JP7398209B2 - Seal structure, reducer, and manufacturing method of seal structure - Google Patents

Description

The present invention relates to a seal structure, a speed reducer, and a method for manufacturing the seal structure.

There is a speed reducer that reduces the rotation of an input shaft connected to a motor shaft or the like and outputs the rotation to an output shaft (for example, see Patent Document 1). Patent Document 1 includes an internal gear, an external gear with a slight difference in the number of teeth from the internal gear, and a casing in which the internal gear and the external gear are housed. A swinging internal mesh type reduction gear that outputs a relative rotational component with a gear is disclosed.

This type of reducer has a seal structure for suppressing leakage of oil sealed inside the device. The seal structure includes a seal member that is attached to the input shaft and comes into sliding contact with the outer peripheral surface of the input shaft. In order to improve sealing performance, the seal member is arranged with its contact portion (lip) facing the outer circumferential surface of the input shaft facing inward in the axial direction (inside the device).

Patent No. 4504899

By the way, when the input shaft rotates at high speed, the sliding portion between the input shaft and the seal member may generate heat and generate sludge. In this case, the sealing member may be damaged by the sludge and the sealing performance may deteriorate. Therefore, if sludge is generated, it is necessary to replace the seal member.

However, when the seal member is assembled to the input shaft incorporated in a predetermined position of the reducer, the seal member may be dragged by the outer circumferential surface of the input shaft and may not contact the outer circumferential surface of the input shaft in the default state. be. In particular, when the sealing member has a lip, the lip may be dragged on the outer circumferential surface of the input shaft and curled outward in the axial direction. For this reason, in order to bring the replaced seal member into contact with the outer circumferential surface of the input shaft in a specified state, a complicated structure is required to assemble the input shaft with the seal member pre-installed on the reducer, and a complicated structure is required to assemble the input shaft with the seal member installed in advance, and the seal member is attached to the input shaft. In order to install it, a process of attaching and detaching the input shaft is required. Therefore, in the conventional reduction gear, there is a problem in that the sealing member can be easily replaced to improve maintainability.

SUMMARY OF THE INVENTION Therefore, the present invention provides a seal structure, a reducer, and a method for manufacturing the seal structure in which the seal member can be easily replaced.

A seal structure according to one aspect of the present invention includes a first member extending in the axial direction, a second member disposed on the outer peripheral side of the first member, and a seal structure disposed between the first member and the second member. a sealing member that is in close contact with the inner circumferential surface of the second member; and a sealing member that is insertable from the outside in the axial direction between the sealing member and the first member, and that is in contact with the inner circumferential side of the sealing member. an annular member disposed so as to be in close contact with the outer circumferential surface of the first member, the sealing member having one or more lip portions that contact the annular member, and all of the one or more lip portions being in contact with the annular member. Extends inward in the axial direction.

In the seal structure according to one aspect of the present invention, by assembling the annular member to the first member and the second member after the seal member, the annular member is inserted between the seal member and the first member. Therefore, the inner peripheral portion of the sealing member is dragged inward in the axial direction by the annular member. Thereby, when assembling the speed reducer, even if the seal member is assembled with the first member and the second member assembled at predetermined positions, the inner peripheral portion of the seal member can be brought into a specified state. Therefore, it becomes possible to replace the seal member without attaching or detaching the first member and the second member. Therefore, it is possible to provide a seal structure in which the seal member can be easily replaced.

In the seal structure of the speed reducer according to the above aspect, the first member may be an input shaft member, and the second member may be a carrier provided as an output shaft .

In the seal structure of the speed reducer according to the above aspect, the seal member may be annular.

In the seal structure of the speed reducer according to the above aspect, the annular member may include a metal tube and a seal tube.

In the seal structure of the speed reducer according to the aspect described above, the one or more lip portions may include a lip portion, and the annular member may contact the seal member at the lip portion.

In the seal structure of the speed reducer according to the above aspect, the one or more lip portions may have another lip portion that contacts the outer circumferential surface of the annular member on the outer side of the lip portion in the axial direction. good.

In the seal structure of the speed reducer according to the above aspect, a material of a portion of the annular member that contacts the lip portion may have a higher thermal conductivity than a material of the first member.

A seal structure according to one aspect of the present invention includes an input shaft member extending in the axial direction, a carrier provided as an output shaft and disposed on the outer peripheral side of the input shaft member, and one or more lip portions, and the input shaft member has an input shaft member extending in the axial direction. an annular seal member disposed between the shaft member and the carrier and in close contact with the inner circumferential surface of the carrier, and formed so as to be insertable from the outside in the axial direction between the seal member and the input shaft member, an annular member disposed in contact with all of the one or more lip portions, closely adheres to the outer circumferential surface of the input shaft member, and includes a metal tube and a seal tube, the one or more lip portions being a lip portion; It has another lip part that contacts the outer circumferential surface of the annular member at an outer side in the axial direction than the lip part, and all of the one or more lip parts extend inward in the axial direction.

In the seal structure according to one aspect of the present invention, by assembling the annular member to the input shaft member and the carrier after the seal member, the annular member is inserted between the lip portion of the seal member and the input shaft member. . Therefore, the lip portion of the sealing member is dragged axially inward by the annular member and faces axially inward. As a result, when assembling the reducer, even if the seal member is assembled with the input shaft member and carrier assembled in the predetermined positions, the lip portion of the seal member will not be curled outward in the axial direction. It can be suppressed. Therefore, it becomes possible to replace the seal member without attaching or detaching the input shaft member and the carrier. Therefore, it is possible to provide a seal structure in which the seal member can be easily replaced.

