Shaft assembly, gear mechanism and oil seal

Abstract

The present invention provides a shaft device, a gear mechanism and an oil seal. The shaft device (15) comprises: a shaft member (40) having a central axis (L1); a cylinder member (11) arranged on the outer periphery of the shaft member (40) in a concentric manner with the shaft member (40); and an oil seal (50) having: a fixing portion (51) fixed to an end face (11b) of the cylinder member (11) and existing on a plane (S) orthogonal to the central axis (L1) of the shaft member (40); a sealing portion (54) at least a portion of which is located on the plane (S) and in contact with the shaft member (40); and a connecting portion (57) connecting the fixing portion (51) and the sealing portion (54).

Description

Technical Field

[0001] The present disclosure relates to a shaft device, a gear mechanism and an oil seal. Background Art

[0002] Conventionally, there is a known reduction gear device such as that disclosed in Patent Document 1, which is configured to output a large torque from a power source such as an electric motor. In this reduction gear device, a rotational driving force input from the electric motor is reduced in speed by a reduction mechanism and output to a pinion gear, so that a driving force is generated between the pinion gear and a gear element meshing with the pinion gear. The reduction mechanism is configured to reduce the speed of the rotational driving force input from the input shaft and transmit it, and output it from an output shaft provided with a pinion gear.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-163374 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] However, for such a reduction gear, the output side sealing member is sealed on the outer periphery of the annular bearing holding member that is threadedly coupled to the output shaft and holds the bearing. In this case, the sealing structure formed by the output side sealing member is enlarged, and the axial length of the output shaft may be increased.

[0008] The present disclosure has been made in consideration of such a point, and an object of the present disclosure is to provide a shaft device, a gear mechanism, and an oil seal capable of suppressing the axial length of an output shaft.

[0009] Solutions for solving problems

[0010] The shaft device disclosed in the present invention comprises: a shaft member having a central axis; a barrel member arranged on the outer periphery of the shaft member in a concentric manner with the shaft member; and an oil seal having: a fixing portion fixed to the end face of the barrel member and existing on a plane orthogonal to the central axis of the shaft member; a sealing portion, at least a portion of which is located on the plane and in contact with the shaft member; and a connecting portion connecting the fixing portion and the sealing portion.

[0011] In the shaft device of the present disclosure, the fixing portion may include a mounting hole for fixing the oil seal to the cylindrical member.

[0012] In the shaft device of the present disclosure, the connection portion may include a cylindrical vertical portion that is perpendicular to the fixing portion and concentric with the shaft member.

[0013] In the shaft device of the present disclosure, the sealing portion may include an elastic body.

[0014] In the shaft device of the present disclosure, the connection portion may include an elastic body, and at least a portion of the elastic body may be located radially outside the cylindrical vertical portion.

[0015] The shaft device disclosed in the present invention comprises: a shaft member having a central axis; a barrel member arranged on the outer periphery of the shaft member in a concentric manner with the shaft member; and an oil seal having: a fixing portion fixed to the end face of the shaft member and existing on a plane orthogonal to the central axis of the shaft member; a sealing portion, at least a portion of which is located on the plane and in contact with the barrel member; and a connecting portion connecting the fixing portion and the sealing portion.

[0016] The gear mechanism of the present disclosure includes the shaft device of the present disclosure.

[0017] The oil seal disclosed herein comprises: a fixing portion, in which a tube member is arranged on the outer periphery of a shaft member having a central axis in a concentric manner with the shaft member, the fixing portion is fixed to the end surface of the tube member and exists on a plane orthogonal to the central axis of the shaft member; a sealing portion, at least a portion of which is located on the plane and in contact with the shaft member; and a connecting portion, which connects the fixing portion and the sealing portion.

[0018] Effects of the Invention

[0019] According to the present disclosure, the axial length of the output shaft can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a partial cross-sectional view showing a gear mechanism and a shaft device according to one embodiment.

[0021] Figure 2 is a partially enlarged cross-sectional view showing a gear mechanism and a shaft device according to an embodiment ( Figure 1 (enlarged view of part II).

[0022] Figure 3 It is a partially cutaway perspective view showing an oil seal according to an embodiment.

[0023] Figure 4 It is a partially enlarged cross-sectional view showing the gear mechanism and the shaft device of the first modified example.

[0024] Figure 5 It is a partially enlarged cross-sectional view showing a gear mechanism and a shaft device according to a second modified example.

