Comparative economics of mechanical and manual dehusking of Arecanut

Objectives: This research was undertaken to examine the economic benefit of mechanization in dehusking arecanut. Methods/Statistical analysis: A sample consisting 15 each of pre-harvest contractors, arecanut farmers using machines of different capacities for dehusking arecanut were randomly selected from Davanagere district of Karnataka. The economic viability of mechanization was assessed under these situations using partial budgeting technique. Findings: The results of the study indicated that the cost of dehusking one quintal of arecanut using machine was ₹141 as compared to manual method (₹276) in case of pre-harvest contractors. The per quintal cost of dehusking of own arecanut produce came to Rs.78 as against manual method(Rs.277)in case of farmers who used the machine for dehusking of their own arecanut produce and rental purpose. Application/Improvements: The study suggested that marginal farmers should use two gear machine, small farmers four gear machine and large farmers six gear machine to economize dehusking their own farm produce and earning rental income. Keywords: Mechanization; Arecanut dehusking; economic evaluation; horticulture

Modeling and adaptive compensation of tooth surface contour error for internal gearing power honing

The machining of high precision gears requires a strict and accurate co-movement relationship controlled by the electronic gearbox between the moving axes of the gear machine tools. This article proposes a tooth surface contour error modeling method and an adaptive electronic gearbox cross-coupling controller for internal gearing power honing. First, the electronic gearbox model is structured according to the generative machining principle of internal gearing power honing and the tooth surface contour error is established by means of homogeneous coordinate transformation and meshing principle. Then, the adaptive electronic gearbox cross-coupling controller is designed, which comprises the electronic gearbox cross-coupling controller and the fuzzy proportional–integral–derivative controllers whose universes of membership functions in fuzzy rules are optimized by particle swarm optimization to improve the adaptability and robustness to disturbance fluctuation and model uncertainty of the system. Finally, experiments are carried out on a self-developed gear numerical control system. The results have demonstrated that the estimated tooth surface contour error using the proposed method is very close to the actual one, and the proposed adaptive electronic gearbox cross-coupling controller can effectively reduce the tracking error and the tooth surface contour error when compared to the electronic gearbox cross-coupling controller and non–electronic gearbox cross-coupling controller (electronic gearbox controller without cross-coupling and adaptive compensation).

A New Method of Motion Rule Synthesis for Face Gear Manufacturing by Plane-Cutter

The application of a Gleason Coniflex cutter (plane-cutter) to a modern Phoenix bevel gear machine tool in face gear manufacturing has an advantage of involving a universal cutter or grinder and an available existing machine. It is valuable to research this method for face gear manufacturing. First, the principle of the application of the plane-cutter in face gear manufacturing is presented. Then, the geometry of the cutter is defined, and the model of the face gear generated by this method in abstract is established. Third, a method that uses a predesigned contact path for the synthesis with the motion parameters of the plane-cutter is proposed; controllable transmission errors are considered in this process. Fourth, based on the equivalence principle of the position and direction, the computer numerical control (CNC) motion rules of all spindles of the machine are determined, and the surface generated by the machine is presented. Finally, numerical simulation of an example demonstrates that although the surface generated by the plane-cutter, to a certain extent, deviates from the theoretical surface generated by the traditional method, the surface, in meshing with the standard involute surface of the pinion, presents a good geometric meshing performance based on tooth contact analysis (TCA), except for a shortened contact ellipse.

Electromagnetic Design of a New Electromagnetic Planetary-Gear Machine

A novel brushless compound-structure permanent-magnet synchronous machine (CS-PMSM) based on the magnetic field modulation principle is proposed for hybrid electric vehicles. As the key part of the brushless CS-PMSM, the operation principle of the electromagnetic planetary-gear machine (EPGM) is investigated by analytical method. The magnetic-field distribution and torque performance of the EPGM are studied by finite-element method (FEM). To obtain the optimal design scheme, the influence of the span ratio and thickness of the magnetic block and the slot-opening on the electromagnetic performance is investigated. Finally, the core loss distribution of the EPGM is investigated and the performance of this machine is fully evaluated.

Research on Machining Simulation of Large Scale Spiral Bevel Gear Machine Tool

The machining coordinate system of spiral bevel gear machine tool is established through analyzing the machining mechanism of spiral bevel gear, and the three dimensional structure model of large scale spiral bevel gear machine tool is also established using the new cutting feed method. The numerical control machining model of large scale spiral bevel gear machine tool is proposed. Finally, the machining simulation of one pair of given large scale spiral bevel gears has been done, the result indicates that the machining simulation model meets the prospective design requirement.