A seal structure according to one aspect of the present invention includes a first member extending in the axial direction, a second member disposed on the outer peripheral side of the first member, and a seal structure disposed between the first member and the second member. a seal member that is in close contact with the outer peripheral surface of the first member; and a seal member that is formed so as to be insertable from the outside in the axial direction between the seal member and the second member, and is arranged in contact with the outer peripheral side of the seal member. an annular member that is in close contact with at least a portion of the inner circumferential surface of the second member; the sealing member has one or more lip portions that contact the annular member; All extend inward in the axial direction.

In the seal structure according to one aspect of the present invention, by assembling the annular member to the first member and the second member after the seal member, the annular member is inserted between the seal member and the second member. Therefore, the outer peripheral portion of the sealing member is dragged inward in the axial direction by the annular member. Thereby, when assembling the speed reducer, even if the seal member is assembled with the first member and the second member assembled at predetermined positions, the outer peripheral portion of the seal member can be kept in a specified state. Therefore, it becomes possible to replace the seal member without attaching or detaching the first member and the second member. Therefore, it is possible to provide a seal structure in which the seal member can be easily replaced.

In the seal structure of the speed reducer according to the above aspect, the first member may be an input shaft member, and the second member may be a carrier provided as an output shaft .

In the seal structure of the speed reducer according to the above aspect, the seal member may be annular.

In the seal structure of the speed reducer according to the above aspect, the annular member may include a metal tube and a seal tube.

In the seal structure of the speed reducer according to the above aspect, the one or more lip portions may have a lip portion disposed on the outer peripheral portion of the seal member and in contact with the inner peripheral surface of the annular member. .

In the seal structure of the speed reducer according to the above aspect, the annular member has another lip portion on the inner peripheral portion that contacts the outer peripheral surface of the seal member on the outer side in the axial direction than the lip portion. Good too.

In the seal structure of the speed reducer according to the above aspect, a material of a portion of the annular member that contacts the lip portion may have a higher thermal conductivity than a material of the first member.

A seal structure according to one aspect of the present invention includes an input shaft member extending in the axial direction, a carrier provided as an output shaft and disposed on the outer peripheral side of the input shaft member, and one or more lip portions, and the input shaft member has an input shaft member extending in the axial direction. an annular sealing member disposed between the shaft member and the carrier and in close contact with the outer circumferential surface of the input shaft member and including a metal tube and a sealing tube; an annular member formed to be insertable and disposed in contact with all of the one or more lip portions so as to be in close contact with at least a portion of the inner circumferential surface of the carrier, the one or more lip portions being in contact with the seal. It has a lip portion disposed on the outer circumferential portion of the member and in contact with the inner circumferential surface of the annular member, and all of the one or more lip portions extend inward in the axial direction.

In the seal structure according to one aspect of the present invention, by assembling the annular member to the input shaft member and the carrier after the seal member, the annular member is inserted between the lip portion of the seal member and the carrier. Therefore, the lip portion of the sealing member is dragged axially inward by the annular member and faces axially inward. As a result, when assembling the reducer, even if the seal member is assembled with the input shaft member and carrier assembled in the predetermined positions, the lip portion of the seal member will not be curled outward in the axial direction. It can be suppressed. Therefore, it becomes possible to replace the seal member without attaching or detaching the input shaft member and the carrier. Therefore, it is possible to provide a seal structure in which the seal member can be easily replaced.

A seal structure according to one aspect of the present invention includes a first member extending in the axial direction, a second member disposed on the outer peripheral side of the first member, and a seal structure disposed between the first member and the second member. a sealing member formed so as to be insertable from the outside in the axial direction between the sealing member and the first member or the second member, the outer circumferential surface of the first member or the inner circumference of the second member; an annular member in close contact with at least one of the surfaces and in contact with the sealing member, the sealing member having one or more lip portions in contact with the annular member, all of the one or more lip portions being in contact with the annular member; Extends inward in the axial direction.

In the seal structure according to one aspect of the present invention, the annular member is assembled to the first member and the second member after the seal member, so that the annular member is disposed between the seal member and the first member or the second member. inserted. Therefore, the inner circumference or outer circumference of the seal member is dragged inward in the axial direction by the annular member. As a result, when assembling the reducer, even if the seal member is assembled with the first member and the second member assembled at predetermined positions, the inner and outer peripheral parts of the seal member can be kept in the specified state. Can be done. Therefore, it becomes possible to replace the seal member without attaching or detaching the first member and the second member. Therefore, it is possible to provide a seal structure in which the seal member can be easily replaced.

A speed reducer according to one aspect of the present invention includes the seal structure of the above aspect.

According to the speed reducer according to one aspect of the present invention, since the seal member can be easily replaced, maintenance efficiency can be improved.

A method for manufacturing a seal structure according to one aspect of the present invention includes a step of arranging a seal member between an input shaft member extending in the axial direction and a carrier provided as an output shaft and disposed on the outer peripheral side of the input shaft member. , an annular member is inserted between the sealing member and at least one of the first member or the carrier from the outside in the axial direction, and all lip portions of the sealing member are dragged by the annular member in the axial direction. in this order.

According to the method for manufacturing a seal structure according to one aspect of the present invention, the annular member is inserted between the seal member and the first member or the second member from the outside in the axial direction. Therefore, the inner circumference or outer circumference of the seal member is dragged inward in the axial direction by the annular member. Thereby, the sealing member can be brought into a specified state when assembling the speed reducer.

According to the present invention, it is possible to provide a seal structure, a reducer, and a method for manufacturing the seal structure in which the seal member can be easily replaced.

FIG. 2 is a partially cutaway side view of the speed reducer according to the first embodiment. FIG. 2 is a partially cutaway and enlarged side view of the speed reducer according to the first embodiment. FIG. 7 is a partially cutaway and enlarged side view of the speed reducer according to the second embodiment.

Hereinafter, a reduction gear 1 equipped with a seal structure according to an embodiment of the present invention will be described with reference to the accompanying drawings. The speed reducer 1 of this embodiment is an eccentric rocking type gear transmission device applied to, for example, a joint of a robot arm. In the following description, components having the same or similar functions are given the same reference numerals. Further, redundant explanations of these configurations may be omitted.

