JP2916122B1 - Brush cutter - Google Patents

Abstract

To provide a brush cutter capable of preventing grease leakage from a gear case with a simple configuration. SOLUTION: The cutter shaft 1 rotates integrally with the cutter shaft 1 on the inner side in the axial direction of the outer bearing 6 so that grease inside the gear case 4 flows out of the gear case 4 through the outer bearing 6. Outflow prevention member 7 is provided to prevent the occurrence of an outflow.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brush cutter capable of preventing grease leakage from a gear case.

[0002]

2. Description of the Related Art An example of a working device including a gear case of a conventional brush cutter is shown in a sectional view of FIG.
-21219). In this working device, the power of an engine (not shown) as a drive source is inserted into the hollow portion of the rod 16 and the drive shaft 1 is rotatably supported.
5, the rotation is finally transmitted to the cutter 2, and the cutter 2 rotates. That is, the power of the engine is transmitted to the cutter 2 supported by the cutter shaft 43 via the driving gear 18 connected to the drive shaft 15 and the driven gear 3 connected to the cutter shaft 43.

[0003] The cutter shaft 43 has a gear case 40 which is opened on one side in the axial direction (downward in the state of FIG. 7).
And is rotatably supported by a pair of bearings 5 and 26 located at an axially inner portion and an opening of the gear case 40. In the gear case 40, mainly the driving gear 18
Grease is filled for lubrication of the driven gear 3 and
The outer bearing 26 located at the opening has a so-called one-sided seal bearing (ball bearing) 26 having a seal member 26c at its lower end and containing grease for self-lubrication inside in this example.
It is. The cutter 2 is sandwiched between an upper holder 9 and a lower holder 10.

[0004]

The general seal bearing used for the outer bearing 26 can seal (seal) the grease contained therein in a normal use state. However, the gear case 40 having such a configuration is used.
In the brush cutter having the gear case 4, the rotation of the drive gear 18, the cutter shaft 43 and the driven gear 3 causes the gear case 4 to rotate.
The grease for gear lubrication in the gear case 40 is stirred and the temperature rises to facilitate the flow, and at the same time, the pressure inside the gear case 40 also increases, as shown by the arrow in FIG. The grease inside 40 is formed between the seal member 26 c of the seal bearing 26 and the inner race (inner race) 2.
6a and flows out of the gear case 40, and further, the gear case 40, the upper holder 9 and the cutter 2
May scatter from the brush cutter to the outside.

On the other hand, if a normal oil seal is separately provided below the bearing 26 in order to prevent the grease inside the gear case 40 from flowing out, the structure becomes complicated, the gear case becomes large, and the cost increases. It will be up.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a brush cutter capable of preventing grease leakage from a gear case with a simple configuration.

[0007]

In order to achieve the above object, in the brush cutter according to the present invention, the gear is rotated integrally with the cutter shaft in an axially inner side of the outer bearing of the cutter shaft. An outflow prevention member is provided to prevent grease inside the case from flowing out of the gear case through the outer bearing.

According to the brush cutter of the first aspect, the grease inside the gear case is guided radially outward with a simple structure in which the outflow prevention member is provided on the cutter shaft on the axially inner side of the outer bearing. Thereby, the grease inside the gear case is prevented from entering the outer bearing, so that the grease can be prevented from leaking from the gear case.

The brush cutter according to a second aspect of the present invention is the brush cutter according to the first aspect, wherein the outer bearing is a double-sided seal bearing having seal members at both ends in the axial direction. It is set larger than the outer diameter of the inner ring of the seal bearing. According to the brush cutter of the second aspect, the grease inside the gear case is prevented from entering the outer bearing together with the labyrinth effect of the outflow prevention member and the seal member at the axial inner end of the both-side seal bearing. Therefore, the effect of preventing grease leakage is further improved.

According to a third aspect of the present invention, in the brush cutter of the first or second aspect, the outflow prevention member is sandwiched between a flange provided on a cutter shaft and an inner ring of an outer bearing. According to the brush cutter of the third aspect, the outflow prevention member, which is a separate component from the cutter shaft, may be sandwiched between the flange of the cutter shaft and the inner ring of the outer bearing, and the cutter shaft is processed into a special shape. Since there is no need, the structure is simpler and the assembly is not complicated.

