JP7356806B2 - Shaft device, gear mechanism and oil seal - Google Patents

Description

The present disclosure relates to a shaft device, a gear mechanism, and an oil seal.

BACKGROUND ART Conventionally, there has been known a reduction gear device configured to output a large torque from a power source such as an electric motor, as disclosed in Patent Document 1, for example. In this speed reduction device, a rotational driving force input from an electric motor is decelerated by a speed reduction mechanism and outputted to a pinion, and a driving force is generated between the gear element and the gear element that meshes with the pinion. The deceleration mechanism is configured to decelerate and transmit the rotational driving force input from the input shaft, and output it from the output shaft provided with the pinion.

Japanese Patent Application Publication No. 2011-163374

Incidentally, in such a reduction gear, the output side seal member is sealed at the outer periphery of a ring-shaped bearing holding member that is screwed onto the output shaft and holds the bearing. In this case, there is a possibility that the seal structure formed by the output-side seal member becomes larger and the axial length of the output shaft becomes longer.

The present disclosure has been made in consideration of such points, and an object of the present disclosure is to provide a shaft device, a gear mechanism, and an oil seal that can suppress the axial length of an output shaft.

A shaft device according to the present disclosure includes a shaft member having a center axis, a cylindrical member disposed on an outer periphery of the shaft member concentrically with the shaft member, and a cylindrical member fixed to an end surface of the cylindrical member, the center of the shaft member being fixed to the end surface of the shaft member. An oil seal having a fixing part that exists on a plane perpendicular to the axis, a seal part that is at least partially located on the plane and comes into contact with the shaft member, and a connecting part that connects the fixing part and the seal part. , is provided.

In the shaft device according to the present disclosure, the fixing portion may have an attachment hole with the cylindrical member that fixes the oil seal.

In the shaft device according to the present disclosure, the connecting portion may include a cylindrical vertical portion that is perpendicular to the fixing portion and concentric with the shaft member.

In the shaft device according to the present disclosure, the seal portion may include an elastic body.

In the shaft device according to the present disclosure, the connecting portion may include an elastic body, and at least a portion of the elastic body may be located outside the cylindrical vertical portion in the radial direction.

A shaft device according to the present disclosure includes a shaft member having a center axis, a cylindrical member disposed on an outer periphery of the shaft member concentrically with the shaft member, and a cylindrical member fixed to an end surface of the shaft member and arranged at the center of the shaft member. an oil seal having a fixing part that exists on a plane perpendicular to the axis; a seal part that is at least partially located on the plane and contacts the cylindrical member; and a connecting part that connects the fixing part and the seal part. , is provided.

A gear mechanism according to the present disclosure includes a shaft device according to the present disclosure.

The oil seal according to the present disclosure is fixed to an end face of a cylindrical member that is arranged concentrically with the shaft member on the outer periphery of the shaft member having a central axis, and the oil seal is fixed to an end surface of a cylindrical member that is disposed concentrically with the shaft member, and the oil seal is fixed on a plane perpendicular to the central axis of the shaft member. a seal portion that is at least partially located on the plane and comes into contact with the shaft member, and a connecting portion that connects the fixing portion and the seal portion.

According to the present disclosure, the axial length of the output shaft can be suppressed.

FIG. 1 is a partial sectional view showing a gear mechanism and a shaft device according to an embodiment. FIG. 2 is a partially enlarged sectional view (enlarged view of section II in FIG. 1) showing a gear mechanism and a shaft device according to an embodiment. FIG. 3 is a partially sectional perspective view showing an oil seal according to one embodiment. FIG. 4 is a partially enlarged sectional view showing a gear mechanism and shaft device according to a first modification. FIG. 5 is a partially enlarged sectional view showing a gear mechanism and shaft device according to a second modification. FIG. 6 is a partially enlarged sectional view showing a gear mechanism and shaft device according to a third modification.

Hereinafter, one embodiment will be described with reference to the drawings.

As shown in FIG. 1, the gear mechanism 10 according to the present embodiment includes a case (cylindrical member) 11, an input shaft 20 and a speed reducer 30 housed in the case 11, and one end 40a protruding from the case 11. It also includes an output shaft (shaft member) 40 whose other end is coupled to the speed reducer 30 .