(First embodiment)
First, a schematic configuration of a reduction gear 1 according to a first embodiment will be described with reference to FIG. 1.
FIG. 1 is a partially cutaway side view of the speed reducer according to the first embodiment.
As shown in FIG. 1, the reducer 1 includes a gear case 2, an input shaft 3 (first member, input shaft member) connected to a rotating shaft of a motor, etc. It has a carrier 4 (second member) as an output shaft and a speed reduction mechanism 5 housed in a gear case 2. By rotating the input shaft 3, the speed reducer 1 decelerates and transmits the rotation of the input shaft 3 to the carrier 4 via the speed reduction mechanism 5. The inside of the reduction gear 1 is filled with lubricating oil.

The speed reducer 1 is formed into a cylindrical shape centered on a predetermined axis O as a whole. The gear case 2 is formed into a cylindrical shape centered on the axis O. The carrier 4 is housed inside the gear case 2. The carrier 4 holds a speed reduction mechanism 5. The carrier 4 is formed into a cylindrical shape coaxial with the gear case 2. The carrier 4 protrudes from the gear case 2 on both sides in the axial direction of the axis O. The carrier 4 rotates around an axis O relative to the gear case 2 and the input shaft 3.

The input shaft 3 functions as an input section into which the driving force of a motor (not shown) is input. The input shaft 3 is made of iron, steel, or stainless steel, for example. The input shaft 3 extends coaxially with the carrier 4. The input shaft 3 is inserted inside the carrier 4. The input shaft 3 rotates relative to the carrier 4 around an axis O. The input shaft 3 includes a gear 6 on the outer peripheral surface of the first end 3a. The gear 6 meshes with the gear of the reduction mechanism 5. The input shaft 3 is relatively rotatably supported by the carrier 4 via a bearing 7 closer to the second end 3b than the first end 3a. A seal member 10 and a cylindrical member 40 (annular member) are arranged between the input shaft 3 and the carrier 4.

Next, the detailed configuration of the vicinity of the seal member 10 and the cylindrical member 40 in the reducer 1 of the first embodiment will be described with reference to FIG. 2. In the following description, the axial direction of the input shaft 3 (that is, the direction along the axis O) is simply referred to as the axial direction.

FIG. 2 is a partially cutaway and enlarged side view of the speed reducer according to the first embodiment.
As shown in FIG. 2, the inner circumferential surface of the carrier 4 has a stepped surface 4a extending along a plane perpendicular to the axis O. As shown in FIG. The stepped surface 4a is disposed axially outward from the bearing 7 and faces outward in the axial direction. The inner circumferential surface of the carrier 4 extends axially outward from the stepped surface 4a with a constant inner diameter. Note that the stepped surface 4a may be inclined with respect to the axis O. Further, the step surface 4a may extend continuously over the entire circumference of the input shaft 3, or may be provided only on a part of the circumference of the input shaft 3.

The outer peripheral surface of the input shaft 3 has a shoulder surface 3c extending along a plane perpendicular to the axis O. The shoulder surface 3c is disposed axially outward from the bearing 7 and faces outward in the axial direction. The outer peripheral surface of the input shaft 3 extends axially outward from the shoulder surface 3c with a constant outer diameter. Note that the shoulder surface 3c only needs to be inclined with respect to the axis O. Further, the shoulder surface 3c may extend continuously over the entire circumference of the input shaft 3, or may be provided only on a part of the circumference of the input shaft 3.

The seal member 10 and the cylindrical member 40 isolate the internal space of the speed reducer 1 from the external space. The seal member 10 and the cylindrical member 40 are each formed in an annular shape and are arranged to surround the input shaft 3. The seal member 10 and the cylindrical member 40 are each arranged closer to the second end 3b of the input shaft 3 than the bearing 7 is. The seal member 10 is in close contact with the inner peripheral surface of the carrier 4. The seal member 10 is disposed axially outside the stepped surface 4a of the carrier 4. The cylindrical member 40 is arranged on the inner peripheral side of the seal member 10. The cylindrical member 40 is disposed between the seal member 10 and the input shaft 3 and is in close contact with the outer peripheral surface of the input shaft 3. The cylindrical member 40 is arranged on the outer side of the shoulder surface 3c of the input shaft 3 in the axial direction. The seal member 10 and the cylindrical member 40 can be attached from the second end 3b side of the input shaft 3 with the bearing 7 and the input shaft 3 assembled to the carrier 4.

The seal member 10 is in close contact with the inner peripheral surface of the carrier 4 over the entire circumference. The seal member 10 includes an annular oil seal 20 having a main lip portion 23 on its inner circumference, and an annular dust seal 30 having a dust lip portion 33 on its inner circumference.

The oil seal 20 suppresses leakage of lubricating oil from inside the reduction gear 1. The oil seal 20 includes a cylindrical base 21 fixed to the carrier 4, a main lip support 22 extending radially inward from the base 21, and a main lip 23 supported by the main lip support 22. A spring 24 that reinforces the main lip portion 23 is provided. The base 21 is in contact with the stepped surface 4a of the carrier 4 from the outside in the axial direction. Thereby, the oil seal 20 is positioned with respect to the carrier 4 in the axial direction of the axis O. The outer peripheral surface of the base 21 is in close contact with the inner peripheral surface of the carrier 4 over the entire circumference. The oil seal 20 is fixed to the carrier 4 by frictional force. The main lip support portion 22 protrudes from the axially outer end of the base portion 21 and extends all around the input shaft 3 . An end portion on the inner peripheral side of the main lip support portion 22 is located radially outward with respect to the cylindrical member 40 with a gap provided therebetween. The main lip portion 23 extends inward in the axial direction from the entire inner peripheral end of the main lip support portion 22 . The main lip portion 23 is in close contact with the outer peripheral surface of the cylindrical member 40. The spring 24 is formed in an annular shape and is arranged to surround the main lip portion 23. The spring 24 presses the main lip portion 23 against the outer peripheral surface of the cylindrical member 40.

