Papers by Keyword: Torque

Abstract: The automotive industry represents one of the most important segments of the world economy that has to be in a continue development. The latest procedures for determination of an internal combustion engine performance have a big acquisition cost and demand special conditions even if the tested engine has smaller dimensions. The present paper presents other accessible solutions for this matter.

Abstract: The robots which are composed of mechanisms with Delta 3 DOF parallel structure are increasingly used due to the advantages they poses such as high rigidity and that they can be used at high speed and acceleration. When the mechanical structure of the parallel robots with Delta 3 DOF structure is designed, a proper selection of the drive servomotors is imposed. The drive servomotors are chosen according to the values of the torque needed for the manipulated object to move in the workspace along a trajectory with a specific speed and acceleration. In this paper, the authors approach the study regarding the variation of the drive torques of parallel robots with Delta 3 DOF structure, when the manipulated object moves along a trajectory with imposed speed and acceleration, in order to choose the drive servomotors. In order to determine the value of the drive torque, SolidWorks software was used. From the results obtained by experimental means, it has been revealed that the usage of the software packages in the dynamic simulation of the mechanical assemblies determines the shorten of time, costs of projection, in comparison with practical testing which supposes the realization of the prototypes physically, expensive and time consuming process.

Abstract: This article can be divided into two parts when first one is focused on essential analyse of torque measuring problematic while second one is focused on design and construction of own measuring device. Goals of this article are to specify each variation of measuring and chose the best one for desired requirements. Designed measuring device will be used for torque analyse in the dissertation.

Abstract: A slip controller that can move against the off-track and control excursion caused by slips while driving a motorized wheelchair is proposed. Detecting slips in a motorized wheelchair is to detect states of the motorized wheelchair and its motors in a traveling condition. For carrying it, slip ratios are calculated using a slip detection algorithm based on the information obtained from the six-axis IMU sensor and the encoders, which are connected to both left and right motors. The calculated slip ratios are used as control variables for improving the safety in a motorized wheelchair. In the experiment of the slip controller proposed in this study, slips are verified in a proposed track. Also, it is verified that the maximum slip ratio section is determined while turning left or right.

Abstract: Inconel 718, a Nickel based superalloy is widely used for aerospace applications mainly due to its high temperature resistance and high strength to weight ratio. Its poor machinability is a limiting factor in commercial, cost intensive applications. This paper investigates the machinability of Inconel 718 in high speed drilling. The impact of the material on thrust forces, torque and chip microstructure have been measured at four different cutting speeds – 19, 27,43 and 67 m/min. The high tensile strength coupled with low thermal conductivity compounds the machining process. The thrust forces decrease with cutting speed, but the torque fluctuates at intermediate cutting speeds. Chip formation is continuous across cutting speeds, with thin cross sections and evidence of saw tooth edges. Inconel work hardens more than titanium alloys and shows good ductile to brittle transition at low temperatures creating chips of lesser length as observed using scanning electron microscopy.

Abstract: Titanium Alloys are unique due to their high strength-weight ratio,good fracture and corrosion resistance characteristics.They form a significant metal portion of the aircraft structural and engine components. However, their low thermal conductivity and high reactivity with cutting tools during machining, makes them difficult-to-machine materials. In this work, an investigationof the thrust force, torque and chip morphology in drilling of Ti6Al4V, titanium alloy using tungsten carbide tipped drill has been carried out at varying cutting speeds of 19.4, 27.14, 43.41 and 67.82m/min at a constant feed rate of 0.15mm/rev.The machinability, work hardening and thermal softening effects of titanium alloy, during drilling, has been analysed through the effects of the machining process on the thrust force, torque and chip microstructure.

Abstract: Flux switching machines (FSMs), new type of electric machines with unique operating principles have been introduced and published recently. FSMs contain armature and excitation sources on the stator with robust rotor structure. According to rotor structure FSMs can be classified into two types namely salient pole rotor and segmental pole rotor. Various topologies have been studied and published using both rotor structures, however salient pole rotor has a demerit of less torque generation due to longer flux path resulting flux leakage surrounding the rotor. In this paper a new structure of hybrid excitation FSM (HEFSM) with segmental rotor is proposed and a comparative analysis with the invented field excitation FSM (FEFSM) and permanent magnet FSM (PMFSM) is presented. Initially, coil arrangement tests are examined to confirm the operating principle of HEFSM with segmental rotor. Moreover, the cogging torque, induced voltage, magnetic flux, torque at various armature current densities and power characteristics are observed based on 2D-finite element analysis (FEA).

Abstract: A new approach substitutes the damper of a passenger car by a cardanic gimbaled flywheel mass. The constructive design leads to a rotary damper in which the vertical movement of the wheel carrier leads to revolution of the rotational axis of the flywheel. In this arrangement, the occurring precession moments are used to control damping moments and to store vibration energy. Different damper characteristics are achieved by different velocities of the inner ring. From almost zero torque output to high torque output, this damper has a huge spread. In this paper a control concept for a LQR is presented. The objective of the control is an adequate motion of the gyroscope to a desired damping characteristic of a passenger car.

Abstract: Ball screw is a high-precision and high performance linear drive of mechanical elements. The frictional heat of internal components what is very significant impact for platform transmission in high speed and the high axial load and causes the thermal expansion of element. In this research , the influence of different greases on ball screw is investigated in thermal rising of nut and driving torque in high speed and high axial load. A vertical motion platform was used for driving performance test. Thermal rising of nut of ball screw and the variance of transmission torque whose lubricated by high viscosity base oil grease is significant larger than the lower one. High viscosity grease is not easy to carry out the friction heat generated at ball and raceway contact area due to the bad flowing properties. It also has more serious wear occurred at contact area and high friction force, whose causes the large variance of transmission torque.

Abstract: The local wall thinning(LWT) is a kind of common volume defect in pressure pipe. The limit loads of elbows with LWT under pressure, bending moment, torque and their combined loads have been studied in detail by orthogonal experimental design and finite element method. The results have shown that the influence of depth and circumferential length of LWT on the limit load is more obvious compared to that of axial length when an elbow is under pressure, bending moment or torque. The change of limit bending moment and torque with the depth of LWT and circumferential length is significant for an elbow under combined bending moment and torque. At last, the safety assessment equations for elbow under combined in-plane closing bending moment and torque were proposed by regression analysis.