[0025] Figure 6It is a partially enlarged cross-sectional view showing a gear mechanism and a shaft device according to a third modified example. DETAILED DESCRIPTION

[0026] Hereinafter, one embodiment will be described with reference to the drawings.

[0027] like Figure 1 As shown, the gear mechanism 10 of this embodiment comprises: a housing (cylindrical member) 11; an input shaft 20 and a speed reduction portion 30, which are accommodated in the housing 11; and an output shaft (shaft member) 40, one end 40a of which protrudes from the housing 11 and the other end is combined with the speed reduction portion 30.

[0028] In the gear mechanism 10, the rotation input from the motor (not shown) via the input shaft 20 is decelerated by the speed reduction unit 30 and output from the output shaft 40. A driving gear (gear) 41 is provided at one end 40a of the output shaft 40 protruding from the housing 11. The rotation input from the input shaft 20 is decelerated and transmitted to the driven gear (not shown) meshing with the driving gear 41. In addition, as the input shaft 20 and the speed reduction unit 30, for example, a conventionally known input shaft and speed reduction unit can be used, and therefore, a detailed description thereof is omitted here.

[0029] In the figure, L1 represents the central axis of the output shaft 40. The output shaft 40 rotates around the central axis L1. Hereinafter, when simply referred to as "axial direction", the direction refers to the direction extending on the central axis L1 or the direction parallel to the central axis L1. In addition, the direction orthogonal to the central axis L1 is referred to as radial direction, and the direction around the central axis L1 is referred to as circumferential direction.

[0030] The housing 11 is generally cylindrical in shape, and the output shaft 40 protrudes from one end (end on the output shaft side) of the housing 11. An annular bearing receiving groove 16 is formed on the inner surface of the housing 11. A bearing 17 is mounted in the bearing receiving groove 16. The illustrated bearing 17 is a tapered roller bearing, and has an outer ring member 17a located radially outward and an inner ring member 17b located radially inward. The bearing 17 has its outer ring member 17a abutting or approaching the top surface of the bearing receiving groove 16 in the axial direction, and has its outer ring member 17a abutting or approaching the side surface of the bearing receiving groove 16 in the radial direction. Thus, the bearing 17 is mounted in the bearing receiving groove 16. In addition, the output shaft 40 is inserted into the inner circumference of the inner ring member 17b of the bearing 17. Thus, the housing 11 is arranged on the outer circumference of the output shaft 40 in a concentric manner with the output shaft 40, and the output shaft 40 is held in the housing 11 in a rotatable manner. Furthermore, an oil seal 50 is fixed to the housing 11 as will be described later.

[0031] As described above, a drive gear 41 is provided at one end of the output shaft 40. The drive gear 41 is composed of a spur gear, and has a plurality of (in this case, 14) teeth (mountain portions) 42 and the same number of valley portions 43 as the number of teeth 42 (in this case, 14), and the valley portions 43 are provided between the teeth 42.

[0032] In addition, an oil seal 50 is disposed between the drive gear 41 and the housing 11 in the axial direction of the central axis L1. The oil seal 50 fills the gap between the housing 11 and the output shaft 40, has a substantially annular shape in a plan view, and is fixed to the housing 11 by a plurality of (e.g., four) bolts (fastening members) 55. That is, a plurality of bolt holes 11c that are threadedly engaged with the bolts 55 are formed along the circumferential direction on the end surface 11b of the housing 11, and the oil seal 50 is fixed to the housing 11 by the bolts 55 inserted into the bolt holes 11c. In addition, as a fastening member for fixing the oil seal 50 to the housing 11, in addition to bolts such as hexagonal bolts and hexagon socket head bolts, screws or the like may also be used.

[0033] In the present embodiment, the shaft device 15 is constituted by at least the above-mentioned output shaft (shaft member) 40 , the housing (cylindrical member) 11 , and the oil seal 50 .

[0034] In addition, the gear mechanism 10 of the present embodiment may also be, for example, an eccentric swing type speed reducer. The gear mechanism 10 is preferably used as a speed reducer for a yaw drive device that performs yaw drive in a manner that the nacelle rotates relative to the tower of the windmill, or a pitch drive device that performs pitch drive in a manner that the shaft of the blade rotates relative to the hub on the nacelle side. In addition, the gear mechanism 10 is not limited to windmills, and can also be used in various industrial machines or construction machines. In addition, in addition to being used for speed reducers, the gear mechanism 10 of the present embodiment can also be used in various speed change mechanisms including gears such as speed increasers.

