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This paper presents a manufacturing method for straight internal beveloid gear pair by shaper cutter with parallel axes between the cutter and the gear blank. The cutting motions are represented using three degrees of freedom that are the rotation along its axes, translations along the axial and radial directions. With the proposed method, the beveloid gear with a linear or nonlinear variable profile shift coefficient along the tooth width direction can be generated and the tilt deviations by the inclined cutting tool shaft can be avoided. The mathematical description of shaper cutter and the coordinate systems for the cutting procedure were defined. And the mathematical model of external and internal beveloid gears were derived and the loaded tooth contact analysis were conducted. Results show that the teeth mesh in at the toe and mesh out at the heel. The length of the simultaneous contact line on tooth surface increases first and then decreases due to the cone angle. As the load increases, the mesh area, contact pressure, mean value of mesh stiffness and the peak-peak value of angular transmission error are increased due to the elastic deformation. However, the speeds of the increase tendency slow down.

Considering the gear manufacturing and meshing theory, a numerical design approach with parabolic modifications was proposed to improve the mesh behaviors of crossed beveloid gear transmission. The generating procedure with parabolic modifications for the crossed beveloid gears with small shaft angle was proposed. And the analytical mesh model with misalignments of crossed beveloid gear transmission was developed. Then the effects of parabolic modifications on contact path and contact ratio were investigated. Also, the misalignments sensitivity was analyzed for the beveloid gears with and without parabolic modifications. Results show that the design situation with a positive parabola coefficient for the pinion and a negative parabola coefficient for the gear is better than other combinations of the parabola coefficients. Both the offset error and shaft angle error tend to deviate the contact path from the theoretical middle region. The parabolic modifications can reduce the sensitivity of contact path to the offset error and shaft angle error for crossed beveloid gear transmission effectively. Both axial pinion and gear position error has little influence on the mesh behaviors for the crossed beveloid gear pair with and without parabolic modifications.

This article investigates the load-carrying ability of helical conical gears used in transmissions with intersecting and crossed axis for V-drive marine transmission. Mathematical models of helical conical non-involute gears, which can realize line contact, were established on the basis of the conjugated theory. Loaded tooth contact analysis was performed to examine the meshing and bearing contact of the helical conical gear pairs. The contact area was measured in an experiment and compared with theoretical results, and good agreement was observed.

Because of their outstanding advantages over other transmissions, rubber V-belt pulley drive CVTs have been extensively used in low-power vehicles, such as scooters and snowmobiles. A rubber V-belt CVT installed on a snowmobile is used here to research transmission efficiency. The power loss of CVTs, including torque loss and speed loss, is studied based on an analysis of the transmission mechanism of CVTs. Experiments on CVT efficiency are conducted on a specific CVT test bench, on which the values of torque, speed, and displacement, etc., are measured. Results show that the variation trend of the efficiency is close to the operating conditions of CVTs and optimal structural parameters are given that can serve as a beneficial references for designing and tuning CVTs.

Because of its incomparable advantages over other transmissions especially in some specific conditions, rubber-V-belt, continuously variable transmissions (CVTs) have been extensively applied in low-power vehicles, such as scooters and snowmobiles. The main structural parameters of a CVT evidently affect the driving performance of the vehicle. The effect of one main structural parameter, namely the masses of the flyweights utilized, on the governing characteristics of the CVT is studied, and the mechanism of the effect is explained. First, a mechanical analysis of the drive pulley and the driven pulley of a rubber-belt CVT employed on a snowmobile is conducted. Through the theoretical analysis, the mathematical model of the system running in a steady state is built. Then the principle of parameter optimization, the running resistance of the vehicle, as well as the external characteristics of the gasoline engine applied in the snowmobile are investigated. Finally, experimental research on the structural tuning based on the building of a CVT test rig is carried out. Since it is difficult to change the parameters of some components such as the torque cam and the profile line of the flyweights, the masses of the flyweights are considered as the unique design variables, and different regulating characteristics of the available groups are obtained. Different applications accordingly require corresponding structural design schemes. The experimental results show that the proposed parameter-tuning principle is theoretically correct and practically feasible, which makes it useful for guidance in designing the CVT, as well as the whole driveline.

Beveloid gears are widely applied in fields like ships, automobiles and industrial precision transmissions. In this paper, the formulas of the beveloid gear tooth surface used in marine transmissions were derived and a mesh model for the intersected beveloid gear pair was setup. Then loaded tooth contact analysis was performed using the finite element method considering the coupling of the assembly errors and the elastic deformation of tooth surface. Through the analysis, the influences of assembly errors on contact patterns, mesh force and tooth surface deformations were investigated. In a further step, the tooth profile modifications were performed to alleviate the edge contact and a subsequent major improvement of the mesh condition was obtained. Finally, loaded tooth contact experiments for marine gearboxes with small shaft angle were conducted. The tested results showed good correlation with the computed results. This work may provide some value for the practical design aiming at improved contact characteristics of the beveloid gears with intersected axes.

To achieve high-volume code capacity for SAW-based radio frequency identification(RFID) tags, it is very important to improve the delay time resolution. An efficient encoding method is to use the phase delay of the carrier wave in the pulses, but one has to solve the issues of the phase ambiguity at unknown temperatures and the location of reflectors to exact positions. In this paper, a method is proposed to obtain a high-phase delay resolution by measuring group delays and constructing a certain restriction on the exact positions of reflectors. To define the restriction parameter for a SAW RFID system with large code capacity, it is imperative to have a priori knowledge of the errors of the phases and group delays. The experimental and simulation errors for both the phases and the group delays, originated from the design procedure, the temperature effect, the fabrication process and the measurement, are presented. The error probability distribution curves in simulation and experiments are plotted. The maximum error of phase delay is about +/- 14 degrees, and the maximum error of group delay is about +/- 4 periods. The temperature range in investigation is from -5 to 45 degrees C.