JPH0378501B2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Field of Industrial Application The present invention is characterized in that rolling balls act as teeth to engage the drive screw shaft and the groove gear for increasing/decelerating, and in particular, increase/decrease or decelerate to accurately eliminate backlash. Since it is a mechanism, it can be widely used as a reducer for various machines.

(2) Conventional technology Conventional gear reducer grooves are a combination of a worm gear or spur gear rotated by a motor and a spur gear or bevel gear with a different rotation ratio, and both gears have teeth directly cut into them. Therefore, the teeth were fixed and the coefficient of friction due to rotation was large, limiting the ability to improve rotational transmission efficiency.

In addition, an increasing/decelerating mechanism that transmits rotation by meshing a worm gear and a spur gear through balls has been developed. is continuous in a spiral shape in one direction, and the balls moving in this spiral ball path are in the same direction, so a rotation transmission force in one direction always acts on the worm wheel, and the spiral ball path is transmitted in the same way as gear meshing. was a structure that could not be expected to be particularly effective in removing bumps.

(3) Problems to be solved by the invention Since the conventional speed-up/deceleration mechanism has a structure that combines a worm gear, a spur gear, and a bevel gear, the frictional resistance due to meshing rotation is large and the rotational efficiency is reduced.
A rotation transmission mechanism that uses balls has higher precision than one that uses gears, improves rotation transmission efficiency in one direction, and reduces noise and heat generation, but it is difficult to eliminate backlash during reverse rotation or alternating forward and reverse rotation. It was hot.

(4) Means for Solving the Problems The present invention fundamentally solves the problems of the conventional technology.It does not use tooth meshing, but instead is interposed between the screw shaft and the groove gear for increasing/decelerating, and It has a structure in which the balls are engaged with each other by balls moving in the direction, and are sent out from an oblique direction opposite to the speed-up/deceleration groove gear.

That is, a ball raceway thread groove is provided on a rotatably driven screw shaft, and the end and start end of the ball raceway thread groove are connected by a circulation path, while a ball raceway groove is provided on an accelerating/decelerating groove gear located close to the screw shaft. In a speed increase/decrease gear in which the balls are continuously loaded into the ball raceway screw groove so as to fit into the ball raceway groove adjacent to the screw shaft, and the balls are interposed between the screw shaft and the gear for increasing/decelerating, the outer periphery of the screw shaft is Separate ball raceway threaded grooves are provided at both ends of the ball raceway threaded grooves, one end is located at the left end, the other is located at the right end, and both start ends are located at the center, and the end and start end are located at the center. The two continuous circulation paths are designed so that the balls continuously fitted into both ball orbit screw grooves move in opposite directions due to the rotation of the screw shaft, and both move from the end of the end to the start of the center. This is an increase/decrease gear that uses balls that are bored diagonally opposite the ball.

(5) Effect The balls that are aligned and interposed continuously between both ball raceway screw grooves provided separately on both ends of the screw shaft outer periphery and the ball raceway groove on the outer periphery of the gear for increasing/decelerating the gear, rotate as the screw shaft rotates. It moves while rolling and transmits the rotation of the screw shaft to the accelerating/decelerating groove gear, causing it to rotate at a predetermined accelerating/decelerating ratio. That is, each successive ball rolls in both ball raceway screw grooves at both ends of the screw shaft, and rolls in the ball raceway groove of the meshing gear for increasing/decelerating to align and move in sequence. It passes through both circulation paths that pass diagonally through the screw shaft in the radial direction from the terminal ends located at the left and right ends of the groove, exits to the starting end in the center, exits at the starting end of the ball raceway thread groove, and returns to the ball track thread groove. Move in circulation. In this case, both circulation paths are diagonally drilled from the ends to the center, and the balls moving in both ball orbit thread grooves move in opposite directions, so at the exits of both circulation paths, the balls sequentially move left and right. It moves circularly while pushing the accelerating/decelerating groove gear between them, effectively removing bumps.

