Vibration damping member for gears and gears

Abstract

To provide a new vibration suppression member for a gear which enables further reduction of abnormal noise, and to provide a gear including the vibration suppression member.SOLUTION: A vibration suppression member 1 for a gear includes: a fixed body 10; and an annular vibration suppression body 12. The fixed body 10 has a support part 11 and a connection part 13. The annular vibration suppression body 12 is a rubber elastic body which contacts with a surface 2a of an axial end of a gear 2. The support part 11 supports the annular vibration suppression body 12. The connection part 13 is fixed to the gear 2. The gear 2 includes at least one vibration suppression member 1 for a gear.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a vibration damping member for gears and a gear.

Background Art

[0002] Gears made of metals such as iron are used in drive parts of machines such as vehicles. In metal gears, generation of abnormal noises such as tooth striking sounds and meshing sounds at the meshing portions of the gears may become a problem. As methods for reducing abnormal noises, a method of improving the accuracy of the gears themselves, and a method of splitting the gear into an inner ring and an outer ring and press-fitting an annular buffer body therebetween as disclosed in Patent Document 1 are known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A method of improving the accuracy of the gears themselves is likely to lead to an increase in cost, while the effect of reducing abnormal noises is limited. Further, even when using gears of types that can generate torsional input, such as helical gears, further reduction of abnormal noises is required.

[0005] [[ID= 38]] The present invention provides a novel vibration damping member for gears capable of further reducing abnormal noises, and a gear provided with the same.

Means for Solving the Problems

[0006] The vibration damping member for gears of the present invention includes a fixed body and an annular vibration damping body. The fixed body has a support portion and a connection portion. The annular vibration damping body is a rubber elastic body that contacts the surface of the axial end portion of the gear. The support portion supports the annular vibration damping body, and the connection portion is fixed to the gear.

[0007] The support portion is an annular plate-shaped member, and the annular vibration damping body may be fixed to the support portion so as to be coaxial with the support portion and overlapping with the support portion in the axial direction.

[0008] The support portion may be inclined toward the annular vibration damper in the axial direction as it extends from the radially inward to the radially outward direction. The connecting portion may be a cylindrical portion that extends axially toward the annular vibration damping body from the radially inner end of the support portion.

[0009] The gear of the present invention comprises at least one of the vibration damping members for gears. The gear of the present invention has an annular slit on at least one of the faces of its axial end, and the connecting portion of the vibration damping member for the gear may be fixed to the slit. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a novel vibration damping member for gears that can further reduce abnormal noise, and a gear equipped therewith. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view showing the meshing state of a gear in one embodiment of the present invention, where the gears mesh with other gears. [Figure 2] This is a cross-sectional perspective view showing the meshing state of a gear in one embodiment of the present invention, where the gears mesh with each other. [Figure 3] This is a magnified cross-sectional view showing the meshing portion where one gear and another gear mesh together according to one embodiment of the present invention. [Figure 4] This is a perspective view showing a vibration damping member for a gear according to one embodiment of the present invention. [Modes for carrying out the invention]

[0012] Hereinafter, a gear vibration damping member 1 and a gear 2 equipped with the gear vibration damping member 1 according to one embodiment of the present invention will be described with reference to Figures 1 to 4. In the following description, the direction along the axis X in the figures will be referred to as the "axial direction," the direction perpendicular to the axis X will be referred to as the "radial direction," and the direction that circles around the axis X will be referred to as the "circumferential direction."

[0013] Figure 1 is a perspective view showing the meshing state of gear 2 in which it meshes with another gear 3. Figure 2 is a cross-sectional view taken in Figure 1, cut by a plane containing the respective axes of rotation of gear 2 and the other gear 3. Figure 3 is a magnified view showing the meshing portion where gear 2 and the other gear 3 mesh in the cross-section taken by a plane containing the respective axes of rotation of gear 2 and the other gear 3. Figure 4 is a perspective view of the gear vibration damping member 1, showing the side of the annular vibration damper 12.

