What are ZQ Definitions and ZQ Gearboxes?

ZQ is one of the most widely used gearboxes in various industries, also known as the ZQ gearbox or overhead crane gearbox. When combined with an electric motor, this gearbox forms a gear motor, which helps reduce rotational speed and increase torque for stable and durable machine operation. With efficient power transmission capabilities, this equipment well meets the working requirements in various industrial production systems.

ZQ Gearbox Construction

The ZQ gearbox is solidly designed to ensure stable transmission and high efficiency, consisting of the following components:

• Housing: Made of cast iron or solid cast steel with high rigidity, helping protect internal components and reduce vibration during operation, while also serving to retain internal lubricant.
• Input shaft: The component that receives motion from the electric motor, transmitting torque to the internal gear system of the gearbox.
• Output shaft: The component that delivers the reduced torque outward, driving working mechanisms such as overhead cranes, conveyors, or hoisting machines.
• Gear system: The main reduction component, consisting of helical gear pairs operating in sequential stages to reduce input speed and increase output torque.
• Bearing: Supports the shafts and rotating elements to operate smoothly, reduces friction, and ensures a long service life for the gearbox.
• Oil seal: Prevents lubricating oil from leaking outward and minimizes the ingress of external dust and impurities.
• Lubrication system: Uses lubricating oil or grease to reduce friction, dissipate heat, and extend the service life of transmission components.
• Auxiliary transmission assembly: Includes couplings, pulleys, belts, or chain sprockets, helping the ZQ gearbox work synchronously with the electric motor and load equipment.

Watch the detailed introduction and construction video of the ZQ 400 gearbox:

Material Details & Manufacturing Technology of the ZQ Gearbox

Unlike standard gear reducers, the ZQ gearbox at Thanh Thai Motor is manufactured according to Heavy Duty standards to operate durably in harsh environments such as stone quarrying, port cranes, or brick pressing machines. The material details are as follows:

Gear

• Material: Made from low carbon alloy steel (20CrMnTi) or high-quality 40Cr steel.
• Technology: Precisely machined using CNC milling machines, followed by carburizing and precision gear tooth grinding.
• Hardness: Reaches tooth surface hardness standards of HRC 58 – 62. Ensures excellent wear resistance, preventing chipping under sudden shock loads.

Shaft

• Material: Uses C45 steel or 40Cr alloy steel.
• Technology: Subjected to quenching and tempering heat treatment to achieve the necessary toughness.
• Advantages: Helps the shaft withstand high torque and bending stress without brittle fracture during operation.

Housing

• Material: Solid cast from gray cast iron (HT200 grade) or ductile iron depending on load requirements.
• Advantages: Thick casing walls, good vibration absorption capacity, helping the gearbox operate smoothly and dissipate heat faster than welded steel casings.

Operating Principle of the ZQ Series

The ZQ gearbox operates based on the internal gear transmission principle.

• When the motor rotates, it turns the input shaft of the ZQ gearbox.
• The input shaft has a small gear attached (driving gear).
• The small gear is linked to a larger gear (driven gear).
• When the small gear makes one revolution, it causes the larger gear to rotate more slowly. This is also the process of reducing the output speed.
• However, while the speed is reduced, the output torque is increased, enabling the gearbox to pull heavy loads.

Depending on the specific application, we can choose 3 different output types for the ZQ gearbox, making it suitable for various types of machinery:

• C Type (Standard): This is the most commonly used output shaft with a simple construction. Suitable for direct drive and basic, less complex applications.
• CA Type (Improved): Designed to be sturdier, used for systems requiring very high rotational force.
• Gear Type: Instead of a smooth shaft, this type features a gear mounted directly on the output shaft. Highly suitable for transmitting high power.

Thanks to precise construction and step-by-step transmission from shaft to shaft, the ZQ gearbox delivers stable, smooth speeds, strong load capacity, and high efficiency.

Classification of ZQ Gearboxes

ZQ gearboxes come in various types to suit all types of hoisting machinery. They are classified based on shaft arrangement, gear shape, size, and reduction stages.

By Shaft Construction

• Inline shaft gearbox: The input and output shafts are arranged parallel to each other. This is the most popular line thanks to its simple design, easy installation, easy maintenance, and stable operation.
• Skewed shaft gearbox: The input and output shafts are designed at a fixed intersecting angle, helping transmit power efficiently and handle heavy loads. Stronger power transmission and better load capacity, but with a more complex structure and higher cost.
• Parallel shaft gearbox: The input and output shafts lie parallel to each other and not on the same straight line. This is the most common design.

By Gear Construction

• ZQ helical gear gearbox: Uses helical gears to increase smoothness, reduce noise, and improve transmission efficiency.
• ZQ bevel gear gearbox: Bevel gears help transmit power between intersecting shafts, suitable for applications requiring a change in transmission direction.
• ZQ spur gear gearbox: Gears are cut straight parallel to the shaft. Less common in newer ZQ lines due to higher noise generation, but easier to manufacture and lower in cost.

By Size

Classifying the gearbox by size is mainly based on a technical parameter called “Size”, which determines the load-bearing capacity of the gearbox. Currently, Thanh Thai Motor offers sizes ranging from 200mm to 1000mm, including:

By Number of Stages

• 1-Stage ZQ gearbox: A simply designed gearbox with only one pair of driving gears. Thanks to its compact structure and low cost, the 1-Stage ZQ is suitable for applications with moderate loads and without excessively large transmission ratios. Commonly used in civil machinery or simple mechanical systems.
• 2-Stage ZQ gearbox: Features a structure of two meshing gear stages, allowing for a larger transmission ratio and better load-bearing capacity. This type is often applied in industrial machines requiring powerful, durable transmission and high efficiency.
• 3-Stage ZQ gearbox: A gearbox consisting of three stages of driving gears, helping increase the transmission ratio to a very high level and significantly reduce the output speed compared to the input speed. As a result, the 3-Stage ZQ gearbox has a large load capacity, operating stably and durably over long periods.

