NORD UNICASE Helical Bevel Gear Units SK 9012.1 to SK 9096.1

Overview

NORD UNICASE helical bevel gear units are right-angle gear units in which the motor shaft and the output shaft form a 90° angle. This geometry gives a compact footprint where space along the driven shaft is limited, for example beside a conveyor, under a mixer or along a screw. The SK 9012.1 to SK 9096.1 series covers 11 housing sizes with maximum output torques from 400 Nm to 50,000 Nm and total ratios from 8.04 to 13,432.68, built in three-stage and four-stage designs.

Seven Star LLC supplies NORD UNICASE helical bevel gear units and gear motors to cement, mining, water, food and logistics customers in Oman and the GCC. Our engineers in Muscat help match the gear unit size, ratio and mounting to each duty, and we provide engineering support for sites in Muscat, Sohar, Duqm and Salalah.

Operating Principle

Power enters through a helical input stage that reduces speed and increases torque, then passes through a bevel gear stage that turns the drive through 90°, and finally through one more helical stage to the output shaft. Four-stage versions add a further helical stage in front of the bevel set for very high ratios. According to NORD, the advantage of this arrangement is almost constant efficiency over the entire ratio range, practically the same as helical inline and parallel shaft gear units, which makes bevel units far more efficient than worm gearing at high ratios.

Gears in the NORD UNICASE series are made of high-quality alloyed steel with case-hardened teeth, and all gears and bearings run in an oil bath for continuous lubrication. In addition to the keyed connection, gears are pressed onto their shafts. NORD calculates bearings, shafts and gearing according to DIN ISO 281, DIN 743, Niermann, DIN ISO 10300, DIN ISO 6336 or DIN 3990. On the NORD UNICASE bevel series, a backstop can be integrated inside the gear unit and lubricated by the gear oil, which prevents reverse rotation on inclined conveyors and bucket elevators.

Engineering Design of the NORD UNICASE Gear Unit

The term NORD UNICASE describes a single housing block into which all bearing seats are integrated. The housing is machined in one setup on CNC machines for precision, rigidity and strength, and there is no joint between the output side and the rest of the housing, so torque and radial forces do not act on a split line as they do in two-piece housings. The bevel series uses torsionally rigid cast iron housings that are low maintenance, offer long service life and accept high axial and radial loads, supported by different bearing concepts.

NORD UNICASE bevel units are available in mounting positions M1 to M6 with solid shafts, hollow shafts with key, GRIPMAXX keyless bushings or shrink discs, and in shaft-, flange- and foot-mounted versions. Standard solid shafts range from 30 × 60 mm on the SK 9012.1 to 190 × 320 mm on the SK 9096.1, and standard hollow shafts from 35 mm to 160 mm. Shaft seals are normally NBR, with FKM (Viton) available as an option, and the gear units combine with IEC or NEMA adapters and NORD motors from the same modular system.

Key Features

NORD UNICASE helical bevel gear units provide these benefits to plant designers:

• Eleven housing sizes from SK 9012.1 to SK 9096.1 with maximum output torque from 400 Nm to 50,000 Nm.
• Total ratios from 8.04 to 13,432.68 in three-stage and four-stage designs.
• One-piece UNICASE cast iron housing with integrated bearing seats for rigidity and long life.
• High, nearly constant efficiency across the full ratio range for low operating costs.
• Solid or hollow output shafts with key, GRIPMAXX or shrink disc, and foot, flange or shaft mounting.
• Integrated, oil-lubricated backstop option on the SK 9012.1 to SK 9096.1 series.
• Case-hardened alloy steel gearing running in an oil bath, with NBR or optional FKM shaft seals.
• ATEX explosion-protected versions documented by NORD for hazardous areas.

Industrial Applications

NORD UNICASE helical bevel gear units are workhorses of the bulk handling and process industries. Typical duties include belt and screw conveyors, bucket elevators, mixers and agitators, clarifier and thickener drives, crushers, cooling tower fans and hoisting gear. The right-angle design lets the motor sit parallel to the conveyor, and the shaft-mounted version with torque arm removes the need for couplings and alignment on many machines.

In Oman, NORD UNICASE bevel gear units suit cement and lime plants, aggregate quarries, port bulk terminals in Sohar and Duqm, desalination and wastewater treatment plants, and food processing lines. Seven Star LLC supplies them as a trusted supplier and supports other power transmission components on the same projects, including the JIE JRT R series helical gearmotor, the JIE JRHH parallel shaft industrial gear unit and the WEG W22 IE3 three-phase motor.

Technical Specifications

The NORD UNICASE helical bevel data below are taken from NORD catalogue G1000 (Constant Speed Drives) and the NORD product page.

How to Order

To order NORD UNICASE helical bevel gear units, send Seven Star LLC an RFQ with the required output torque and speed, the driven machine, service factor, mounting position and shaft type, or the nameplate data of the unit you want to replace. Our Muscat team will propose a size and ratio, confirm availability and lead time and provide the NORD B1000 gear unit manual for download. Seven Star LLC supplies NORD DRIVESYSTEMS gear units across Oman and the GCC with engineering support in Muscat.