According to a fourth aspect of the present invention, in the brush cutter according to any one of the first to third embodiments, the outflow prevention member has a disk shape, and its outer peripheral portion is bent inward in the axial direction to form a dish shape. Has become. According to the brush cutter of the fourth aspect, the grease moving inside the gear case in the outer bearing direction is scattered inward in the axial direction and returned by the shape of the outflow prevention member.
Grease leakage from the gear case can be more effectively prevented, and the returned grease improves the gear lubrication effect.

According to a fifth aspect of the present invention, in the bush cutter according to any one of the first to third aspects, the outflow prevention member is provided on an outer peripheral portion of the disk-shaped main body, and inside the gear case in an outer bearing direction. A plurality of blades are provided so that the moving grease is scattered inward in the axial direction and returned. According to the brush cutter of the fifth aspect, the function and effect of the brush cutter of the fourth aspect are further increased by the shape of the outflow prevention member.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a brush cutter according to a first embodiment of the present invention will be described with reference to the drawings. First, the configuration of the brush cutter will be described. This brush cutter 30 is shown in FIG.
As shown in a perspective view of FIG. 1, a small engine 31 is used as a drive source, and a rod 16 connected to a working device K having a cutter 2 is attached to a front portion of the engine 31. Drive shaft 1 freely supported
5, the power of the engine 31 is transmitted to the cutter 2,
The cutter 2 is rotated. A handle 32 that is grasped by an operator is attached to the center of the rod 15. Working device K
In addition to the cutter 2, a gear case 4, a rod mounting portion 17 integrally formed with the gear case 4, a cover 13 surrounding the opening of the gear case 4, and the like are also included.

In the working unit K, as shown in the sectional view of FIG. 1, a drive gear 18 is connected to the drive shaft 15 to transmit the power of the engine 31 (FIG. 6) to the driven gear 3. The drive-side gear 18 is rotatably supported by a drive-side bearing 19 at a shaft portion 18a thereof, and is spline-fitted to a drive shaft 15 inserted into a hollow portion of the shaft portion 18a to rotate integrally with the drive shaft 15. I do. The inner ring of the drive-side bearing 19 is press-fitted into the shaft portion of the drive-side gear 18 and is prevented from falling off by the circlip 20. The outer ring of the drive-side bearing 19 is fitted to the inner surface of a hollow rod mounting portion 17 projecting obliquely upward from the gear case 4, and is prevented from falling off toward the engine 31 (FIG. 6) by the circlip 21. The rod mounting portion 17 is configured to be detachably mounted by inserting the distal end of the rod 16 similarly to the conventional brush cutter.

A driven gear 3 to which power of an engine 31 (FIG. 6) is transmitted via the drive shaft 15 and the driving gear 18 is provided on the cutter shaft 1. The cutter shaft 1 is housed in a gear case 4 that is open on one side (downward in the state of FIG. 1) in the axial direction,
The gear case 4 is rotatably supported by a pair of bearings 5 and 6 located at an axially inner portion and an opening. The inside of the gear case 4 is filled with grease mainly for lubrication of the driving gear 18 and the driven gear 3, and the outer bearing 6 located at the opening is provided with sealing members 6 c at both ends in the axial direction. And a so-called double-sided seal bearing (ball bearing) 6 having grease for self-lubrication inside. The sealing member 6c is locked to the outer ring 6b on the stationary side, does not rotate, and the inner side contacts the inner ring 6a to provide a sealing effect.

The inner ring 6a of the outer bearing 6 supporting the cutter shaft 1 sandwiches an outflow preventing member 7 described later between the inner ring 6a and the flange 1a provided on the cutter shaft 1 while being pressed into the cutter shaft 1. ing. Inner ring of outer bearing 6
The outer end surface of a is pressed against the upper end surface of the inner peripheral portion of the upper holder 9 from below. The outer ring 6 b of the outer bearing 6 is fitted to the inner surface of the opening of the gear case 4, and is prevented from falling off (toward the cutter 2) by the circlip 8.

The lower holder 10 is tightened by a nut 12 screwed to a screw portion provided at the lower end of the cutter shaft 1 via a washer 11 so as to sandwich the cutter 2 together with the upper holder 9. That is, the cutter 2 is fixed to the cutter shaft 1 via the upper and lower holders 9 and 10 and the like. Although not shown, splines or serrations are respectively formed on the inner surface of the shaft hole of the upper holder 9 and the outer surface of the cutter shaft 1 in contact with the shaft hole, so that they mesh with each other and rotate integrally.

