What is Direct-Drive Motor in Sewing Machines?

The direct-drive motor is a compact servomotor. This servomotor is directly coupled with the main shaft of the sewing machine. In the conventional sewing machines clutch motor is used which is connected to the main shaft with V-belt.

Sewing machine

Direct-drive means no external motor is attached to the machine table. The servomotor motor is housed inside the machine and has no mechanisms, such as a V-belt, which transmit vibrations and noise.

Example of direct-drive machine: Juki Industrial Sewing Machine Model DDL-9000B

An image servo motor used in sewing machine.

servo motor.  Image source: tradekey.com

Why direct-drive motor is preferred in industrial sewing machines?

The direct-drive motor in sewing machine has benefit compared to the conventional clutch motor machines. Some of those are as following

1. Less power consumption - since the direct-drive motor transfers the motor power to the machine with no energy loss, a significant reduction in power consumption is achieved, offering remarkable economical benefits. 
2. The motor runs without vibration and noise helping reduce operator fatigue if the machine is used for a long period of time.

Article reference: Juki machine brochure (jukiindia.com)