The Versatile World of Grinding with Corundum

ZEMA NUMERIKA Cylindrical Grinding Machine

Large quantities, precise geometries and a wide range of parts: the automotive industry, in particular, has high demands when it comes to production. With the ZEMA NUMERIKA corundum-grinding machine, the JUNKER Group is offering a versatile solution. From drive shafts to journals, it reliably machines a wide range of workpieces.

The name ZEMA stands for machine concepts and special solutions for grinding with corundum, thus the world market leader in CBN high-speed grinding machines is now also offering efficient solutions for conventional grinding. Customers worldwide will also benefit from JUNKER’s various solutions.

 

France: pinion shafts…

The ZEMA NUMERIKA meets all the requirements for series production of a wide variety of workpieces: with its extensive range and high productivity, it has also impressed one of the leading manufacturers of drive technology. Since 2017, the NUMERIKA has been in use at the branch office in Alsace, where the drive technology specialist manufactures pinion shafts.

The workpieces vary in length from 34 to 128 millimeters, with diameters between 9 and 30 millimeters. Production changeover is taking place at least three times per day. Short setup times were therefore one of the customer’s main requirements. The NUMERIKA G 800 Plus masters this in next to no time – thanks, in part, to the user-friendly CNC control system, where several types of a workpiece family can be stored, allowing a quick changeover from one workpiece to another in production.

…in a single plunge cut operation

The NUMERIKA also boasts extraordinarily short cycle times, as it can grind pinion shafts in a single plunge cut operation. This is made possible by the extra-large grinding packages, which are exclusive to ZEMA. The NUMERIKA thus reduces the downtimes while increasing the customer’s productivity to around 1,000 parts per day.

The ZEMA NUMERIKA impressed the specialist in drive technology right from the start: with short cycle times, high productivity and reliability, it takes on a demanding role in the factory. The versatile corundum-grinding machine replaces two previously used machines for the customer.

Brazil: crankshafts…

The NUMERIKA G 800 Plus also proves to be a reliable line machine when used together with the JUCRANK 6S. In Brazil, two machines from ZEMA and two from JUNKER are used to manufacture crankshafts for one of the world’s largest automotive manufacturers. Flanges and journals are ground with corundum while main and pin bearings are machined using CBN.

A combination of a corundum and CBN grinding machine from a single source brings advantages: the machines’ technology and control systems are perfectly matched. A quantity of around 150,000 per year in three-shift operation calls for high productivity from both machines.

…call for team work

Three different crankshafts with lengths ranging from 335 to 435 millimeters are machined. The automotive manufacturer also requires flexibility: each machine must be able to process each of the crankshaft types on offer. Thus, both machine types are designed to produce crankshafts with lengths between 300 and 570 millimeters.

This perfect combination of ZEMA and JUNKER working together on a line won over the global player. The customer is now planning to expand production to up to 280,000 crankshafts per year, using NUMERIKA and JUCRANK machines. The German-Brazilian duo is now demonstrating its strengths here in prototype production.

Mexico: drive shaft…

Endurance, robustness and effectiveness – these are just a few of the factors that have contributed to the success of the ZEMA NUMERIKA. After all, high-tech features are not always required. One of the global suppliers to the automotive industry has opted for the robust corundum-grinding machine primarily because it is easy to operate.

This customer manufactures drive shafts on vehicle axles at their plant in Mexico. A warp-resistant machine bed, hydrostatic guides and grinding spindles on roller or hydrostatic bearings form the basis for perfect grinding results. The customer was particularly attracted by the fact that, thanks to an exceptionally short delivery time, the NUMERIKA was quickly ready for use, which is why they went on to install two further ZEMA machines. With the cylindrical grinding machine, the JUNKER Group is offering a unique solution, which provides excellent value for the money.

…with proven JUNKER precision

The ZEMA NUMERIKA impresses on many fronts. One thing above all sets the corundum-grinding machine apart: its excellent adaptability. This applies to both the NUMERIKA as well as the other machines from the JUNKER Group. They are all easy to integrate into existing production lines and are equipped with a uniform, intuitive user interface. What is more, they cover all grinding processes and an extensive range of workpieces.

As a partner for precision, the JUNKER Group can specifically adapt each machine to meet customer requirements and provide solutions, as needed. In doing so, JUNKER adheres to the highest standards of precision, both in terms of perfect grinding results and the individual configuration of the machines.

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