JPS6322094Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention provides an input shaft linked to the engine and an output shaft linked to the axle in a vertically concentric manner, and both shafts are interlocked and connected via a gear type reduction mechanism, and The present invention relates to a walk-behind working machine in which various rotating bodies such as wheels and tiller shafts can be attached to the axle.

To configure a gear type reduction mechanism in the above working machine, conventionally, a planetary gear member is rotatably attached to a holder connected to an output shaft, and the planetary gear member is gear-transmitted to the input shaft. An outer ring gear was provided so as to mesh with the outer ring gear, and it was constructed with a so-called planetary reduction mechanism using a planetary gear member that rotated and revolved (for example,
(Refer to Utility Model Application Publication No. 56-23744).

However, when changing the transmission reduction ratio from the input shaft to the output shaft, it was necessary to prepare expensive outer ring gears with different diameters with machined internal teeth, which had the disadvantage of being uneconomical. .

In view of the above points, the present invention aims to make changing the transmission reduction ratio inexpensive and easy to assemble, and to make it possible to easily change the transmission reduction ratio while ensuring good transmission. With the goal.

In order to achieve the above objectives, the walking type work machine according to the present invention has an input shaft linked to the engine and an output shaft linked to the axle arranged vertically and concentrically, and a holder is attached to the transmission case. A large-diameter external gear in which three or more support shafts are connected to the holder at equal intervals in the circumferential direction and mesh with an external gear part provided at the shaft end of the input shaft for deceleration transmission. and a small-diameter external gear that is rotatably integrally engaged with an external gear provided at the end of the output shaft for deceleration transmission, are loosely fitted and supported on each of the support shafts, and It is characterized in that the ends of each support shaft are connected and supported by a reinforcing member.

The effects of the above configuration are as follows.

In other words, since it is a reduction transmission using a two-stage gear that combines a large-diameter external tooth gear and a small-diameter external tooth gear, it is possible to reduce the speed by changing the gear member that has external teeth machined, such as the large-diameter gear and the small-diameter gear. This changes the transmission reduction ratio from the input shaft to the output shaft, and also causes the reinforcing member to receive the reaction forces applied to the support shaft due to gear transmission in a state where these forces cancel each other out.

The effects of the above action are shown below.

In other words, any of the gear members prepared for changing the transmission reduction ratio can be made into easily machined external gear parts, which reduces the expense required to prepare these parts and allows the transmission reduction ratio to be changed at low cost. It became like that.

Since three or more two-stage gears each consisting of a pair of a large-diameter external gear and a small-diameter external gear are used, and they are arranged at equal intervals in the circumferential direction, The small-diameter external gears of the two-stage gears sandwich the external gear part provided at the shaft end of the output shaft from three or more directions, and the two
If the external gear part provided at the shaft end of the input shaft is inserted into the center of the common circle for each large-diameter external gear of the stage gears, the axis of the output shaft and the axis of the input shaft will be aligned. necessarily match. Therefore, for example, by using one or two of the two-stage gears, the small-diameter external gear of the two-stage gear can mesh with the external gear part provided at the shaft end of the output shaft, with the small-diameter external gears of the two-stage gears facing each other from one or both sides. This has the advantage that centering of the output shaft and input shaft can be easily performed, and assembly can be easily performed, compared to the case where the output shaft and the input shaft are aligned.

Moreover, since the large and small gears are loosely fitted onto the support shaft protruding from the holder, compared to, for example, a case where the large and small gears are integrally and rotatably attached to the support shaft and the support shaft is rotatably attached to the holder, the large and small gears are It can be attached to or removed from the support shaft by inserting and removing from one side of the holder, making it easy to replace large and small gears with gears of different diameters, that is, to easily change the transmission reduction ratio. It became like that.

Furthermore, since the support shaft is cantilever-supported by the holder, as power is transmitted from the input and output shafts to the large and small gears, a force acts to displace the support shaft away from the input and output shafts, and gear transmission is reduced. However, according to the present invention, in cooperation with the configuration in which the support shafts are attached to the holder at equal intervals in the circumferential direction, the support shafts are pushed against each other through the reinforcing member, and the input shaft and It has now become possible to reliably avoid separation from the output shaft and achieve good gear transmission.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

A transmission case 2 is connected to the lower part of the engine 1, a tiller claw shaft 4 is attached to an axle 3 protruding from the lower part of the transmission case 2, a handle 5 is extended rearward from the transmission case 2, and a resistor is installed. A walking type cultivator is provided with a rod 6, and the tiller claws 4a are also used as propulsion wheels to carry out tilling work while traveling.

