Constant Torque Spring Motor

source：Qianye Precision time：2022-9-14

A constant torque spring motor is a strip of prestressed spring material that forms a coil and is stored on a small storage drum. The free end is then pinned and rewound onto the larger output drum; this is the “winding” part of the constant torque spring cycle. When the output drum is released, the spring will return to the storage drum to assume its natural curvature, rotating the output drum and providing an almost constant torque.

Constant torque springs are made of type 301 high quality stainless steel and are supplied in coil form for mounting on the motor drum. Its main features are: 1. Long time deflection under almost constant torque. Positive or limited negative gradients can be achieved. 2. Minimal inter-coil friction and resulting hysteresis, which is common in power springs. 3. Rotary motion is provided directly from the output drum or linear displacement by using cables and spools.

Many applications utilize constant torque spring motors, such as: cord retractors, balance retrieval and return applications, drive motors, cordless curtains, and more. The spring features a high turn design, making it ideal for balancing applications. When they are fully turned, the springs apply a constant torque. You can also guarantee high torque levels. This is due to their compactness and high efficiency.

The function of the constant torque spring motor depends on the design. The size of the spring can vary. Therefore, they make them suitable for use in a variety of applications. We strongly recommend that you consult Qianye Precision at the design stage, which will greatly facilitate the further assembly process.

There are two ways to connect a constant torque spring motor. If the connection direction is the same, it is called a type A motor. If the connection is reversed, it is called a B-type motor. See illustration below.

A type constant torque spring motor B type constant torque spring motor

Type A and Type B constant torque spring motors share some similarities. These include ease of assembly and operation. Almost constant torque force, high number of turns, however, the torque level of the B type is higher than that of the A type. The spring on the stretch storage drum ensures constant torque. Spring wants to return to its original shape. The movement of the output drum produces a constant torque.

The design of constant torque spring motors plays an important role in the efficiency of your application. The factors you should consider are: 1. Shaft – including inner and outer diameters. 2. The working height of the applied load. 3. Carrying capacity. 4. Load capacity depends on application. 5. Material, we usually use stainless steel or high carbon steel as the raw material of the spring.

You can choose our standard constant torque spring for motor design. Additionally, if your application requires unique springs, customization is possible. Shenzhen Qianye Precision Metal Co., Ltd. is designed for customer-specific applications. Using professional technology to meet your specified requirements, we sincerely recommend that customers obtain consulting services from our R&D engineers in the early stage of product introduction and development. Design, develop, and sample products according to your needs, so that your products can find the best solution to meet your application needs.