The base 21 and main lip support 22 include a soft flexible member 26 and a frame 27 disposed within the flexible member 26. The flexible member 26 is made of a material that can shield lubricating oil and is flexible. For example, the flexible member 26 is made of rubber. The flexible member 26 is arranged at least at the contact portion between the oil seal 20 and the carrier 4. The frame 27 is made of a harder material than the flexible member 26. The frame 27 is made of, for example, a metal material, a resin material, or the like. At least a portion of frame 27 is covered by flexible member 26. The frame 27 is continuous from the base portion 21 to the main lip support portion 22 and is provided as one member. Note that the main lip portion 23 is integrated with the flexible member 26 of the main lip support portion 22. That is, the flexible member 26 and the main lip portion 23 of the base portion 21 and the main lip support portion 22 are formed of a single material and are integrated.

The dust seal 30 is arranged axially more inward than the oil seal 20. The dust seal 30 prevents foreign matter from entering the sliding contact area between the oil seal 20 and the cylindrical member 40 from the inside of the device. The dust seal 30 includes a cylindrical fixed part 31 fixed to the oil seal 20, a dust lip support part 32 extending radially inward from the fixed part 31, and a dust lip part 33 supported by the dust lip support part 32. and. The outer circumferential surface of the fixing portion 31 is in close contact with the inner circumferential surface of the base portion 21 of the oil seal 20 over the entire circumference. The dust seal 30 is fixed to the oil seal 20. For example, the dust seal 30 is fixed to the oil seal 20 by frictional force. The dust lip support portion 32 protrudes from the axially inner end of the fixed portion 31 and extends all around the input shaft 3 . An end portion on the inner peripheral side of the dust lip support portion 32 is located radially outward with respect to the cylindrical member 40 with a gap provided therebetween. The dust lip portion 33 extends inward in the axial direction from the entire inner peripheral end of the dust lip support portion 32 . The dust lip portion 33 is in close contact with the outer peripheral surface of the cylindrical member 40.

The fixed part 31 and the dust lip support part 32 include a flexible member 36 and a frame 37 disposed inside the flexible member 36. The flexible member 36 is made of a material that can shield lubricating oil and is flexible. For example, the flexible member 36 is made of rubber. The frame 37 is made of a harder material than the flexible member 36. The frame 37 is made of, for example, a metal material, a resin material, or the like. At least a portion of frame 37 is covered by flexible member 36. The frame 37 is continuous from the fixed part 31 to the dust lip support part 32, and is provided as one member. Note that the dust lip portion 33 is integrated with the flexible member 36 of the dust lip support portion 32. That is, the flexible member 36 of the fixed part 31 and the dust lip support part 32 and the dust lip part 33 are formed of a single material and are integrated.

The cylindrical member 40 is formed into a cylindrical shape coaxial with the input shaft 3. The cylindrical member 40 is an annular member that is in close contact with the outer peripheral surface of the input shaft 3 and in contact with the main lip portion 23 and the dust lip portion 33. The cylindrical member 40 is in contact with the shoulder surface 3c of the input shaft 3 from the outside in the axial direction. Thereby, the cylindrical member 40 is positioned with respect to the input shaft 3 in the axial direction of the axis O. The cylindrical member 40 includes a metal tube 41 and a seal tube 42 joined to the inner peripheral surface of the metal tube 41. The seal tube 42 constitutes the inner peripheral portion of the cylindrical member 40. The seal tube 42 is made of a flexible material that can shield lubricating oil. For example, the seal tube 42 is made of rubber. The inner circumferential surface of the seal tube 42 is in close contact with the outer circumferential surface of the input shaft 3 over the entire circumference. The cylindrical member 40 is fixed to the input shaft 3 by frictional force. The metal tube 41 constitutes the outer circumference of the cylindrical member 40. The material of the metal tube 41 has higher thermal conductivity than the material of the input shaft 3. The metal tube 41 is made of aluminum, for example. Note that the metal tube 41 may be made of gold, silver, or copper, for example. The outer peripheral surface of the metal tube 41 includes a tapered surface 43. The tapered surface 43 is provided at the inner end of the metal tube 41 in the axial direction. The diameter of the tapered surface 43 gradually decreases from the outside to the inside in the axial direction. The outer circumferential surface of the metal tube 41 extends with a constant outer diameter except for the tapered surface 43. The main lip portion 23 and the dust lip portion 33 come into sliding contact with the outer peripheral surface of the metal tube 41 as the carrier 4 and the input shaft 3 rotate relative to each other.

Next, a method for assembling the seal member 10 and the cylindrical member 40 will be described as part of the method for manufacturing the reducer 1 of this embodiment.
As described above, the seal member 10 and the cylindrical member 40 are attached to the prescribed positions with the bearing 7 and the input shaft 3 assembled to the carrier 4. Specifically, the seal member 10 and the cylindrical member 40 are assembled in the following order.

First, the seal member 10 is placed between the input shaft 3 and the carrier 4. Specifically, the second end 3b of the input shaft 3 is inserted into the inside of the seal member 10, and the seal member 10 is moved axially inward with respect to the carrier 4 and the input shaft 3. Assemble in the specified position. For example, the seal member 10 is assembled to the carrier 4 with the oil seal 20 and dust seal 30 integrated.

