Cavity design method for injection-molded spur gears

2000 ◽  
Vol 14 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Choong Hyun Kim ◽  
Sung-Chul Lee ◽  
Hyo-Sok Ahn ◽  
Tae Hyong Chong
Keyword(s):  
Design Method ◽  
Spur Gears ◽  
Cavity Design ◽  
Injection Molded

scholarly journals Research on the Design and Modification of Asymmetric Spur Gear

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaohe Deng ◽  
Lin Hua ◽  
Xinghui Han
Keyword(s):  
Computer Aided Design ◽  
Design Method ◽  
Geometric Model ◽  
Simulation Method ◽  
Transmission Error ◽  
Spur Gear ◽  
Geometric Shape ◽  
Spur Gears ◽  
Gear Design ◽  
Aided Design

A design method for the geometric shape and modification of asymmetric spur gear was proposed, in which the geometric shape and modification of the gear can be obtained directly according to the rack-cutter profile. In the geometric design process of the gear, a rack-cutter with different pressure angles and fillet radius in the driving side and coast side was selected, and the generated asymmetric spur gear profiles also had different pressure angles and fillets accordingly. In the modification design of the gear, the pressure angle modification of rack-cutter was conducted firstly and then the corresponding modified involute gear profile was obtained. The geometric model of spur gears was developed using computer-aided design, and the meshing process was analyzed using finite element simulation method. Furthermore, the transmission error and load sharing ratio of unmodified and modified asymmetric spur gears were investigated. Research results showed that the proposed gear design method was feasible and desired spur gear can be obtained through one time rapid machining by the method. Asymmetric spur gear with better transmission characteristic can be obtained via involute modification.

Effects of frequency on hysteretic heating and fatigue life of unreinforced injection molded polyamide 66 spur gears

2017 ◽  
Vol 233 (5) ◽  
pp. 781-789 ◽  
Author(s):  
M Kodeeswaran ◽  
Arnika Verma ◽  
R Suresh ◽  
S Senthilvelan
Keyword(s):  
Fatigue Life ◽  
Surface Temperature ◽  
Hysteresis Loop ◽  
Angular Displacement ◽  
Spur Gears ◽  
Polyamide 66 ◽  
Gear Mesh ◽  
Self Heating ◽  
Injection Molded ◽  
Root Crack

Gears are subjected to different rotational speeds/frequencies during their service life. The effect of the rotational speed on the performance of a metal gear is insignificant; however, it affects the thickness of the lubricant film. Polymer gears generate hysteretic self-heating because of the viscoelastic behavior of the material, thereby limiting their performance and usage in applications. The injection molded polyamide 66 spur gears were loaded by ground steel gear at different torques and frequencies using in-house realized servo motor driven gear test rig. Bidirectional loads at frequencies 2, 5, and 7.5 Hz and unidirectional loads at double the frequencies (4, 10, and 15 Hz) were applied on the polymer gears. The surface temperature of the gear due to the material hysteretic self-heating was continuously monitored and was recorded using an infrared thermal camera. Torque applied and angular displacement of the gear mesh were acquired to plot a hysteresis loop. The hysteresis loop area and surface temperature increase with the increase in the torque. Moreover, the bidirectional loads induce higher temperature than the unidirectional loads. This is because the gear tooth deflection increases under the bidirectional loads compared to that under the unidirectional loads for the tested frequencies. The fatigue life of the polymer gears was evaluated at higher frequency for different torques and was compared with that obtained at lower frequency. The gears tested at frequencies 15 and 7.5 Hz under unidirectional and bidirectional loads, respectively, exhibited inferior fatigue life compared to that at 10 and 5 Hz under unidirectional and bidirectional loads, respectively, because the temperature of the gear increases (30.6% and 43.7% for unidirectional and bidirectional loads, respectively) at higher frequencies. Both thermomechanical and root crack failures were observed under the bidirectional loads, whereas the gears exhibited only the root crack failures under the unidirectional loads. The failure morphology studied using the scanning electron microscope indicated straight root crack with overlapping fractured surfaces under both the bidirectional and unidirectional loads.

On the Dynamic Gear Tooth Loading as Affected by Bearing Clearances in High Speed Machinery

1982 ◽  
Vol 104 (4) ◽  
pp. 724-730 ◽  
Author(s):  
B. M. Bahgat ◽  
M. O. M. Osman ◽  
T. S. Sankar
Keyword(s):  
High Speed ◽  
Design Method ◽  
Gear Tooth ◽  
Contact Point ◽  
Velocity Ratio ◽  
Spur Gears ◽  
Governing Equations ◽  
Contact Mode ◽  
Gear Teeth ◽  
Geometrical Constraints

The paper studies the effect of bearing clearances in the dynamic analysis of gear mechanisms in high speed machinery. For this purpose, an analytical model is developed based on the interdependence between kinematics and kinetic relationships that must be satisfied when contact is maintained between the journal and its bearing. The contact modes are formulated such that the bearing eccentricity vector must align itself with bearing normal force at the point of contact. The analysis mainly relies on determining the direction of the bearing eccentricity vector defined as the clearance angles βi at the bearing revolutes for each contact mode of the gear teeth. The governing equations of the clearance angles are developed using the geometrical constraints of the contact point location and the velocity ratio. The clearance angles and their derivatives are subsequently used to systematically evaluate kinematic and dynamic quantities of each gear as well as the dynamic tooth load. A pair of rigid tooth spur gears with two revolute clearances is analyzed to illustrate the procedure. The model presented in the paper provides a design method for investigating the effect of bearing tolerances and wear on the evaluation of dynamic tooth load in high speed gearing systems.

