SIJIEoffers three worm gear screw jack series developed for different application requirements. The SJW series provides a proven classic design, the SJC series delivers a premium cubic housing design with international compatibility, while the SJM series offers a cost-effective solution for general industrial applications.
| Series | Recommended For | Key Advantages |
|---|---|---|
| SJW Series | General industrial lifting and positioning applications | Classic design, proven reliability and wide application range |
| SJC Series | High-performance applications and European brand replacement projects | Premium cubic housing, precision positioning and compatibility with international designs |
| SJM Series | Cost-sensitive industrial projects requiring reliable performance | Cost-effective solution with competitive pricing and dependable operation |
Our classic SJW series screw jack features a powerful trapezoidal screw, high-precision worm gear, and rugged jack housing, offering the perfect balance of price, performance, and quality.
Available in 10 sizes, the SJW screw jacks’ load capacity ranges from 1 ton to 100 tons as standard. We can also customize our SJW screw jacks to load capacities of 150 tons, 200 tons, and 250 tons to meet your specifications. Suitable for low-speed, low-frequency, and large load operation, our classic worm gear screw jacks are constantly being developed with new drive solutions.
Featuring a unique square groove shell, our SJC series worm gear screw jacks are built with high performance and precise positioning in mind.
These worm gear screw jacks can be used individually or in multiple arrangements and handle a load capacity up to 100 tons. The screw jacks incorporate a square groove shell to increase heat dissipation capacity and extended grease life and designs are available with optional accessories, including anti-backlash devices. Our SJC series worm gear screw jacks are commonly used in OEM machinery and although manufactured in China, they are fully interchangeable with several US and European products.
Whether your project requires lifting, lowering, moving or tipping, our SJM series screw jack offer a Cost-Effective solution for a wide range of industrial applications.
With a standard load capacity up to 120 tons, our SJM screw jacks have a self-locking function, supporting the load and holding its position with no need to employ a brake mechanism or other locking system. Available to use individually or in a multiple arrangement, our screw jacks can be custom-made to meet your specifications. SIJIE provide over 15 years of manufacturing and application experience, meaning our worm gear screw jacks deliver reliable performance you can trust.
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Worm gear screw jacks are widely used for controlled lifting, lowering, pushing and positioning applications in industrial machinery. With reliable worm gear transmission and self-locking capability, they provide precise linear motion solutions for various mechanical systems.
Industrial Automation: Used for accurate positioning, adjustment and synchronized lifting in automated machinery.
Machinery Equipment: Suitable for mechanical adjustment systems, production equipment and custom machinery.
Lifting Systems: Applied in platforms, assembly equipment and industrial lifting mechanisms.
Customized Mechanical Solutions: Designed for OEM equipment requiring reliable linear motion and load positioning.
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A ball screw jack is a mechanical linear actuator that converts rotational motion into precise linear motion. It uses a worm gearbox to drive a precision-ground ball screw, with recirculating steel balls rolling between the screw shaft and ball nut. This rolling-contact design replaces the sliding friction of a traditional machine screw, resulting in much higher efficiency (typically 80-90% at the ball nut), smoother operation, and higher travel speeds.
No. Due to their high efficiency (typically above 50%), ball screw jacks are not self-locking. When power is removed, the load can back-drive and drift. To hold position, you must use a brake motor, an external brake on the input shaft, or another mechanical locking device. This is a critical safety consideration during selection.
The key difference is the friction mechanism. A trapezoidal screw jack uses a sliding trapezoidal thread (metal-on-bronze), offering lower cost and inherent self-locking, but lower efficiency (20-35%) and limited duty cycle. A ball screw jack uses recirculating balls, delivering more than 50% efficiency, higher speeds, longer life, and suitability for high-cycle automation – but it is not self-locking and requires a brake or external locking device. Ball screw jacks also require up to two-thirds less input torque than equivalently rated trapezoidal screw jacks.
