Spiroid Gear with Composite Profile of the Worm – Hob Mill Tool

2014 ◽  
Vol 1036 ◽  
pp. 376-381
Author(s):  
Sofia Totolici ◽  
Virgil Gabriel Teodor ◽  
Nicuşor Baroiu ◽  
Silviu Berbinschi
Keyword(s):  
Contact Pressure ◽  
Carrying Capacity ◽  
Active Zone ◽  
Contact Length ◽  
Gear Ratio ◽  
Spiroid Gear ◽  
Spiroid Worm

The spiroid gears are known and used due to their performances: increased gear ratio; reduced overall dimensions; the simplicity of the construction; increased carrying capacity on the gear flanks etc. The gears construction demand assurance of a certain geometry of the worm, which constitutes, in the same time, the basics for the generating tool of the spiroid wheel. In this paper, a worm with a composite profile is proposed. The profile is composed by an assembly of circles arc, in order to increase the length of the flank active zone. This design is intended to increase the contact length between the flanks of the spiroid worm and spiroid wheel, in order to decrease the contact pressure between the two parts and to improve the gear function process.

A Method for Generating Desired Contact Pressure Distributions in Experimental Interfacial Studies

1985 ◽  
Vol 107 (3) ◽  
pp. 241-246 ◽  
Author(s):  
M. H. Attia ◽  
L. Kops
Keyword(s):  
Rigid Body ◽  
Contact Pressure ◽  
Flexural Rigidity ◽  
Thermal Contact ◽  
Contact Length ◽  
Wear Testing ◽  
Elastic Response ◽  
Rigid Base ◽  
Two Dimensional ◽  
Pressure Distributions

Computer simulation of the thermal deformation behavior of machine tools requires a priori knowledge of the correlation between the contact pressure distribution and the thermal contact resistance distribution along the structural joint. To establish this correlation experimentally, a method for generating different distributions of contact pressure has been devised in the present work. The method provides also a basic tool toward the satisfaction of the requirements of simulative wear testing. In this paper, the effect of the relative flexural rigidity of two solids in contact on the shape of the distribution of contact pressure is presented as a means for generating desired contact pressure distributions. The theoretical background of the concept is discussed considering two limiting cases: a rigid body on an elastic semi-infinite mass, and an elastic layer on a rigid base. Through a photoelastic analysis, the geometric parameters of contacting bodies, which allow us to generate the desired distributions, have been defined. The results of the analysis were verified by a two-dimensional, plane-stress finite element model. The results indicated that a finite plate, whose dimensions are not less than threefold the contact length can simulate a two-dimensional rigid base or a semi-infinite elastic mass. A change in the height-to-contact length ratio of the contacting beam from 0.5 to 2.5, causes a significant change in its elastic response from a flexural to a rigid body.

Analysis of High Temperature Creep on the Nut Connection Components of a 600MW Supercritical Steam Turbine

2012 ◽  
Author(s):  
P. N. Jiang ◽  
W. Z. Wang ◽  
G. C. Jiao
Keyword(s):  
Steam Turbine ◽  
Contact Pressure ◽  
Complex Structure ◽  
Contact Length ◽  
Element Analysis ◽  
Structure Reliability ◽  
Pressure Zone ◽  
Creep Time ◽  
High Pressure Zone ◽  
Safety Operation

A model of the nut connection components of a 600MW supercritical steam turbine was established by finite element analysis to investigate the influence of creep on the nut connection components. Due to the complex structure and the multi-axial loadings, Cocks-Ashby coefficients were used to depict the multi-axial creep behavior. Multi-axial creep deformation criteria (MCDC) and multi-axial creep rupture criteria (MCRC) were used to assess the structure reliability. In addition, sealing performance of the nut connection components in the creep time of 2×105 hours was numerically investigated in terms of the contact pressure and the radial contact length. The results demonstrated that the creep strength of the nut connection components after 2×105 hours could maintain the safety operation of the nut connection components. The contact pressure distribution and the radial contact length in circumferential could prevent the leakage steam flow from the high pressure zone to the low pressure zone.

scholarly journals Modeling the process of shaping worm gears of spiroid gear

Mechanik ◽  
2018 ◽  
Vol 91 (1) ◽  
pp. 24-27
Author(s):  
Kamil Wojtko ◽  
Piotr Frąckowiak
Keyword(s):  
Geometric Model ◽  
Experimental Studies ◽  
Cutting Parameters ◽  
Worm Gear ◽  
Test Results ◽  
Cnc Lathe ◽  
Worm Gears ◽  
Cutting Inserts ◽  
Spiroid Gear ◽  
Spiroid Worm

