DOCSLIB.ORG

(12) United States Patent (10) Patent No.: US 6,311,659 B1 Pierik (45) Date of Patent: Nov

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
(12) United States Patent (10) Patent No.: US 6,311,659 B1 Pierik (45) Date of Patent: Nov USOO6311659B1 (12) United States Patent (10) Patent No.: US 6,311,659 B1 Pierik (45) Date of Patent: Nov. 6, 2001 (54) DESMODROMIC CAM DRIVEN VARIABLE 1,740,790 12/1929 Stanton ............................. 123/90.25 VALVE TIMING MECHANISM 4,364,341 12/1982 Holtmann .......................... 123/90.17 5.988,125 11/1999 Hara et al. ........................ 123/90.16 (75) Inventor: Ronald Jay Pierik, Rochester, NY (US) * cited by examiner (73) Assignee: Delphi Technologies, Inc., Troy, MI (US) Primary Examiner Thomas Denion (*) Notice: Subject to any disclaimer, the term of this ASSistant Examiner Jaime Corrigan patent is extended or adjusted under 35 (74) Attorney, Agent, or Firm John A. Vanophen U.S.C. 154(b) by 0 days. (57) ABSTRACT (21) Appl. No.: 09/482,798 A desmodromic cam driven variable valve timing (VVT) (22) Filed: Jan. 13, 2000 mechanism includes dual rotary opening and closing cams Related U.S. Application Data for actuating a rocker mechanism that drives valve actuating (60) Provisional application No. 60/136,923, filed on Jun. 1, oscillating cams. The dual rotary cam drive positively actu 1999. ates the rocker mechanism in both valve opening and valve (51) Int. Cl." .................................................... F01L 1/30 closing directions and thus avoids the need to provide return (52) U.S. Cl. ..................................... 123/90.24; 123/90.15; Springs as required in prior cam driven mechanisms to bias 123/90.16; 123/90.17; 123/90.25 the mechanisms toward a valve closed position. A variable (58) Field of Search .............................. 123/90.16, 90.17, ratio Slide and slot control lever drive as well as a back force 123/90.24, 90.25 limiting worm drive for the control shaft are combined with (56) References Cited the desmodromic cam mechanism to provide additional System advantages. U.S. PATENT DOCUMENTS 1,671,973 * 6/1928 Anderson .......................... 123/90.25 15 Claims, 8 Drawing Sheets U.S. Patent Nov. 6, 2001 Sheet 1 of 8 US 6,311,659 B1 U.S. Patent Nov. 6, 2001 Sheet 2 of 8 US 6,311,659 B1 70 N to 59 6O 59 52 54 56 U.S. Patent Nov. 6, 2001 Sheet 3 of 8 US 6,311,659 B1 35 12 10-N -s FIG. 3 U.S. Patent Nov. 6, 2001 Sheet 4 of 8 US 6,311,659 B1 FIG. 4 U.S. Patent Nov. 6, 2001 Sheet 5 of 8 US 6,311,659 B1 Os 56 14 Fs, FIG. 5 U.S. Patent Nov. 6, 2001 Sheet 6 of 8 US 6,311,659 B1 9 / U.S. Patent Nov. 6, 2001 Sheet 7 of 8 US 6,311,659 B1 U.S. Patent Nov. 6, 2001 Sheet 8 of 8 US 6,311,659 B1 14 is FIG. 8 US 6,311,659 B1 1 2 DESMODROMC CAM DRIVEN VARIABLE BRIEF DESCRIPTION OF THE DRAWINGS VALVE TIMING MECHANISM In the drawings: CROSS REFERENCE TO RELATED FIG. 1 is a pictorial view of a first embodiment of desmodromic cam VVT mechanism for dual valves of a APPLICATIONS 5 Single engine cylinder, This application claims the benefit of U.S. Provisional FIG. 2 is a view similar to FIG. 1 but having portions of Application No. 60/136,923, filed Jun. 1, 1999. the mechanism omitted for clarity; TECHNICAL FIELD FIG. 3 is a transverse cross-sectional view of the embodi ment of FIG. 1 taken from the near side of the desmodromic The invention relates to variable valve timing mecha CamS, nisms and, more particularly, to Valve actuating mechanisms FIG. 4 is a cross-sectional view showing a pin and Slot for varying the lift and timing of engine valves. control in a maximum valve lift position; BACKGROUND OF THE INVENTION FIG. 5 is a view similar to FIG. 4 but showing the 15 minimum valve lift