The periphery of the opening of the gear case 4 is covered with an outer peripheral portion of the upper holder 9 with a gap so as not to come into contact with the gear case 4.
Further, the outer peripheral portion of the upper holder 9 is covered with a cap-shaped cover 13 with a gap so as not to contact. Cover 13
Is ring-shaped, but the ring is divided on the right side in FIG.
It has a C-shape in a plan view, and a convex portion 13a on the inner periphery of the upper portion of the cover 13 is fitted into a groove formed on the outer periphery of the gear case 4, and a dividing portion is formed with a thumb screw 14 and a nut in a direction perpendicular to the paper surface. It is attached to the gear case 4 by being tightened. The lower end surface of the cover 13 covers the center of the upper surface of the cutter 2 with a gap so as not to make contact.

The outflow prevention member 7 includes a cutter shaft 1.
Is provided on the inner side in the axial direction of the outer bearing 6 at
It rotates together with the cutter shaft 1 to prevent grease inside the gear case 4 from flowing out of the gear case 4 through the outer bearing 6, and as shown in FIG. It has a disk shape with a hole through which it passes (FIG. 1). As shown in FIG. 1, the outer diameter of the outflow prevention member 7 is preferably larger than the outer diameter of the inner ring 6a of the outer bearing 6, and is preferably 2 mm or more in radius. However, it should not be so large that it contacts the inner surface of the gear case 4 or the like. Also,
It is preferable to make the material about 0.3 mm thick and made of SUS (rolled stainless steel) or SK (carbon tool steel) so as not to be thin and easily deformed.

Next, the operation and effect of the brush cutter 30 (FIG. 6) will be described. The power of the engine (FIG. 6) as the driving source is finally transmitted to the cutter 2 by the drive shaft 15, and the cutter 2 rotates. At this time, the grease for gear lubrication inside the gear case 4 is agitated by the rotation of the cutter shaft 1 and the driven side gear 3 and the temperature rises to facilitate the flow, and at the same time, the pressure inside the gear case 4 also increases. However, according to the brush cutter of the first embodiment, the cutter shaft 1 has a simple configuration in which the outflow prevention member 7 is provided on the cutter shaft 1 on the axially inner side of the outer bearing 6.
As the outflow prevention member 7 rotates, grease inside the gear case 4 is guided radially outward, and the outflow prevention member 7 and the sealing members 6c at the axially inner ends of the two-sided seal bearings 6 serving as outer bearings are formed. And prevents the grease inside the gear case 4 from entering the outer bearing 6 through the space between the seal member 6c and the inner ring 6a. Thereby, the grease inside the gear case 4 can be prevented from flowing out of the gear case 4 via the outer bearing 6.

In the brush cutter according to the first embodiment, the outflow preventing member 7, which is a separate component from the cutter shaft 1, may be sandwiched between the flange 1a of the cutter shaft and the inner ring 6a of the outer bearing 6. Since it is not necessary to machine the cutter shaft 1 into a special shape, the configuration is simple and the assembly is not complicated. In the brush cutter of the first embodiment, the outflow prevention member 7 is a separate component from the cutter shaft 1. However, in the present invention, the outflow prevention member may be formed integrally with the cutter shaft. The shape need not be a thin disk.

Next, a brush cutter according to a second embodiment of the present invention will be described with reference to the drawings. In the brush cutter according to the second embodiment, as shown in FIG. 3, the outflow prevention member 22 to be used has a disk shape, and its outer peripheral portion is bent inward in the axial direction of the gear case 4 (FIG. 1) to form a dish shape. Only in the following point, it differs from the brush cutter of the first embodiment, and the description of the other points is omitted. FIG. 3 shows the outflow prevention member 22 in FIG.
FIG. 2 is a perspective view seen from the inside in the axial direction (upward in FIG. 1) when stored in the gear case 4 of FIG. According to the brush cutter of the second embodiment, the shape of the outflow prevention member 22 causes the shape shown in FIG.
The grease moving inside the gear case 4 in the direction of the outer bearing 6 is scattered inward (upward) in the axial direction and returned, so that grease leakage from the gear case 4 can be more effectively prevented and returned. The lubricating effect of the driving gear 18 and the driven gear 3 is also improved by the grease.

