Rack and pinion transmission, how to calculate the center distance between the rack and the gear?

Calculation formula:

The distance between the gear center and the rack tooth top = m(z-2)÷2=4(20-2)÷2=36 (mm).

The distance between the gear center and the rack tooth root = m(z 2.5)÷2=4(20 2.5)÷2=45 (mm).

Note: As long as they mesh with each other, the center distance of the two gears remains unchanged, no matter what kind of rhombus they are.

The national standard for gear module is GB1357-78.

Preferred modulus: 0.1mm, 0.12mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.8mm, 1mm, 1.25mm, 1.5mm, 2mm, 2.5mm, 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 20mm, 25mm, 32mm, 40mm, 50mm.

Extended information:

The gear rack will have its own unique motion characteristics during the transmission process: gear transmission is used to transmit motion and power between any two axes, and its circumference The speed can reach 300m/s, the transmission power can reach 105KW, and the gear diameter can range from less than 1mm to more than 150m. It is the most widely used mechanical transmission in modern machinery.

Screw drive has high precision and high cost. However, under heavy load over long distances, the screw is prone to bending. These conditions do not exist with racks. Compared with belt transmission, rack and pinion transmission mainly has the following advantages:

1. The characteristics of large transmission power and efficient gear transmission. Gear transmission is used to transmit motion and power between any two axes. Its peripheral speed can reach 300m/s, the transmission power can reach 105KW, and the gear diameter can range from less than 1mm to more than 150m. It is the most widely used type of modern machinery. Mechanical transmission.

2. Long life, stable operation and high reliability.

3. It can ensure a constant transmission ratio and can transmit motion between two axes at any angle.

Reference: Baidu Encyclopedia--Gear