CN1300489C - Screw reversing mechanism in a state of rolling friction - Google Patents

Abstract

The invention relates to a spiral reversing mechanism in a rolling friction state, mainly composed of an upper limit block, a stop block, a lower limit block, a screw rod, a fixed point pin, a floating pin, a swing body, a nut, and a guide rod, and the fixed point pin is located in the nut , can rotate along its own axis, the floating pin is eccentrically located in the oscillating body, and can rotate along its own axis, the oscillating body is located in the nut, and there is a sliding bearing between them, which can rotate relatively, and the stopper is fixed On the swing body, the upper limit block and the lower limit block are fixed on the nut, and the nut moves up and down along the guide rod. The present invention replaces the sliding block in the spiral reversing mechanism with double pins, utilizes the left-handed and right-handed helixes connected end to end, transforms the continuous unidirectional rotational motion into a reciprocating linear motion mechanism, and changes sliding friction into rolling friction , The structure is simple and novel, the performance is reliable, and the transmission efficiency, movement speed and mechanism life are greatly improved.

Description

Helical reversing mechanism in rolling friction state

technical field

The invention relates to a screw reversing mechanism in a state of rolling friction.

Background technique

In the current helical reversing mechanism that converts unidirectional rotary motion into reciprocating linear motion, due to the intersection of two left-handed and right-handed helixes on the screw, a "groove" appears on the helical surface. The transmission member on the nut of the mechanism can cross these "ditches", and the transmission member has to adopt a slide block whose length is greater than the width of the "ditch". Therefore, the mechanism is in a state of sliding friction during motion, with large friction resistance, low efficiency, slow motion speed, and short service life of relative moving parts.

Contents of the invention

The object of the present invention is to provide a spiral reversing mechanism in a state of rolling friction, which uses the left-handed and right-handed helixes connected end to end to convert continuous unidirectional rotational motion into reciprocating linear motion. The structure is novel, the performance is reliable, and the The working efficiency and service life of the reversing mechanism.

The present invention is realized in the following way: in the screw reversing mechanism, the transmission part on the nut is replaced by a pin that can rotate around its own axis to replace the sliding block, and the sliding friction transmission is changed into rolling friction transmission to improve the transmission efficiency.

The spiral reversing mechanism in a rolling friction state is characterized in that it is mainly composed of an upper limit block, a stopper, a lower limit block, a screw, a fixed point pin, a floating pin, a swing body, a nut, and a guide rod. , it can rotate along its own axis, the floating pin is located in the oscillating body, and can rotate along its own axis, the oscillating body is located in the nut, and there is a sliding bearing between them, which can rotate relative to each other, and the stopper is fixed On the swing body, the upper limit block and the lower limit block are fixed on the nut, and the nut can move up and down along the guide rod, but cannot rotate around the screw rod.

The present invention replaces the sliding block with two pins that can rotate around their own axes, and converts the sliding friction transmission of the existing spiral reversing mechanism into rolling friction transmission.

In order to prevent the transmission pin from falling into the "groove" at the intersection of the left and right helix lines, so that the transmission cannot be carried out, the present invention adopts a double pin (fixed pin and floating pin) structure. The "groove" formed by the crossing of right-handed helixes enables continuous transmission.

When the two pins are in different positions in the helical grooves of the variable lift angle section, the pitch difference generated during the movement is compensated by the swing of the oscillating body. That is, through the swing of the oscillating body, the floating pin produces a displacement in the direction of the screw axis to compensate for the pitch difference between the floating pin and the fixed point pin due to the different positions of the helical groove with variable lift angle, and to avoid the two pins due to different lift pitches. "Stuck" phenomenon.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention replaces the slide block in the helical reversing mechanism with double pins, utilizes the left-handed and right-handed helixes connected end to end, and converts the continuous unidirectional rotary motion into a reciprocating linear motion mechanism, and the sliding friction becomes For rolling friction, the structure is simple and novel, and the performance is reliable;

(2) The present invention is in constant acceleration and constant deceleration motion state when reversing, and is in uniform motion state when doing work;

(3) The present invention greatly improves transmission efficiency, movement speed and mechanism life.