The article presents various methods of shaping cylindrical spiroid worm gear of asymmetrical outline using two tools. Cutting thread of worm gears is made on CNC lathes with blades in the form of universal inserts. Shows the geometric model and technological machining cylindrical worm gear spiroid on a CNC lathe. The correctness of the test results obtained in numerical developed program was tested through experimental studies of the process of cutting worm gears given parameters. Cutting process of worm gears was made on a lathe CTX210 using overlay ShopTurn in module for threading. The process uses a standard turning tool with interchangeable inserts and turning tools with a specially designed geometry. Studies performed on various cutting parameters and for a various materials of cutting inserts.

Mechanical Analysis of a Hexagonal Joint

2017 ◽  
Vol 754 ◽  
pp. 272-275
Author(s):  
S. Mantovani
Keyword(s):  
Finite Element ◽  
Plane Strain ◽  
Contact Pressure ◽  
Contact Zone ◽  
Cross Section ◽  
Mechanical Analysis ◽  
Contact Length ◽  
Male And Female ◽  
Peak Contact Pressure ◽  
Receding Contact

A hexagonal joint is mechanically analysed. A cross section of the receding contact between the male and female components is modelled as a plane strain problem. Particular attention is paid to the effect of the presence of fillets in the hexagonal male. Finite Element (FE) results show that, for each side of the hexagonal contact, the contact zone constitutes a small portion of the length of the hexagonal side, and separation occurs elsewhere. The normalized peak contact pressure and the contact length along the male sides are numerically evaluated.

The Influence of Lubricants on Static Friction Characteristics Under Boundary Lubrication

1985 ◽  
Vol 107 (2) ◽  
pp. 188-194 ◽  
Author(s):  
S. Kato ◽  
E. Marui ◽  
A. Kobayashi ◽  
S. Senda
Keyword(s):  
Machine Tool ◽  
Surface Topography ◽  
Contact Pressure ◽  
Boundary Lubrication ◽  
Carrying Capacity ◽  
Static Friction ◽  
Load Carrying Capacity ◽  
Sliding Speed ◽  
Friction Characteristics ◽  
Load Carrying

Based on a new boundary lubrication model, the characteristics of lubricants under boundary lubrication at low sliding speed and low contact pressure such as in machine tool slideways are investigated in relation to surface topography. It is clarified theoretically and ascertained experimentally that the property of lubricants under boundary lubrication can be estimated by the newly defined appraisal coefficient of boundary lubrication property determined by the thickness and load carrying capacity of adsorbed lubricant film and the surface topography.

Study of Wet Friction Material Test Under Severe Thermal and Mechanical Loading (“Bump Test”)

2000 ◽  
Vol 123 (1) ◽  
pp. 224-229 ◽  
Author(s):  
Wenping Zhao ◽  
Przemyslaw Zagrodzki
Keyword(s):  
Contact Problem ◽  
Contact Pressure ◽  
Frictional Heating ◽  
Friction Material ◽  
Contact Length ◽  
Fatigue Tests ◽  
Transient Temperature ◽  
Local Pressure ◽  
Contact Conditions ◽  
Static Conditions

One of the fatigue tests used for friction materials is the so called “bump test”. In this test, one of the reaction disks in a pack of disks has machined bumps across the contact surface. These bumps generate locally high contact pressure and temperature. In this way, severe contact conditions like that arising in service can be reproduced. The major difficulty in utilizing the “bump test” is estimation of the local pressure and temperature. In this paper, a model is developed and experimental verification of thermoelastic contact is presented. The model represents a multi-surface contact problem for a pack of disks. Due to the presence of bumps, contact surfaces are not conforming. To solve this strongly nonlinear contact problem, a robust finite element code is used. The model also includes thermal effects generated by frictional heating. The coupled elastic contact and thermal problems are solved sequentially. Contact pressure at interfaces is measured in static conditions (without sliding) using pressure sensitive film. Good agreement between the model and the measurement is observed in sense of contact length and magnitude of pressure. In order to verify the full thermoelastic model, the transient temperature inside one of the disks is measured by thermocouples. The results agree with model predictions. The study shows that the local contact pressure is an order of magnitude higher than nominal pressure. Also temperatures are much higher than that predicted for uniform contact conditions. The developed model helps to understand complex thermoelastic effects accompanying the test and to control the test parameters.

Sign in / Sign up

Export Citation Format

Share Document