position; U.S. Pat. No. 5,937,809, issued Aug. 17, 1999, discloses FIG. 6 is a cross-sectional view of a worm drive for cam driven variable valve timing (VVT) mechanisms which actuating the control shaft of the mechanism; are relatively compact, and are applicable for operating FIG. 7 is a pictorial view similar to FIG. 2 but showing an individual or multiple valves. In these mechanisms, an engine valve is driven by an oscillating rocker cam that is alternative embodiment including a hydraulic or mechanical actuated by a linkage driven by a rotary eccentric, preferably lash adjuster, and a rotary cam. The linkage is pivoted on a control member FIG. 8 is a view similar to FIG. 3 but showing the that is, in turn, pivotably about the axis of the rotary cam and embodiment of FIG. 7. angularly adjustable to vary the orientation of the rocker DESCRIPTION OF THE PREFERRED cam and thereby vary the valve lift and timing. The rotary 25 EMBODIMENT cam may be carried on a camshaft. The oscillating cam is Referring first to FIGS. 1-5 of the drawings, numeral 10 pivoted on the rotational axis of the rotary cam. generally indicates a portion of an internal combustion U.S. patent application Ser. No. 09/129,270, filed Aug. 5, engine including a valve actuating mechanism 12 operative 1998, discloses a similar cam actuated VVT mechanism to actuate dual indict valves 14 for a single cylinder of an having various additional features, including a variable ratio engine. Mechanism 12 includes a rotary camshaft 16 that pin and Slot control member drive providing advantageous extends the length of a cylinder head, not shown, of a control characteristics and a worm drive for the control shaft multi-cylinder engine, of which the mechanism for only a designed to prevent backdrive forces from overcoming the single cylinder is illustrated. The camshaft 16 may be driven actuating force of the Small drive motor. A particular 35 from the engine crankshaft by a chain or any other Suitable embodiment of flat spiral mechanism return Springs is also CS. disclosed. Camshaft 16 includes a pair of mechanism actuating cams SUMMARY OF THE INVENTION including a valve opening cam 18 and a valve closing cam 20 Spaced axially adjacent one another along a primary axis The present invention provides improved VVT mecha 40 22 of the camshaft 16. Rotation of the crankshaft 16 is nisms wherein dual desmodromic rotating cams are pro optionally counterclockwise as shown by the arrow 24 but Vided for actuating oscillating cam drive mechanisms. The an opposite rotation could be used if desired. dual rotating cam drive includes both opening and closing Control members (or frames) 26 are mounted on the cams that actuate the mechanisms in both valve opening and camshaft 16 for pivotal motion about the primary axis 22. If Valve closing directions. The desmodromic cams thus avoid 45 desired, the control members could be mounted other than the need to provide return Springs which are required in on the camshaft. The nearer one of the dual control members previous cam driven VVT mechanisms to bias the mecha is omitted from FIG. 2 for clarity. The control members 26 nisms toward a valve closed position. The dual cams may be each include an outer end 28 connected with a pivot pin 30 located at axially adjacent positions on a Single camshaft. A disposed on a first pivot axis 32. A rocker 34 is pivotally Single rocker with dual arms may carry Separate followers, 50 mounted to the pivot pin 30 which connects it with the one engaging each cam to provide the positive opening and control members 26. A first rocker arm 35 of the rocker 34 closing action needed to eliminate mechanism return Springs extends from a first end at the pivot