Rack And Pinion Transmission Advantages And Application Areas

The rack and pinion transmission structure is composed of gears and racks, and the racks are also divided into straight teeth and helical teeth, which are widely used in factory automation. Among them, laser cutting machine, gantry truss, seventh axis, etc. are the ones we use more, with perfect technology and rich experience in model selection. Rack and pinion will have its own advantages in transmission. What are the advantages of rack and pinion transmission?

The gear has large bearing capacity, high transmission accuracy, up to 0.1 mm, can be extended indefinitely, and the transmission speed can be very high. Application: Layout steel plate, glass CNC cutting machine, building construction elevator up to 30 stories high. The timing belt has a large bearing capacity, if the load is large, the belt should be widened. The transmission precision is high, and the transmission length should not be too large. Otherwise, large elastic deformation and vibration should be considered, and large transmission distance is especially not suitable for precise positioning and continuous motion control, such as CNC equipment layout with large XY axis, but it can be used from servo motors to transmission gears or from servo motors Short distance transmission from motor to screw. Advantages: Short distance transmission speed can be very high, low noise. Typical use: Small CNC equipment.

What is the difference between rack applications?

In long-distance heavy-load linear motion, the screw may not be rigid enough, which will cause the machine to vibrate, shake, etc. In severe cases, the screw will bend, deform, or even break, etc.; however, the rack will not have this. The rack can run infinitely long distances and at high speed without affecting the rack accuracy (of course, this is related to assembly and bed accuracy), the screw can't do this, but in short-distance linear motion, the screw's accuracy is significantly higher the accuracy of the rack. In addition, in terms of the structural design of the dryer, the rack and pinion drive is relatively simple. Regardless, each has its own strengths and weaknesses. Therefore, the screw market and the rack market will not affect each other.

When the number of teeth of the standard external gear increases to infinity, the base circle and other circles on the gear become parallel straight lines, and the involute tooth profile on the same side also becomes a parallel oblique straight line tooth profile, which is the rack. Compared with gears, racks have the following two characteristics:

(1) Since the rack tooth profile is straight, the normals of each point on the tooth profile are parallel. And because the rack is translated during the transmission process, the speed and direction of each point on the tooth profile are the same, so the pressure angle of each point on the rack is all equal, equal to the tooth profile angle, and the standard value is 20°.

(2) The pitch on each line parallel to the addendum line is the same, and the modulus is the same standard value. The straight line whose tooth thickness is equal to the width of the tooth space and is parallel is called the center line, which is the reference line for determining the dimensions of each part of the rack.

However, in the stamping process, since the stamping stroke is the working stroke in the stamping process, the return process is not the working process, when processing the workpiece, when returning, we should try our best to meet the restoration time of the workpiece. Therefore, it is necessary to satisfy the emergency port characteristics of this mechanism. However, the gear cannot meet the characteristics of the emergency port, cannot improve the stamping efficiency of the workpiece, and the motion form of the rack processing does not conform; then the processing method of this process is excluded.