Valve gears such as stephenson s for example are variable lead valve gears. It is named after robert stephenson but was invented by his employees. It is named after robert stephenson but was actually invented by his employees. They are not large scale drawings but the layout is all there. The british patent has not been found but the us patent us252224 of 10 january 1882 has. Joy valve gear is a type of steam locomotive valve gear, designed by david joy 3 march 1825 1903, locomotive and marine engineer, and patented no. Lead is a function of the valve gear geometry and not a physical quantity that can be machined, so the valve can only respond to the ability of the gear to produce the necessary lead at each dead centre crank position. Charlies has by far the most numerous of valve gear designs there are 67.
It is not necessary to guess the angle of advance as per lbsc to set the valves correctly. About the only thing that survived with stephenson valve gear were the brooks built engines that had piston valves inboard of the frames. To view his description and download the programs, click here. Valve gear simulation spreadsheets one for walschaerts simulation, the other for stephensons by don ashton and downloadable from his website. Valve gear design simulator software southwest cyberport. Zoom right into the valve gear to see the detail and timing methods used by the gear. In 1986 i wrote the first of the msdos versions of the software to simulate baker valve gear. I think this finding is interesting because i believe that both the stephenson and the walschaerts produce even event at each side. Design and simulation analysis of transplanters planting mechanism. Charlie dockstader has produced a comprehensive set of valve gear simulation programs for windows. Wallace of adelaide, author of another valve gear simulator, has kindly removed the anchor link constraint, very cleverly maintaining first design principles by using an optional tick box that also includes the eccentric rod and return crank. Don ashtons steam locomotive valve gear treatise on full and scale valve gears, including simulation and setting of model valve gears, is quite useful. Joys valve gear was used in the doble steam car until replaced by stephensons valve gear. The design used eccentrics on the driving axle of the locomotive to control valve motion.
The longer valve travel was connected with super power engines, as it allowed larger steam openings in the valve bushings, making the steam flow more efficient. Principles of steam locomotive valve systems dougkerr. Valve gear simulation software for ms windows, showing twenty different valve gear designs. The video model is taken from beyerpeacocks order 890. Joy valve gear is a type of steam locomotive valve gear, designed by david joy 3 march 1825. Valve gear design simulator software charles dockstader has written a program for ms windows which will take the geometry of your valve gear design pretty much every gear type imaginable and show the physical arrangement of the motion, animate the events, draw an indicator card, etc. Stephenson valve gear running off compress air zx10rjer.
Design and simulation analysis of transplanters planting. This is, as it were, the control station of the engine. Animations of 5 stephenson, walschaert, baker, southern, and young valve. Fully steerable, kinematically simulated locomotives with working stephenson valve gear, rods, pistons. The kinematics simulation software of this mechanism was compiled.
Charles has placed his programs in the public domain as freeware. The stanley steam engine stephenson valve gear computer simulation program charles dockstader has created an excellent program that simulates the operation of stephenson valve gear action. The stephenson valve gear or stephenson link or shifting link is a simple design of valve gear that was widely used throughout the world for all kinds of steam engines. Diagrams of walschaerts valve gear and stephenson valve gear, as supplied on working steam model locomotives. The stephenson valve gear or stephenson link or shifting link is a simple design of valve gear that was widely used throughout the world for all kinds of steam. The program offers you detailed, profiled and 3d views, giving you a comfortable display of different aspects of the system.
Stephenson valve gear for climax loco the home machinist. Walschaerts valve gear steam engine demonstrator as used on steam locomotives. At any setting, the valve gear satisfies the following two conditions. The hall simulator automatically sets the valve for equal leads, but with some choice in the case of stephenson s, even if the gear design does not support equal leads. As far as the eccentrics go, i need to fix their angle onto the crank shaft. The first simulator software i came across was the famous one by charlie dockstader who originally came up with the idea for proving the valve gear on one of his friends locos. I feel that it wouldnt be too hard to design a cam for a double acting cylinder that could operate a slidepiston valve. My usual practice in the simulator is to set the valves for lead equality, which was the valve setters primary operation. This is where certain data computations are displayed in counters or registers. Gear generator is a tool for creating involute spur gears and download them in svg format. Allan wallace also has a steam locomotive valve gear simulator and notes on full and scale valve gears. In the interests of keeping these available to everyone, i have installed the programs and his documentation on my website. As his simulator permits manual adjustment of the valve.