pin 30 to a distal end 35' without requiring extended motion of the oscillating cams as pivotally connected by a pin to a link36. Between its ends, in a crank driven mechanism. rocker arm 35 carries a follower roller 37 which engages the A mechanism lash adjuster or a Semi-compliant return 55 valve opening cam 18. As pictured, the roller 37 is shown follower arm may be used to take up lash between the dual riding on the base circle 38 of the opening cam 18 instead cam followers of the rotary cams. of the valve lift portion 39 as will be subsequently discussed. The advantages of control by a variable ratio Slide and Slot Link 36 extends from the rocker lever 34 to outer ends 40 control lever drive as well as a back force limiting worm of a pair of actuating levers 41 to which the link36 is pinned. drive for the control shaft may be combined with the dual 60 Levers 41 have inner ends 42 which are mounted on the cam mechanism to provide additional System advantages camshaft 16 and pivotable about the primary axis 22. These comparable to those designed for Single cam actuated inner ends define oscillating cam is 44, each having a base mechanisms requiring return Springs. circle portion 46 and a valve lift portion 48. The base circle These and other features and advantages of the invention and valve lift portions are similar to those discussed in the will be more fully understood from the following description 65 previously mentioned U.S. Pat. No. 5,937,809, which may of certain specific embodiments of the invention taken be consulted for additional details of their appearance and together with the accompanying drawings. operation. US 6,311,659 B1 3 4 The oscillating cams 44 are engaged by rollers 50 of roller cams 44 counterclockwise, returning the finger follower finger followers 52, each having inner ends 54 which are rollers 50 to the base circles of the oscillating cams and pivotally Seated on Stationary hydraulic lash adjusters 56 thereby allowing the valves 14 to be closed by their valve mounted in the engine cylinder head, not shown.
Load more

Recommended publications
  • Desmodromics Mick Walker Explains How Ducati Beat Tbe World with Spring-Less Valve Operation
    og , Desmodromics Mick Walker explains how Ducati beat tbe world with spring-less valve operation HE WORD desmodmmic wil! not be the bounce and get a higher-revving engine successful and was not developed, but in found in the Oxford or any other - in theory. the 1920s several other manufacturers tried T English dictionaries. It was coined This had been known since the early days variants of it. One layout, the Vagova, from two Greek words, meaning 'controlled of the internal combustion engine but for utilized a cam track embodying inner and run' and its mechanical function is to elimi- many years no designer managed to success- outer cam forms which guided a roller nate one of the phenomenon of valve float, fully harness it. One of the first examples of attached to one end of a 'rocker', the other or 'bounce'. This happens at high revs when completely positive mechanical valve oper- end of the rocker was forked to embrace the valve springs are unable to respond ation was used by the French Delage concern the valve stem. To provide the required quickly enough to close the valve back on in its grand prix car of 1914 - and the freedom for seating, the pivot of the rocker their seats. 11le desmodromic idea was to French knew the method as desmod- was given a small amount of spring-Ioaded replace troublesome springs with a romique. float parallel to the valve axis. me(\. jcal closing system much like that The Delage engine employed four valves Alternative methods investigated were to usedló open them.
