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.

All wheel-slip limiter for automobile

Abstract: PURPOSE: To prevent a self-locking by setting the normal module of all gears as small as possible in proportion to the drive moment to be transmitted, and setting the operating pressure angle as large as possible. CONSTITUTION: In order to minimize the mechanical friction loss of a planetary gear and avoiding the self-locking of a planetary gear type slip limiting device in the start of an automobile under a load, the teeth of sun gears 7, 9 and a planetary gear 14 are formed in special mode. The normal module (m) of all gears is selected as small as possible to be proportional to the drive moment to be transmitted from the reason of strength, and the operating pressure angle αis set to be as large as possible.

Paw oscillating type ratchet mechanism

Abstract: The utility model relates to a pawl oscillating type ratchet mechanism, which is composed of ratchet wheels, ratchets and pawls. The utility model is characterized in that the pawl pushes the ratchet wheel to rotate to touch the ratchet; the connecting line of a tooth crest and an oscillating shaft of the pawl forms a closed angle beta with the direction of movement of the pawl; the closed angle beta is greater than or equal to the sum of a ratchet pressure angle alpha and a friction angle; the closed angle beta is smaller than 40 DEG. The utility model can realize high precision transmission with smaller pawls and ratchets and can reduce the movement loss to minimum and the theoretical value can be zero. The utility model is capable of combining with a superposed ratchet wheel mechanism and the flexual and folding working surfaces of the ratchets and the pawls are acceptable.

Vehicle acceleration sensor for emergency locking type take-up device

Abstract: PURPOSE:To obtain an acceleration sensor of high response characteristics and less hysteresis phenomena by incorporating a prescribed shape of an inertia body rolling on the top surface of an inclined supporting table in accordance with accelerations and by other things. CONSTITUTION:An inertia body 12 provided with an horn part 12b of a shape which is freely penetrated through the through-hole 16 of a supporting table and permits sliding movement without any interference in accordance with accelerations oscillates by the angles corresponding to the accelerations and the accelerations are detected by an actuator 13 of a small pressure angle with respect to the inertia body 12 interlocking thereto. The inertia bottom surface 12a of this inertia body 12 assumes a spherical shape centering at the center of gravity of the inertia body 12 and resets with good stability by contacting the inclined supporting surface of the required wedge angle of a table 11. By this constitution which is hard to receive the effect of frictional force, has less dynamic and static directivities and is good in stability, the vehicle acceleration sensor for the purpose of emergently locking a take-up device of a sheet belt, etc. of high responsive characteristics and less hysteresis phenomena is obtained.

3D Analysis of Combined Extrusion-Forging Processes

Abstract: Combined extrusion-forging processes are now getting importance for its abilities to give improved material properties, high production rate and less material waste when compared with that produced by machining, casting or by assembling the individual parts produced by different manufacturing processes. In its simplest form of combined extrusion-forging process, a billet is forged by punch and dies with punch/die or both containing an opening for extrusion. This tooling arrangement permits the simultaneous lateral spread due to forging, and backward/forward extrusion or both forward and backward extrusion simultaneously through the die/punch opening(s). The flow pattern of the material is dependent on a number of factors, including the frictional conditions at the work piece/tooling interface; the geometry of the dies, particularly the size of the dies hole; the material type; and the percentage area reductions. Due to the complexity of the analysis, and because of the large number of process variables, it is difficult to estimate the forming force required to manufacture a given component. In this direction, the present work emphasizes on estimation of forming force for forward and forward-backward extrusion-forging process of regular shapes and different tooth spur gear shapes. Though technological barriers exist, as in most manufacturing areas, it is important to overcome them by developing proper understanding of the process with related attributes. In this direction, present work emphasis on the forward and forward-backward extrusion-forging process analysis of different methodology applied to different section heads with circular shaft. Based on these guiding principles, the methodology applied are upper bound analysis (particularly reformulated spatial elemental rigid region (SERR) technique), finite element analysis (commercial package DEFORM®-3D codes), and experimentation. The understandings generated in this work not only properly explain the complex material flow mechanism but also presents in detail the upper bound analysis. The results of UBA are well validated with that of finite element analysis and experimental results. The achievements realized from the present work can be summarized as follows:  Experimental studies are carried out with a view to compare some of the theoretical results predicated using the upper bound method in general, modified SERR technique in particular, with that obtained from the experiment. SERR technique is used to analysis the last stage of the combined extrusion forging process, which requires maximum load.  A computational model for forward and forward-backward extrusion-forging process with and without considering friction is developed by incorporating all special features for all the section extrusions. Three formulations for forward extrusion-forging process and six formulations for forward-backward extrusion-forging processes are analyzed and the optimal solution for non-dimensional extrusion pressure is found out for further computation. The model is developed using FORTRAN code.  Experiments are performed for triangle, square, pentagon, hexagon, 4-tooth, 6-tooth, 8-tooth and 12-tooth spur gear (involutes profile and pressure angle 14½o) is form using flat / square dies. Both forward and forward-backward extrusion-forging processes are carried out.  FEM based commercial package DEFORM®-3D code is used for finite element analysis of the processes.  The results obtained from experimental investigation are found to be in good agreement with the similar one predicted by theoretical analysis using the proposed modified SERR technique and finite element analysis.

Sector gear for steering device and its manufacture

Abstract: PROBLEM TO BE SOLVED: To improve the gear profile of a sector gear, thereby enhance its forming and workability, and furthermore strengthen the whole of the sector gear including sector teeth SOLUTION: The sector gear 8 is formed out of sector gear raw material processed by forging as plastic working Each dedendum 7c at the sector tooth forming portion possesses each corner part 23 in a curved shape, and a portion 21 inclined along a pressure angle is continuously formed As machining works, each sector tooth is generated so as to be formed into a tooth flank shaped by an involute curve by cutting and grinding only the tooth flank to be meshed with a rack tooth only by a working margin Each dedendum and each addendum 7d are left as they are plastically processed with its forged raw material surface exposed