Latest ZQ Gearbox Prices for 10/2026

ZQ Gearbox Price Quotation Video for 10/2026 at Thanh Thai Motor

ZQ Specifications

The ZQ gearbox is a specialized gearbox for heavy machinery such as overhead cranes, so the ZQ features many different variants to suit each job type. The ZQ gearbox is divided into 2 main lines based on the number of reduction stages:

• ZQH (ZQA, JZQ) 2-Stage: This line has only 2 reduction stages
• ZQD 3-Stage: This line has 3 consecutive reduction stages, producing a slower speed and stronger rotational force.

Below are the detailed specifications of the ZQ:

Maintenance, Installation & Lubrication Guide for ZQ

To keep the ZQ gearbox operating durably without overheating or gear wear, filling the correct and sufficient amount of oil is vital. Below is the reference oil capacity table for each gearbox size:

(Note: The above figures are average estimates. Actual oil quantity depends on the installation position. Always observe the oil sight glass or dipstick on the gearbox body).

3 Golden Notes When Changing Oil for the ZQ Gearbox

1. Standard oil level check method: The most reasonable oil level is when the oil submerges about 1/3 to 1/2 of the largest gear (or lies between the Min-Max marks of the dipstick/sight glass). Do not overfill as it causes overheating and oil leakage through the seals.
2. Oil viscosity: For heavy-duty gearboxes like ZQ, it is mandatory to use high-viscosity industrial oil: ISO VG 320 or ISO VG 460 (commonly known as 320 oil, 460 oil). Do not use motorcycle oil or thin hydraulic oil.
3. Oil change intervals:

• First time: After 500 running-in hours (about the first month). Drain all old oil to remove machining metal shavings.
• Periodically: Replace with new oil after every 2,500 – 3,000 subsequent operating hours.

Notes on Selecting and Installing the ZQ Gearbox

For the ZQ gearbox to operate efficiently, durably, and achieve a high service life, choosing the right type and installing it correctly are key factors. The following notes will help you maximize the efficiency of the equipment once you understand what a ZQ gearbox is.

• Determine exact usage requirements: First, accurately assess motor power, transmission ratio, required torque, as well as working conditions (temperature, humidity, dusty environment…). Accurately determining these factors helps you choose the most suitable gearbox model for each specific application.
• Choose a reputable supplier: Buying from an experienced distributor like Thanh Thai Motor helps ensure product quality, clear origins, transparent warranty policies, and reliable technical support.
• Install with correct technique: During installation, align the input and output shafts concentrically with the motor and load, and check the tightness of bolts and nuts. If installed incorrectly, the equipment may vibrate, create loud noise, or even cause serious damage.
• Periodic maintenance: Clean, inspect, and change oil periodically to maintain stable transmission efficiency. Regular maintenance also helps detect abnormal signs early, avoiding unexpected machine downtime.

Customers can view more gearbox product lines being sold at Thanh Thai Motor at the gearbox video category summary page to get an overview of products, prices, and technical instructions.

Advantages of the ZQ Gearbox

• Extremely high load capacity and durability: Sturdy materials, casing made of cast iron or alloy steel, specialized steel gears undergoing heat treatment and precision grinding to increase hardness and wear resistance, capable of withstanding large torque forces over a long period.
• Smooth operation and high efficiency: The ZQ gearbox uses helical gears to make the teeth mesh gradually and continuously. This helps reduce noise and vibration during the operation of the ZQ gearbox, enhancing efficiency.
• Diverse transmission ratios: Easily choose from 2 main lines: ZQH 2-stage and ZQD 3-stage, providing a full transmission ratio range from 10 times to over 317 times, suitable for various loads, helping users easily select a gearbox that matches machinery needs.
• Specialized design for heavy industry: Various sizes from 200 to 1000, with flexible installation styles including 9 input shaft mounting styles and 3 output shaft mounting styles.

Applications of the ZQ Gearbox

Below are common applications of the ZQ gearbox:

• Overhead crane systems and hoisting equipment: This is a common and important application of the ZQ gearbox, especially for large sizes.
• Large conveyor systems: The ZQ gearbox is used to transmit slow and stable rotational force for conveyor systems used in mineral processing, mining, etc., where large loads need to be moved gradually and continuously.
• Construction and mining machinery: Applied in concrete mixers, stone crushers, extruders, etc.
• Textile, paper, and chemical industries: In paper or steel production, ZQ is applied in rolling rolls to compress and roll materials. Additionally, it is installed on large-capacity chemical, paint, or food mixing tanks.

Where to Buy Quality ZQ Gearboxes?

Thanh Thai Motor is one of the leading quality and reputable ZQ gearbox suppliers, with many quality commitments and good after-sales services.

• Full CO, CQ
• Warranty up to 24 months
• Goods always available in stock
• Nationwide doorstep delivery
• View goods at the warehouse address: 90/8 Phan Van Hon, Tan Thoi Nhat Ward, District 12, HCMC

FAQ about ZQ Gearboxes

What is the best oil to use for the ZQ gearbox?

Industrial oil with viscosity VG 320 or VG 460 should be used to ensure lubrication for heavy-duty gears.

How do ZQ and JZQ differ?

Basically, installation dimensions are the same; JZQ is an improved standard in gear quality compared to the older ZQ generation.

What is the commonly used transmission ratio for the ZQ 500 gearbox?

The most popular are transmission ratios of 1/40 and 1/50 used for winches and overhead cranes.