[0014] [gear] As shown in Figures 1 and 2, gear 2 is a helical bevel gear with multiple teeth 21 formed diagonally on the circumferential surface of a truncated cone. The other gear 3 is also a helical bevel gear. Gear 2 and the other gear 3 are arranged in opposite directions, and the teeth 21 of gear 2 and the teeth 31 of the other gear 3 mesh with each other. However, gear 2 and the other gear 3 may be other gears such as spur gears or (non-helical) bevel gears. Furthermore, gear 2 may be a pinion gear, in which case it may mesh with a rack instead of the other gear 3 to form a so-called rack and pinion.

[0015] Gear 2 is equipped with a gear vibration damping member 1 on one end in the axial direction (the end on the smaller diameter side of gear 2) surface 2a (hereinafter also simply referred to as "surface 2a"), and a gear vibration damping member 100 on the other end in the axial direction (the end on the larger diameter side of gear 2) surface 2b (hereinafter also simply referred to as "surface 2b"). Here, the gear vibration damping member 100 has a similar configuration to the gear vibration damping member 1, but is a gear vibration damping member with a larger diameter than the gear vibration damping member 1.

[0016] As shown in FIG. 3, in the gear 2, an annular slit 22a centered on the axis X is formed in a surface 2a which is an end surface extending in a direction orthogonal to the axis X. The slit 22a is formed annularly in the vicinity of the teeth 21 of the gear 2 so as to be coaxial with the gear 2. The axial depth of the slit 22a is slightly deeper than the difference between the axial length of a connecting portion 13 (to be described later) of the vibration damping member 1 for gears and the axial length (thickness) of an annular vibration damping body 12 (to be described later). The radial width of the slit 22a is the same as or slightly larger than the thickness of the connecting portion 13 (to be described later) of the vibration damping member 1 for gears.

[0017] Also, as shown in FIG. 3, in the gear 2, an annular slit 22b larger in diameter than the slit 22a and centered on the axis X is formed in a surface 2b which is an end surface (the end surface on the opposite side to the surface 2a) extending in a direction orthogonal to the axis X. The slit 22b is formed annularly in the vicinity of the teeth 21 of the gear 2 so as to be coaxial with the gear 2. The axial depth of the slit 22b is slightly deeper than the difference between the axial length of a connecting portion 113 (to be described later) of the vibration damping member 100 for gears and the axial length (thickness) of an annular vibration damping body 112 (to be described later). The radial width of the slit 22b is the same as or slightly larger than the thickness of the connecting portion 113 (to be described later) of the vibration damping member 100 for gears.

[0018] [Vibration damping member for gears] As shown in FIGS. 1 to 4, the vibration damping member 1 for gears includes a fixing body 10 and an annular vibration damping body 12.

[0019] The fixing body 10 has a support portion 11 and a connecting portion 13. The support portion 11 is a portion that supports the annular vibration damping body 12 (to be described later), and the connecting portion 13 is a portion for fixing the vibration damping member 1 for gears to the gear 2 via the connecting portion 13. The support portion 11 and the connecting portion 13 are integrated such that a cross section obtained by cutting the fixing body 10 along the axis X is substantially L-shaped.

[0020] The fixed body 10 is formed of a metal material such as iron. However, the material of the fixed body 10 is not limited to this, and it may be formed of other metals such as aluminum, alloys such as stainless steel and brass, or resins, etc. The material of the fixed body 10 may be a member having higher rigidity than the annular vibration damping body 12 described later. Also, the fixed body 10 does not necessarily have to be integrally formed from the beginning, and may be formed by connecting a support portion 11 and a connecting portion 13 which are separate members.

[0021] In the present embodiment, the support portion 11 is an annular plate-like member. That is, the support portion 11 has a circular shape (concentric circles) where the radially inner end portion 11a and the radially outer end portion 11b are coaxial, and in any part in the circumferential direction, the distance from the radially inner end portion 11a to the radially outer end portion 11b does not change (the radial width is uniform), forming a ring shape.

