JPH0512574B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a ball worm gear device configured to transmit power through a plurality of ball groups.

[Conventional technology]

Conventionally, as a ball worm gear device configured to transmit power through a plurality of ball groups, there is, for example, the one shown in Japanese Patent Publication No. 50-39220 (Figures 8 and 9). can.
That is, in this type of worm, the frame body 20 is made of a material having the required mechanical strength and is formed into a drum-like or cylindrical shape, and has a screw-like ball track 22 on the surface of which a group of balls 21 roll and move. 2
3 is rotatably arranged via bearings 24A, 24B. The ball track 22 of the worm 23 is formed on the surface of the worm 23, and is formed in a semicircular groove shape so that the spherical ball 21 can roll freely. The ball track 2 is formed in a screw shape and allows the ball group to roll and move continuously.
Both ends of the worm are connected through a communication hole 25 inside the worm. Further, the frame body 2
0, a worm wheel 26 is rotatably arranged via a bearing (not shown) in a direction perpendicular to the worm 23, and the ball group 21 of the worm 23 meshes with the ball groove of the worm wheel 26 to form a ball. It is adapted to be rotated by group 21. The frame body 20 also includes the worm 2.
A ball cover 27 is arranged to protect the third ball group 21 from falling off.

[Problem that the invention seeks to solve]

However, in the conventional ball worm gear device, it is necessary to connect both ends of the ball track 22 of the worm 23 through the communication hole 25 to form an annular track, which makes manufacturing the worm 23 troublesome.
Further, in order to provide the communication hole 25, the worm 23 must be made of a material having a required mechanical strength, which limits the material to be used and increases the cost. Furthermore, it is necessary to attach the ball cover 27 to the frame 20 in order to prevent the ball group 21 from coming off, which poses problems such as the labor involved in manufacturing and attaching the ball cover.

The present invention has been made in view of these conventional problems, and it is not necessary to provide a communication hole for the ball trajectory in the worm, and the material can be easily selected and manufacturing is simple. A technical problem is to create a ball worm gear device that can omit a cover.

[Means for solving problems]

In order to solve the above technical problem, the present invention takes the following technical measures.

That is, a worm having a required number of balls formed in a spherical shape, a ball trajectory formed in a screw shape so as to rotate the worm wheel when the balls roll, and a ball trajectory arranged in the worm. In a ball worm gear device comprising a worm wheel formed to be rotated by a ball, as shown in FIG. The structure is such that they can be freely reciprocated.

[Effect]

When the worm is rotated in the forward and reverse directions, the worm wheel rotates in the forward and reverse directions via the group of balls in the worm orbit, and the group of balls is guided by the moving body and moves.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 6.

1 is a ball worm gear device, and this ball worm gear device 1 is equipped with a frame 2,
In the space 3 of the frame 2, a worm 6 is formed into a cylindrical shape made of a material having the required mechanical strength and has a screw-shaped ball track 5 on the surface of which a group of balls 4 roll and move. , 7B. The ball track 5 of the worm 6 is provided on the surface of the worm 6, and is formed in the shape of an arcuate groove so that the group of spherical balls 4 can roll freely. is formed, ball group 4
The ball trajectory 5 allows the ball to roll and move continuously.
Both ends are open. One end 6A of the worm 6 extends outside the frame 2. A cylindrical moving body 8 is loosely fitted to the outer circumference of the worm 6. The movable body 8 rotatably holds a ball group 4 that fits into the ball track 5 of the worm 6, and as the ball group 4 moves, the movable body 8 reciprocates in the axial direction. is configured to do so.

The ball group 4 of this moving body 8 is connected to the worm 6
The leads are also arranged in a screw-like manner similar to the ball trajectory 5 of the above. The movable body 8 may hold the ball group 4 in any configuration as long as the ball group 4 does not come off and is rotatable. For example, as shown in FIG. 5, two members may be held together. Further, the movable body 8 is not limited to a cylindrical shape, but may be formed in a spiral shape in accordance with the lead of the ball group 4.