[0035] Next, refer to Figure 2 and Figure 3 Next, the oil seal 50 of the present embodiment will be described.

[0036] like Figure 2 and Figure 3 As shown in FIG. 1 , the oil seal 50 of the present embodiment includes: a planar fixing portion 51; and a main lip portion (also referred to as a sealing portion) 54, which is located on the plane S where the fixing portion 51 exists and includes an elastic body 54a. A connecting portion 57 is arranged between the fixing portion 51 and the main lip portion 54. The main lip portion 54 is a portion of the elastic body that is formed in an annular shape to one end of the connecting portion 57 and contributes to the seal with the output shaft 40, and includes not only a portion that contacts the output shaft 40 but also a portion that does not contact the output shaft 40 but is formed of the elastic body.

[0037] The fixing portion 51 is a flat plate in a circular ring shape when viewed from above, and is formed of metal. The fixing portion 51 exists on a plane S that is orthogonal to the central axis L1. Here, the plane S where the fixing portion 51 exists refers to the plane S where the upper surface of the fixing portion 51 (the surface in contact with the end surface 11b of the housing 11) exists. In addition, the fixing portion 51 has mounting holes 51a in a circular shape when viewed from above for inserting bolts 55 at positions corresponding to the bolt holes 11c of the housing 11. Each mounting hole 51a is composed of a through hole that penetrates the fixing portion 51 in the thickness direction. In this way, the fixing portion 51 has the mounting holes 51a for fixing the housing 11 and the oil seal 50, so that the oil seal 50 can be stably fixed to the end surface 11b of the housing 11.

[0038] The connecting portion 57 is used to connect the fixing portion 51 and the main lip portion 54, and includes a vertical portion 52 located radially outward and an inner portion 53 located radially inward. The connecting portion 57 includes elastic bodies 52a, 53a and metal portions 52b, 53b.

[0039] The vertical portion 52 of the connecting portion 57 extends from the fixed portion 51 to the upper side (the input shaft 20 side) in the axial direction. The vertical portion 52 is a cylindrical member that is perpendicular to the fixed portion 51 (plane S) and extends concentrically with the output shaft 40. The 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 formed of an elastic material such as rubber. The elastic body 52a is in close contact with the inner surface of one end portion 11a of the housing 11, and elastically pushes the housing 11 toward the radially outer side. As a result, the oil seal 50 and the housing 11 are sealed.

[0040] The inner portion 53 extends radially from the upper end of the vertical portion 52 (the end portion on the input shaft 20 side) toward the main lip portion 54. The inner portion 53 is composed of a plate that is annular in shape when viewed from above. In addition, the inner portion 53 has an inclined portion 53c located on the radial outside and a flat portion 53d located on the radial inside. Among them, the inclined portion 53c is inclined toward the lower side (the drive gear 41 side) as it moves toward the radial inside. In addition, the inner portion 53 has an elastic body 53a located on the upper side (the input shaft 20 side) and a metal portion 53b located on the lower side (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 formed of a material having elasticity, such as rubber. In addition, the elastic body 53a of the inner portion 53 may not necessarily be provided.

[0041] Furthermore, at least a portion of the connection portion 57 protrudes upward (toward the input shaft 20 ) relative to the plane S and is accommodated in the space below the bearing 17 (toward the drive gear 41 ). Thus, the space below the bearing 17 can be effectively utilized.

[0042] The main lip 54 is a roughly cylindrical or cylindrical truncated cone-shaped member, and includes an elastic body 54a. In this case, the main lip 54 is composed of the elastic body 54a as a whole, but it may also include other members (such as metal members). At least a part of the main lip 54 is located on the plane S, that is, the main lip 54 and the plane S intersect. As a result, the oil seal 50 can be shortened in the axial direction. In addition, the main lip 54 has an annular groove 54b for the spring 56 to be embedded on its radial outer side. The spring 56 is annular and extends in the entire circumferential direction. The spring 56 is embedded in the annular groove 54b to press the main lip 54 radially inward. In addition, the main lip 54 contacts the output shaft 40 below the inner ring member 17b of the bearing 17. As a result, the output shaft 40 is maintained in a state where it can rotate freely relative to the main lip 54 and is sealed between the main lip 54. The main lip portion 54 also has a retaining portion 54 c extending radially outward, and the retaining portion 54 c retains the metal portion 53 b of the inner portion 53 so as not to fall off.

