CN1425861A - Transmission mechanism that eliminates backlash - Google Patents

Abstract

A transmission mechanism for eliminating tooth clearance utilizes an actuator connected to a transmission member and a driven tooth, and the driven tooth meshes with a driving tooth to receive the power transmitted by the driving tooth. With the aid of an actuator, the driving tooth and the driven tooth are tightly meshed in a normal state to eliminate the tooth clearance during positioning. During transmission, the pressure between the driving tooth and the driven tooth is reduced to reduce the friction during transmission.

Description

Transmission mechanism that eliminates backlash

technical field

The invention relates to a transmission mechanism, which is applied to a gear-shaped combined transmission device, in particular to a transmission mechanism for eliminating backlash.

Background technique

In a general system or device, power transmission is unavoidable. With the development of science and technology, the transmission device is also required to be more precise and precise. The way is most in line with the current requirements. There are quite a variety of tooth-shaped combined transmission devices, such as the combination of gears, lead screws, meshing teeth, racks, etc., all of which are combined to transmit power by means of tooth-shaped objects.

The biggest disadvantage of the tooth-shaped combination transmission mechanism is the backlash; as the name suggests, the backlash is the gap between the teeth. The cause of the backlash may come from manufacturing tolerances, wear, or it may be to reduce the transmission. Designed for friction. However, for more and more sophisticated optical systems, the existence of backlash will cause errors in control positioning and unnecessary vibrations.

Taking the optical disc drive system as an example, the optical disc drive uses the power of the lead screw to drive the motor, and engages on the lead screw with the help of a meshing tooth, and drives the optical read-write head to move, because the optical read-write head needs to be fast and fast when tracking. Accurate positioning, so the existence of backlash is not allowed, so a pre-compression elastic force is usually applied to the meshing teeth to make the fit between the lead screw and the meshing teeth more tightly. However, after applying the pre-compression elastic force, it increases The friction between the meshing teeth and the lead screw makes the transmission difficult and the transmission speed is reduced, making it impossible to quickly locate; on the other hand, if the pre-loaded elastic force is not enough, the backlash cannot be effectively eliminated, causing the optical read-write head to shake. Even when it reciprocates, it will vibrate, which will affect the reading of data. In this dilemma, the previous case proposed quite a few solutions, but either the control was too difficult and complicated, or the result was not as expected, and an effective and practical solution could not be provided.

Contents of the invention

The purpose of the present invention is to provide a backlash-eliminating transmission mechanism to solve the above problems, which can eliminate the backlash and reduce the friction during transmission, and at the same time, it is quite easy to control.

The above-mentioned purpose of the present invention is achieved in that a kind of transmission mechanism that eliminates backlash is used for transmission-to-be-transmitted part, and wherein said transmission mechanism comprises:

an active tooth;

a driving unit, connected to the driving gear, capable of providing power to the driving gear;

A driven tooth structure, comprising at least one driven tooth, and meshing with the driving tooth through the driven tooth;

an actuator, installed on the driven tooth structure, can change the pressure between the driving tooth and the driven tooth; and

A controller is used to synchronously control the actions of the drive unit and the actuator.

The transmission mechanism for eliminating backlash according to the present invention, wherein the controller controls the action of the actuator so that under normal conditions, the driving teeth and the driven teeth are tightly meshed, and when the driving unit operates, the The actuator acts to reduce the pressure between the driving teeth and the driven teeth.

The transmission mechanism for eliminating backlash according to the present invention, wherein the controller controls the action of the actuator so that under normal conditions, the action of the actuator makes the driving teeth and the driven teeth closely mesh, When the driving unit operates, the actuator recovers to reduce the pressure between the driving teeth and the driven teeth.

In the transmission mechanism for eliminating backlash according to the present invention, the active tooth is a lead screw.

In the transmission mechanism for eliminating backlash according to the present invention, the driving tooth is a gear.

In the transmission mechanism for eliminating backlash according to the present invention, the driven tooth is a gear.

In the transmission mechanism for eliminating backlash according to the present invention, the actuator is selected from one of electromagnetic actuators, piezoelectric actuators, shape memory alloys, and thermally deformable bimetals.