In this gear mechanism 10 , rotation input from a motor (not shown) through the input shaft 20 is decelerated by the speed reduction section 30 and output from the output shaft 40 . A drive gear (gear) 41 is provided at one end 40a of the output shaft 40 that protrudes from the case 11. The rotation input from the input shaft 20 is decelerated and transmitted to a driven gear (not shown) that meshes with the drive gear 41. Note that, as the input shaft 20 and the speed reducer 30, for example, conventionally known ones can be used, so a detailed explanation will be omitted here.

In the figure, L1 indicates the central axis of the output shaft 40. The output shaft 40 rotates around the central axis L1. In the following description, when the term "axial direction" is simply used, this direction means a direction extending on the central axis L1 or a direction parallel to the central axis L1. Further, a direction perpendicular to the central axis L1 is called a radial direction, and a direction around the central axis L1 is called a circumferential direction.

The case 11 has a substantially cylindrical shape as a whole, and the output shaft 40 protrudes from one end 11a (output shaft side end) thereof. An annular bearing housing groove 16 is formed on the inner surface of the case 11. A bearing 17 is mounted in the bearing housing groove 16 . The illustrated bearing 17 is a tapered roller bearing, and has an outer ring member 17a located on the radially outer side and an inner ring member 17b located on the radially inner side. The bearing 17 has its outer ring member 17 a in contact with or in close proximity to the top surface of the bearing receiving groove 16 in the axial direction, and in contact with or in close proximity to the side surface of the bearing receiving groove 16 in the radial direction. Thereby, the bearing 17 is attached to the bearing housing groove 16. Further, an output shaft 40 is inserted into the inner peripheral side of the inner ring member 17b of the bearing 17. Thereby, the case 11 is arranged on the outer periphery of the output shaft 40 concentrically with the output shaft 40, and the output shaft 40 is rotatably held by the case 11. Further, an oil seal 50 is fixed to the case 11 as described later.

The drive gear 41 is provided at one end of the output shaft 40 as described above. The drive gear 41 is made of a spur gear, and has a plurality of (14 in this case) teeth (crests) 42 and the same number of troughs (14 in this case) as the teeth 42 provided between each tooth 42. 43.

Further, an oil seal 50 is disposed between the drive gear 41 and the case 11 in the axial direction of the central axis L1. The oil seal 50 has a generally annular shape in plan so as to fill the gap between the case 11 and the output shaft 40, and has a plurality of (for example, four) bolts (fastening members) 55 attached to the case 11. Fixed by That is, a plurality of bolt holes 11c into which bolts 55 are screwed are formed along the circumferential direction in the end surface 11b of the case 11, and the oil seal 50 is fixed to the case by the bolts 55 inserted into the bolt holes 11c. It is fixed at 11. The fastening member for fixing the oil seal 50 to the case 11 may be a bolt such as a hexagon bolt or a hexagon socket head bolt, or a screw.

In this embodiment, the shaft device 15 is configured by at least the output shaft (shaft member) 40, the case (cylindrical member) 11, and the oil seal 50 described above.

Note that the gear mechanism 10 according to the present embodiment may be, for example, an eccentric rocking type reduction gear. This gear mechanism 10 may be, for example, a yaw drive device that drives the nacelle in a yaw manner to rotate the nacelle relative to the tower of the wind turbine, or a pitch drive device that drives the shaft portion of the blade in a pitch manner to rotate the shaft portion of the blade relative to the hub on the nacelle side. It is suitable as a speed reducer for use in equipment. Note that the gear mechanism 10 is not limited to use in wind turbines, but can also be used in various industrial machines, construction machines, and the like. Further, the gear mechanism 10 according to the present embodiment may be used in various transmission mechanisms including gears, such as a speed increaser, in addition to a reduction gear.

Next, the oil seal 50 according to this embodiment will be described with reference to FIGS. 2 and 3.

As shown in FIGS. 2 and 3, the oil seal 50 according to the present embodiment includes a flat fixing portion 51 and a main lip portion ( (also referred to as a seal portion) 54. A connecting portion 57 is arranged between the fixed portion 51 and the main lip portion 54. The main lip portion 54 is a portion of the elastic body 54 a formed in an annular shape at one end of the connecting portion 57 that contributes to sealing with the output shaft 40 , and includes not only a portion that contacts the output shaft 40 but also a portion that contributes to sealing with the output shaft 40 . It also includes portions that are not in contact but are made of an elastic material.