Research on Tooth Profile Design of Spur Gears Based on Line of Action

2013 ◽  
Vol 631-632 ◽  
pp. 817-823
Author(s):  
Jian Wang ◽  
Liang Hou ◽  
Shan Ming Luo
Keyword(s):  
Mathematical Model ◽  
Design Method ◽  
Tooth Profile ◽  
Spur Gears ◽  
On Line ◽  
Profile Design ◽  
The Mathematical Model

This paper aims to propose a design method for tooth profiles of spur gears based on given line of action. A simplified derivation of the mathematical model of tooth profiles is introduced according to the meshing theory. Tooth profiles of spur gears, using a parabola as line of action, is established. The result shows that it will be better to control the performances of a gear set by specifying the shape of the line of action rather than specifying tooth profiles of mating gear.

Simplified Spur Gear Design

2016 ◽  
Author(s):  
Edward E. Osakue
Keyword(s):  
Contact Stress ◽  
Design Method ◽  
Spur Gear ◽  
Load Factor ◽  
Spur Gears ◽  
Bending Stress ◽  
Hertz Contact ◽  
Gear Design ◽  
Simplified Method ◽  
The Difference

A simplified design method (SDM) for spur gears is presented. The Hertz contact stress and Lewis root bending stress capacity models for spur gears have been reformulated and formatted into simplified forms. A scheme is suggested for estimating the AGMA J-factor in Lewis root bending stress for spur gears from a single curve for both pinion and gear instead of the conventional two curves. A service load factor is introduced in gear design that accounts for different conventional rated load modifier factors. It represents a magnification factor for the rated load in a gear design problem. Two design examples are considered for applications of the stress capacity models. In Example 1, the Hertz contact stress of the SDM deviates from AGMA value by 1.95%. The variance in Example 2 between the contact stress of the SDM and FEM is 1.184% while that between SDM and AGMA is 0.09%. The root bending stress of AGMA and SDM for the pinion in Example 1 differs by 1.44% and that for the gear by 6.59%. The difference between the root bending stress of AGMA and SDM for pinion and gear in Example 2 is 0.18%. These examples suggest that the new simplified method gives results that compare very favorably with both AGMA and FEM solutions. The simplified method developed is recommended mainly for preliminary design when quick but reliable solutions are sought.

Optimizing the performance parameters of injection-molded polymer spur gears

2020 ◽  
pp. 146442072097756
Author(s):  
Prashant Kumar Singh ◽  
Akant Kumar Singh ◽  
Siddhartha ◽  
Prabir Sarkar
Keyword(s):  
Analytical Hierarchy Process ◽  
Acrylonitrile Butadiene Styrene ◽  
Transmission Efficiency ◽  
Spur Gears ◽  
Performance Parameters ◽  
Optimal Setting ◽  
Injection Molded ◽  
Torque Values ◽  
Hierarchy Process ◽  
Butadiene Styrene

This research focuses on the optimization of the performance parameters namely, surface temperature, wear rate, and transmission efficiency of polymer gears. Three different polymers namely, acrylonitrile butadiene styrene, high-density polyethylene, and polyoxymethylene are selected for manufacturing the gears. A total of 27 experiments are carried out to test these gears at different torque and speed conditions. The torque values are taken as 0.8, 1.2, and 1.6 Nm, whereas the speeds of 600, 900, and 1200 r/min are chosen for the study. The optimal setting of operating parameters (gear material, speed, and torque) is obtained by using a hybrid multi-criteria decision-making approach that includes the analytical hierarchy process and technique for order of preference by similarity to ideal solution. The optimal setting of performance parameters is obtained with polyoxymethylene gear running at the torque and speed conditions of 0.8 Nm and 900 r/min, respectively.

Geometric Influence of a Molded Part on the Draw Direction Range and Parting Line Locations

1996 ◽  
Vol 118 (1) ◽  
pp. 29-39 ◽  
Author(s):  
M. Weinstein ◽  
S. Manoochehri
Keyword(s):  
Heuristic Rules ◽  
Design Features ◽  
Molded Part ◽  
Draw Direction ◽  
Cavity Design ◽  
Injection Molded

This paper presents a methodology based on the geometry of the injection molded part to identify the draw direction range and parting line locations. These parameters are shown to be a function of the interaction of the outward normals of the surfaces that have been divided into concave and convex regions of the part. This approach can also be applied incrementally to determine these mold parameters for a part as design features are added. The designer can then select from the choices provided to find the optimum parting line location and draw direction using heuristic rules. An absence of an allowable draw direction indicates the presence of an undercut that complicates the mold by requiring a side action so that the mold cost increases. The designer can either redesign the part or accept the undercut by specifying a side core or cavity. Design examples are provided which illustrate the effectiveness of the developed approach.

Development of a simulation method for the prediction of transmission errors of injection molded spur gears

2019 ◽  
Author(s):  
Dominik Schubert ◽  
Sebastian Hertle ◽  
Tobias Kleffel ◽  
Dietmar Drummer
Keyword(s):  
Simulation Method ◽  
Spur Gears ◽  
Transmission Errors ◽  
Injection Molded
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