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With many of its precision gears produced in small lot sizes, Spanish gear producer Engranajes Juaristi S.L. depends on Gleason machines for exceptional speed and flexibility.
Zarautz, Spain, might seem an unlikely place for a precision gear manufacturer. This beautiful coastal town in the heart of the Basque region is known for its beaches and considered among the top surfing destinations in the world. Surprisingly, the relaxed holiday atmosphere and laid-back surfer ‘vibe’ turn out to be highly conducive to the production of gears. It is here that you will find Engranajes Juaristi, a renowned gear producer, owned and operated for over 65 years by the Juaristi family. The company specializes in the production of high-precision external and internal gears up to 1,200 mm in diameter, as well as worm gear sets, spline shafts, and other transmission components for everything from wind turbines to tractors, machine tools to trains. Significantly, 30 percent of the many thousands of gears produced by Engranajes Juaristi annually are in lot sizes of just one, and the average lot size is just seven parts. It’s a bold strategy that attracts business and gives them a competitive edge. It also requires machines that can deliver faster cycle times and more flexibility.
Doing More with Less
Over the course of the last two decades, Engranajes Juaristi has phased in a new generation of highly productive Gleason hobbing, shaping, and profile grinding machines, for which one of the company owners, Inigo Juaristi, general technical manager, and his son Jokin Juaristi, sales manager, take credit for much of their company’s success. For example, two Gleason P400 hobbing machines and one P600/800 hobbing machine have replaced more than six older manual hobbing machines, eliminating countless hours of costly downtime once required for part changeover. “When any of the manual machines needed to be set up for a new part type, it usually tied up the machine operator for hours, thus bringing all the machines to a costly standstill,” explains Jokin Juaristi. “With the Gleason machines, this costly bottleneck is all but eliminated. Fewer machines are producing more parts faster, with less changeover time part to part.”
Additionally, these hobbing machines are designed with highly accessible, ergonomically designed work areas with large operating doors to aid in manual part loading. The operator’s task is further simplified with current Siemens controls and operator-friendly Gleason hobbing software, including support and service functions.
The machines are ideally suited as well to accommodate the widest possible range of workpiece types and sizes and have extended ranges for workpiece diameters and shaft lengths: axial slide travels of 600 mm on the P400 machines, and 1,000 mm on the P600/800 machine, for shaft applications.
The company also says that the machines have operated with exceptional reliability and minimal maintenance over the years. Robust guideways are standard, and the use of proven, reliable direct-drive work spindles or double worm gear table drives delivers the desired high precision cutting results.
New Business Shapes Up
It’s not surprising, given Engranajes Juaristi’s breadth of products, that shaping is a key capability. For internal gears and those that can’t be hobbed efficiently, the company uses two Gleason P600/800ES gear shaping machines. Both machines feature an electronic helical guide–an additional CNC rotary axis–to replace the mechanical helical guides required in the older generation of shaping machines that these machines replace. In the past, the cutting of a new helical gear first required the expensive and time-consuming production of a mechanical guide used to produce the necessary helix by superimposing a rotary motion on the cutting stroke. Then, there was additional time needed to change guides for a new part. Now, changeover on the Gleason machines is done in minutes, via dialog-guided input on the Siemens CNC. All gear cutting, tooling, and part parameters, including the helix angle to be shaped, are entered, and the controller calculates all the necessary machine data and settings automatically. The machines are considerably more productive as well, featuring a backlash-free direct drive for the cutter spindle to deliver flexibility and operating ranges much greater than the previous conventional shaping machines. An extended stroke length using Gleason’s optional shuttle shaping feature accommodates face widths of approximately 400 mm–well beyond what was previously possible. Finally, one of the machines is equipped with a B-axis, which enables an inclination of the column under CNC to produce tapered parts and improve quality when shaping parts made from high-strength steels.
