide taper portion 522 that serves as a guide during insertion. In this case, since the slinger 5 is centered with respect to the shaft member 2, the eccentricity of the slinger after assembly can be reduced. From the perspective of ensuring the centering function, chamfering (for example, about 0.1 mm) for removing burrs and flash is insufficient. According to investigations, it is suggested that the axial size of the taper portion 522 is preferably 0.5 mm or more, and more preferably 0.7 mm or more. In this embodiment, the axial size of the taper portion 522 is set to 0.7 mm to 1.5 mm.

[0030] Also, according to investigations, it is suggested that the inclination of the taper portion 522 with respect to the central axis line La is preferably 45° or less, and more preferably 35° or less. In this embodiment, the inclination of the taper portion 522 with respect to the central axis line La is set to 25° to 35°. That is, it is preferable that the axial size of the taper portion 522 is longer than the radial size of the taper portion 522.

[0031] In this embodiment, the taper portion 522 is provided at the corner portions on the inner peripheral side of both ends of the first flange portion 53 and the second flange portion 54. In this example, the axial size of the taper portion 522 is larger than the axial size of the other chamfered portions 523 on the inner peripheral side of the first flange portion 53 and the second flange portion 54.

[0032] For example, since the slinger of Patent Document 1 is asymmetric in the axial direction and the insertion direction is limited to one direction, there is a risk that defective products due to incorrect insertion with the wrong insertion direction will flow into the market. On the other hand, in the slinger 5 of this embodiment, since the taper portion 522 is provided at the outer corner portions of the first flange portion 53 and the second flange portion 54, the shaft member 2 can be inserted from the first flange portion 53 and can also be inserted from the second flange portion 54. For this reason, there is almost no risk of defective products due to incorrect insertion flowing out. Also, since the insertion work can be performed without worrying about the orientation of the slinger 5, the working man-hours can be reduced.

[0033] It is desirable that the axial position of the slinger 5 with respect to the shaft member 2 be constant. Therefore, in the present embodiment, the slinger 5 is restricted from moving axially inward with respect to the shaft member 2 by the flange portion 52. In the example of FIG. 2, the shaft member 2 has an abutting wall portion 23 that extends radially outward from the outer peripheral surface 22, and the first flange portion 53 of the slinger 5 abuts against the abutting wall portion 23. In this case, the positional accuracy is higher than that of the configuration restricted by the elastic member 56, and the radial dimension of the abutting wall portion 23 can be made smaller than that of the configuration restricted by the cylindrical portion 51. The abutting wall portion 23 may be a wall portion of a radially convex portion or a wall portion of a stepped portion. The radially outer position of the abutting wall portion 23 may be radially inner than the outer periphery of the flange portion 52. In the example of FIG. 2, the radially outer position of the abutting wall portion 23 is radially outer than the outer periphery of the flange portion 52 and radially inner than the chamfer on the outer peripheral surface on the insertion side of the cylindrical portion 51.

[0034] Referring to FIGS. 1 and 2, the outer peripheral surface 22 of the shaft member 2 will be described. As described above, the present embodiment has a bearing 8 disposed between the shaft member 2 and the case 3. The outer peripheral surface 22 of the shaft member 2 has an inner ring side rolling surface 83 of the rolling element 82 of the bearing 8, a slinger arrangement surface 24 on which the slinger 5 is disposed, and a connection surface 25 provided between the inner ring side rolling surface 83 and the slinger arrangement surface 24. In the example of FIG. 2, the outer diameter of the slinger arrangement surface 24 is smaller than the outer diameter of the connection surface 25. In this case, it is possible to prevent the slinger 5 from entering the connection surface 25 beyond the slinger arrangement surface 24. Further, in the example of FIG. 2, the outer diameter of the outer peripheral surface 512 of the cylindrical portion 51 of the slinger 5 is larger than the outer diameter of the connection surface 25. In this case, the gap between the inner peripheral surface 32 of the case 3 and the outer peripheral surface 512 of the cylindrical portion 51 of the slinger 5 can be narrowed to improve the sealing performance.

[0035] The features of the device 100 of the present embodiment configured as described above will be described. The device 100 is a device including a shaft member 2, a case 3 that houses at least a part of the shaft member 2, and a sealing mechanism 4 that seals between the shaft member 2 and the case 3. The sealing mechanism 4 includes a slinger 5 provided on the outer peripheral surface 22 of the shaft member 2, and a sealing member 6 provided between the case 3 and the slinger 5. The slinger 5 includes a cylindrical portion 51 and a flange portion 52 that protrudes from the cylindrical portion 51 toward the shaft member 2. An elastic member 56 having an elastic coefficient smaller than that of the flange portion 52 is provided between the cylindrical portion 51 and the shaft member 2. The flange portion 52 is in radial contact with the shaft member 2.

[0036] According to this configuration, since the flange portion 52 is in radial contact with the shaft member 2, the inclination of the slinger 5 with respect to the shaft member 2 can be reduced and the eccentricity of the slinger 5 after assembly can be made smaller than in a configuration where they are not in contact.

[0037] [Second Embodiment] Next, a second embodiment of the present invention will be described. In the drawings and description of the second embodiment, the same or equivalent components and members as those in the first embodiment are denoted by the same reference numerals. Descriptions overlapping with those of the first embodiment will be omitted as appropriate, and configurations different from those of the first embodiment will be mainly described.

