Cam based Infinitely Variable Transmission Theoretic Modelling

Infinitely variable transmission (IVT) is a system which delivers the ratio between two turning elements to a continuous (non-discrete) variation (including zero). This article uses Solidworks software to build and simulate a cam-based IVT system. There are two identical units in the system under examination. Each unit comprises a cam with an oscillating slot connection that swings on a hinge and can be vertically shifted by changing the transmission rate. This modifier can be a power screw or a hydraulic ram. In addition, a grooved wheel and followers or an actuator are included in the system units. The raised wheels swing rotating movement, such that they are coupled by a single-way clutch to the output shaft (ratchet) to move the output shaft one way. During the performance research, cam shapes are considered and examined inside the mechanism. a mixture of the unchanging speed and 1-5 polynomial shapes, used for the current investigation and tailored for The results produced from the simulation generally reveal the theoretical results expected in accordance with the layout of the current IVT system. For all parts in these units, the findings imply a uniform velocity while each unit is powered. In this investigation, nevertheless, the ratchets used cause remarkable fluctuations in the angular speed of the output axis. Further research is therefore urgently needed in the choice and investigation of more efficient ratchets.

Analysis of the cycloidal reducer output mechanism while taking into account machining deviations

There are three main rolling nodes in the cycloidal gear reducer: the gear, output mechanism and central bearing. To transfer the drive from the active side to the output side of the gear, an output mechanism is used, which is formed by bushings mounted on pins located in the output shaft. During the operation of the reducer, the bushings roll around the wheel holes with a cycloidal contour. Using the structure and geometry of the output mechanism, an analysis of the backlash distribution in it was conducted, taking into account the machining deviations of the elements and surfaces forming this mechanism. Then, the distribution of forces and contact pressures were determined. The results of the analysis suggest that the backlash distribution, forces and contact pressures largely depend on the tolerance of the radius of the bushings’ arrangement and the holes in the planet wheel. The results obtained allow for the optimal selection of machining deviations in terms of received contact pressures.

SYNCHRONOUS ELECTRIC MOTOR WITH HIGHER SPEED ROTATION AND BALANCED ROTOR

Increasing the speed of rotation of electric motors is an urgent task for turbine mechanisms – pumps, fans, compressors. Traditional synchronous motors have a rotation speed that is less than or equal to the frequency of the supply voltage. The article proposes a design and considers the principle of operation of a synchronous electric motor with double rotation speed. It has three reluctance rotors with one pole, for static and dynamic balancing, and the stator winding is supplied with voltages out of phase by π/6. The proposed design of a synchronous motor with eighteen phases of the stator winding and, with three rotors, the axes of which are offset relative to the axis of rotation of the output shaft. The use of such a design makes it possible to double the rotation speed of the output shaft in comparison with the frequency of the supply voltages. A description of the principle of operation of the motor and its mathematical description are given, taking into account the structural features of the stator-rotor magnetic circuit. The main advantage of the proposed engine in comparison with a high-speed engine is static and dynamic balancing.

Lubrication and Fluid Film Study on the Vane Tip in a Vane Pump Hydraulic Transmission Considering a Fluid and Structure Interaction

A mathematical modeling approach to determine fluid film thickness on the vane tip in a vane pump transmission is developed. The transmission is based on a double-acting vane pump with an additional output shaft coupled to a floating ring. Owing to the floating ring design, the internal viscous friction helps to drive the output shaft, whereas the friction is turned into heat in a conventional vane pump. To study the mechanical efficiency, it is crucial to investigate the fluid film thickness between the vane tip and the ring inner surface. The modeling approach in this study takes the interactions between vane radial motion and chamber pressure dynamics into consideration, without using a computational fluid dynamics approach. The lubrication on the vane tip is considered as elasto-hydrodynamic lubrication and the fluid film thickness calculation is based on the Hooke lubrication diagram. Results show that the developed simulation model is capable of revealing the fluid film thickness change and vane radial motion in different operation regions. Sensitivity studies of several parameters on the minimum fluid film thickness are also presented.

APPLICATION OF IMPACT THEORY TO ANALYSIS OF GEAR SHIFTS IN DUAL-CLUTCH TRANSMISSIONS

The article discusses a dynamic model of a transmission containing a dual-clutch gearbox. The absence of a torque converter in such gearboxes, taking into account the short duration of gear shifting (0.2 - 0.5 sec), allows us to present the gear shifting process as an impact. Gear shifting excites the output shaft of the gearbox. Thus, the transmission of the vehicle can beconsidered as a vibro-impact self-oscillating system.

Prediction of Synchronization Time for Tractor Power-Shift Transmission Using Multi-Body Dynamic Simulation

HighlightsPrediction of synchronization time was performed for a power-shift transmission.We derived an analytical equation for synchronization time and developed a multi-body dynamics model.Model results were compared with results of a power-shift test on a synchronizer.Reduced computation and design time was achieved for automatic transmission design.Abstract. Synchronization time determines the capacity of a shift actuator for an automatic transmission system. Existing approaches for measuring this time only consider one rotational inertia and therefore cannot be applied to the power-shift transmission (PST) of a tractor with wet multi-plate clutches on both sides of the synchronizer. This study aims to predict the PST synchronization time by considering time-varying axial forces as first-order functions and the equivalent rotational inertias of the hub and the gear. First, we derive an analytical equation for the synchronization time. We then develop a multi-body dynamics (MBD) model that includes the drag torque of the wet multi-plate clutches. The MBD model is composed of a synchronizer, a linkage, and an output shaft of a shift actuator as a rigid-body system. A power-shift test was performed on the synchronizer at two shift stages requiring the maximum shift force of the system. The torque of the shift actuator (the input of the shift system) and the angular displacement of the output shaft of the shift actuator (the output of the shift system) were measured. The results of the simulation model were then compared with those of the shift test. Compared with the test results, the simulation results were validated within 7.63% accuracy, based on the maximum value for the torque of the shift actuator. The proposed equation was validated within a maximum error range of 8.25%. The proposed equation did not consider drag torque of the wet multi-plate clutches because that torque is much smaller than the cone torque of the synchronizer in the target shift system. The proposed equation can reduce computation time and will enable more precise sizing of the synchronizer and shift actuator in the early design stages of automatic transmissions. Keywords: Multi-body dynamics, Power-shift transmission, Synchronization time, Synchronizer, Tractor transmission.

Manufacturability of the design of the transfer case of the truck MZKT-500200

A kinematic calculation of technological design transfer case changes gear of the truck MZKT-500200 was carried out. The disadvantage of this design is the need to completely stop the car to lock the differential, which is eliminated by installing a friction clutch on the output shaft.

SYNCHRONOUS MOTOR WITH INCREASED ROTOR SPEED

Development of the design of a synchronous electric motor with six C-shaped stator teeth, the rotor axis of rotation of which is displaced relative to the axis of rotation of the output shaft. The rotational speed of the output shaft is equal to twice the rotational speed of the stator magnetic flux. Determination of the phase shifts of the supply voltages in time and the spatial position of the stator windings. Visualization of the principle of operation of the electric motor under consideration, namely, step-by-step observation of the position of the rotor in space, when the sinusoidal voltage wave changes by an angle equal to π, with a step of π/6. Mathematical description of the engine under consideration, with all the structural features of the stator-rotor magnetic circuit. In the course of the work, analytical calculation methods were applied. As a result of the study, the basic laws of operation were determined, as well as the design and principle of operation of the considered electric motor with a suspended rotation speed.