In the high-precision servo feed system, when the permanent magnet synchronous motor is operated at low speed in the classical drive feed system, the speed fluctuation caused by the motor torque harmonics seriously affects the speed smoothness of the servo system. In this paper, a novel double-drive differential feed system is proposed to effectively suppress the effect of torque harmonics of PMSM on speed fluctuation of a linear feed system at low-speed operation.

The performance of different models of grooves with various tip gap height on NASA rotor 37 is investigated by discretizing 3D RANS equations based on finite volume technique. Rectangular circumferential grooves casing treatment (CGCT) profile and smooth wall casing performances are evaluated. Moreover, the adiabatic efficiencies and the stall margins of smooth wall casing, rectangular grooves and rectangular grooves with fillet and chamfer corners are compared to assess the impacts of profiles

This paper examines a code-to-code verification between two thermal models. One used a non-commercial code; the other a commercial. A point heat source was applied to one end of a cylindrical geometry. Melting and re-solidfying of a 316 L stainless steel alloy was considered. Temperature dependent material properties and latent heat were included. Mesh independency was achieved. Positive agreement of thermal histories, temperature profiles, melt pool depth and maximum temperature along the rod.

The bending-torsional-axial coupling nonlinear dynamic model of double-sided meshing nutation drive system has been established. The modal analysis of double circular arc spiral bevel gears is carried out, and the ten order natural frequencies and their corresponding modes are obtained. The natural frequencies of nutation drive system and double circular arc spiral bevel gears are different, and there is no resonance.