by Mike Walsh » Wed Feb 17, 2010 9:58 am, Powered by phpBB® Forum Software © phpBB Limited. Compared to the existing Stephenson valve gear, Walschaert's gear had the advantage that it only required one eccentric per val… Bid now on Invaluable: DOLL ET CIE TOY STEAM PLANT & WORKSHOP 1920s Copper boiler mounted on tinplate brick effect oven with chimney, boiler with pressure gauge, water level glass, safety valves and whistle, piping to horizontal twin cylinder engine with slip eccentric ... from Bonhams on November 4, 0120 10:00 AM PST. The earlier version for fixed gauge models is similar but the stop collars are on the inside (back to back) and the eccentrics are to the outside, just behind the wheels. pump slip You will notice that this curve has two speed vs. flow lines at different discharge pressures. ... with a nice animation. It has a double acting cylinder and piston valve. Roundhouse Engineering Co. Ltd., Doncaster, UK. This forum is dedicated to the Live Steam Hobbyist Community. idea is to get both ports opening when the outside cranks are at the same position after rear dead centre. Click Here To Return To The Homepage. These are the ports that allow steam to travel too and from the ends of the There is one variation. A short time spent running the engine and making adjustments of just half a turn of the valve spindle at a time should soon show its optimum positions. I am trying to wrap my head around how it works, though as LBSC said in his books if the builder constructs it to plans, eventually he will see how it functions... and if not, who cares? PLEASE NOTE - this model and explanation contain a glaring error. Left hand drive axle outside crank. 6 - Rocker arm pivot screw. Repeat this several times and it will soon show up if there is a 'dead spot' at any particular point of the valve cycle. If it stalls, note the position of the drive crank pins and if either is at front or rear dead center. In 1848, Heusinger independently invented a very similar valve gear in Prussia, and Walschaert gear is occasionally known as Heusinger gear.Walschaert's gear proved to be reliable and light weight with only moderate space requirements. by JJG Koopmans » Mon Feb 15, 2010 7:43 am, Post However, in this case it is less easy to relate the valvegear mechanism to the equivalent eccentric. Metal seats are available for HP Butterfly valves allowing operation to around 1200F. This should again be a little after dead centre. valve chest in place. baggo Guest. When looking at right hand side of locomotive, forward rotation of wheels is clockwise. Publication date 1906 Topics Steam-engines Publisher London, E. Arnold Collection americana Digitizing sponsor Google Book from the collections of University of California Language English. It's basically a fixed eccentric gear with a fixed cut-off but with the ability to reverse by rotating the eccentric around the axle. There’s a twin cylinder Stuart 10 hidden up front just as in the 5″ gauge published design for a Sentinel 100hp loco ‘Serena’, and the boiler is also far more like the 5″ loco size. That is, at the neutral position, the valve ports should not open at all. by baggo » Sun Feb 14, 2010 7:22 pm, Post Does not cover 'Basic Series' locomotives. Each reverse lever position video sequence continues for six revolutions of the driving wheel. Regards, John. Eccentric plug rotary control valves control erosive, coking, and other hard-to-handle fluids, providing either throttling or on/off operation. DIRECTIONS FOR VALVE SETTING Directions for Setting the Woolf Reverse — In setting this valve gear, just as in setting any of the others, the first thing to do is to take up all lost motion in the cross head, connecting rod and main bearings, as well as in the eccentric, eccentric strap and all the valve connections. API 609 Centric butterfly valves (soft seated) are preferred to gate and ball valves for low-pressure and non-critical applications as they are cheaper, lighter and easier to install. Both components of the motion come from a single crank or eccentric. Animated Steam Valve Gears By fisker76 From a page on SteamLocomotive.com which shows detailed animations on how all 5 of the common American valve gear systems work. The Detailed relationships of piston to valve over a 360o cycle can be printed out to aid valve setting on completing the running chassis. The “Rocket’s” gear worked on this principle. "One cannot learn to swim without getting his feet wet." Repeat for the other side. cylinders. The stop collars rotate with the axle and the eccentrics 'slip' untill the drive pins reach the ends of the slots, at which point they start to drive the valves. Always check for excess wear in the valve gear first as it will not be possible to achieve correct timing if there is too much lost motion. Stephenson valve gear has one advantage that I know of over the other types of gear. The flanged valves feature streamlined flow passages and rugged, metal trim components for dependable service in slurry applications. This is like a gab hook or slip-eccentric engine, fundamentally. by Benjamin Maggi » Tue Feb 16, 2010 7:18 am, Post Post Since there is only one eccentric there is only one direction the engine can run in unless it is a slip eccentric and it does not look to be. Shown above is the later version of the slip-eccentric valve gear as used on adjustable gauge models. With slip eccentric you are stuck with whatever full-gear cutoff you decide on. opening fully. If it does not, adjust its position by unscrewing the rocker arm This describes the procedure for adjusting the slide valves on the internal slip-eccentric valve gear as fitted to early Roundhouse Lady Anne and Dylan locomotives and also, in a slightly shorter form, to the L & B locomotive. As Fred says, if you want to go forwards you push the loco forwards before opening the regulator. Make sure that the eccentric is always free to "slip" on the axle so that forward and reverse gear are being fully set. 3 - Eccentric. Notes to Valve Gear Animation Videos. If it is not, the valve spindle will lock up and may be damaged when the valve chest cover screws are tightened. When, therefore, the gear connecting-rod is swung back and froth by the action of the return crank and eccentric rod, both gear connecting-rod and radius bars swing in unison, and no movement of the bell-crank takes place; the valve rod, or course, also remains stationary. 2 - Eccentric rod. Loose eccentric is the same as slip eccentric and works the same way. To get the loco moving the eccentic rod is lifted off the valve rod and its associated rocker. The slot has to go in a paticular quadrant so that the ecentric is loading the pin against the sot end when in forward or reverse. STEAM ENGINE VALVE GEAR ON THE COMPUTER Windows Version by Charles Dockstader HCR 69 Box 3111 California Valley CA 93453 805 475 2519. Charlie's valve gear program has a simulation for slip eccentric. by Benjamin Maggi » Wed Feb 17, 2010 8:40 am, Post pushing the engine the other way causes the ecc. The article discusses the geometry of slip eccentric valve gear to be used in building the Gauge One locomotive. To illustrate the action rod has a simulation for slip eccentric for the Belgian State Railways the! Software Q & a and Maintenance Notices vary depending on the Computer Here we have a really cool little!... 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