ZQ 250 Gearbox (Size 250) – Output Shaft 50mm

The ZQ 250 reduction gearbox (also known as JZQ 250) is the most popular mid-range gearbox model in the heavy-duty ZQ gearbox series. With a 50mm output shaft diameter and a thick cast weight (~85kg), the ZQ 250 Gearbox offers superior load-bearing capacity compared to its younger sibling, the ZQ 200, and is specialized for lifting hoist and crane systems with loads ranging from 500kg to 1 ton.

Overall Design of the ZQ Gearbox

The ZQ 250 Gearbox features the characteristics of industrial heavy-duty gearboxes with a sturdy rectangular block design, specialized for harsh working environments. The input shaft (primary shaft) and output shaft (secondary shaft) are arranged in a parallel eccentric layout, optimizing sprocket chain drive systems or couplings.

The outer housing surface of the gearbox is designed with large embossed cooling ribs, maximizing the air contact area and helping the gearbox dissipate heat naturally and excellently during continuous work shifts. In particular, the positioning bolt holes on the base and housing cover are CNC flat-milled and precisely coordinate-machined, making it easy for mechanical technicians to mount and align coaxially onto machine frames and crane girders without worrying about misalignment.

Structure of the Heavy-Duty ZQ 250 Gearbox

At Thanh Thai Motor, the ZQ 250 Gearbox is imported according to Heavy Duty standards to ensure the highest lifespan:

• Housing: Cast from solid gray cast iron, with a large wall thickness that provides excellent impact resistance and prevents cracking during sudden overload pulls.
• Gears: 100% helical gears made from 20CrMnTi alloy steel. After CNC machining, the gears undergo carbonitriding to achieve a hardness of 58-62 HRC.
• Shaft: Quenched and tempered C45 steel, offering good torsional resistance.

Technical Specifications of ZQ 250 Gearbox (Size 250)

The ZQ 250 Gearbox is a power-upgraded version compared to the ZQ 200 with gear ratios: i = 10, 12.5, 16, 20, 25, 31.5, 40, 48.57, most suitably installed with 2.2kW (3HP), 3kW (4HP) or up to 4kW (5.5HP) motors at 1450 rpm. Below are the important dimensional parameters you need to note in order to choose the appropriate motor and coupling:

Practical Applications of ZQ 250 Size

With significantly greater traction (torque) than the ZQ 200, the ZQ 250 Gearbox is the number one choice for mid-range applications:

• Construction winches: Used for ground winches or lifting winches pulling materials with loads of 500kg – 1000kg.
• Crushers/mixers: Installed in plastic crushers and 350-liter concrete mixers.
• Factory cranes: Used as the traveling mechanism for 1-ton to 2-ton single-girder overhead cranes.
• Conveyor belts: Rubber conveyor belts for transporting stone, coal, and minerals (low gradient).

Guide on Adding Oil to the ZQ Gearbox

Proper technical lubrication determines the lifespan of the gearbox gears. Below is a guide from Thanh Thai Motor experts:

• First run: Completely replace with new oil after the first 300 – 400 hours of operation. This time is very important to drain out microscopic metal particles generated during the break-in process of new gears.
• Subsequent times: Periodically replace oil every 2500 – 3000 operating hours (or once every 6 months depending on environmental conditions).
• Procedure: Open the drain plug at the bottom while the gearbox is still slightly warm so that the oil drains quickly and clears sediment. Tighten the bottom plug, open the breather plug on the top cover, and slowly add oil.

The ZQ 250 Gearbox (JZQ 250) is truly a durable transmission solution with superior pulling force for lifting hoists, cranes, and mid-range conveyor systems in mechanical and mining plants.

For the most intuitive and vivid view of the internal structure and the actual running sound of the machine at the warehouse, we cordially invite you to watch detailed gearbox videos on our channel, as well as our rich document library of videos summarizing disassembly and product introductions produced by Thanh Thai Motor.

Warranty, Shipping, and Commitment Policy at Thanh Thai Motor

When purchasing gearboxes at Thanh Thai Motor, you will receive benefits such as:

Warranty up to 24 months

Gearbox products at Thanh Thai Motor are covered by a genuine warranty for up to 24 months. Customers can be completely confident in using them with a clear, transparent, and prompt after-sales policy.

Nationwide Delivery

We support fast delivery to all provinces and cities nationwide. Wherever you are, products are guaranteed to arrive on time and safely.

Products meeting European quality standards with German technology

Gearboxes at Thanh Thai Motor are manufactured using advanced German technology, meeting European quality standards. Ensuring high durability and stable operation for extended periods.

Competitive prices, good discounts for dealers and bulk customers

Reasonable prices, many attractive offers for wholesale buyers and distribution agents. The more you buy, the higher the discount – optimizing profits for customers.

Full certification documents: CO, CQ,...

Each product comes with full Certificate of Origin (CO) and Certificate of Quality (CQ). This provides assurance for customers when using them in projects or constructions requiring technical documentation.

Contact for Purchase

Do you need advice on choosing the right gearbox for your needs? Contact Thanh Thai Motor immediately using the methods below:

• WhatsApp: +84966596219
• Email: codienthanhthai@gmail.com