JPH10271901A - Transmission mechanism of power tiller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission mechanism of a power tiller capable of reducing vibration and noise by absorbing the vibration caused by looseness, etc., of a fitting part, and improving operability by installing a vibrational absorbing member in a transmission system. SOLUTION: A worm gear is installed in a transmission system from a shaft 5 of a driving part 4 to a rotor 2, a warm shaft 10a of the warm gear is connected to a shaft 5 through a fitting part 13, and a vibrtation-absorbing member 15 is installed in the transmission system. Further, the vibration-absorbing member 15 is preferably a flexible shaft and the fitting part 13 is preferably fixed thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission mechanism for a cultivator.

[0002]

2. Description of the Related Art In a conventional power transmission mechanism of a cultivator, a motor shaft mounted in a motor case is connected to a worm shaft of a worm gear via a fitting portion, and a worm wheel meshes with a worm on the worm shaft. The rotor is fixed to the worm wheel shaft. By the rotation of the motor, its power is transmitted to the shaft, the worm, and the worm wheel, and the rotor rotates.

[0003]

However, in the above-mentioned conventional transmission mechanism, the fitting portion is engaged with the spline shaft and the spline hole, so that there is some backlash during rotation. At the time of non-load drive without pressing, vibration from the fitting portion is transmitted from the shaft to the motor case via the ball bearing, and the motor case may resonate, generating large noise and vibration.
Further, when a magnet motor is used for the drive unit, the quietness, which is a characteristic of the magnet motor, is lost.

[0004] Such a problem can be solved by integrating the motor shaft with the worm, but the worm gear below the worm shaft has a larger diameter than the worm shaft, and a bearing to be attached to the worm shaft is assembled. And a new problem arises in that the gear case and the bearing of the worm gear must be formed separately if the assembly is attempted.

Accordingly, an object of the present invention is to solve such a problem.

[0006]

To achieve the above object, according to the first aspect of the present invention, a worm gear is interposed in a transmission system from a shaft 5 of a drive unit 4 to a rotor 2, and a worm shaft 10a of the worm gear is provided. Is connected to the shaft 5 via fitting portions 13, 21, 22 in a transmission mechanism of a cultivator, wherein the vibration absorbing members 15, 1 are provided in the transmission system.
According to a second aspect of the present invention, the vibration absorbing member includes flexible shafts (19, 2).
The worm gear transmission mechanism according to claim 1, wherein the worm gear is interposed in a transmission system extending from the shaft 5 of the drive unit 4 to the rotor 2, and the worm shaft 10a of the worm gear is provided. Is fitted to the shaft 5
In the transmission mechanism of the cultivator connected via 3, 21, 22, the fitting portions 13, 21, 22 are fixed.

[0007]

Next, an embodiment of the present invention will be described with reference to the drawings.

Embodiment 1 As shown in FIGS. 1 and 2, this cultivator has a rotor 2 and a handle 3 below and behind a motor case 1 which is a cultivator body.

In the motor case 1, a motor 4, which is a drive unit of the cultivator, is mounted vertically.
The motor case 1 is divided into right and left, and the motor 4 is sandwiched and fixed from the left and right.

The shaft 5 of the motor 4 also extends in the motor case 1 in the vertical direction, and is supported by the motor case 1 via bearings 6 and 7 at portions where the motor body projects upward and downward, respectively. Motor 4
Although the shaft 5 is integral with the shaft in the motor body in the illustrated example, it may be made as a separate body and connected via a connector.

An upper end of a pipe 8 through which the shaft 5 passes is fixed to a lower side of the motor case 1, and a gear case 9 is fixed to a lower end of the pipe 8. A worm 10 is vertically inserted into a portion of the gear case 9 which communicates with the pipe 8, and worm shafts 10 a are provided with bearings 11 and 12.
Through the gear case 9.

The upper end of the worm shaft 10a is detachably connected to the lower end of the shaft 5 of the motor 4 via a fitting portion 13. The fitting portion 13 is formed by a connection between a spline shaft and a spline hole, a connection between a square shaft and a square hole, and the like. Therefore, the shaft 5 of the motor 4 can be connected to the worm shaft 10a after the worm shaft 10a is mounted in the gear case 9 together with the bearings 11 and 12.

The worm 1 is provided in the gear case 9.
The worm wheel 14 that meshes with the worm wheel 0 is inserted, the worm wheel shaft 14a is rotatably supported by the gear case 9, and the rotor 2 is fixed to both left and right ends of the worm wheel shaft 14a. As a result, when the motor 4 is started, its driving force is sequentially transmitted to the shaft 5, the fitting portion 13, the worm 10, and the worm wheel 14, and the rotor 2 rotates.