[0022] As shown in FIG. 3, the support portion 11 is inclined in the axial direction toward the side of the annular vibration damping body 12, that is, in the direction approaching the gear 2, as it goes from the radially inner side (the side of the radially inner end portion 11a) to the radially outer side (the side of the radially outer end portion 11b). The support portion 11 supports the annular vibration damping body 12 on the surface on the side of the connecting portion 13, that is, the inner surface facing the gear 2.

[0023] In the present embodiment, the connecting portion 13 is a cylindrical tubular portion that extends upward from the support portion 11 in the axial direction toward the side of the annular vibration damping body 12, that is, in the direction approaching the gear 2, from the radially inner end portion 11a of the support portion 11. The axial length of the connecting portion 13 is longer than the axial length (thickness) of the annular vibration damping body 12.

[0024] The annular vibration damping body 12 is a member that contacts the surface 2a at the axial end of the gear. The annular vibration damping body 12 has a circular shape (concentric circles) where the radially inner end face 12a and the radially outer end face 12b are coaxial, and in any part in the circumferential direction, the distance from the radially inner end face 12a to the radially outer end face 12b does not change (the radial width is uniform), forming a ring shape.

[0025] The annular vibration damper 12 has a predetermined thickness that is longer in the axial direction than the support portion 11 of the fixed body 10. However, depending on the purpose, the axial thickness of the annular vibration damper 12 may be the same as that of the support portion 11, or it may be thinner than that of the support portion 11.

[0026] The annular vibration damper 12 is fixed to the inner surface of the support portion 11, which is close to the gear 2, so as to be coaxial with the support portion 11, which is also annular, and so as to overlap with the support portion 11 in the axial direction. In other words, the inner and outer diameters of the annular vibration damper 12 and the inner and outer diameters of the support portion 11 are set so that the annular vibration damper 12 and the support portion 11 can overlap in the axial direction.

[0027] In this embodiment, the outer diameter of the annular vibration damper 12 is approximately equal to the outer diameter of the support portion 11. In addition, in this embodiment, the inner diameter of the annular vibration damper 12 is larger than the inner diameter of the support portion 11. As a result, the radially inner end face 12a of the annular vibration damper 12 is separated from the connection portion 13. However, the radially inner end face 12a of the annular vibration damper 12 may be in contact with the connection portion 13.

[0028] The annular vibration damper 12 is formed from a rubber elastic material. Examples of materials for the rubber elastic material that can form the annular vibration damper 12 include thermosetting elastomers such as natural rubber and synthetic rubber, and thermoplastic elastomers such as styrene-based, olefin-based, PVC-based, acrylic-based, polyamide-based, polyester-based, and polyurethane-based materials. The annular vibration damper 12 may also be formed from a porous material such as urethane foam. The annular vibration damper 12 may be fixed to the support part 11 by vulcanization bonding, or by fixing using an adhesive or the like. Alternatively, the fixing body 10 and the annular vibration damper 12 may be integrally molded by insert molding or the like.

[0029] As shown in Figure 3, the gear damping member 1 is fixed in an integrated state with the gear 2 by press-fitting the connecting portion 13 into the slit 22a. However, the fixing of the connecting portion 13 and the slit 22a may be done with adhesive or the like. The annular damping body 12 of the gear damping member 1 is in contact with the surface 2a of the gear 2 and the end faces 21a of the multiple teeth 21 in the axial direction. Since the annular damping body 12 is sandwiched between the multiple teeth 21 of the gear 2 and the support portion 11, it is pre-pressurized in the axial direction and is slightly deformed.

[0030] As shown in Figures 2 and 3, the gear vibration damping member 100 comprises a fixed body 110 and an annular vibration damping body 112. The fixed body 110 has a support portion 111 and a connecting portion 113. Except for the points described below, the configuration of the gear vibration damping member 100, fixed body 110, annular vibration damping body 112, support portion 111, and connecting portion 113, and their relationships with each other, are the same as the configuration of the gear vibration damping member 1, fixed body 10, annular vibration damping body 12, support portion 11, and connecting portion 13, respectively, and their relationships with each other, so some explanation will be omitted.

