China OEM Pneumatic Actuator Declutchable Manual Override Worm Gearbox bevel gearbox

Product Description

Declutchable gear override of ZHangZhoug CHINAMFG Auto-Tech Co,.Ltd is a rotary manual control device used to support the normal operation of pneumatic actuator even the emergency situation happened. The gear override is used to connect pneumatic actuators with rotary valves. It has the compact design and light weight. The unique design allows it provide high output torque by simply rotating the hand-wheel. CHINAMFG provides several optional size of gear override to fit different size of valves and actuators. The standard ISO 5211 Mounting pad allows it be installed directly. It is primarily used to manually open and close 90-degree angular travel valves.




Parts Name




Aluminum Alloy



Aluminum Alloy


Drive Gear

Ductile Iron


Gear Cover

Aluminum Alloy


Upper Male Square Stem

Carbon Steel


Handwheel Shaft

Carbon Steel with Chrome Plated



Plated Carbon Steel


Position Lever Assy

Plated Carbon Steel


Position Lock Assy

Plated Carbon Steel


Cover Bolts

Carbon Steel with Zinc Plated


Limit Stops

Stainless Steel


Gear Cover Bolts

Carbon Steel with Zinc Plated


Shaft Bushings

Carbon Steel


Grease Fitting






O Rings



JSD-1 101 16 14 14 19 90 185 160 53 50 6 8 70 50 57 70 M6X12 M6X12 M8X12 155
JSD-2 110 17 17 17 25 124 225 200 74 70 8 10 102 70 70 102 M8X13 M8X13 M10X16 200
JSD-3 124 23 22 22 25 140 308 320 126 102 10 12 125 102 89 125 M10X16 M12X20 M12X20 400
JSD-4 185 25 27 27 29 185 400 450 186 125 12 14 140 102 108 140 M10X16 M12X20 M16X25 500



Gear Ratio

Output Torque (Nm)














We are specializing in manufacturing pneumatic actuator, electric actuator, pneumatic actuated butterfly and ball valve, electric actuated butterfly and ball valve, Limited Switch box and other Accessories………



1.Price: As we are the professional manufacture in valve actuators and accessories, we ensure that the price offered must be very competitive compare with others.

2. Raw material inspection: All material test high quality, and keep in warehouse.

3. Workers: All workers training 3 monthes, skilled workers on production line.

Sample Order

We will charge express fee only for old customers in generally, and for new customers we will charge 50% of the units cost and express fee mostly. (It can be discussed, we keep options always.)


Delivery Time

We usually take 20days for official orders after received the prepayment, And Sample orders will be ready within 7days.


Quality Control

We got very strict and complete quality system to ensure that each product will meet quality requirements as per clients, incoming quality control, final quality control, out-going quality control. Meanwhile, all of the products will be strictly inspected before delivery.”‘ Quality First, Service First” that we are pursuing All the time.


Warranty Period

18 months from the date we signed the contract or PI. Technical support for the whole life. 


Payment Terms And Conditions

1. TT Terms: The payment will be 30% of prepayment by direct bank remittance (T/T),remaining 70% before Shipment or the copy of BL send by us Via Fax or Email.

2. L/C Terms: Payment by L/C at sight and Unrestricted. (L/C must allow 30days minimum from the shipment date of presentation of documents for negotiation, all the clauses within L/C must be clear, concise and acceptable. Do not allow special clauses, terms and conditions.)


Competitive Price

We provide competitive price, good quality and best service to reach the CHINAMFG goal.



Custom-made is acceptable.


Application: Motor, Pneumatic Actuator
Function: Change Drive Torque, Manual Control
Layout: Three-Ring
Hardness: Hardened Tooth Surface
Installation: Vertical Type
Type: Worm Gear Box
US$ 40/Piece
1 Piece(Min.Order)

Request Sample



Customized Request

worm gearbox

Calculating Gear Ratio in a Worm Reducer

The gear ratio in a worm reducer is determined by the number of teeth on the worm wheel (also known as the worm gear) and the number of threads on the worm shaft. The gear ratio formula for a worm reducer is:

Gear Ratio = Number of Teeth on Worm Wheel / Number of Threads on Worm Shaft

For example, if the worm wheel has 60 teeth and the worm shaft has a single thread, the gear ratio would be 60:1.