The fixing portion 51 is a flat plate having an annular shape in plan view, and is made of metal. The fixed portion 51 exists on a plane S orthogonal to the central axis L1. Here, the plane S on which the fixed part 51 exists refers to the plane S on which the upper surface of the fixed part 51 (the surface in contact with the end surface 11b of the case 11) exists. Furthermore, the fixing portion 51 has mounting holes 51a having a circular shape in plan view, at positions corresponding to the respective bolt holes 11c of the case 11, into which bolts 55 are inserted. Each attachment hole 51a is a through hole that penetrates the fixing portion 51 in the thickness direction. As described above, since the fixing portion 51 has the attachment hole 51a for fixing the case 11 and the oil seal 50, the oil seal 50 can be stably fixed to the end surface 11b of the case 11.

The connecting portion 57 connects the fixing portion 51 and the main lip portion 54 to each other, and includes a vertical portion 52 located on the radially outer side and an inner portion 53 located on the radially inner side. Further, the connecting portion 57 includes elastic bodies 52a and 53a and metal portions 52b and 53b.

The vertical portion 52 of the connecting portion 57 extends upward in the axial direction from the fixed portion 51 (toward the input shaft 20 side). The vertical portion 52 is a cylindrical member that extends perpendicularly to the fixed portion 51 (plane S) and concentrically with the output shaft 40 . This vertical portion 52 has an elastic body 52a located on the radially outer side and a metal portion 52b located on the radially inner side. The elastic body 52a and the metal portion 52b are integrated by integral molding or the like. The elastic body 52a is made of an elastic material such as rubber. This elastic body 52a is in close contact with the inner surface of one end portion 11a of the case 11, and elastically presses the case 11 radially outward. Thereby, the oil seal 50 and the case 11 are sealed.

The inner portion 53 extends in the radial direction from the upper end of the vertical portion 52 (the end on the input shaft 20 side) toward the main lip portion 54 . This inner portion 53 is made of a plate having an annular shape in plan view. Moreover, the inner part 53 has an inclined part 53c located on the radially outer side and a flat part 53d located on the radially inner side. Among these, the inclined portion 53c is inclined downward (toward the drive gear 41 side) as it goes radially inward. Moreover, the inner part 53 includes an elastic body 53a located on the upper side (on the input shaft 20 side) and a metal part 53b located on the lower side (on the drive gear 41 side). The elastic body 53a and the metal portion 53b are integrated by integral molding or the like. The elastic body 53a is made of an elastic material such as rubber. Note that the elastic body 53a of the inner part 53 does not necessarily have to be provided.

Note that at least a portion of the connecting portion 57 protrudes above the plane S (on the input shaft 20 side), and is accommodated in a space below the bearing 17 (on the drive gear 41 side). Thereby, the space below the bearing 17 can be effectively utilized.

The main lip portion 54 is a substantially cylindrical or cylindrical truncated conical member, and includes an elastic body 54a. In this case, the main lip portion 54 is composed of an elastic body 54a as a whole, but may include other members (for example, metal members). At least a portion of the main lip portion 54 is located on the plane S, that is, the main lip portion 54 and the plane S intersect with each other. Thereby, the oil seal 50 can be shortened in the axial direction. Further, the main lip portion 54 has an annular groove 54b on the outside in the radial direction into which the spring 56 is fitted. The spring 56 has an annular shape and extends in the entire circumferential direction. This spring 56 is fitted into the annular groove 54b and presses the main lip portion 54 radially inward. Further, the main lip portion 54 is in contact with the output shaft 40 below the inner ring member 17b of the bearing 17. As a result, the output shaft 40 is held in a state where it can freely rotate with respect to the main lip portion 54 and in a sealed state with the main lip portion 54. Further, the main lip portion 54 has a holding portion 54c extending radially outward, and the holding portion 54c holds the metal portion 53b of the inner portion 53 so that it does not fall off.

