A comprehensive milling and boring center for manufacturing large rock and mineral crushers in India

TX 3S MILLING AND BORING CENTER_ The Finnish multinational Metso put their trust in JUARISTI to manufacture a milling-boring center for the plant in Alwar, Rajasthan.

Metso is a large Finnish multinational that manufactures industrial machinery at its headquarters in Helsinki. They are specialised in technology and machinery for the aggregate, mining and processes industries and they have production plants around the world. In 2019, they expanded their facilities in Alwar, Rajasthan. Production capacity was increased by 40 % to respond to the growing demand for crushing and sifting centers in the Indian subcontinent. Long-time customers of JUARISTI, this year they once again put their trust in the company to manufacture a multitasking center for critical pieces of their jaw crushers.

Metso management in India needed to install a new machining center they could use for making some critical parts for their stone crushers with maximum productivity. Because they already knew JUARISTI perfectly – they have several of the company’s machines in Finland – they contacted the technical managers to show them the challenge they were facing.

Specifically, they talked about an extremely complex part, which was the pitman for their jaw crushers. The moving jaw is assembled on this structural piece and it is the part that makes the alternative movement that makes the crushing action possible.

The part is made of a very hard material because of the demands placed upon it in production and it has a very complex shape. It includes an upper support point to anchor the piece to the body of the crusher and a panel structure open in the crushing direction that has several transversal supports.

Machining the piece required several phases: milling, boring and finishing inside and out, in addition to demanding a lot of rough machining power. Because of that, the JUARISTI experts suggested a completely automated TX-S multitasking Planer milling and boring center with ATC, APC and AAC and equipped with a boring spindle, automatic universal milling head and a D’Andrea facing head.

JUARISTI TX, one of the company emblems

The solution manufactured for Metso is one of the most well-known machine configurations from JUARISTI. It is a T type milling and boring center with long travels that are 3,500 mm, 2,500 mm, 2,500 mm and 800 mm on the X, Y, Z, W axes.

The heart of the machine is the boring spindle, which in this case has a diameter of 150 mm, 46 kW of power and a 2,046 Nm torque. Those characteristics are highly significant when working with large boring tools and facing heads, because they require a high spindle torque. In addition, the main spindle can reach a rotation speed of 3,500 min^-1 thanks to the oil-air lubrication system in the main gears.

Another notable benefit is that the spindle cone can be disassembled, which makes it easy to change the tool-holder cone if there is a collision without having to replace the entire boring bar.

In addition to the boring spindle, the TX delivered to Metso has an ACD2 universal milling head with 0.001°x0.001° automatic positioning. It is a very robust head with gears that are lubricated automatically using an oil-air system. Because of that it can achieve high levels of productivity. Alongside the universal head, the machine has a 360 mm D’Andrea facing head with a 120 mm radial travel (U axis) and it can reach rotation speeds of 500 min^-1.

The most important structural characteristic of the TX is that it is a completely symmetrical machine, which prevents technical deformation of the column even when the temperature of the workshop is unstable. That characteristic improves machining precision and increases cutting capacity.

Insofar as guiding systems, it has 65 mm linear guides of G1 class precision, which is higher than the standard used by most manufacturers. The vertical travel is reinforced with two guides on the front part and another two on the back of the column. This design contributes to achieving high dynamics and lengthening the machine’s useful life, in addition to increasing the dynamic up to 2 m/s² of acceleration.

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Productivity and Maximum Precision

The rotary table with a hydrostatic guide on the B axis and a double pinion motor drive is added to the characteristics mentioned above. This configuration reduces backlash in rotation and makes it possible to work in continuous mode, in that case a hydraulic clamping system is used to keep the table position stable. Likewise, the table has a high precision encoder at its center that provides ± 2“ precision, which makes it possible to machine parts in different angular positions with maximum precision and repeatability.

The center also includes an automatic pallet change (APC) system with two pallet stations, with the possibility of increasing its number. Insofar as automation systems, also notable are the automatic head change with an automatic closing pick-up station and the chain type automatic tool change (ATC) system with a moving tool magazine on the Z-axis to improve ergonomics.

Lastly, the machine has built-in housing and the control panel is very close to the machining area so the CNC operator has a direct line of sight.

JUARISTI in India

India has been one of the pillars in JUARISTI’s international growth strategy in recent decades. The company began its expansion in India in the late 70s, becoming one of pioneering companies in commercialising machine tools in the country.

From the outset, JUARISTI believed that one of the keys for driving its growth in the country was to accompany its commercial advance with extraordinary technical service.

To those ends, when it began operations in India JUARISTI started to collaborate with a local partner and together they founded the JUARISTI Oriental Engineering Services company in Mumbai. And that company opened new offices in the same city this year.

Commercial management is centralised at those offices and it is home to a sales network that covers all India. The same applies to the Technical Services management, which coordinates several technical teams strategically located in the most industrial areas.

In order to guarantee the quality of the technical service and the satisfaction of its customers, JUARISTI has developed a specialised training plan through which local JUARISTI Oriental technicians receive training at the Azkoitia headquarters. In those sessions, the technicians receive training in the specifications of the mechanical, electrical and hydraulic aspects of JUARISTI solutions and they participate in pre-acceptance tests of machines with customers.

Thanks to that training plan, the local Technical Services in India are perfectly trained to carry out the installation of new machines and manage the Warranty and After-Sales Services with the utmost professionalism and speed. They likewise provide AMC (Annual Maintenance Contract) services that help significantly increase machine productivity.

40 Years Working for the Best

These 40 years of activity in the country have consolidated JUARISTI as one of the leading companies in the boring and milling machine sector. The keys to its success are the machines that give shape to the company’s approach to business: Professionalism, personal service and technological development and innovation to provide top quality machine tools.

Over the years, it has had very successful collaborative relationships with its customers, in both the public and private sectors. And it has installed more than 400 machines for very diverse fields of application: Energy (wind, hydraulic, nuclear), gear boxes, earth moving machinery and construction equipment, defence, aerospace, mould making, textiles, printing machines, general machining, oil & gas, railway, steel, diesel engine blocks, etc.

Among the company’s most important customers in the country are names like Elecon Group, with 33 machines, Larsen & Toubro, Siemens, Alstom, Bhel, LPSC, Tata, Jindal Steel Works, Premier, HVF, Bestall, Sharp Engineering, Brahmos Aerospace, Steel Cast, Plasser, Voith Hydro, Schwing Stetter, Hindustan…