Rack and pinion is a common mechanical transmission mode in which gears and racks are used together to transmit power.

How it works:

The working principle of the rack and pinion is based on the meshing principle of the gear. When the pinion and rack are used together, each tooth of the gear will mesh with the corresponding tooth slot of the rack, so as to achieve the transmission of power. By changing the speed or direction of the gear, you can change the speed and direction of the rack.

Type of rack and pinion:

Gears can be classified according to tooth shape, gear shape, tooth line shape, the surface where the teeth are located and the manufacturing method, as follows:

1. Gear can be classified according to tooth profile curve, pressure Angle, tooth height and displacement;

2, gear according to its shape is divided into cylindrical gear, bevel gear, non-circular gear, rack, worm - worm gear;

3, according to the shape of the tooth line gear is divided into spur gear, helical gear, herringbone gear, curve gear;

4. According to the surface gear where the gear teeth are located, it is divided into external gear and internal gear, of which the top circle of the outer gear is larger than the root circle, and the top circle of the inner gear is smaller than the root circle;

5, according to the manufacturing method, the gear is divided into casting gear, cutting gear, rolling gear, sintering gear, etc.

6, the rack is mainly divided into straight teeth and helical rack, do not use with straight gear and helical gear pair; The tooth profile of the rack is a straight line rather than an involute line (it is a plane for the tooth surface), which is equivalent to a cylindrical gear with an infinite index circle radius.

Precision grade of rack and pinion:

The national standard stipulates 13 precision grades for gear pairs used in gears.

Use the Arabic numerals 0, 1, 2,... ... 12 indicates that the accuracy of level 0 is the highest, the remaining levels are successively reduced, and the accuracy of level 12 is the lowest. The accuracy grade of the two gears in the gear pair is generally the same grade, and different grades are also allowed, and the accuracy grade of the gear pair should be determined according to the one with the lower accuracy.

Among the 13 accuracy levels, the current processing technology level and measurement means of 0, 1 and 2 levels of accuracy are still difficult to promote, and need to be further developed, and the 6 level is the basic level and the commonly used level in design, and the commonly used processing methods such as hobbing and gear shaper can be achieved for a long time, and the general measuring instruments can be used to measure. We generally choose levels 6-8 in non-standard applications.

Rack and pinion installation precautions

First, when installing, it is strictly prohibited to use the hammer loading method to avoid damage to the gear or its surface.

2. Before use, check whether the gear rotates briskly and evenly on the full length. If there is a blockage or obvious uneven weight, check whether the installation is correct.

Third, in the two pairs of meshing gears of the same transmission device, the center distance must be ensured to remain unchanged, otherwise it will affect the transmission ratio, and even make the gear cannot mesh normally.

Fourth, the rack should be installed in the prescribed direction, not reverse installation.

When disassembling the gear, the debris around the gear should be removed first to prevent debris from entering the inner cavity of the gear.

6. The working condition of the gear should be checked frequently in use. If serious wear or damage is found, it should be replaced in time.

7. Check the lubrication system regularly to ensure the smooth supply of lubricating oil.