A helical bevel gearbox for the food industry

BJ-Gear’s newly developed stainless steel helical bevel gearbox is ideal for the food industry and other industries with high demands on hygiene, high requirements for the resistance of the product as well as the product’s ability to perform processes with great accuracy.

The helical bevel gearbox has a dynamic efficiency of 96%, which results in a minimal energy waste. The gearbox is available in sizes SX22, SX32 and SX42 and is with its hygienic design ideal for the food industry. The smooth surfaces are easy to clean, as they are without any recesses or other areas, where dirt can gather or where bacteria can accumulate. Consequently, you completely avoid having to shield the gearbox and end up with a solution that is much harder to keep clean and sanitary.

Yearlong development collaboration with Marel

The stainless steel helical bevel gearbox is developed in collaboration with Marel Støvring, Denmark, who supplies equipment to and solutions for the meat and salmon industries. The project has its basis in a long cooperation between the two companies, where BJ-Gear supplies stainless steel gearboxes and food approved NG bearings to Marel’s machines for the food industry. Previous development projects with adjustments made to our stainless steel worm gearbox has laid the foundation for the development of the stainless steel helical bevel gearbox.

The development project derives from Marel’s development of their new Salmon Deheader MS 2720. Therefore, the collaboration has been a question of adapting the helical bevel gearbox to Marel’s specific needs.

Product and Development Engineer at Marel, Mads Dahl says: “We have been looking for a stainless steel helical bevel gearbox in the sizes we require for a long time. It has been of great importance that BJ-Gear can deliver the gearboxes with special hollow output shafts with shrink disc and input flanges with couplings that fit our engines while maintaining a hygiene friendly design.”

A great degree of precision minimises waste and enhances the yield

BJ-Gear has supplied three SX22 helical bevel gearboxes and one SX32 helical bevel gearbox to Marel’s Salmon Deheader MS 2720. The three SX22 gearboxes run three conveyor belts that transport the fish from the previous process to the blade. SX32 gearbox is mounted to the blade, which cuts off the tail of the fish with immense precision.

The Salmon Deheader is part of a bigger trend in the industry, which is moving towards a bigger degree of automation. The machine replaces an older model by having a gentler handling of the fish in the process, where the head is cut off. The cutting processes at the head and tail are characterised by consistency and accuracy in each cut, which gives an optimum yield of the expensive salmon meat from every fish.

The correct gear ratio gives the perfect tail cut

To ensure a perfect tail cut it is important that the tail cutter runs at a certain speed. Therefore, the tail cutter runs with a maximum speed of 1000 revolutions per minute. The high speed of the tail cutter is achieved by means of a ratio of 7.33 of the SX32 helical bevel gearbox, which is mounted with a servomotor. It is the gear ratio together with the properties of the servomotor that allow the blade to accelerate and decelerate, ensuring a high degree of precision in the handling of the fish.

The three conveyor belts are mounted with the smaller SX22 gearboxes that have a ratio of 24.18, giving a far lower output speed of 75 revolutions per minute. The SX22 gearbox together with the mounted servomotor makes it possible to start and stop the conveyor belts with great exactness. This is especially important when it comes to knowing the exact position of the fish on the third conveyor belt, where the tail is cut off.

Our stainless steel helical bevel gearbox is also featured in Marel’s brand new QC-scanner, which uses a special scanning technology to colour grade the salmon fillets and automatically detect melanin and blood spots. This detection reduces waste and increases quality and productivity.

All flange bearings in the MS 2720, the QC scanner and all other of Marel’s machines are also provided by BJ-Gear. The NG bearing is a waterproof, spherical flange bearing, which is FDA and USDA approved. The bearing unit is with its design, its high degree of protection and its high resistance towards chemicals and detergents ideal for the food industry.

Read or download our brochure to learn more about the stainless steel helical bevel gearbox.