In this embodiment, the elastic body 54a of the main lip part 54, the elastic body 53a of the inner part 53, and the elastic body 52a of the vertical part 52 are made of nitrile rubber, acrylic rubber, silicone rubber, fluoro rubber, or ethylene. It is made integrally from an elastic member such as propylene rubber. Further, the metal portion 53b of the inner portion 53, the metal portion 52b of the vertical portion 52, and the fixing portion 51 are integrally manufactured from a metal member such as stainless steel.

Next, the operation of this embodiment will be explained.

In the gear mechanism 10 shown in FIG. 1, an input shaft 20 is rotated by a motor (not shown). Next, the rotation of the input shaft 20 is decelerated by the deceleration section 30 and transmitted from the deceleration section 30 to the output shaft 40 . This causes the output shaft 40 to rotate, making it possible to transmit torque from the drive gear 41.

When the output shaft 40 rotates in this manner, the main lip portion 54 of the oil seal 50 contacts and slides on the output shaft 40. In this case, the oil seal 50 seals the annular gap between the case 11 and the output shaft 40. By providing the oil seal 50 in this way, it is possible to prevent the lubricant filled inside the case 11 from leaking from between the case 11 and the output shaft 40.

According to this embodiment, a planar fixing portion 51 that exists on a plane S orthogonal to the central axis L of the output shaft 40 is fixed to the end surface 11b of the case 11. Further, at least a portion of the main lip portion 54 of the oil seal 50 is located on the plane S where the fixing portion 51 exists. In this way, the structure of the oil seal 50 can be simplified by reducing the portion of the oil seal 50 located below the plane S (on the drive gear 41 side). Moreover, by suppressing the axial length of the oil seal 50, the axial length of the output shaft 40 can be suppressed.

Further, according to the present embodiment, since the fixing portion 51 has the attachment hole 51a with the case 11, the oil seal 50 can be stably fixed to the case 11.

Further, according to this embodiment, the connecting portion 57 includes a cylindrical vertical portion 52 that is perpendicular to the fixed portion 51 and concentric with the output shaft 40 . As a result, the oil seal 50 and the case 11 come into contact with each other over a wide area, so that the oil seal 50 can be stably fixed to the case 11.

Further, according to the present embodiment, at least a portion of the elastic bodies 52a and 53a (elastic body 52a) is located on the outside of the cylindrical vertical portion 52 in the radial direction. Thereby, the oil seal 50 can be positioned on the case 11 and the sealing performance between the oil seal 50 and the case 11 can be improved.

Further, according to this embodiment, the elastic body 52a located on the radially outer side of the vertical portion 52 is the same member as the elastic body 54a of the main lip portion 54. Thereby, the sealing performance between the oil seal 50 and the case 11 and the sealing performance between the oil seal 50 and the output shaft 40 can be improved.

(Modified example)
Next, each modification of the above embodiment will be described with reference to FIGS. 4 to 6. 4 to 6 are diagrams showing each modification of this embodiment. The modified examples shown in FIGS. 4 and 5 differ in the configuration of the oil seal 50, and the other configurations are substantially the same as in the embodiment described above. Further, the modified example shown in FIG. 6 is different in the mounting direction of the oil seal 50, and the other configurations are substantially the same as the embodiment described above. In FIGS. 4 to 6, the same parts as those shown in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

(First modification)
FIG. 4 is a partial sectional view showing the gear mechanism 10 and shaft device 15 according to the first modification. In the oil seal 50 of the gear mechanism 10 shown in FIG. 4, the fixed portion 51 and the metal portion 52b of the vertical portion 52 are constructed from separate members. On the other hand, the metal portion 53b of the inner portion 53 and the metal portion 52b of the vertical portion 52 are integrally configured. Furthermore, the fixed part 51 has a support part 51b on the inside in the radial direction. This support portion 51b supports the metal portion 52b of the vertical portion 52. With such a configuration, the manufacturability of the oil seal can be improved, and an increase in internal pressure from the gear mechanism section (reduction section 30, etc.) can be countered.