[0038] The second embodiment of the present invention is also a device including a sealing mechanism. FIG. 3 is an enlarged view showing the sealing mechanism according to the second embodiment, corresponding to FIG. 2. The sealing mechanism 4 according to the present embodiment is different in the shape of the slinger 5. In particular, the flange portion 52 includes a third flange portion 55 that overlaps the lip portion 62 of the sealing member 6 when viewed in the radial direction, which is different from the example in FIG. 2. In this example, the third flange portion 55 is provided between the first flange portion 53 and the second flange portion 54 in the axial direction and at a position that overlaps the lip portion 62 of the sealing member 6 when viewed in the radial direction. In particular, part or all of the third flange portion 55 overlaps the main lip 623 when viewed in the radial direction.

[0039] The features of the third flange portion 55 are the same as those of the first flange portion 53 and the second flange portion 54. In this example, an example in which the flange portion 52 includes three flange portions is shown, but the number of flange portions is not limited to three, and may be two or less, or four or more.

[0040] This embodiment has the same operational effects as the first embodiment. In addition, since the flange portion 52 overlaps the lip portion 62 of the seal member 6 when viewed in the radial direction, even if the radial wall thickness of the cylindrical portion 51 is reduced, the deflection due to the contact pressure of the lip portion 62 can be reduced. Also, when the radial wall thickness of the cylindrical portion 51 is constant, the contact pressure of the lip portion 62 can be increased to enhance the sealing function.

[0041] As described above, the examples of the embodiments of the present invention have been described in detail. The above-described embodiments are merely specific examples for implementing the present invention. The content of the embodiments does not limit the technical scope of the present invention, and many design changes such as changes, additions, and deletions of components are possible without departing from the idea of the invention defined in the claims. In the above-described embodiments, regarding the content for which such design changes are possible, explanations have been given with notations such as "in the embodiment" and "in the embodiment", but design changes are not necessarily not allowed for the content without such notations. Also, the hatching in the drawings does not limit the material of the object with hatching.

[0042] [Modification Example] Hereinafter, the modification example will be described. In the drawings and descriptions of the modification example, the same reference numerals are given to the components and members that are the same as or equivalent to those in the embodiment. Descriptions overlapping with the embodiment will be omitted as appropriate, and the configurations different from the embodiment will be mainly described.

[0043] In the description of the embodiment, an example where the device 100 is a speed reducer has been shown, but the present invention is not limited to this. The device 100 may be any device having a shaft member, a case, and a sealing mechanism, and may be, for example, a motor, various speed changers, or a coupling mechanism. Further, the shaft member 2 is not limited to a specific shape, and may be, for example, a cylindrical member, a tubular member, or a member having another shape.

[0044] In the description of the embodiment, an example where the sealing mechanism 4 is a sealing mechanism of a speed reducer has been shown, but the present invention is not limited to this. The sealing mechanism 4 is not limited to a specific device and can be applied to any device having a rotating member.

[0045] In the description of the embodiment, an example where the sealing mechanism 4 is provided on one side in the axial direction of the device 100 has been shown, but the sealing mechanism 4 may be provided on both sides in the axial direction of the device 100.

[0046] In the description of the embodiment, an example where the inner ring side rolling surface 83 is formed on the outer peripheral surface of the shaft member 2 has been shown, but an inner ring separate from the shaft member 2 may be provided, and the inner ring side rolling surface may be formed on the inner ring.

[0047] Each of the above-described modification examples has the same operations and effects as the embodiment.

[0048] Any combination of the above-described embodiments and modification examples is also useful as an embodiment of the present invention. The new embodiment resulting from the combination has the effects of each of the combined embodiments and modification examples.

Description of Reference Numerals

[0049] 2 Shaft member, 3 Case, 4 Sealing mechanism, 5 Slinger, 6 Sealing member, 8 Bearing, 51 Cylindrical portion, 52 Flange portion, 53 First flange portion, 54 Second flange portion, 55 Third flange portion, 56 Elastic member, 62 Lip portion, 522 Guide taper portion, 100 Device.

Claims

1. A shaft member, a case that houses at least a part of the shaft member, and a sealing mechanism that seals between the shaft member and the case, the apparatus comprising: the sealing mechanism includes a slinger provided on an outer peripheral surface of the shaft member, and a sealing member provided between the case and the slinger, the slinger includes a cylindrical portion and a flange portion that protrudes from the cylindrical portion toward the shaft member, the sealing member includes a lip portion that is in radial contact with the cylindrical portion of the slinger, and a lip support portion that supports the lip portion, an elastic member having a smaller elastic modulus than the flange portion is provided between the cylindrical portion and the shaft member, the flange portion abuts against the shaft member in the radial direction, the shaft member is located radially outside of an arrangement surface of the slinger of the shaft member, and has a wall portion that restricts axial movement of the slinger via the flange portion. The apparatus is characterized by this.

2. The apparatus according to claim 1, wherein the flange portion is arranged on the insertion side with respect to the elastic member.

3. The apparatus according to claim 1 or 2, wherein the flange portions are arranged at both axial ends of the cylindrical portion.

4. The apparatus according to any one of claims 1 to 3, wherein axial inward movement of the slinger with respect to the shaft member is restricted by the flange portion.

5. The apparatus according to any one of claims 1 to 4, wherein a tapered portion for guiding is provided on the flange portion for guiding when inserting into the shaft member.

6. The apparatus according to any one of claims 1 to 5, wherein, when viewed in the radial direction, the flange portion overlaps the lip portion of the sealing member.

7. having a bearing arranged between the shaft member and the case, an outer peripheral surface of the shaft member has an inner ring side rolling surface of a rolling element of the bearing, a slinger arrangement surface where the slinger is arranged, and a connection surface provided between the inner ring side rolling surface and the slinger arrangement surface, The apparatus according to any one of claims 1 to 6, wherein an outer diameter of the slinger arrangement surface is smaller than an outer diameter of the connection surface.

8. The apparatus according to claim 7, wherein an outer diameter of the cylindrical portion of the slinger is larger than the outer diameter of the connection surface.

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