    [Show full text]
  • A Camshaft Non-Linear Model for the Desmodromic Valve Train Simulation
    A Camshaft Non-Linear Model for the Desmodromic Valve Train Simulation A. Rivola, *A. Carlini DIEM – Mechanical Engineering Department, University of Bologna viale Risorgimento, 2 – I40136, Bologna, Italy email: [email protected] *Test Bench Engineer, DucatiCorse s.r.l., via Cavalieri Ducati, 3 – I40132, Bologna, Italy Abstract In this paper the dynamic behaviour of the desmodromic valve train of a motorbike engine is simulated and analysed. The valve train model takes into account the mass distribution, the link elastic flexibility, and the presence of several non-linearities. The camshafts, which are supported by hydrodynamic journal bearings, are modelled by means of finite rotating elements based on Timoshenko beams with the effect of gyroscopic moment. The non-linear bearing forces are analytically obtained under the finite-length bearing assumption. The comparison between the numerical results and the experimental data – in terms of valve acceleration and camshaft angular velocity – shows that the effectiveness of the model is satisfactorily assessed. The paper mainly focuses on two points: the validation procedure of the finite element model of the camshafts, and the study of the simulated camshaft centreline trajectories. 1 Introduction This paper deals with a kineto-elastodynamic model of the desmodromic valve train of a Ducati motorbike engine. The desmodromic train is a mechanism with positive-drive cams and – in comparison with the widely-used trains having a closing spring [1–3] – presents different dynamic behaviour, as shown in [4– 7]. When operating at high-speed, a mechanism shows a dynamic behaviour which is affected by the link elastic flexibility and mass distribution, as well as the effects of backlashes and friction in joints.
    [Show full text]
  • Design of an Effective Timing System for ICE
    Design of an Effective Timing System for ICE Andrea Miraglia∗ and Giuseppe Monteleoney yDepartment of Electrical, Electronics, and Informatics Engineering, University of Catania, Catania Italy ∗Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania Italy Abstract—The present paper describes the design and the a four-stroke engine, generally conical valves are employed; prototype realization process of a new effective timing system they open under the action of cams, fitted on the camshaft par- for ICE (internal combustion engine). In particular, the present allel to and activated by the crankshaft, subsequently closing paper outlines the dynamic behavior and related performance of the innovative timing system applied to a two cylinder engine. at the position due to the push by appropriate calibrated coil The procedure to validate the prototype, based on experimental springs [1], [2], [3], [4], [5]. tests carried out on a test bench, is presented and discussed. The traditional finite elements method and computational fluid A. The main timing elements dynamics (CFD) analysis are used to estimate the dynamic performance of the engine with the new timing system. The The main elements of a timing system are: comparison with the data reported in bibliography shows the • Camshaft effectiveness of the new timing system. The study indicates that the proposed system is of great significance for the development • Valves (guides, seals and springs) of timing system in an automotive engine. • Tappets • Pushrods Keywords-Specific power; Computational dynamic analysis; 3D modeling; CFD analysis; Reliability. • Rocker arms The most common valve train system involves pushrods I. INTRODUCTION and rocker arms; however, there are other valve train systems The idea of a new timing system originated from the passion available, offering such solutions as single or double camshaft.
    [Show full text]
  • Modelling the Elastodynamic Behaviour of a Desmodromic Valve Train
    Modelling the Elastodynamic Behaviour of a Desmodromic Valve Train Alessandro RIVOLA (*), Andrea CARLINI (*), and Giorgio DALPIAZ (**) (*) DIEM - University of Bologna Viale Risorgimento, 2, I - 40136 Bologna, Italy e-mail: [email protected] (**) Dept. of Engineering, University of Ferrara Via Saragat, 1, I - 44100 Ferrara, Italy e-mail: [email protected] Abstract This paper deals with a lumped-parameter model of a motorbike engine’s desmodromic valve train. The model of such an uncommon cam system is developed and validated with the aid of experimental measurements carried out on a test bench which operates the cam mechanism by means of an electrically powered driveline. The model describes the mechanical system taking into account the mass distribution, the link elastic flexibility, and the presence of several non-linearities. The model parameter estimation is discussed and the effectiveness of the model is assessed by a comparison with experimental results. In addition, the model is employed to estimate the magnitude of contact forces and to predict the system behaviour as a consequence of changes in some design parameters; therefore, it may be used as a tool both in design optimisation and diagnostics. 1 Introduction train of a Ducati motorbike engine. Only works on widely-used trains with closing spring were found in Nowadays the study of the dynamic response of literature [7–9]; in those cases the valve spring plays flexible mechanisms operating at high speed is an important role in the system dynamics. becoming more and more important and several Conversely, in the case of desmodromic valve trains studies can be found in literature [1–4].
