Pressure angle

About: Pressure angle is a research topic. Over the lifetime, 1373 publications have been published within this topic receiving 10245 citations. The topic is also known as: angle of obliquity.

Drafting of involute spur-gears in AutoCAD-VBA customized

Abstract: The design of efficient and reliable gearing mechanism is governed, among other factors, by its ability to withstand the frictional contact condition and high bending stresses experienced at the tooth root. One of the major impediments facing designers is the effective drafting of gears to required configuration. For involutes spur gears, the geometry is tedious and time-consuming; and the geometric complexity increases with helical, bevel and worm gears. This study presents a model developed by utilizing the integration of VBA technology built in AutoCAD for the drafting of spur gear to standard configuration. The design was based on full-depth involute gears of pressure angles 14½°, 20°, and 25°; with module ranging between 0.3 and 25 mm, and number of teeth varying between 12 and 60. The algorithm employed the conventional manual drafting techniques by navigating the IDE of VBA with AutoCAD objects, properties, methods, events, and application of errors handling techniques that will ensure smooth running of the model. The model was tested by physically comparing gear tooth template of the automated and manual techniques for three cases of 14-tooth spur gears with pressure angles 20° and modules 6, 8, and 10; and gave a good representation of the tested cases. The model was implemented for simulation of cases of varying modules and varying number of teeth to investigate the significance of module and pressure angle on the gear structure and tooth profile. The model’s flexibility for simulation makes it a virtual prototyping tool that can enhance design, analysis and also makes it a veritable educational tool.

The Development of an Analyses-Intensive Software for Improved Cams System Design

Abstract: The computer-aided software developed in this research work is used in designing cam systems by generating various follower motions and cam profiles. It is highly suited for extensive dynamics, kinematics and geometric design analysis based on some inherent features that are unique. The plate cam with either flat-face or roller followers can be designed. Most of the standard and acceptable cam functions are included such as double harmonic, modified trapezoidal, cycloid, 4-5-6 polynomial and others. Various prime circle radii and follower face widths are calculated for flat-face follower design option for any user selected cam angle, follower profile and cam function. Other parameters such as minimum and maximum values of radii of curvature, pressure angle, are also calculated for roller follower design option. In every design the follower motion and cam profiles are calculated and coordinate files can be exported in Cartesian format and automatically imported into a spreadsheet package thereby using all its features for better analysis of results. All dynamic, kinematics and geometric parameters can be plotted and all data may be printed to the screen, to a printer, or to a file. Keywords : Cams; Design; software; simulations; validation Journal of Science and Technology Vol. 28 (1) 2008 pp. 103-115

Double-contact hobbing cutter

Abstract: The utility model relates to a double-contact hobbing cutter which is characterized in that tip circle radius of a tooth of the hobbing cutter is 0-0.3 times of modulus, a standard pressure angle with an angle of 15 degrees-30 degrees is arranged on a tooth face 0.3-0.8 times of tooth height down from a tooth tip, a cutting-off-interference-quantity pressure angle with an angle of 22 degrees-37 degrees is arranged on a tooth face 0.05-0.6 times of tooth height down from the standard pressure angle, and a tooth tip chamfering pressure angle alpha 3 with an angle of 25 degrees-50 degrees is arranged on a tooth face 0.05-0.3 times of tooth height down from the cutting-off-interference-quantity pressure angle. The double-contact hobbing cutter is simple in structure, easy to manufacture, low in cost, convenient and fast in cutter assembly and disassembly, simple in procedure and short in machining time, is used for machining a double-contact gear, can accurately provide cutting off interference quantity and uproot quantity for fine machining of the gear, ensures smooth connection of an involute part and a transition curve part, improves machining accuracy of the double-contact gear, reduces machining cost, and improves machining efficiency.

Technological solution to profile and generate the teeth of central gear for precessional gear drives

Abstract: The transmission based on precessional gear pairs, mostly used for rotation speed reduction, has some important advantages relative to the common gear drives, such as the capability to produce very low transmission ratios, or the high loading capacity/dimensions ratio (due to the fact that all the teeth of a precessional gear pair are simultaneously in contact during its functioning). One among the likeliest constructive solutions for the precessional gear pair uses a satellite built with conical rollers. However, its practical use is restricted by the difficulty to realize the central gear teeth machining without using special and relative complicated devices. This paper introduces a technological substitutive profile for the central gear tooth, which enables the use of a simpler and more productive method for working it, without bringing major negative consequences regarding the teeth contact correctness or the drive loading capacity. The profile was found by analyzing the contact surface and the pressure angle evolution during the contact between conjugate teeth. The paper also presents technological solutions to generate the new tooth profile by milling it with a disk-tool or an end-mill cutter, together with methods to profile the required tools.

Face milling for hypoid internal bevel gear using new type of tilt milling machine

Abstract: To improve the machining efficiency, a new model is set up in this paper, which could machine hypoid internal bevel gears by using the tilt cutting method. An algorithm is developed to calculate the processing parameters. Unlike the traditional tilt structure machines, the tilt drum of the new model can only be adjusted in a vertical plane. Firstly, according to its special structure, the machine tool mathematical model is built. Then, the tilt angle is calculated and converted into a machine root angle and machine tilt angle equivalently. Based on the principle that the unit normal vector of the internal bevel gear tooth surface should be equal to that of hypoid gear at the reference point, the pressure angle and spiral angle of the internal bevel gear are calculated. Moreover, by adjusting the cutter position and machine root angle, the pressure angle of the shape gear is revised, which greatly extended the universality of the cutter. Finally, the cutter position affected by tilt angle is compensated. To demonstrate the performance of the proposed method, cutting simulation is carried out and the processing experiment is conducted. The results indicate that the simulation model and the actual model are basically in line with the theoretical model, which verifies the feasibility of the proposed processing method.