(6) Examples Next, the present invention will be explained with reference to examples. In FIGS. 1 and 2, 1 is a screw shaft driven by a motor, and 2 is an accelerating/decelerating groove gear whose rotation is transmitted by the rotation of the screw shaft 1 and rotates at a predetermined speed increase ratio or speed reduction ratio. A helical ball raceway screw groove 3 is formed on the outer periphery of both ends of the screw 1, and a fourth
As shown in the figure, the terminal ends of both ball raceway screw grooves 3 are arranged at the left end, the other at the right end, and the starting end is arranged at the center of the screw shaft, and both terminal ends and both starting ends are at the same angle on the shaft circumference. Both circulation paths 4, which are provided at different positions and which connect both terminal ends and both starting ends, respectively, pass obliquely through the inside of the screw shaft 1 in the radial direction from the terminal end of the end portion, and are connected to the starting end of the central portion.

On the other hand, the groove gear 2 for increasing/decelerating is provided with a ball raceway groove 5, and the ball 6 is connected to the screw shaft 1 via the ball 6 continuously loaded so as to freely roll and move in the ball raceway screw groove 3. mesh together.

Therefore, when the screw shaft 1 rotates, the balls 6 continuously loaded into both ball raceway thread grooves 3 move while rolling due to contact with the ball raceway groove 5 of the gear 2 for increasing/decelerating From the terminal end of the ball raceway thread groove 3, the ball 6 sequentially passes through both circulation paths 4, exits to both starting ends in the center, and moves again in the ball raceway thread groove 3, but at this time, the ball 6 passes through both circulation paths 4, respectively, and exits at both starting ends in the center part. As shown in the figure, it moves in opposite left and right directions, and is sent out so as to sandwich the accelerating/decelerating groove gear 2 through both circulation paths 4 diagonally bored in the radial direction toward the center.

FIG. 3 shows an embodiment in which each of the ball raceway screw grooves 3 provided at both ends of the screw shaft 1 has one and a half turns.
FIG. 4 shows the relationship between both ball raceway screw grooves 3 and both circulation paths 4, the dotted line shows the back side, the dashed line shows the inside, and the balls 6 circulate in the opposite direction as shown in FIGS. 5 and 6. Moving.

(7) Effects of the Invention In the present invention, the balls that are continuously aligned in the ball raceway screw groove provided on the screw shaft to be driven fit into the ball raceway groove provided on the gear for increasing/decelerating, and the rotation of the screw shaft is controlled. The ball that transmits force to the accelerating/decelerating groove gear presses the fitted accelerating/decelerating groove gear in a sandwiching manner from the left and right diagonal directions, thereby eliminating rattling in meshing and eliminating backlash. Therefore, it is particularly suitable as a speed increaser or reducer when vibration impact loads are applied or when high positioning accuracy or rotational accuracy is required.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIG. 2 is an axial longitudinal sectional view of the screw shaft shown in FIG. Figure 4 is a relationship diagram between both ball raceway screw grooves and both circulation paths in Figure 3, Figure 5 is a left-view locus diagram of the ball raceway screw groove and circulation path at the left end in Figure 4, and Figure 6
The figure is a left-view locus diagram of the ball raceway screw groove and circulation path at the right end in FIG. 4. In the figure, 1 is a screw shaft, 2 is an accelerating/decelerating groove gear, 3 is a ball raceway screw groove, 4 is a circulation path, 5 is a ball raceway groove, 6 is a ball, and 7 is a ball protection cover.

Claims (1)

[Claims] 1 A ball raceway thread groove is provided on the screw shaft that is driven to rotate, and the end and start end of the ball raceway thread groove are connected by a circulation path, and a ball raceway groove is provided on the accelerating/decelerating groove gear located close to the screw shaft, and the screw In a speed reducer in which balls are continuously loaded into the ball raceway screw groove so as to fit into the ball raceway groove close to the shaft, and the balls are interposed between the screw shaft and the gear for increasing/decelerating, the outer periphery of the screw shaft is Separate ball raceway screw grooves are provided at both ends, and both ball raceway screw grooves are
One end is located at the left end, the other at the right end,
Both circulation paths have their starting ends located in the center, and the terminal end and the starting end are continuous. The balls that are continuously fitted into both ball raceway screw grooves move in opposite directions due to the rotation of the screw shaft, and both reach the end. An increase/decrease gear that utilizes balls that are bored diagonally opposite each other so as to move from the end of the section to the start of the center section.