In the transmission mechanism for eliminating backlash according to the present invention, the driven tooth structure further includes a connecting portion for connecting the to-be-transmitted member.

In the backlash-eliminating transmission mechanism of the present invention, the actuator connects the to-be-transmitted member to the driven gear.

The transmission mechanism for eliminating backlash according to the present invention includes a driving gear, a driven gear structure, a driving unit, an actuator and a controller. The driving gear is connected to the driving unit and can accept the power output of the driving unit , and the driven tooth structure meshes with the driving tooth by means of a driven tooth, and is driven by the driving tooth to drive the connected to-be-transmitted parts, and the actuator is installed in the driven tooth structure, which can change the driven gear and the pressure between the driving teeth, while the controller is used to synchronously control the drive unit and the actuator.

Normally, when the transmission mechanism is not in motion, the driven teeth and the driving teeth are closely meshed by means of the actuator, so that the driven teeth, that is, the to-be-transmitted parts are positioned without shaking; The drive unit and the actuator make the drive unit act to drive the driving gear, and use the actuator to reduce the pressure between the driving gear and the driven gear, thereby reducing the friction between the driving gear and the driven gear, so that it can be eliminated Backlash during positioning, and reduce friction during transmission.

To change the pressure between the driving teeth and the driven teeth is to change the meshing degree between the driving teeth and the driven teeth through the tiny deformation generated by the action of the actuator. The control of the actuator can be deformed in the normal state, so that the driving teeth and the driven teeth are kept in close mesh, and when the drive unit is in motion, the actuator is controlled by the controller at the same time to restore it to its original state, and the driving teeth and the driven teeth are lowered. On the other hand, it can also maintain the original state under normal conditions, so that the driving teeth and the driven teeth are kept in close mesh, and when the drive unit is in motion, the actuator is controlled by the controller to deform it at the same time, and the driving teeth and the driven teeth are reduced. pressure between the movable teeth.

In order to further understand the purpose, structural features and functions of the present invention, the following detailed description will be given in conjunction with the accompanying drawings.

Description of drawings

Fig. 1 is the schematic diagram of the transmission mechanism of eliminating backlash according to the present invention;

Fig. 2 is the schematic diagram of controller circuit of the present invention;

FIG. 3 is a schematic diagram of controller signals of the present invention.

Detailed ways

The transmission mechanism for eliminating backlash according to the present invention includes a driving gear, a driven gear structure, a driving unit, an actuator and a controller. Taking the optical disc drive system as an example, Please refer to Fig. 1, comprise optical read-write head 10, slide bar 21,22, meshing tooth structure 30, lead screw rod 90, controller 50, motor driver 60, power amplifier 70 and stepper motor 80, stepper motor 80 is It is the driving unit, and the lead screw 90 receiving the power of the stepping motor 80 is the active tooth, the meshing tooth structure 30 meshed with the lead screw 90 is the driven tooth structure, and the optical read-write head 10 is the to-be-transmitted member.

The optical read-write head 10 is straddled between the two slide bars 21, 22, and can slide on the slide bars 21, 22 to track the optical disc and read or write data, and the lead screw 90 is installed in the stepping On the motor 80, the rotational power of the stepper motor 80 can be accepted, and the meshing tooth structure 30 is meshed with the lead screw 90 by means of a meshing tooth 31, and can receive the rotational power of the lead screw 90 to perform linear motion, and with the aid of an actuator 40 can change the pressure between the meshing teeth 31 and the lead screw 90 , and is connected to the optical pick-up head 10 via a connecting portion 32 , thereby driving the optical pick-up head 10 to slide between the slide bars 21 and 22 . And the controller 50 controls the stepping motor 80 and the actuator 40 respectively by means of the motor driver 60 and the power amplifier 70 .

For a stepper motor 80 with bipolar and two-phase excitation, the driving method can be shown in FIG. A-), φ4 (B-), while generating a drive signal _V0 through the power amplifier 70 to drive the actuator 40, as shown in Figure 3, that is to say, utilize the controller to synchronously control the stepper motor 80 and actuator 40 .