In order to transmit power from the engine 1 to the axle 3, an input shaft 7 and an output shaft 8 from the engine 1 are provided vertically concentrically with each other, and the first cylindrical shaft 9 is integrally rotatable with the output shaft 8. At the same time, the second cylinder shaft 10 is loosely fitted onto the first cylinder shaft 9, and the input shaft 7 and the second cylinder shaft 10 are interlocked and connected via the gear type reduction mechanism 11. The output shaft 8 is interlocked with the first cylindrical shaft 9 via a ball clutch 12.
and the axle 3 are interlocked and connected via a bevel gear mechanism 13.

To configure the gear type reduction mechanism 11, an annular holder 14 is attached to the transmission case 2, and three support shafts 14a are provided protruding from the holder 14 with a phase difference of 120 degrees. 14a...A cylindrical shaft 15 for intermediate transmission is rotatably attached to each of the cylindrical shafts 15...A large diameter gear (large diameter external gear) 16 is integrally and rotatably attached to the upper side of each of the cylindrical shafts 15...
On the other hand, there is a small diameter gear (small diameter external gear) 17 on the lower side.
are integrally connected to each other, the large-diameter gear 16 is engaged with an externally toothed gear portion 7a that is connected to the lower end side of the input shaft 7, and a small-diameter gear 17 is connected to the second cylindrical shaft 10. The input shaft 7 is engaged with the external gear part 10a.
The structure is such that the speed is reduced in two steps and transmitted to the output shaft 8.

The holder 14 is rotatably attached to the mission case 2, and the outer peripheral surface of the holder 14 is
Forming recesses 18 with different phases by 90°,
On the other hand, balls 19 that fit into the recesses 18 are provided on the case wall 2a of the transmission case 2, and are biased toward the fitting side by a spring 20, so that the drive load of the axle 3 exceeds a set value. When the force increases, the balls 19 are separated from the recesses 18 against the biasing force of the spring 20, and the input shaft 7
The torque limiter 21 is configured so that the power transmission from the to the second cylinder shaft 10 is automatically cut off. The torque limiter 21 may be constructed, for example, by sandwiching the peripheral edge of the holder 14 between a pair of plates and attaching a spring or the like to one of the plates to apply a predetermined clamping pressure. Various structural modifications are possible as long as the holder 14 is frictionally held to the mission case 2 so as to be rotatable under the above load.

An annular reinforcing member 22 is removably attached across the lower ends of the support shafts 14a.
a... is the large and small gear 1 from the input shaft 7 and output shaft 8.
It is configured to reliably prevent it from being knocked outward as a result of power transmission to each of the parts 6 and 17.

In the gear reduction mechanism 11, when changing the reduction ratio from the input shaft 7 to the output shaft 8, for example, gears of a predetermined diameter are attached to the input shaft 7 and output shaft 8, respectively, and large and small gears corresponding to the gears are attached. The gear is replaced with the support shaft 14a.

According to the present invention, four or more supporting shafts 14a may be provided.

Note that although reference numerals are written in the claims section of the utility model registration for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by such entry.

[Brief explanation of the drawing]

The drawings show an embodiment of the walk-behind power cultivator according to the present invention; FIG. 1 is an overall side view of the walk-behind cultivator, FIG. 2 is a vertical sectional view of the main parts, and FIG. It is a partially cutaway view taken along the arrow. 1... Engine, 2... Mission case, 3
...Axle, 7...Input shaft, 8...Output shaft, 14...
...Holder, 14a... Support shaft, 16... Large diameter external gear, 17... Small diameter external gear, 22... Reinforcement member, 7a, 10a... External gear part.

Claims (1)

[Scope of utility model registration request] An input shaft 7 linked to the engine 1 and an output shaft 8 linked to the axle 3 are provided vertically and concentrically, and a holder 14 is attached to the transmission case 2, and the holders 14 are spaced apart from each other at equal intervals in the circumferential direction. three or more support shafts 14a are arranged in series, and the input shaft 7
A large-diameter external gear 16 is provided at the shaft end of the output shaft 8 and is rotatable integrally with the large-diameter external gear 16 that engages with the external gear portion 7a provided at the shaft end of the output shaft 8 for deceleration transmission. A small-diameter external gear 17 that engages with the shaft 10a to transmit deceleration transmission is loosely fitted and supported on each of the support shafts 14a, and the ends of the support shafts 14a are connected to each other by a reinforcing member 22. A walking type work machine characterized by being supported.