The shaft 5 is vertically divided into two parts in a pipe 8, and the upper and lower parts of the shaft 5 are connected by a joint 15 which is a vibration absorbing member. The joint 15 is made of rubber,
It is made of a material such as a synthetic resin capable of absorbing vibration. The joint 15 is a cylindrical body rotatable in the pipe 8, and has a square hole formed on both sides thereof, into which square shafts 5 a and 5 b formed on the upper and lower portions of the shaft 5 are fitted. The rotation of the shaft 5 is transmitted to the rotor 2 via the joint 15, and at this time, vibration generated due to a gap or the like in the fitting portion 13 is absorbed by the joint 15.

The handle 3 is fixed to the motor case 1 with fixing screws 16 so that the position can be adjusted. The motor 4 is turned on and off near the grip 3a of the handle 3.
A switch device 17 for performing FF operation or the like is attached. A resistance bar 18 is provided below the handle 3 so as to be in contact with the ground. The resistance bar 18 is attached to the motor case 1 so that the position of the resistance bar 18 can be adjusted in the vertical direction.

Embodiment 2 In this embodiment, the vibration absorbing member is constituted by a flexible shaft 19 as shown in FIG.
As in the first embodiment, the shaft 5 is divided into upper and lower parts, and both ends of the flexible shaft 19 are
Are bonded to the upper and lower portions by caulking, bonding, or the like.

Embodiment 3 In this embodiment, the vibration absorbing member is constituted by a flexible shaft 20, as shown in FIG. The lower part is omitted, and the lower end of the flexible shaft 20 and the upper end of the worm shaft 10a are connected via the fitting part 21.

The fitting portion 21 includes a square shaft 20a formed at the lower end of the flexible shaft 20, and a square hole formed at the upper end of the worm shaft 10a into which the square shaft 20a is inserted. The position where the square shaft 20a and the square hole are provided may be switched between the flexible shaft 20 and the worm shaft 10a.

Embodiment 4 In this embodiment, as shown in FIG. 5, the vibration absorbing member includes a shaft 5 of a motor 4 and a worm shaft 10.
a is provided in the fitting portion 22.

A gap is formed in the fitting portion 22, and a synthetic resin film 23 is inserted into the gap as a vibration absorbing member. Instead of the synthetic resin film 23, a spacer made of rubber, synthetic resin, or the like, which has been formed in a shape to fit into the gap, may be inserted. Alternatively, rubber, resin, grease, a foaming agent, or the like may be injected into the gap to form a vibration absorbing member.

The gap may be filled with an adhesive, and the shaft 5 and the worm shaft 10a may be integrated with the adhesive, or a pin may be used instead of the adhesive or together with the adhesive. The shaft 5 and the worm shaft 10a may be connected. Thus, vibration can be prevented even if the shaft 5 is connected to the worm shaft 10a and both are integrated by bonding or the like to eliminate the gap.

[0022]

According to the present invention, there is provided a tilling machine in which a worm gear is interposed in a transmission system from a shaft of a driving section to a rotor, and a worm shaft of the worm gear is connected to the shaft via a fitting section. In the transmission mechanism, since the vibration absorbing member is interposed in the transmission system, the vibration generated by rattling of the fitting portion or the like is absorbed by the vibration absorbing member,
Vibration and noise of the cultivator can be reduced, and workability can be improved.

Further, in the present invention, when the fitting portion is fixed, no vibration is generated from the connection portion between the shaft and the worm shaft, so that the vibration and noise of the cultivator can be reduced, and the workability can be reduced. Can be increased.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a cultivator equipped with a transmission mechanism according to the present invention.

FIG. 2 is an elevation view of the cultivator viewed from the back.

FIG. 3 is a vertical sectional view showing another embodiment of the present invention.

FIG. 4 is a vertical sectional view showing another embodiment of the present invention.

FIG. 5 is a vertical sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 2 rotor 4 drive unit 5 shaft 10a worm shaft 13, 21, 22 fitting part 15 joint 19, 20 flexible shaft 23 synthetic resin film

Claims (3)

[Claims] A worm gear is interposed in a transmission system from a shaft of a drive section to a rotor, and a worm shaft of the worm gear is connected to the shaft via a fitting section. A transmission mechanism for a tiller, wherein a vibration absorbing member is interposed in the system. 2. The transmission mechanism for a cultivator according to claim 1, wherein the vibration absorbing member is a flexible shaft. 3. A transmission mechanism for a cultivator, wherein a worm gear is interposed in a transmission system from a shaft of a driving section to a rotor, and a worm shaft of the worm gear is connected to the shaft via a fitting section. A transmission mechanism for a cultivator, wherein the joint is fixed.