    [Show full text]
  • 19FFL-0023 2-Stroke Engine Options for Automotive Use: a Fundamental Comparison of Different Potential Scavenging Arrangements for Medium-Duty Truck Applications
    Citation for published version: Turner, J, Head, RA, Chang, J, Engineer, N, Wijetunge, RS, Blundell, DW & Burke, P 2019, '2-Stroke Engine Options for Automotive Use: A Fundamental Comparison of Different Potential Scavenging Arrangements for Medium-Duty Truck Applications', SAE Technical Paper Series, pp. 1-21. https://doi.org/10.4271/2019-01-0071 DOI: 10.4271/2019-01-0071 Publication date: 2019 Document Version Peer reviewed version Link to publication The final publication is available at SAE Mobilus via https://doi.org/10.4271/2019-01-0071 University of Bath Alternative formats If you require this document in an alternative format, please contact: [email protected] General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Download date: 27. Sep. 2021 Paper Offer 19FFL-0023 2-Stroke Engine Options for Automotive Use: A Fundamental Comparison of Different Potential Scavenging Arrangements for Medium-Duty Truck Applications Author, co-author (Do NOT enter this information. It will be pulled from participant tab in MyTechZone) Affiliation (Do NOT enter this information. It will be pulled from participant tab in MyTechZone) Abstract For the opposed-piston engine, once the port timing obtained by the optimizer had been established, a supplementary study was conducted looking at the effect of relative phasing of the crankshafts The work presented here seeks to compare different means of on performance and economy.
    [Show full text]
  • Desmosedici Twinpulse Engine to Power Ducati Attack on Motogp Championship
    DESMOSEDICI TWINPULSE ENGINE TO POWER DUCATI ATTACK ON MOTOGP CHAMPIONSHIP Four-cylinder 989cc ‘L’ engine, with simultaneous firing order in cylinders of the same bank and desmodromic timing – Track tests to get underway in July also in traditional firing layout – Race debut with two riders at first round of MotoGP 2003. Bologna, 4 February 2002 - Nine months after the start of the MotoGP project, announced last May at Jerez de la Frontera, Ducati Corse has completed the design stage of its new engine, called Desmosedici (16-valve Desmo), which will begin testing on the dyno within the next three months. Ducati Corse Managing Director Claudio Domenicali explained the decision-making process behind the choice of the new engine: “After analysing all the possibilities offered by the regulations and on the basis of computer simulations, we are convinced that a massive power output is required to be competitive in MotoGP. It would have been difficult to obtain this power with conventional twin-cylinder engines, which amongst other things are only given a 10 kg weight advantage over 4 and 5 cylinder engines in the regulations. As a result, the bore size would have to be taken to an extremely high value, with the risk of incurring serious combustion problems.” “For this reason, in the preliminary study phase, we considered a twin-cylinder oval piston engine to be an excellent layout for the new regulations. With the same weight as 4 and 5 cylinder engines, this layout combines the typical advantages of a twin in terms of power output and delivery, with the performance necessary to compete at the same level as the multi-cylinder units”.