(Second modification)
FIG. 5 is a partial sectional view showing a gear mechanism 10 and a shaft device 15 according to a second modification. In the oil seal 50 of the gear mechanism 10 shown in FIG. 5, the fixed portion 51 and the metal portion 52b of the vertical portion 52 are constructed from separate members. On the other hand, the metal part 53b of the inner part 53 and the metal part 52b of the vertical part 52 are manufactured integrally. In this case, the elastic body 53a of the inner part 53 is located below (on the drive gear 41 side) than the metal part 53b. Further, the vertical portion 52 extends upward (toward the input shaft 20 side) from the radially outer side of the inner portion 53. With such a configuration, the manufacturability of the oil seal can be improved, and an increase in internal pressure from the gear mechanism section (reduction section 30, etc.) can be countered.

(Third modification)
FIG. 6 is a partial sectional view showing a gear mechanism 10 and a shaft device 15 according to a third modification. In the gear mechanism 10 and shaft device 15 shown in FIG. 6, the fixed portion 51 of the oil seal 50 is fixed to the end surface 40b of the output shaft 40. A plurality of bolt holes 44 into which bolts 55 are screwed are formed along the circumferential direction in the end surface 40b of the output shaft 40, and the oil seal 50 is fixed to the output shaft by the bolts 55 inserted into the bolt holes 44. It is fixed at 40. Further, the fixed portion 51 exists on a plane S perpendicular to the central axis L1, and the main lip portion 54 is at least partially located on the plane S and is in contact with the case 11. The connecting portion 57 connects the fixing portion 51 and the main lip portion 54. With such a configuration, the axial length of the oil seal 50 can be suppressed, and the axial length of the output shaft 40 can be suppressed.

Although the embodiment and the modified example have been described above, the present embodiment and the modified example are presented as examples, and are not intended to limit the scope of the invention. The embodiments and modifications described above can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. The present embodiment and the modified examples described above are included within the scope and gist of the invention, as well as within the scope of the invention described in the claims and its equivalents.

10 Gear mechanism 11 Case (cylindrical member)
16 Bearing accommodation groove 17 Bearing 20 Input shaft 30 Reduction section 40 Output shaft (shaft member)
41 Drive gear (gear)
42 Teeth (mountain)
43 Valley part 50 Oil seal 51 Fixed part 52 Vertical part 53 Inner part 54 Main lip part (seal part)
55 Bolt (fastening member)
56 Spring 57 Connection part

Claims (6)

a shaft member having a central axis;
a cylindrical member disposed concentrically with the shaft member on the outer periphery of the shaft member;
a fixed part that is fixed in contact with an end surface of the cylindrical member and exists on a plane perpendicular to the central axis of the shaft member; a seal part that is at least partially located on the plane and comes into contact with the shaft member; an oil seal having a connecting portion that connects the fixing portion and the seal portion;
Equipped with
The connecting part includes a cylindrical vertical part perpendicular to the fixing part and concentric with the shaft member, and an inner part located radially inward from the vertical part,
the inner part passes through the plane;
The connecting portion includes an elastic body, and at least a portion of the elastic body is located on the radially outer side of the cylindrical vertical portion . 2. The shaft device according to claim 1, wherein the fixing portion has an attachment hole for fixing the oil seal to the cylinder member. The shaft device according to claim 1 or 2, wherein the seal portion includes an elastic body. a shaft member having a central axis;
a cylindrical member disposed concentrically with the shaft member on the outer periphery of the shaft member;
a fixed part that is fixed in contact with an end surface of the shaft member and exists on a plane perpendicular to the central axis of the shaft member; a seal part that is at least partially located on the plane and comes into contact with the cylindrical member; an oil seal having a connecting portion that connects the fixing portion and the seal portion;
A shaft device comprising: A gear mechanism comprising the shaft device according to any one of claims 1 to 4 . a fixing portion that is fixed to the outer periphery of a shaft member having a central axis in a state in contact with an end surface of a cylindrical member that is arranged concentrically with the shaft member, and that exists on a plane orthogonal to the central axis of the shaft member;
a seal portion at least partially located on the plane and in contact with the shaft member;
a connecting portion connecting the fixing portion and the sealing portion;
Equipped with
The connecting part includes a cylindrical vertical part perpendicular to the fixing part and concentric with the shaft member, and an inner part located radially inward from the vertical part,
the inner part passes through the plane;
The connecting portion includes an elastic body, and at least a portion of the elastic body is located on the radially outer side of the cylindrical vertical portion .