It’s important to note that worm reducers have an inherent self-locking property due to the angle of the worm threads. As a result, the gear ratio also affects the mechanical advantage and the system’s ability to resist backdriving.

When calculating the gear ratio, ensure that the worm reducer is properly designed and that the gear ratio aligns with the desired mechanical characteristics for your application. Additionally, consider factors such as efficiency, load capacity, and speed limitations when selecting a gear ratio for a worm reducer.

worm gearbox

Worm Gearbox vs. Helical Gearbox: A Comparison

Worm gearboxes and helical gearboxes are two popular types of gear systems, each with its own set of advantages and disadvantages. Let’s compare them:

Aspect Worm Gearbox Helical Gearbox
Efficiency Lower efficiency due to sliding friction between the worm and worm wheel. Higher efficiency due to rolling contact between helical gear teeth.
Torque Transmission Excellent torque transmission and high reduction ratios achievable in a single stage. Good torque transmission, but may require multiple stages for high reduction ratios.
Noise and Vibration Generally higher noise and vibration levels due to sliding action. Lower noise and vibration levels due to smoother rolling contact.
Backlash Higher inherent backlash due to the design. Lower backlash due to meshing of helical teeth.
Efficiency at Higher Speeds Less suitable for high-speed applications due to efficiency loss. More suitable for high-speed applications due to higher efficiency.
Overload Protection Natural self-locking feature provides some overload protection. May not have the same level of inherent overload protection.
Applications Commonly used for applications requiring high reduction ratios, such as conveyor systems and heavy-duty machinery. Widely used in various applications including automotive transmissions, industrial machinery, and more.

Both worm and helical gearboxes have their place in engineering, and the choice between them depends on the specific requirements of the application. Worm gearboxes are preferred for applications with high reduction ratios, while helical gearboxes are chosen for their higher efficiency and smoother operation.

worm gearbox

Advantages of Using a Worm Reducer in Mechanical Systems

Worm reducers offer several advantages that make them suitable for various mechanical systems:

  • High Gear Reduction Ratio: Worm gearboxes provide significant speed reduction, making them ideal for applications that require a high gear reduction ratio without the need for multiple gears.
  • Compact Design: Worm reducers have a compact and space-saving design, allowing them to be used in applications with limited space.
  • Self-Locking: Worm gearboxes exhibit self-locking properties, which means that the worm screw can prevent the worm wheel from reversing its motion. This is beneficial for applications where the gearbox needs to hold a load in place without external braking mechanisms.
  • Smooth and Quiet Operation: Worm gearboxes operate with a sliding motion between the teeth, resulting in smoother and quieter operation compared to some other types of gearboxes.
  • High Torque Transmission: Worm gearboxes can transmit high torque levels, making them suitable for applications that require powerful torque output.
  • Heat Dissipation: The sliding action between the worm screw and the worm wheel contributes to heat dissipation, which can be advantageous in applications that generate heat during operation.
  • Stable Performance: Worm reducers offer stable and reliable performance, making them suitable for continuous operation in various industrial and mechanical systems.

Despite these advantages, it’s important to note that worm gearboxes also have limitations, such as lower efficiency compared to other gear types due to the sliding motion and potential for higher heat generation. Therefore, selecting the appropriate type of gearbox depends on the specific requirements and constraints of the application.

China OEM Pneumatic Actuator Declutchable Manual Override Worm Gearbox   bevel gearbox	China OEM Pneumatic Actuator Declutchable Manual Override Worm Gearbox   bevel gearbox
editor by CX 2023-09-13

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