[0043] In addition, in the present embodiment, the elastic body 54a of the main lip portion 54, the elastic body 53a of the inner portion 53, and the elastic body 52a of the vertical portion 52 are integrally made of elastic members such as nitrile rubber, acrylic rubber, silicone rubber, fluororubber, ethylene propylene rubber, etc. In addition, 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 made of metal members such as stainless steel.

[0044] Next, the operation of this embodiment will be described.

[0045] for Figure 1 In the gear mechanism 10 shown, the input shaft 20 is rotated by a motor (not shown). Then, the rotation of the input shaft 20 is decelerated by the speed reduction unit 30 and transmitted from the speed reduction unit 30 to the output shaft 40. As a result, the output shaft 40 rotates, and torque can be transmitted from the drive gear 41.

[0046] When the output shaft 40 rotates in this way, 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 housing 11 and the output shaft 40. In this way, by providing the oil seal 50, it is possible to prevent the lubricant filled in the housing 11 from leaking from between the housing 11 and the output shaft 40.

[0047] According to the present embodiment, the planar fixing portion 51 existing on the plane S orthogonal to the central axis L1 of the output shaft 40 is fixed to the end surface 11b of the housing 11. In addition, 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, by reducing the portion of the oil seal 50 located below the plane S (on the driving gear 41 side), the structure of the oil seal 50 can be simplified. In addition, by reducing the axial length of the oil seal 50, the axial length of the output shaft 40 can be reduced.

[0048] Furthermore, according to the present embodiment, since the fixing portion 51 has the mounting hole 51 a for mounting to the housing 11 , the oil seal 50 can be stably fixed to the housing 11 .

[0049] According to the present embodiment, the connection portion 57 includes the cylindrical vertical portion 52 which is perpendicular to the fixing portion 51 and concentric with the output shaft 40. Thus, the oil seal 50 is in contact with the housing 11 over a large area, and thus the oil seal 50 can be stably fixed to the housing 11.

[0050] According to the present embodiment, at least a portion of the elastic bodies 52a and 53a (elastic body 52a) is located radially outside the cylindrical vertical portion 52. This allows the oil seal 50 to be positioned relative to the housing 11, thereby improving the sealing performance between the oil seal 50 and the housing 11.

[0051] According to the present embodiment, the elastic body 52a located radially outward of the vertical portion 52 is the same member as the elastic body 54a of the main lip portion 54. This improves the sealing performance between the oil seal 50 and the housing 11 and between the oil seal 50 and the output shaft 40.

[0052] (Variation Example)

[0053] Next, refer to Figures 4 to 6 Various modifications of the above-described embodiment will be described. Figures 4 to 6 The diagrams show various modified examples of the present embodiment. Figure 4 and Figure 5 The structure of the oil seal 50 of each modified example shown is different, and the other structures are substantially the same as those of the above-mentioned embodiment. Figure 6 The installation direction of the oil seal 50 in the modified example shown is different, and the other structures are substantially the same as those of the above-mentioned embodiment. Figures 4 to 6 In, with Figure 1 to Figure 3 In the illustrated embodiment, the same components are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0054] (First Modification)

[0055] Figure 4FIG. 1 is a partial cross-sectional view showing the gear mechanism 10 and the shaft device 15 according to the first modified example. Figure 4 In the oil seal 50 of the gear mechanism 10 shown, the fixed portion 51 and the metal portion 52b of the vertical portion 52 are composed of independent components. 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 formed. In addition, the fixed portion 51 has a support portion 51b on the radial inner side thereof. The support portion 51b supports the metal portion 52b of the vertical portion 52. According to such a structure, the manufacturability of the oil seal can be improved, and it can counteract the increase in internal pressure caused by the gear mechanism portion (speed reduction portion 30, etc.).

[0056] (Second Modification)

[0057] Figure 5 FIG. 2 is a partial cross-sectional view showing the gear mechanism 10 and the shaft device 15 according to the second modified example. Figure 5 The oil seal 50 of the gear mechanism 10 shown, the fixed portion 51 and the metal portion 52b of the vertical portion 52 are composed of independent components. On the other hand, the metal portion 53b of the inner portion 53 and the metal portion 52b of the vertical portion 52 are made into one piece. In this case, the elastic body 53a of the inner portion 53 is located below (on the driving gear 41 side) than the metal portion 53b. In addition, the vertical portion 52 extends from the radially outer side of the inner portion 53 toward the upper side (on the input shaft 20 side). According to such a structure, the manufacturability of the oil seal can be improved, and it can counteract the increase in internal pressure caused by the gear mechanism part (the speed reduction part 30, etc.).

