MHI Machine Tool launches two new hobbing machines

Mitsubishi Heavy Industries Machine Tool Co., Ltd., a part of Mitsubishi Heavy Industries (MHI) Group, announces June 2021 launch of the new GE15HS and GE25HS models of hobbing machines. Emphasizing high precision and efficiency, the new machines focus on electric and hybrid cars amid the global trend toward decarbonization. The new machines produce high-precision gears required in these new vehicles. These new machine models are a significantly improved addition to the GE Series of hobbing machines, which has shipped more than 2,800 units since its launch in 2004.

The GE15HS model is for gears with a maximum diameter of 150mm, widely used in automobiles and motorcycles. The high-speed, high-torque direct-drive motor(1) for the main cutting spindleprovides a maximum spindle speed of 6,000 min-1(2), three times faster than previous models. The high efficiency work table spindle holding the work piece uses a special table that provides high rigidity and high-speed rotation to handle the necessary thrust load(3) for high efficiency machining. Further, processing with the use of Mitsubishi super-hard cutting tools yields a surface roughness of less than Ra0.4(4), on a par with gear grinding. The GE15HS provides process efficiency, eliminating the finishing process of shaving prior to heat treatment, improving productivity and reducing processing cost.

The GE25HS model for large-diameter gears up to 250mm in diameter, such as automobile differential gears. With its high-efficiency processing, this model utilizes a high-speed, high-power spindle eliminating the effects of temperatures variation during production. The high rigidity table has the backlash eliminator incorporated as standard equipment. In addition, the motor torque and maximum spindle rotation speed of the main spindle have been increased 1.5 times from previous models, providing a 42% reduction in processing time(5). Used in combination with MHI Machine Tool's new materials and coatings for cutting tools, the GE25HS model provide stable mass production with a cutting speed of more than 400m/min.

Demand for mass production of high-precision gears is continuing to rise with the shift to electrification of vehicles. With the need for improvements in NVH and fuel efficiency, and the move toward low-cost manufacturing. MHI Machine Tool, with expertise in both gear machine tools and cutting tools, offers a full lineup of gear production machines, including these two new models. By delivering precision cutting tools and processing solutions to achieve high-precision, high-efficiency processing, MHI Machine Tool provides comprehensive support for manufacturing in a wide variety of industries.

(1) Direct-drive mechanism motors utilize the torque coming from a motor without passing through a gear box or other mechanism in order to control driving loss due to friction and reduce wear on parts.
(2) The "min-1" notation is a unit expressing the number of turns in one minute, synonymous with "revolutions/rotations per minute" (rpm).
(3) Thrust load is the force applied to the shaft in a horizontal (parallel) direction (the axial direction of the rotor).
(4) In-house machining result with GE15S (Workpiece data: Module 1.6mm; No. of teeth 19; Torsion angle: 24degrees; Tooth width: 24mm)
(5) In-house machining result with GE25A-S (Workpiece data: Module 3mm; No. of teeth 54; Torsion angle: 30degrees; Tooth width: 40mm)