[0031] The support portion 111 is an annular plate-shaped member similar to the support portion 11, but the inner diameter and outer diameter of the support portion 111 are larger than the inner diameter and outer diameter of the support portion 11, respectively. The radial width of the support portion 111 is the same as the radial width of the support portion 11. The connecting portion 113 is a cylindrical tubular part similar to the connecting portion 13, but the inner diameter and outer diameter of the connecting portion 113 are larger than the inner diameter and outer diameter of the connecting portion 13, respectively.

[0032] The annular vibration damper 112 is a ring-shaped member similar to the annular vibration damper 12, but its inner and outer diameters are larger than those of the annular vibration damper 12, respectively. The radial width of the annular vibration damper 112 is the same as the radial width of the annular vibration damper 12.

[0033] As shown in Figure 3, the gear damping member 100 is fixed in an integrated state with the gear 2 by press-fitting the connecting portion 113 into the slit 22b. However, the fixing of the connecting portion 113 and the slit 22b may be done with adhesive or the like. The annular damping body 112 of the gear damping member 100 is in contact with the surface 2b of the gear 2 and the end faces 21b of the multiple teeth 21 in the axial direction. Since the annular damping body 112 is sandwiched between the multiple teeth 21 of the gear 2 and the support portion 111, it is pre-pressurized in the axial direction and is slightly deformed.

[0034] In a gear 2 equipped with gear vibration damping members 1 and 100, the annular vibration damping bodies 12 and 112 are in contact with the teeth 21 of the gear 2, and preload is applied to the annular vibration damping bodies 12 and 112 by the support portion 11 of the fixed body 10 and the support portion 111 of the fixed body 110, thereby providing a vibration damping effect to the gear 2 and suppressing the generation of abnormal noise. In the gear 2, since the gear 2 and the teeth 21 are sandwiched between the annular vibration damping bodies 12 and 112, a vibration damping effect against omnidirectional vibrations of the teeth 21 caused by torsional forces is obtained more effectively.

[0035] Furthermore, in the gear vibration damping members 1 and 100, the support portions 11 and 111 are inclined toward the annular vibration dampers 12 and 112 in the axial direction as they move from the radially inward to the radially outward direction. Therefore, even if permanent deformation occurs due to compression set in the rubber-elastic annular vibration dampers 12 and 112 after long-term use, the preload applied to the annular vibration dampers 12 and 112 is maintained, and the noise reduction effect due to vibration damping is sustained over a long period of time.

[0036] [Other embodiments] Although embodiments of the present invention have been described above, the present invention is not limited thereto and can be modified as appropriate without departing from its technical spirit.

[0037] In the above embodiment, the gear 2 is provided with a gear vibration damping member 1 on surface 2a and a gear vibration damping member 100 on surface 2b. However, the gear of the present invention is not limited to this, and may be provided with only one gear vibration damping member on either surface.

[0038] In the above embodiment, the support portion 11 of the fixed body 10 of the gear vibration damping member 1 is an annular plate-shaped member and has a ring shape with a uniform radial width. However, the gear vibration damping member of the present invention is not limited to this, and the support portion may have an uneven pattern by having one or more notches or protrusions on its inner circumference and / or outer circumference. Furthermore, the support portion does not necessarily have to be an annular plate-shaped member. For example, a support portion consisting of multiple plate-shaped members or wires may extend radially from the radially inner side to the outer side to support the annular vibration damping body.

[0039] In the above embodiment, the support portion 11 of the fixed body 10 of the gear vibration damping member 1 is inclined toward the annular vibration damping body 12 in the axial direction as it moves from the radially inward end 11a to the radially outward end 11b. However, the gear vibration damping member of the present invention is not limited to this, and the support portion may not be inclined and may extend radially (perpendicular to the axial direction).