Subsequently, the cylindrical member 40 is inserted between the seal member 10 and the input shaft 3 from the outside in the axial direction. Specifically, the second end 3b of the input shaft 3 is inserted inside the cylindrical member 40, and the cylindrical member 40 is moved axially inward with respect to the carrier 4 and the input shaft 3, and the input shaft 3 Assemble it in the specified position. At this time, the cylindrical member 40 is inserted between the input shaft 3 and the seal member 10 from the outside in the axial direction to the inside. As a result, the main lip portion 23 and the dust lip portion 33 of the seal member 10 are dragged from the outside in the axial direction to the inside by the cylindrical member 40, and are in a state facing inward in the axial direction.
Through the above steps, the assembly of the seal member 10 and the cylindrical member 40 is completed.

As explained above, the seal structure of the reducer 1 of the present embodiment includes a seal member 10 disposed between the input shaft 3 and the carrier 4 and in close contact with the inner circumferential surface of the carrier 4, and an inner surface of the seal member 10. The input shaft 3 includes a cylindrical member 40 that is disposed in contact with the circumferential side and tightly adheres to the outer circumferential surface of the input shaft 3.
In this configuration, by assembling the cylindrical member 40 to the input shaft 3 and the carrier 4 after the seal member 10, the cylindrical member 40 is inserted between the seal member 10 and the input shaft 3. Therefore, the inner peripheral portion of the seal member 10 is dragged inward in the axial direction by the cylindrical member 40. As a result, when assembling the reducer 1, even if the seal member 10 is assembled with the input shaft 3 and carrier 4 assembled at predetermined positions, the inner circumferential portion of the seal member 10 cannot be brought into the specified state. can. Therefore, it becomes possible to replace the seal member 10 without attaching or detaching the input shaft 3 and carrier 4. Therefore, it is possible to provide a seal structure for the reducer 1 in which the seal member 10 assembled to the input shaft 3 can be easily replaced.

In particular, in this embodiment, the sealing member 10 includes a dust lip portion 33 on the inner peripheral portion. For this reason, by assembling the cylindrical member 40 to the input shaft 3 and carrier 4 after the seal member 10, the dust lip portion 33 is dragged axially inward by the cylindrical member 40 and faces axially inward. As a result, when assembling the reducer 1, even if the seal member 10 is assembled with the input shaft 3 and carrier 4 assembled at predetermined positions, the dust lip portion 33 will be rolled up outward in the axial direction. can be suppressed. Therefore, it becomes possible to replace the seal member 10 without attaching or detaching the input shaft 3 and carrier 4. Therefore, it is possible to provide a seal structure in which the seal member 10 can be easily replaced.

Further, the sealing member 10 is in close contact with the carrier 4, the cylindrical member 40 is disposed on the inner circumferential side of the sealing member 10 and is in close contact with the outer circumferential surface of the input shaft 3, and the dust lip portion 33 is in close contact with the inner circumferential portion of the sealing member 10. It is arranged and contacts the outer circumferential surface of the cylindrical member 40.
According to this configuration, the seal member 10 is in close contact with the carrier 4, the cylindrical member 40 is in close contact with the input shaft 3 on the inner peripheral side of the seal member 10, and the dust lip portion 33 is in contact with the cylindrical member 40. The seal member 10 and the cylindrical member 40 can seal between the input shaft 3 and the carrier 4. Then, by assembling the sealing member 10 on the outer circumferential side of the input shaft 3 and then assembling the cylindrical member 40 on the outer circumferential side of the input shaft 3, the dust lip portion 33 of the sealing member 10 is dragged by the cylindrical member 40 in the axial direction. facing inward. Therefore, when assembling the reducer 1, even if the seal member 10 is assembled with the input shaft 3 and the carrier 4 assembled at predetermined positions, the dust lip portion 33 will not be rolled up axially outward. can be suppressed.

Further, the seal member 10 has a main lip portion 23 that contacts the outer circumferential surface of the cylindrical member 40 on the outer side of the dust lip portion 33 in the axial direction.
According to this configuration, since the dust lip portion 33 is arranged axially inside the main lip portion 23, foreign matter enters the sliding contact portion between the main lip portion 23 and the cylindrical member 40 from the inside in the axial direction. This can be suppressed by the dust lip portion 33. Therefore, sealing performance can be improved.
Furthermore, when assembling the cylindrical member 40 to the input shaft 3, the main lip portion 23 is also dragged by the cylindrical member 40 and turns inward in the axial direction. Therefore, when assembling the reducer 1, even if the seal member 10 is assembled with the input shaft 3 and the carrier 4 assembled at predetermined positions, the main lip portion 23 will not be curled outward in the axial direction. can be suppressed.

Further, the material of the portion of the cylindrical member 40 that contacts the dust lip portion 33 has higher thermal conductivity than the material of the input shaft 3 .
According to this configuration, compared to a configuration in which the dust lip portion slides on the input shaft, the cooling performance at the sliding contact portion of the dust lip portion 33 can be improved. Therefore, it is possible to suppress the temperature around the dust lip portion 33 from becoming high.

In addition, the method for manufacturing the seal structure of the present embodiment includes a step of arranging the seal member 10 between the input shaft 3 and the carrier 4, and a step of arranging the cylindrical member 40 between the seal member 10 and the input shaft 3 in the axial direction. and a step of inserting from the outside, in this order.
According to this method, the cylindrical member 40 is inserted between the dust lip portion 33 of the seal member 10 and the input shaft 3. Therefore, the dust lip portion 33 is dragged inward in the axial direction by the cylindrical member 40 and faces inward in the axial direction. Thereby, when assembling the speed reducer 1, it is possible to prevent the dust lip portion 33 from being rolled up outward in the axial direction.

Since the reducer 1 of the present embodiment includes the above-described seal structure in which the seal member 10 can be easily replaced, it is possible to improve maintainability.