Description of drawings

Fig. 1 is the front view of the screw reversing mechanism of the present invention

Fig. 2 is a top view of the spiral reversing mechanism of the present invention

Fig. 3 is a schematic diagram of the principle of the spiral reversing mechanism of the present invention

Detailed ways

The details and working conditions of the specific device of the present invention will be described in detail below in conjunction with FIG. 1 , FIG. 2 and FIG. 3 .

The spiral reversing mechanism in the state of rolling friction is mainly composed of upper limit block 1, stop block 2, lower limit block 3, screw rod 4, fixed point pin 5, floating pin 6, swing body 7, nut 8, and guide rod 9. The fixed point pin 5 is located in the nut 8 and can rotate along its own axis. The floating pin 6 is located in the oscillating body 7 and can rotate along its own axis. The oscillating body 7 is located in the nut 8 with sliding movement between the two Bearings can rotate relatively, the stopper 2 is fixed on the swing body 7, the upper limit block 1 and the lower limit block 3 are fixed on the nut 8, and the nut 8 can move up and down along the guide rod 9, but cannot go around Screw rod 4 rotates.

When the main shaft rotates clockwise, the floating pin 6 and the fixed point pin 5 are located in the equal-rise angle section in the right helical groove. At this time, the load on the nut is downward, and the floating pin 6 is subjected to the reaction force of the lower groove surface of the right helical groove. The stopper 2 on the swinging body 7 is forced to be pressed to death on the lower limiter 3, so that the relative positions of the two pins are fixed, and the nut is driven to move upward in the helical groove with equal elevation angles.

When the floating pin 6 moves to the "ditch" at the intersection of the left and right helixes, the fixed pin 5 bears all the load on the helical surface alone, allowing the floating pin 6 to pass through the "ditch"; when the fixed pin 5 moves to the "ditch" At this time, the floating pin 6 has passed the "ditch" and bears all the load alone, allowing the fixed pin 5 to pass through the "ditch", so that the bearings are alternately passed through the "ditch" alternately, so that the movement of the nut is continuous.

When the two pins have crossed the last helical line intersection at the upper end and entered the variable-angle helical groove without a "groove", the helix angle at the point where the floating pin 6 is located is smaller than that of the helical groove at the point where the fixed pin 5 is located. Lift angle, at this time the screw rotates an angle, the lift distance of the spiral groove surface where the floating pin 6 is located is just smaller than the lift distance of the spiral groove surface where the fixed point pin 5 is located, so the load will all act on the fixed point pin 5, and drive The nuts continue to rise. And the floating pin 6 breaks away from the lower groove surface and contacts with the upper groove surface. And under the action of the reaction force of the upper groove surface, the swinging body is driven to rotate counterclockwise, and the floating pin 6 on the swinging body moves downward, thus compensating for the lift distance difference between the two pins, so that the two pins will not be stuck in the in the spiral groove. At this time, the nut performs a uniform deceleration motion (determined by the design parameters of the spiral groove) in the variable lift angle section. When reaching the apex, the rise speed of the nut drops to zero. Then the two pins cross the highest point of the spiral groove and enter the left-handed groove, and the floating pin 6 continues to push the swing body to rotate to compensate the pitch difference between the two pins.

When the two pins enter the equal helix angle section of the left helical groove, the stopper 2 on the rotating body is crushed to the upper limit block 1, and the two pins alternately carry the load and pass through the "groove" alternately, so that The nut descends at a constant speed and goes round and round, which converts the continuous one-way rotational motion of the screw rod 4 into the reciprocating linear motion of the nut 8 . During the movement, the guide rod 9 ensures that the nut 8 can only move up and down, but cannot rotate around the screw rod 4.

Claims (1)

1 is in the spiral changement of rolling friction state, it is characterized in that, mainly by upper limit position block (1), block (2), lower position block (3), screw rod (4), fixed point pin (5), pin (6) floats, swing member (7), nut (8), guide rod (9) is formed, described fixed point pin (5) is arranged in nut (8), can be along himself rotational, described unsteady pin (6) is arranged in swing member (7), can be along himself rotational, described swing member (7) is arranged in nut (8), sliding bearing is arranged between the two, can relatively rotate, described block (2) is fixed on the swing member (7), described upper limit position block (1), lower position block (3) is fixed on the nut (8), and described nut (8) can move up and down along guide rod (9).

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