[0058] (Third Modification)

[0059] Figure 6 FIG. 1 is a partial cross-sectional view showing the gear mechanism 10 and the shaft device 15 according to the third modified example. Figure 6 In the gear mechanism 10 and the shaft device 15 shown, the fixing portion 51 of the oil seal 50 is fixed to the end face 40b of the output shaft 40. A plurality of bolt holes 44 are formed along the circumferential direction on the end face 40b of the output shaft 40 to which bolts 55 are threadedly engaged, and the oil seal 50 is fixed to the output shaft 40 by the bolts 55 inserted into the bolt holes 44. In addition, the fixing portion 51 exists on a plane S orthogonal to the central axis L1, and at least a part of the main lip portion 54 is located on the plane S and contacts the housing 11. The connecting portion 57 connects the fixing portion 51 and the main lip portion 54. According to such a structure, the axial length of the oil seal 50 can be suppressed, and the axial length of the output shaft 40 can be suppressed.

[0060] The above embodiments and modifications are described, but the present embodiments and modifications are presented as examples, and are not intended to limit the scope of the invention. The above embodiments and modifications can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. The above embodiments and modifications are included in the scope and purpose of the invention as well as the invention described in the claims and their equivalents.

Claims

1. A shaft device, wherein: The shaft device has: a shaft member having a central axis; a cylindrical member disposed on the outer periphery of the shaft member in a concentric manner with the shaft member, wherein at least a portion of the cylindrical member overlaps at least a portion of the shaft member in a direction along the central axis; as well as an oil seal having: a fixing portion fixed to the end surface of the cylinder member in a state of contact with the end surface of the cylinder member and existing on a plane orthogonal to the central axis of the shaft member; a sealing portion, at least a portion of which is located on the plane and in contact with the shaft member; and a connecting portion connecting the fixing portion and the sealing portion, The connecting portion includes a cylindrical vertical portion that is perpendicular to the fixing portion and concentric with the shaft member, and an inner portion that is located radially inward of the vertical portion. The inner portion passes through the plane.

2. The shaft device according to claim 1, wherein: The fixing portion has a mounting hole for fixing the oil seal to the cylindrical member.

3. The shaft device according to claim 1, wherein: The sealing portion includes an elastomer.

4. The shaft device according to claim 1, wherein: The connecting portion includes an elastic body, and at least a portion of the elastic body is located radially outside the cylindrical vertical portion.

5. A shaft device, wherein: The shaft device has: a shaft member having a central axis; a cylindrical member disposed on the outer periphery of the shaft member in a concentric manner with the shaft member, wherein at least a portion of the cylindrical member overlaps at least a portion of the shaft member in a direction along the central axis; as well as An oil seal having: a fixing portion fixed to the end surface of the shaft member in a state of contact with the end surface of the shaft member and existing on a plane orthogonal to the center axis of the shaft member; a sealing portion, at least a portion of which is located on the plane and in contact with the cylinder member; and a connecting portion connecting the fixing portion and the sealing portion, The connecting portion includes a cylindrical vertical portion that is perpendicular to the fixing portion and concentric with the shaft member, and an outer portion that is located radially outward of the vertical portion. The outer side passes through the plane.

6. A gear mechanism, wherein: This gear mechanism includes the shaft device according to any one of claims 1 to 5.

7. An oil seal, wherein: The oil seal has: a fixing portion, wherein a cylindrical member is arranged on the outer periphery of a shaft member having a central axis in a manner concentric with the shaft member, the fixing portion being fixed to the end face of the cylindrical member in a state of contact with the end face of the cylindrical member and existing on a plane orthogonal to the central axis of the shaft member, and at least a part of the cylindrical member overlaps at least a part of the shaft member in a direction along the central axis; a sealing portion, at least a portion of which is located on the plane and in contact with the shaft member; and a connecting portion connecting the fixing portion and the sealing portion, The connecting portion includes a cylindrical vertical portion that is perpendicular to the fixing portion and concentric with the shaft member, and an inner portion that is located radially inward of the vertical portion. The inner portion passes through the plane.

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