Ball screw jacks are available in a wide range, from 5 kN (0.5 ton) for light-duty precision positioning up to 1000 kN (100 tons) for heavy industrial lifting. Common standard sizes include 10 kN, 25 kN, 50 kN, 100 kN, 200 kN, and 500 kN. Custom capacities and stroke lengths can be engineered for specific applications.
The ball screw and nut assembly itself typically achieves 80-95% efficiency. When combined with the worm gear reduction, overall jack efficiency ranges from approximately 45% to 60%, depending on gear ratio and load. This is significantly higher than trapezoidal screw jacks (20-35%), meaning less motor power is needed to move the same load.
Unlike tapezoidal screw jacks, ball screws cannot be keyed – a keyway would interrupt the ball track and cause ball loss. Instead, anti-rotation is achieved by fitting a square anti-rotation tube (square guide block) that slides inside a square stem tube, or by guiding the load externally. Note that adding an anti-rotation device increases required input torque by approximately 8%.
Yes, a ball screw jack can drift after the motor is stopped because it is not self-locking. Drift is influenced by motor inertia, load weight, and gear ratio. To prevent drift and ensure safety, always install a brake of sufficient capacity on the input shaft or use a brake motor. For vertical loads, a holding brake is mandatory.
Ball screw jacks are widely used in: automotive assembly lines (chassis lifting, engine positioning), steel and metal processing (rolling mills, coil handling), packaging and printing machinery, food and beverage equipment, maritime and rail systems, aerospace test rigs, construction formwork, solar tracking systems, and general industrial automation requiring precise, repeatable linear motion.
Thanks to low rolling friction and reduced heat generation, ball screw jacks can handle higher duty cycles than trapezoidal screw jacks – often up to 30-50% in well-lubricated, properly sized applications. Exact limits depend on load, speed, lubrication, and ambient temperature. Continuous operation at high loads may require oil lubrication and thermal monitoring.
– Grease lubrication is standard for most applications. Use a high-quality lithium-based or EP grease suitable for ball screws.
– Relubrication interval: approximately every 100-300 operating hours (reduce to 100 hours under heavy loads or dusty conditions).
– Grease quantity: roughly 1 ml per cm of screw diameter per lubrication point, or until grease slightly escapes from the nut ends.
– Inspection: check for contamination, abnormal noise, or increased backlash every 6 months; keep the screw protected with bellows boots in dirty environments.
Yes. Multiple ball screw jacks can be connected in tandem or multi-jack systems using bevel gearboxes,couplings, and drive shafts to achieve synchronized lifting. With a servo motor and closed-loop control,synchronization accuracy can reach within 0.05 mm. This is commonly used for lifting platforms, stage equipment, and large industrial structures requiring even load distribution.
Standard ball screw jacks operate within -15 to +80 C (5 F to 176 F). Larger or heavy-duty models may extend to +100 C (212 F). For extreme temperatures (cryogenic or high-heat environments), special lubricants, seals, and materials can be specified. High-speed continuous operation may generate additional heat requiring cooling or oil lubrication.
Yes. Common customizations include: special stroke lengths, stainless steel screws and housings for food/corrosive environments, protective bellows boots, custom end fittings (top plate, clevis, plain end, threaded end), integrated position encoders, manual handwheel operation, special gear ratios, and complete multi-jack lifting systems with motors, gearboxes, and controls. In addition, we can completely customize alternatives to any European and American brands according to customer drawings.
Ball screw life is typically calculated based on travel distance (e.g., 50 million revolutions or 10,000-50,000 km of travel, depending on load and lead). Under proper lubrication and within rated load/speed, a ball screw jack can provide many years of reliable service. The worm gearbox, when properly maintained, is often considered lubricated-for-life under normal conditions.
Standard models are typically available with 20-25 days lead time.Custom configurations may require additional engineering and production time. We offer EXW, FOB, and CIF trade terms, and can ship viasea freight for large orders or air freight/DHL express for samples and urgent deliveries. Contact our engineering team with your application specifications for a quotation and lead time estimate.
