Articles on: Learning & FAQ

PG, HG, MG, EG Gearboxes Adapt to the Specifications of the Motor Output Shaft

Many customers want to know the differences between PG, HG, MG and EG series gearboxes. In order to answer these questions, we will introduce in detail the characteristics of each gearbox and the specifications of its adapted motor output shaft.

PG/HG series planetary gearbox motor

PG (economical type) and HG (precision type) gearboxes are both planetary gearboxes. Their input and output shaft structures are special and we only sell them pre-assembled. It is not recommended that customers disassemble and replace the gearbox and motor by themselves.

Output shaft type: The motor output shaft adapted to the PG/HG gearbox is mainly divided into two types:

Hobbing shape output shaft

The output shaft where the press presses the sun gear into

EG series high-precision planetary gearbox

EG series gearboxes offer superior accuracy and reliability. It has a built-in input shaft coupling and is available in a variety of speed ratios to match most standard Nema 17 stepper motors and brushless DC motors. Compared with the PG and HG series, the EG gearbox has the lowest requirements for the input shaft, and customers can install it by themselves.

MG series gearbox

The gears of the MG series gearbox are manufactured using powder metallurgy and are suitable for applications requiring high precision but low cost. It is an in-line planetary gearbox with a built-in input shaft coupling that needs to be matched with a short-axis motor.

Conventional shaft specifications

Circular Shaft


Double D-CU

The above types of motor output shafts can be directly installed with the EG/MG gearbox within the allowable size range.

Updated on: 27/05/2024

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