(Second embodiment)
Next, a reduction gear according to a second embodiment will be described with reference to FIG. 3.
FIG. 3 is a partially cutaway and enlarged side view of the speed reducer according to the second embodiment.
In the first embodiment shown in FIG. 2, the dust seal 30 is provided as a separate component from the cylindrical member 40. On the other hand, the second embodiment shown in FIG. 3 differs from the first embodiment in that the dust seal 50 is integrated with the cylindrical member 40. Note that the configuration other than that described below is the same as that of the first embodiment.

As shown in FIG. 3, in this embodiment, a first seal member 11 and a second seal member 12 are provided between the input shaft 3 and the carrier 4 instead of the seal member 10 and the cylindrical member 40 of the first embodiment. is located. The first seal member 11 and the second seal member 12 isolate the internal space of the reducer 1 from the external space. The first seal member 11 and the second seal member 12 are each formed in an annular shape and are arranged to surround the input shaft 3. The first seal member 11 and the second seal member 12 are each arranged closer to the second end 3b of the input shaft 3 than the bearing 7 is. The first seal member 11 is in close contact with the outer peripheral surface of the input shaft 3. The first seal member 11 is disposed on the outer side of the shoulder surface 3c of the input shaft 3 in the axial direction. The second seal member 12 is arranged on the outer peripheral side of the first seal member 11. The second seal member 12 is disposed between the carrier 4 and the first seal member 11 and is in close contact with the inner peripheral surface of the carrier 4. The second seal member 12 is disposed on the outer side of the stepped surface 4a of the carrier 4 in the axial direction. The first seal member 11 and the second seal member 12 can be attached from the second end 3b side of the input shaft 3 in a state where the bearing 7 and the input shaft 3 are assembled to the carrier 4.

The first seal member 11 includes a cylindrical member 40 and a dust seal 50. The cylindrical member 40 has the same shape as the cylindrical member 40 of the first embodiment. A main lip portion 23 of an oil seal 20 (described later) comes into sliding contact with the outer peripheral surface of the cylindrical member 40 as the carrier 4 and the input shaft 3 rotate relative to each other. Note that in the illustrated example, the cylindrical member 40 is not in contact with the shoulder surface 3c of the input shaft 3, but the cylindrical member 40 may be in contact with the shoulder surface 3c as in the first embodiment.

The dust seal 50 is arranged between the cylindrical member 40 and the second seal member 12. The dust seal 50 has a dust lip portion 53 on the outer periphery. Specifically, the dust seal 50 includes a dust lip support portion 52 fixed to the cylindrical member 40 and a dust lip portion 53 supported by the dust lip support portion 52. The dust lip support portion 52 is fixed to the inner end of the cylindrical member 40 in the axial direction. Dust lip support 52 extends radially outward from cylindrical member 40 . The dust lip support portion 52 protrudes from the axially inner end of the cylindrical member 40 and extends all around the input shaft 3 . The outer circumferential end of the dust lip support portion 52 is located radially inward with respect to the base 21 of the oil seal 20 with a gap provided therebetween. The dust lip portion 53 extends inward in the axial direction from the entire outer peripheral end of the dust lip support portion 52 . The dust lip portion 53 is in close contact with the inner peripheral surface of the base portion 21 of the oil seal 20.

The dust lip support 52 includes a flexible member 56 and a frame 57 disposed inside the flexible member 56. The flexible member 56 is formed of the same material as the seal tube 42 of the cylindrical member 40 and is integrated therewith. The frame 57 is formed of the same material as the metal tube 41 of the cylindrical member 40 and is integrated therewith. The entire frame 57 is covered from the inside in the axial direction by the flexible member 56. Note that the dust lip portion 53 is integrated with a flexible member 56 of the dust lip support portion 52. That is, the seal tube 42 of the cylindrical member 40, the flexible member 56 of the dust lip support part 52, and the dust lip part 53 are formed of a single material and are integrated. As a result of the above, the dust seal 50 and the cylindrical member 40 are integrated into a single component.

The second seal member 12 includes an oil seal 20. The oil seal 20 has a similar shape to the oil seal 20 of the first embodiment. That is, the oil seal 20 includes a base portion 21, a main lip support portion 22, a main lip portion 23, and a spring 24. In this embodiment, the base portion 21 is an annular member that is in close contact with the inner circumferential surface of the carrier 4 and in contact with the dust lip portion 53 . The configuration of the oil seal 20 differs from the oil seal 20 of the first embodiment in the following points. The oil seal 20 includes a flexible member 26 and a frame 27 disposed inside the flexible member 26. The flexible member 26 is arranged at least at the contact portion between the oil seal 20 and the carrier 4. The material of the frame 27 has higher thermal conductivity than the material of the input shaft 3. The frame 27 is made of aluminum, for example. Note that the frame 27 may be made of gold, silver, or copper, for example. The frame 27 is exposed radially inward at least on the inner circumferential surface of the base portion 21 . That is, the base 21 includes a metal tube formed by the frame 27 and a seal tube formed by the flexible member 26 and joined to the outer peripheral surface of the metal tube. A dust lip portion 53 comes into sliding contact with the inner circumferential surface of the base portion 21 as the carrier 4 and the input shaft 3 rotate relative to each other.

Next, a method for assembling the first seal member 11 and the second seal member 12 will be described as part of the method for manufacturing the reducer 1A of this embodiment.
The first seal member 11 and the second seal member 12 are attached to prescribed positions with the bearing 7 and the input shaft 3 assembled to the carrier 4. Specifically, the first seal member 11 and the second seal member 12 are assembled in the following order.

First, the first seal member 11 is placed between the input shaft 3 and the carrier 4. Specifically, the second end 3b of the input shaft 3 is inserted inside the cylindrical member 40, and the first seal member 11 is moved axially inward with respect to the carrier 4 and the input shaft 3 to perform input. Attach it to the specified position on shaft 3.