Stephenson valve gear was invented by employees of the stephensons. Ive been simulating the baker valve gear on a 3d cad software and i believe i got a reasonably grasp of how it works. Bill hall papers and locomotive simulation software by chris newman jul 18, 2017 the ast trust is grateful to mrs mary hall, the widow of the late bill hall for granting permission to make available for download copies of her husbands steam locomotive simulation software suites perform and perwal. Baker gear is more efficient than stephenson gear and. Allan wallace valve gear simulation software for walschaerts, stephensons and bakers valve gear downloadable from his own website. This page uses frames, but your browser doesnt support them.
In addition it let you compose full gear layouts with connetcted gears to design multiple gears system with control of the inputoutput ratio and rotation speed. What you decide to do can easily be checked on a valve gear simulator program these days before you cut metal. It is an early example of misusing a launchtype link and although centrally suspended appears not to incorporate correction. The first drawing is for juliet with stephensons valve gear and shows the position of. I am afraid that i wll need to become an expert with the software to figure this out. For those that would like to study how valve the valves of a stanley engine function this program is highly recommended. Since then i have made continuous additions and improvements to add other types of valve gear and improve functionality and ease of use. A software simulation of joy and other common valve gear configurations is available for download from. The walschaerts valve gear is an improvement on the earlier stephenson valve gear in that it enables the driver to operate the steam engine in a continuous range of settings from maximum economy to maximum power. Charlie has put this program in the public domain but is. These days if someone asked me to reset their stephenson valve gear for me i would probably first check the valve gear on a computer simulator, play around with it a bit, and the computer will then work out for me the correct angle or amount of advance.
Bill hall papers and locomotive simulation software. What we know now thanks to h s gowan and don ashton really only was made public from circa 19745 onwards. At the time, i was writing programs to solve the kinematics for a sheep shearing robot, so i sat down. There are other valve gear analysis tools available. The amount of lead remains constant over the whole range of cut offs that the gear is designed to provide. The soo liked walschaerts valve gear, equipping just about everything on the road with it during the teens and twenties as they rebuilt and superheated engines built as compounds. Both diagrams and figures then provide immediate verification of any detailed alterations and confirm expected performance, once the user becomes conversant with the program. American railroads summit river and pine valley is a first person railroad simulation set in the steam era, at the turn of the 19th century the core game focuses expanding your transportation business. This software is a must for any steam or live steam enthusiast fantastic stuff. You could model the linkage in dockstaders valve gear simulator software to be sure you had it correct before cutting any metal. Bill halls programs serve both walschaerts and stephensons gears in. Contains 82% of the steam locomotives remaining worldwide.
Railway preservation news view topic valve gear drawings. Stephenson valve gear running off compress air youtube. Valve gears such as walschaerts are said to be constant lead valve gears. In the main window seen below are controls which immediately affect the computations and influence the valve gear simulation.
Setting eccentrics model engineering clearing house. Please note that this software is neither supported by charles or myself. Gears simulator is a program that helps in the design of mechanical systems including gear meshes, friction wheels and belt and chain drives. Charlie has put this program in the public domain but is not to be sold. Gears can be animated with various speed to demonstrate working mechanism. Lbsc made serious mistakes on all his 5g valve gear designs except his joy valve gear minx and maid of kent. Shorttravel slide valve engines like the ones i believe you are building with properly maintained and calibrated stephenson s valve gear would not be driven any cutoff much lower than 35% because it ends being more inefficient than to drive at a higher cutoff, as the steam doesnt have the time or port area to fill the cylinder up to the.
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