[0040] In the above embodiment, the connecting portion 13 of the fixed body 10 of the gear vibration damping member 1 is a cylindrical portion that extends from the radially inner end 11a of the support portion 11 so as to rise axially toward the annular vibration damping body 12, and the gear vibration damping member 1 is fixed in an integral state with the gear 2 by press-fitting the connecting portion 13 into an annular slit 22a formed on the surface 2a of the gear 2. However, the manner of connection between the gear vibration damping member and the gear of the present invention is not limited to this, and any manner is acceptable as long as the fixed body of the gear vibration damping member is fixed to the gear via the connecting portion.

[0041] For example, the connecting portion may have a plane of any shape perpendicular to the axial direction (extending radially), and this plane and the surface of the axial end of the gear may be fixed together with an adhesive or the like. In this case, it is not necessary to form an annular slit on the surface of the axial end of the gear.

[0042] Alternatively, for example, the connecting portion may be a plurality of pins or protrusions provided intermittently in the circumferential direction so as to rise axially toward the annular vibration damping body side from the radially inner end of the support portion, and the vibration damping member for the gear may be fixed to the gear by press-fitting the plurality of pins or protrusions into a plurality of corresponding holes or recesses formed on the surface of the axial end of the gear, or by fixing them via adhesive or the like.

[0043] In the above embodiment, the annular vibration damper 12 of the gear vibration damping member 1 is in contact with the surface 2a of the gear 2 and the end faces 21a of the multiple teeth 21 in the axial direction, and the annular vibration damper 112 of the gear vibration damping member 100 is in contact with the surface 2b of the gear 2 and the end faces 21b of the multiple teeth 21 in the axial direction. However, the annular vibration damper of the gear vibration damping member of the present invention may not be in contact with the end faces of the gear teeth, but may only be in contact with the end faces of the gear (corresponding to surfaces 2a and 2b in the above embodiment). Conversely, the annular vibration damper of the gear vibration damping member of the present invention may only be in contact with the end faces of the gear teeth.

[0044] Furthermore, those skilled in the art may modify the gear damping member and gear of the present invention as appropriate in accordance with conventionally known knowledge. As long as such modifications still possess the configuration of the present invention, they are of course included within the scope of the present invention. [Explanation of symbols]

[0045] 1,100... Vibration damping member for gears, 2... Gear, 2a,2b... Surface, 3... Other gears, 10,110... Fixed body, 11,111... Support part, 11a... Radially inner end, 11b... Radially outer end, 12,112... Annular vibration damping body, 12a... Radially inner end face, 12b... Radially outer end face, 13,113... Connecting part, 13a... End, 21... Tooth, 21a,21b... End face, 22a,22b... Slit, 31... Tooth, X... Axis

Claims

1. A fixed body and Equipped with an annular vibration damping body, The aforementioned fixed body has a support portion and a connecting portion, The aforementioned annular vibration damper is a rubber elastic body that contacts the surface of the axial end of the gear. The support portion supports the annular vibration damping body. The aforementioned connection part is fixed to the gear, The annular vibration damping body is formed coaxially with the gear, The annular vibration damping body is a gear vibration damping member that contacts the end faces of multiple teeth of the gear in the axial direction.

2. The support portion is an annular plate-shaped member, The annular vibration damping body is fixed to the support so as to be coaxial with the support and overlapping with the support in the axial direction. The vibration damping member for gears according to claim 1.

3. The support portion is inclined toward the annular vibration damper in the axial direction as it extends from the radially inward to the radially outward direction. The vibration damping member for gears according to claim 1 or 2.

4. The connecting portion is a cylindrical portion that extends axially toward the annular vibration damping body from the radially inner end of the support portion. A vibration damping member for gears according to any one of claims 1 to 3.

5. A gear comprising at least one vibration damping member for gears as described in any one of claims 1 to 4, The gear has multiple teeth, The annular vibration damper is in contact with the end faces of the plurality of teeth in the axial direction, and is a gear.

6. The gear has an annular slit on at least one of the faces at its axial end, The connecting portion of the gear vibration damping member is fixed to the slit. The gear according to claim 5.

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