Under normal conditions, the meshing teeth 31 and the lead screw 90 maintain a tight meshing state, so that the optical read-write head 10 is positioned accurately and prevents it from shaking. And the actuator 40, by means of the actuator 40, the pressure between the meshing teeth 31 and the lead screw 90 is reduced, and the friction force during transmission is also reduced, and the stepping motor 80 drives the lead screw 90 to rotate, so that the meshing teeth 31 Perform linear motion to achieve the effect of optical read-write head 10 tracking. After positioning, the controller 50 also controls the stepper motor 80 and the actuator 40 at the same time, so that the pressure between the meshing teeth 31 and the lead screw 90 is restored to a tight meshing state, so that the positioning does not shake.

The actuator 40 can use electromagnetic actuators, piezoelectric actuators, shape memory alloys, and thermally deformable bimetals, and use its small deformation to change the pressure between the meshing teeth 31 and the lead screw 90, which can be normal The lower actuator 40 maintains its original shape, and when driven, the actuator 40 deforms to reduce the pressure between the meshing teeth 31 and the lead screw 90; or the actuator 40 deforms normally, and when driven, the actuator 40 returns to its original state To reduce the pressure between the meshing teeth 31 and the lead screw 90 .

The optical read-write head 10 can also be directly connected to the meshing gear mechanism 30 by means of the actuator 40. Meanwhile, the driven teeth and the driving teeth are not limited to the meshing teeth 31 and the lead screw 90, and can be any combination of teeth. The transmission can be any, such as gears, lead screws, racks, etc., and any tooth-shaped combination that can produce backlash (backlash) can be used.

The present invention is a transmission mechanism for eliminating backlash, which uses an actuator to change the meshing degree of the driving gear and the driven gear, that is, to change the pressure between the driving gear and the driven gear, when the controller controls the drive unit to move At the same time, the actuator is synchronously controlled to change the pressure between the active tooth and the driven tooth, so that when the transmission is made, the pressure of the two is reduced to facilitate the transmission and increase the transmission speed. The transmission part is stable and does not shake; at the same time, it is quite easy to control because the degree of engagement between the driving teeth and the driven teeth is changed by the simple action of the actuator.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention; that is, all equivalent changes and modifications made according to the patent scope of the present invention are covered by the patent scope of the present invention.

Claims (9)

1, a kind of driving mechanism of eliminating backlash is used for transmission one and treats driving component, it is characterized in that described driving mechanism includes:

One driving tooth;

One driver element is connected in described driving tooth, and described driving tooth power can be provided;

One driven tooth structure includes a driven tooth at least, and described driven tooth is engaged in described driving tooth excessively;

One actuator is installed on the described driven tooth structure, can change the pressure between described driving tooth and described driven tooth; And

One controller is in order to described driver element of synchronization control and described actuator action.

2, the driving mechanism of elimination backlash as claimed in claim 1, it is characterized in that, described controller is controlled described actuator action, when making normality, tight engagement between described driving tooth and described driven tooth, and driver element when action, described actuator action and make the pressure between described driving tooth and the described driven tooth reduce.

3, the driving mechanism of elimination backlash as claimed in claim 1, it is characterized in that, described controller is controlled described actuator action, when making normality, described actuator action makes tight engagement between described driving tooth and described driven tooth, and driver element when action, described actuator recovers and makes the pressure between described driving tooth and the described driven tooth reduce.

4, the driving mechanism of elimination backlash as claimed in claim 1 is characterized in that, described driving tooth is a driving screw.

5, the driving mechanism of elimination backlash as claimed in claim 1 is characterized in that, described driving tooth is a gear.

6, the driving mechanism of elimination backlash as claimed in claim 1 is characterized in that, described driven tooth is a gear.

7, the driving mechanism of elimination backlash as claimed in claim 1 is characterized in that, described actuator is selected from one of them of combination that electromagnetic actuator, piezoelectric actuator, marmem and thermal distortion bimetal constituted.

8, the driving mechanism of elimination backlash as claimed in claim 1 is characterized in that, described driven tooth structure also includes a junction, is used to connect the described driving component for the treatment of.

9, the driving mechanism of elimination backlash as claimed in claim 1 is characterized in that, described actuator connects the described driving component for the treatment of in described driven tooth.

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