Subsequently, the second seal member 12 is inserted between the first seal member 11 and the carrier 4 from the outside in the axial direction. Specifically, the second end 3b of the input shaft 3 is inserted into the inside of the oil seal 20, and the second seal member 12 is moved axially inward with respect to the carrier 4 and the input shaft 3. Assemble it in the specified position in step 4. At this time, the base portion 21 of the oil seal 20 is inserted between the dust lip portion 53 of the dust seal 50 and the carrier 4 from the outside in the axial direction to the inside. As a result, the dust lip portion 53 of the dust seal 50 is dragged from the outside in the axial direction to the inside in the axial direction by the oil seal 20, so that it faces inward in the axial direction.
Through the above steps, the assembly of the first seal member 11 and the second seal member 12 is completed.

As explained above, the seal structure of the reducer 1A of the present embodiment includes the first seal member 11 disposed between the input shaft 3 and the carrier 4 and in close contact with the outer circumferential surface of the input shaft 3; The oil seal 20 includes a base 21 of an oil seal 20 that is disposed in contact with the outer circumferential side of the member 11 and tightly adheres to the inner circumferential surface of the carrier 4.
In this configuration, by assembling the base 21 of the oil seal 20 to the input shaft 3 and the carrier 4 after the first seal member 11, the base 21 of the oil seal 20 is placed between the first seal member 11 and the carrier 4. is inserted. Therefore, the outer peripheral portion of the first seal member 11 is dragged inward in the axial direction by the base 21 of the oil seal 20. As a result, when assembling the reducer 1A, even if the first seal member 11 is assembled with the input shaft 3 and carrier 4 assembled at predetermined positions, the inner circumferential portion of the first seal member 11 is kept in the specified state. It can be done. Therefore, it becomes possible to replace the first seal member 11 without disassembling the input shaft 3 and carrier 4. Therefore, it is possible to provide a seal structure for the reducer 1 in which the first seal member 11 assembled to the input shaft 3 can be easily replaced.

In particular, in this embodiment, the first seal member 11 includes a dust lip portion 53 on the outer peripheral portion. Therefore, by assembling the base 21 of the oil seal 20 to the input shaft 3 and carrier 4 after the first seal member 11, the dust lip portion 53 is dragged inward in the axial direction by the base 21 of the oil seal 20. facing inward in the axial direction. As a result, when assembling the reducer 1A, even if the first seal member 11 is assembled with the input shaft 3 and the carrier 4 assembled at predetermined positions, the dust lip portion 53 is rolled outward in the axial direction. can be prevented from becoming. Therefore, the first seal member 11 can be replaced without attaching or detaching the input shaft 3 and carrier 4. Therefore, it is possible to provide a seal structure in which the first seal member 11 can be easily replaced.

Further, the first seal member 11 is in close contact with the outer peripheral surface of the input shaft 3, the base 21 of the oil seal 20 is disposed on the outer peripheral side of the first seal member 11 and is in close contact with the carrier 4, and the dust lip portion 53 is in close contact with the outer peripheral surface of the input shaft 3. It is disposed on the outer circumferential portion of the seal member 11 and is in contact with the inner circumferential surface of the base portion 21 of the oil seal 20 .
According to this configuration, the first seal member 11 is in close contact with the input shaft 3, the base 21 of the oil seal 20 is in close contact with the carrier 4 on the outer peripheral side of the first seal member 11, and the dust lip portion 53 is in close contact with the input shaft 3. Since it is in contact with the base 21, the first seal member 11 and the base 21 of the oil seal 20 can seal between the input shaft 3 and the carrier 4. Then, by assembling the first seal member 11 to the outer circumferential side of the input shaft 3 and then assembling the base 21 of the oil seal 20 to the outer circumferential side of the input shaft 3, the dust lip portion 53 of the first seal member 11 becomes an oil seal. 20 and faces inward in the axial direction. Therefore, when assembling the reducer 1A, even if the first seal member 11 is assembled with the input shaft 3 and carrier 4 assembled at predetermined positions, the dust lip portion 53 is not rolled up axially outward. You can suppress what happens.

Further, the seal structure of the reducer 1A includes an annular second seal member 12 that includes the base 21 of the oil seal 20 and is disposed between the input shaft 3 and the carrier 4. The second seal member 12 has a main lip portion 23 on its inner circumference that contacts the outer circumferential surface of the first seal member 11 on the outer side of the dust lip portion 53 in the axial direction.
According to this configuration, the dust lip portion 53 is disposed axially inside the main lip portion 23, so that foreign matter may not come into contact with the sliding contact portion between the main lip portion 23 and the second seal member 12 from the inside in the axial direction. The dust lip portion 53 can prevent the dust from entering. Therefore, sealing performance can be improved.

Further, the material of the portion (frame 57) of the base 21 of the oil seal 20 that contacts the dust lip portion 53 has higher thermal conductivity than the material of the input shaft 3.
According to this configuration, compared to a configuration in which the dust lip portion slides on the input shaft, the cooling performance at the sliding contact portion of the dust lip portion 53 can be improved. Therefore, it is possible to suppress the temperature around the dust lip portion 53 from becoming high.

Further, in the method for manufacturing the seal structure of the present embodiment, the step of arranging the first seal member 11 between the input shaft 3 and the carrier 4 and the step of arranging the oil seal 20 between the first seal member 11 and the carrier 4 are performed. The step of inserting the base portion 21 from the outside in the axial direction is provided in this order.
According to this method, the base portion 21 of the oil seal 20 is inserted between the dust lip portion 53 of the first seal member 11 and the carrier 4. Therefore, the dust lip portion 53 is dragged axially inward by the base 21 of the oil seal 20 and faces axially inward. Thereby, when assembling the speed reducer 1A, it is possible to prevent the dust lip portion 53 from being rolled up outward in the axial direction.