Next, a brush cutter according to a third embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 4, the brush cutter according to the third embodiment uses the outflow prevention member 23.
There are a plurality of blades on the outer peripheral portion of the disk-shaped main body 23a, in which grease moving inside the gear case 4 (FIG. 1) toward the outer bearing 6 (FIG. 1) is scattered inward in the axial direction and returned. The brush cutter according to the first embodiment differs from the brush cutter according to the first embodiment only in that the brush cutter 23b is provided, and the description of other points is omitted. FIG.
FIG. 3 is a perspective view when the outflow prevention member 23 is accommodated in the gear case 4 of FIG. According to the brush cutter of the third embodiment, due to the shape of the outflow prevention member 23, the action of scattering the grease in the brush cutter of the second embodiment inward (upward) in the axial direction and returning it is further increased. As a result, the effect of preventing grease leakage from the gear case 4 (FIG. 1) and the effect of improving the lubrication effect of the driving gear 18 and the driven gear 3 (FIG. 1) are further increased.

Next, a brush cutter according to a fourth embodiment of the present invention will be described with reference to the drawings. In the brush cutter according to the fourth embodiment, as shown in FIG. 5, the outer bearing 6 is a one-sided seal bearing 26 having a seal member 26c only at an axially outer end portion. Only at the point that the diameter is set to be larger than the inner diameter of the outer ring 26b of the one-sided seal bearing 26 and the outer peripheral portion is slightly bent inward in the axial direction of the gear case 4 in order to avoid contact with the outer ring 26b. Since it differs from the brush cutter of the first embodiment, the description of other points is omitted. According to the brush cutter of the fourth embodiment, the above-mentioned labyrinth effect cannot be expected, but the grease inside the gear case 4 is guided radially outward and axially inward (upward), so that the gear case 4 Since the inside grease is suppressed from entering the outer bearing 26, grease leakage from the gear case 4 can be prevented.

[0025]

As described above, according to the brush cutter of the present invention, the grease leakage from the gear case has a simple structure in which the cutter shaft is provided with the outflow prevention member on the inner side in the axial direction of the outer bearing. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a working device of a brush cutter according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an outflow prevention member used in the bush cutter.

FIG. 3 is a perspective view of an outflow prevention member used in a brush cutter according to a second embodiment of the present invention, as viewed from the inside in the axial direction when stored in a gear case.

FIG. 4 is a perspective view of an outflow prevention member used in a brush cutter according to a third embodiment of the present invention, when viewed from an axially inner side when housed in a gear case.

FIG. 5 is a sectional view showing a main part of a working device of a brush cutter according to a fourth embodiment of the present invention.

FIG. 6 is a perspective view showing the brush cutter according to the first embodiment of the present invention.

FIG. 7 is a sectional view showing a working device of a conventional brush cutter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cutter shaft, 1a ... Flange provided in the cutter shaft, 2 ... Cutter, 3 ... Gear (driven side gear),
4 gear case, 5 inner bearing, 6, 26 outer bearing,
6a, 26a: inner ring of outer bearing; 6c, 26c: seal member of outer bearing; 7, 22, 23, 24: outflow prevention member.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tadao Yatsushiro 1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries, Ltd. Inside the Akashi Plant (56) References Japanese Utility Model No. 1-1121317 (JP, U) ( 58) Fields surveyed (Int.Cl. ⁶ , DB name) A01D 34/63-34/86

Claims (5)

(57) [Claims] 1. A brush cutter for rotating a cutter fixed to a cutter shaft by using an engine as a driving source, wherein a gear to which power of the engine is transmitted is provided on the cutter shaft, and the cutter shaft is arranged in an axial direction of the cutter shaft. It is housed in a gear case that is open on one side, and is rotatably supported by a pair of bearings that are located in an axially inner portion and an opening of the gear case. An outer bearing that is located in the opening is at least axially A seal bearing having a seal member at an outer end portion, wherein the cutter shaft rotates integrally with the cutter shaft on the axially inward side of the outer bearing in the cutter shaft, and grease inside the gear case passes through the outer bearing to form a gear. A brush cutter provided with an outflow preventing member for preventing the outflow to the outside of the case. 2. The outer bearing according to claim 1, wherein the outer bearing is a double-sided seal bearing having seal members at both ends in an axial direction, and an outer diameter of the outflow prevention member is larger than an outer diameter of an inner ring of the double-sided seal bearing. A brush cutter that is set large. 3. The brush cutter according to claim 1, wherein the outflow prevention member is sandwiched between a flange provided on the cutter shaft and an inner ring of the outer bearing. 4. The brush cutter according to claim 1, wherein the outflow prevention member has a disk shape, and an outer peripheral portion thereof is bent inward in the axial direction to have a dish shape. 5. The outflow prevention member according to any one of claims 1 to 3, wherein the outflow prevention member is provided with grease moving inside the gear case in an outer bearing direction on an outer peripheral portion of the disk-shaped main body. A brush cutter that has a plurality of blades that are scattered back.