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.

Elastohydrodynamic lubrication design of internal gear transmission

Abstract: Based on elastic hydrodynamic lubrication (EHL or EHD) theory, an EHL model of the internal meshing between ring gear and planet gear in Planetary Gear Transmission was established. The EHL oil film thicknesses and those distributions for two operation cases on meshing line were calculated: one case with the sun gear as the driving gear and another case with the ring gear as the driving gear. The worse Lubrication occurred near the root of the tooth of the planetary gear in the second case that has the lower speed. Through the many comparing calculations the lubrication oil film thickness can be significantly increased by the raise of oil viscosity and gear pressure angle. The increase of oil film thickness can improve the lubrication of gears and prevent wearing and reduce the production cost of gears, which have great practical value.

Optimum Design of Cam Mechanisms

Abstract: The paper presents some considerations about the optimum design of cam mechanisms with reciprocal and oscillating roller followers. The objective function express the dimension of the cam, while the constraints limit the size of the pressure angle and / or the magnitude of the unit stress to the higher contact between cam and follower or cam and roller. Finally, the result of solving a numerical example is presented.

Contact Fatigue Strength Design of a Slewing Bearing Based on i-PGS

Abstract: To overcome the large ring gear manufacturing problems seen in slewing bearings and girth gears, pin gear drive units have been developed. Among them, a novel slewing bearing with an internal pinwheel gear set (i-PGS) is introduced in this paper. First, we consider the exact cam pinion profile of i-PGS with the introduction of a profile shift coefficient. Furthermore, a new root relief profile modification for the i-PGS cam pinion is presented. Then, the contact stresses are investigated to determine the characteristics of the surface fatigue by varying the shape design parameters. The results show that the contact stresses of i-PGS can be reduced significantly by increasing the profile shift coefficient. In addition, the contact ratio, a measure of teeth overlapping action, decreases with the decrease of the allowable pressure angle.

High Angle of Attack Model Identification Without Air Flow Angle Measurements

Abstract: The purpose of this work is to identify a high angle of attack model of an unmanned aerial vehicle in the absence of air flow angle measurements, using data from flight tests. Initially, flight path reconstruction techniques were applied to dedicated maneuvers, in order to calibrate the aircraft sensors. Once the instrumentation errors were obtained, the high angle of attack model identification process was applied to a quasi-steady stall maneuver. A new flight path reconstruction step was conducted to estimate initial conditions and angle of attack during the entire maneuver. The model formulates lift, drag, and pitch moment as functions of an internal state, namely the position of the flow separation point along the wing chord. From the nonlinear model obtained, it was possible to define a new flight envelope that takes into account nonlinear effects due to high angle of attack.

Worm type tool with two lead modes and variable pressure angles and operating method thereof

Abstract: Provided is a worm type tool with two lead modes and variable pressure angles. The worm type tool comprises a worm body and spiral cutting edge portions. The spiral cutting edge portions are distributed on the worm body, and the spiral cutting edge portions have pressure angle changes. The worm body is described through a rack tool coordinate system, and the spiral cutting edge portions are described through a tool coordinate system. The vector parameter of the rack tool coordinate system is converted into the vector parameter of the tool coordinate system, the worm body can be assumed as a rack tool, then the shape of the spiral cutting edge portions is led for variable-pressure-angle distribution, and after the pressure angles are changed, the structural characteristic of two leads is achieved in the lead direction. Therefore, when lead raised tooth buds are machined, the central distance between a tool bit seat and a workpiece main shaft can be fixed, the radial feeding freedom degree is omitted, and the tooth face distortion of the tooth buds is restrained.