Note that the present invention is not limited to the above-described embodiments described with reference to the drawings, and various modifications can be made within the technical scope thereof.
For example, in the embodiment described above, the oil seal 20 and the cylindrical member 40 are separate parts. However, the present invention is not limited to this, and the oil seal and the cylindrical member may be integrated into a single component.

Further, in the first embodiment, the oil seal 20 and the dust seal 30 are separate parts that are fixed to each other. However, the present invention is not limited to this, and the oil seal and the dust seal may be integrated into a single component.

Further, in the above embodiment, the seal structure between the input shaft 3 and the carrier 4 has been described, but the present invention can also be applied to a seal structure between the input shaft and the case.

In addition, it is possible to appropriately replace the components in the above-described embodiments with well-known components without departing from the spirit of the present invention.

1, 1A...Reducer 3...Input shaft (first member, input shaft member) 4...Carrier (second member) 10...Seal member 11...First seal member (seal member) 12...Second seal member (other Seal member) 21... Base (annular member) 23... Main lip part (other lip part) 33, 53... Dust lip part 40... Cylindrical member (annular member)

Claims (19)

a first member extending in the axial direction;
a second member disposed on the outer peripheral side of the first member;
a sealing member disposed between the first member and the second member and in close contact with the inner circumferential surface of the second member;
an annular member formed to be insertable from the outside in the axial direction between the sealing member and the first member, disposed in contact with the inner peripheral side of the sealing member, and closely adhering to the outer peripheral surface of the first member; and,
Equipped with
the sealing member has one or more lip portions that contact the annular member;
A seal structure in which all of the one or more lip portions extend inward in the axial direction. the first member is an input shaft member,
The seal structure according to claim 1, wherein the second member is a carrier provided as an output shaft. The seal structure according to claim 1, wherein the seal member is annular. The seal structure according to claim 1, wherein the annular member includes a metal tube and a seal tube. the one or more lip portions include a lip portion;
The seal structure according to claim 1, wherein the annular member contacts the seal member at the lip portion. The seal structure according to claim 5, wherein the one or more lip portions have another lip portion that contacts the outer circumferential surface of the annular member at an outer side in the axial direction than the lip portion. The seal structure according to claim 5, wherein a material of a portion of the annular member that contacts the lip portion has a higher thermal conductivity than a material of the first member. an input shaft member extending in the axial direction;
a carrier provided as an output shaft and disposed on the outer peripheral side of the input shaft member;
an annular seal member having one or more lip portions, disposed between the input shaft member and the carrier, and closely contacting the inner circumferential surface of the carrier;
A metal member is formed so as to be inserted between the seal member and the input shaft member from the outside in the axial direction, is disposed in contact with all of the one or more lip portions, and is in close contact with the outer circumferential surface of the input shaft member. an annular member comprising a tube and a seal tube;
The one or more lip portions have a lip portion and another lip portion that contacts the outer circumferential surface of the annular member at an outer side in the axial direction than the lip portion,
A seal structure in which all of the one or more lip portions extend inward in the axial direction. a first member extending in the axial direction;
a second member disposed on the outer peripheral side of the first member;
a sealing member disposed between the first member and the second member and in close contact with the outer peripheral surface of the first member;
The sealing member is formed so as to be inserted between the sealing member and the second member from the outside in the axial direction, and is disposed in contact with the outer circumferential side of the sealing member so as to be at least partially on the inner circumferential surface of the second member. an annular member that comes into close contact with the
Equipped with
the sealing member has one or more lip portions that contact the annular member;
A seal structure in which all of the one or more lip portions extend inward in the axial direction. the first member is an input shaft member,
The seal structure according to claim 9, wherein the second member is a carrier provided as an output shaft. The seal structure according to claim 9, wherein the seal member is annular. The seal structure according to claim 9, wherein the annular member includes a metal tube and a seal tube. The seal structure according to claim 9, wherein the one or more lip portions have a lip portion disposed on an outer peripheral portion of the seal member and in contact with an inner peripheral surface of the annular member. The seal structure according to claim 13, wherein the annular member has another lip portion on the inner peripheral portion that contacts the outer peripheral surface of the seal member at an outer side in the axial direction than the lip portion. The seal structure according to claim 13, wherein a material of a portion of the annular member that contacts the lip portion has a higher thermal conductivity than a material of the first member. an input shaft member extending in the axial direction;
a carrier provided as an output shaft and disposed on the outer peripheral side of the input shaft member;
an annular seal member having one or more lip portions, disposed between the input shaft member and the carrier, closely contacting the outer peripheral surface of the input shaft member, and including a metal tube and a seal tube;
It is formed to be insertable from the outside in the axial direction between the sealing member and the carrier, is arranged in contact with all of the one or more lip portions, and is in close contact with at least a portion of the inner circumferential surface of the carrier. An annular member;
The one or more lip portions have a lip portion disposed on the outer peripheral portion of the sealing member and in contact with the inner peripheral surface of the annular member,
A seal structure in which all of the one or more lip portions extend inward in the axial direction. a first member extending in the axial direction;
a second member disposed on the outer peripheral side of the first member;
a sealing member disposed between the first member and the second member;
The seal member is formed to be insertable from the outside in the axial direction between the seal member and the first member or the second member, and is in close contact with at least one of the outer circumferential surface of the first member or the inner circumferential surface of the second member. and an annular member in contact with the sealing member;
Equipped with
the sealing member has one or more lip portions that contact the annular member;
A seal structure in which all of the one or more lip portions extend inward in the axial direction. A speed reducer comprising the seal structure according to any one of claims 1 to 17. arranging a sealing member between an input shaft member extending in the axial direction and a carrier provided as an output shaft and disposed on the outer peripheral side of the input shaft member;
An annular member is inserted between the seal member and at least one of the input shaft member or the carrier from the outside in the axial direction, and all the lip portions of the seal member are dragged by the annular member so that the axial direction A method for manufacturing a seal structure comprising, in this order, a step of turning inward.

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