The worm 6 is placed in the space 9 in the frame 2.
The worm wheel 10 is perpendicular to the bearing 1.
It is rotatably arranged via 1A and 11B. This worm wheel 10 has a ball groove 12 formed on its outer circumferential surface in which the ball group 4 engages. The worm wheel 10 is configured to be rotated by the ball group 4 of the worm 6. The worm wheel 10
One shaft portion 10A is extended to the outside of the frame 2,
For example, it is connected to a steering wheel or the like via a well-known steering link mechanism.

The ball worm gear device 1 configured in this manner is in a neutral state as shown in FIG. Next, when the shaft portion 6A of the worm 6 is rotated in the direction of the arrow A, the ball group 4 fitted in the ball track 5 of the worm 6 is guided by the movable body 8 and moves while rotating.
The ball worm 10 meshing with the ball group 4 is rotated in the direction of arrow B. At this time, the moving body 8 moves in the direction of arrow C, and the ball group 4 of the moving body 8
A portion of the worm 6 separates from the end of the ball track 5 and is held only by the moving body 8 (see solid line in FIG. 6).

On the other hand, when the shaft portion 6A of the worm 6 is rotated in the direction of arrow A', the ball group 4 fitted in the ball track 5 of the worm 6 moves while being guided by the movable body 8 while rotating. The worm wheel 10 meshed with is rotated in the direction of arrow B'.
At this time, the moving body 8 moves in the direction of arrow C',
A part of the ball group 4 of the movable body 8 separates from the end of the ball trajectory 5 of the worm 6 and is held only by the movable body 8 (the state shown by the chain line in FIG. 6).
As described above, the worm wheel 10 is rotated forward and backward to operate the wheels connected thereto. Moreover, the moving distance of the moving body 8 is only 1/2 the distance of the lead of the worm shaft for one revolution of the worm shaft due to the rotation and revolution of the ball group 4, so that the structure can be made smaller.

FIG. 7 is a longitudinal sectional front view of the main part showing another embodiment of the ball worm gear device of the present invention, which shows the groove in which the ball group 4 fits into the part of the frame 2 that the ball group 4 comes into contact with. 13, and when the ball group 4 is guided by the movable body 8, it moves along this groove 13. With this configuration, the frame body 2 absorbs the force in the direction of the arrow D. As a result, the diameter of the worm shaft can be reduced. Since the other configurations and operations are the same as those shown in FIGS. 1 to 6, detailed explanation thereof will be omitted.

In addition, the length l of the moving body 8 in the above embodiment,
The number of ball groups 4, the range of movement, etc. are determined as appropriate depending on the purpose of use. Further, the device to be used may be any device as long as it is capable of forward and reverse rotation, and is not particularly limited. And the worm wheel 10 is also 1
If there is no need for rotation, a fan shape is fine.

〔Effect of the invention〕

According to the present invention, there is no need to provide a communication hole connecting both ends of the ball track of the worm, and the material used for the worm can be easily selected and manufacturing is simple. Further, the ball cover can be omitted, and the structure is simple and assembly is easy.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional front view of the ball worm gear device of the present invention, Fig. 2 is a longitudinal sectional side view thereof, Fig. 3 is a longitudinal sectional front view of the movable body, Fig. 4 is a front view of the worm, and Fig. 5 is a ball worm gear device. 6 is a longitudinal sectional view of the main parts showing the operating state; FIG. 7 is a longitudinal sectional front view of the main parts showing another embodiment of the ball worm gear device of the present invention; FIG. FIG. 8 is a longitudinal sectional front view showing an example of a conventional ball-worm gear device, and FIG. 9 is a front view of the worm. 1... Ball worm gear device, 2... Frame, 4...
Ball group, 5... Ball trajectory, 6... Worm, 7
A, 7B, 11A, 11B...bearing, 8...moving body,
10... Worm wheel.

Claims (1)

[Claims] 1 A group of required several balls formed in a spherical shape,
A worm is formed to roll a group of balls and has a ball trajectory formed in a screw shape so that the rolling of the ball group rotates a worm wheel, and a ball arranged in the ball trajectory of the worm. In a ball worm gear device comprising a worm wheel formed to be rotated by the worm, a movable body rotatably holding the group of balls is disposed on the outer periphery of the worm so as to be able to reciprocate in the axial direction of the worm. A ball worm gear device characterized by: