JP2004232767A - Breather mechanism of gear device of work machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a breather mechanism of a gear device of a work machine for increasing a grease supply quantity, reducing external leakage, lengthening a grease supply interval, and superior in working efficiency. <P>SOLUTION: A gear case 20 of the gear device 10 is rotatably installed on an output shaft 13 having a first bevel gear 14 via first and second bearings 15 and 16, and a first oil seal 17 is arranged outside the first bearing 15. A gear shaft 22 integrally constituted in a base end part of a second bevel gear 21 is rotatably installed in the right-angled direction to the output shaft 13 in the gear case 20 via third and fourth bearings 23 and 24, and a second oil seal 25 is arranged outside the fourth bearing 24. The first bevel gear 14 meshes with the second bevel gear 21. A connecting hole 26 with a flexible shaft for driving the work machine is arranged in an end part on the opposite side of the gear of the gear shaft 22, and a shaft hole 27 for communicating with the connecting hole 26 is arranged in a gear side end part. A blind cover 30 having a breather hole 31 is fitted in a bottom part of the shaft hole 27. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a breather mechanism of a gear device of a power take-out unit for driving a working machine, which is provided in an engine of the working machine.
[0002]
[Prior art]
Regarding the configuration of the engine portion of a backpack-type working machine, which is a working machine, for example, Patent Literature 1 discloses a backpack-type working machine carrying frame.
[0003]
According to the above configuration in FIG. 2, reference numeral 1 denotes a backing frame, on which the engine 2 and the fuel tank 3 are mounted. The engine 2 is mounted with the cylinder horizontal and the output shaft facing upward, and a gear device 10a for transmitting power to the flexible shaft 7 for driving the working machine is provided at the tip of the output shaft. I have. The backpack frame 1 is manufactured by integral molding of a resin material. Frames 5 are provided at the left and right ends of the vertical portion 4 of the backpack frame 1, and the vertical portion 4 and the frame 5 form a storage portion. ing. A handle portion 6 is formed at an upper portion of the vertical portion 4, and the fuel tank 3 is stored in the storage portion. Thereby, the fuel tank 3 and the engine 2 can be held near the back of the worker, so that the burden on the worker can be reduced, and the fuel tank 3 may come into contact with obstacles and be damaged during the work. There is no.
[0004]
Although not specifically described in Patent Document 1, two bevel gears (not shown) are rotatably supported via bearings in a gear case 20a of the conventional gear device 10a, and a flexible bevel gear on the driven side is provided. A connection portion with the shaft 7 is provided. The bearing and the bevel gear are lubricated by grease injected into the gear case 20a. The gear device 10a is not provided with an oil seal, and the amount of grease to be injected is set to be small in advance in order to minimize leakage of grease to the outside.
[0005]
[Patent Document 1]
Japanese Patent Application No. 2002-234893 (pages 5 to 6, FIG. 1)
[0006]
[Problems to be solved by the invention]
However, in the above configuration, since the amount of grease injected into the gear case is set to be small, the greasing interval is short, and the working efficiency is reduced. In addition, since there is no oil seal, if the grease temperature increases during operation, the viscosity may decrease, and the oil may flow out of the gear case, which further shortens the greasing interval.
[0007]
The present invention has been made by paying attention to the above problems, and it is possible to improve the work efficiency by increasing the grease supply amount and lengthening the greasing interval, and there is no possibility that the grease leaks to the outside. Another object of the present invention is to provide a breather mechanism for a gear device of a working machine.
[0008]
Means for Solving the Problems, Functions and Effects
In order to achieve the above object, a first invention is directed to a gear device provided in an engine output take-out portion of a work machine, wherein a first bevel gear attached to an output shaft of an engine and one end of the gear shaft are integrated. A second bevel gear configured to mesh with the first bevel gear, a gear case that rotatably supports the output shaft and the gear shaft via a bearing, and stores lubricating grease; A connection hole with a flexible shaft for driving a working machine, provided at an end opposite to the gear, and provided between the gear case and the output shaft and between the gear case and the gear shaft. An oil seal, a blind cover fitted at the bottom of a shaft hole communicating with the connection hole, provided at an end of the gear shaft on the gear side, and a breather hole provided in the blind cover. It has a configuration.
[0009]
According to the first invention, since the oil seal is provided between the gear case, the output shaft, and the gear shaft, the outflow of grease can be prevented, and the grease supply interval can be increased. In addition, the breather hole provided in the bevel gear housed in the gear case allows grease to escape from the breather hole to the outside at the initial stage even if the gear case is filled with grease when injecting grease. Can be suppressed, and damage to the oil seal can be prevented. Furthermore, since the breather hole is fitted in the bottom of the shaft hole provided in the gear shaft and provided on the blind lid, an outward force acts on the grease due to centrifugal force due to rotation of the gear during operation. As a result, the grease moves back into the gear case and prevents the grease from flowing out of the breather. Therefore, the grease can be filled in the gear case at the time of injecting grease so that the greasing interval can be lengthened, and the workability can be improved.
[0010]
According to a second invention, in the first invention, the breather hole has a diameter of 0.5 to 2 mm, and the plate thickness of the blind lid is 0.4 to 3 times the diameter of the breather hole.
[0011]
According to the second aspect of the present invention, the diameter of the breather hole is reduced, and the thickness of the blind lid is set to 0.4 to 3 times the diameter of the breather hole. Therefore, even if the breather hole is turned downward during stoppage, grease does not flow out.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a breather mechanism of a gear case of a backpack type working machine which is a working machine according to the present invention will be described in detail with reference to the drawings.
[0013]
FIG. 1 is a side cross-sectional view of a gear device 10 provided in an engine output extracting portion of a backpack working machine. In FIG. 1, an output shaft 13 connected to a crankshaft of an engine (not shown) is rotatably supported via a bearing 12 on a lid 11 attached to a power take-out portion of a crankcase of the engine (not shown). A first bevel gear 14 is fixed to the output shaft 13, and a gear case 20 is rotatably mounted via a first bearing 15 and a second bearing 16. A first oil seal 17 is provided outside the first bearing 15. A gear shaft 22 integrally formed at the base end of a second bevel gear 21 is rotatably mounted on the gear case 20 via a third bearing 23 and a fourth bearing 24 in a direction perpendicular to the output shaft 13. Have been. The second bevel gear 21 meshes with the first bevel gear 14. A second oil seal 25 is provided outside the fourth bearing 24. The gear shaft 22 is provided at the end opposite to the second bevel gear 21 with a connection hole 26 for connection to the working machine driving flexible shaft 7 described with reference to FIG. Is provided with a shaft hole 27 communicating with the connection hole 26. A blind cover 30 is fitted into the bottom 28 of the shaft hole 27, and the blind cover 30 has a breather hole 31. The diameter D of the breather hole 31 is, for example, 1 mm, and the plate thickness T of the blind lid 30 is, for example, 1.6 mm. The gear case 20 is provided with an injection port 18 for injecting grease.
[0014]
Grease is injected from the injection port 18 so as to substantially fill the area surrounded by the first oil seal 17 and the second oil seal 25 of the gear case 20. At this time, the air in the gear case 20 is discharged outside through the breather hole 31. When the engine is driven, the rotation of the output shaft 13 is transmitted from the first bevel gear 14 to the second bevel gear 21, and drives the working machine via the flexible shaft 7 (not shown) connected to the connection hole 26. At this time, the grease lubricates the first bevel gear 14, the second bevel gear 21, the first bearing 15, the second bearing 16, the third bearing 23, and the fourth bearing 24.
[0015]
Since the breather mechanism of the gear device of the working machine according to the present invention has the above-described configuration, the following effects can be obtained.
A breather hole is provided in the bevel gear stored in the gear case, so even if grease is excessively filled in the gear case at the time of grease injection, grease can escape from the breather hole to the outside at the initial stage, causing a sharp pressure increase in the gear case. And the oil seal is not damaged. Therefore, a sufficient amount of grease can be supplied, and the greasing interval can be lengthened to improve workability.
Since the breather hole is fitted in the bottom of the shaft hole provided in the gear shaft and provided in the blind lid, during operation, as shown by arrow a in FIG. An outward force acts on the inner grease. Therefore, the grease moves back into the gear case 20 to prevent the grease from flowing out from the breather hole 31.
The diameter of the breather hole was 0.5 to 1.5 mm, and the thickness of the blind lid was 0.4 to 3 times the diameter of the breather hole. Therefore, grease does not flow out even if the breather hole is turned downward during stop.
[0016]
Although the working machine according to the present invention has been described by taking a backpack working machine as an example, the breather mechanism of the gear device of the working machine of the present invention can be applied to other working machines such as, for example, a hand-held mower. Needless to say, there is no change in operation and effect even when applied.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a gear device of a backpack type working machine according to the present invention.
FIG. 2 is a perspective view of an engine portion of the backpack type working machine.
[Explanation of symbols]
Reference Signs List 10 gear device, 13 output shaft, 14 first bevel gear, 15 first bearing, 16 second bearing, 17 first oil seal, 18 injection port, 20 gear case, 21 second bevel Gears, 22: gear shaft, 23: third bearing, 24: fourth bearing, 25: second oil seal, 26: connecting hole, 27: shaft hole, 28: bottom, 30: blind cover, 31: breather hole.

Claims (2)

In the gear device (10) provided in the engine output extraction portion of the work machine,
A first bevel gear (14) mounted on an output shaft (13) of the engine (2);
A second bevel gear (21) integrally formed at one end of the gear shaft (22) and meshing with the first bevel gear (14);
A gear case (20) that rotatably supports the output shaft (13) and the gear shaft (22) via bearings (15, 16, 23, 24) and stores lubricating grease;
A connection hole (26) provided at an end of the gear shaft (22) on the opposite side of the gear, for connection with a working machine driving flexible shaft (7);
Oil seals (17, 25) provided between the gear case (20) and the output shaft (13) and between the gear case (20) and the gear shaft (22);
A blind cover (30) fitted in a bottom (28) of a shaft hole (27) communicating with the connection hole (26) provided at a gear-side end of the gear shaft (22);
A breather mechanism for a gear device of a working machine, comprising a breather hole (31) provided in the blind lid (30). The breather mechanism for a gear device of a working machine according to claim 1,
The breather hole (31) has a diameter of 0.5 to 2 mm, and the thickness of the blind lid (30) is 0.4 to 3 times the diameter of the breather hole (31). Breather mechanism of gear unit of work machine.

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