    [Show full text]
  • Pattakon Vvas –A Solution for the Idling Problem of the Known Throttle-Less Vvas
    pattakon VVAs –A solution for the idling problem of the known throttle-less VVAs. –Mechanical VVAs with independently variable lift and duration. –Mechanical VVAs without valve springs (desmodromic) for racing engines. To the point Every motorcycle maker has in production a 1,000cc bike engine with top power at around 12,000 rpm and red line at 13,000 rpm or even higher. Such an engine cannot replace the engine of a heavy car. The peaky torque curve, the medium to low revs characteristics, the partial load response etc cannot meet the needs of a heavy vehicle. Think of replacing the conventional valve train of the 1,000cc bike engine by a high revving VVA. But, do high revving VVAs exist? pattakon VVAr 4cylinder, 1600cc (9,000rpm rev limiter) accelerating on a highway (click on the button) Rod-version and roller-version VVA prototypes pattakon VVAr, 4cylinder, 1600cc, 9000 rpm full version pattakon VVAr, 1600cc, 9000 rpm, full version pattakon VVAr, 4cylinder, 1600cc, 9000 rpm light version (intake side only) pattakon VVAr, 4cylinder, 1600cc, 9000 rpm light version (intake side only) VVAr parts. 0.150 Kp each “complete new rocker arm” versus 0.260 Kp of the original 2-mode. Control of the VVAr prototype engine (a modified B16A 1600cc) The rotation of the intake control shaft defines the lift of the intake valves. A rheostat is displaced by the intake control shaft and its signal is fed to the MAP input of the ECU (the original MAP sensor is removed: without a throttle valve the pressure just before the intake valves is always atmospheric).
    [Show full text]
  • Four-Stroke Cycle
    FOUR-STROKE CYCLE The four-stroke cycle (or Otto cycle) of an internal combustion engine is the cycle most commonly used for automotive and industrial purposes today (cars and trucks, generators, etc). It was conceptualized by the French engineer, Alphonse Beau de Rochas in 1862, and independently, by the German engineer Nikolaus Otto [[1]] in 1876. The four-stroke cycle is more fuel-efficient and clean burning than the two-stroke cycle, but requires considerably more moving parts and manufacturing expertise. Moreover, it is more easily manufactured in multi-cylinder configurations than the two-stroke, making it especially useful in high-output applications such as cars. The later-invented Wankel engine has four similar phases but is a rotary combustion engine rather than the much more usual, reciprocating engine of the four-stroke cycle. Four-stroke cycle (or Otto cycle) The Otto cycle is characterized by four strokes, or straight movements alternately, back and forth, of a piston inside a cylinder: intake (induction) stroke compression stroke power (combustion) stroke exhaust stroke The cycle begins at top dead center, when the piston is at its uppermost point. On the first downward stroke (intake) of the piston, a mixture of fuel and air is drawn into the cylinder through the intake (inlet) port. The intake (inlet) valve (or valves) then close(s), and the following upward stroke (compression) compresses the fuel-air mixture. The air-fuel mixture is then ignited, usually by a spark plug for a gasoline or Otto cycle engine, or by the heat and pressure of compression for a Diesel cycle of compression ignition engine, at approximately the top of the compression stroke.
    [Show full text]
  • VALVE CONTROLS INFINITE POSSIBILITIES ROGER STONE, CAMCON AUTOMOTIVE TECHNICAL DIRECTOR Where All the Pieces Fall Into Place
    The pan-European magazine of SAE International May/June 2013 VALVE CONTROLS INFINITE POSSIBILITIES ROGER STONE, CAMCON AUTOMOTIVE TECHNICAL DIRECTOR Where All the Pieces Fall Into Place Let’s face it; driveline design can be a real brainteaser. Reduced emissions. Improved fuel economy. Enhanced vehicle performance. Getting all the pieces to fit is challenging—especially when you can’t see the whole picture. That’s why you need one more piece to solve the driveline puzzle. Introducing DrivelineNEWS.com—a single, all-encompassing website exclusively dedicated to driveline topics for both on- and off-road vehicles. Log on for the latest news, market intelligence, technical innovations and hardware animations to help you find solutions and move your business forward. It takes ingenuity and persistence to succeed in today’s driveline market. Test your skills at DrivelineNEWS.com/Puzzle. Solve the puzzle to enter to win a Kindle Fire. © 2013 The Lubrizol Corporation. All rights reserved. 121569 Contents 12 12 Cover Story 5 Comment Valve controls Imagine a valve control system that is infinitely 6 variable irrespective of engine speed and load. News Impossible? Not according to Camcon Automotive’s • Exclusive: technical director Roger Stone, as Ian Adcock Engine knock discovers predicted 16 Biomimicry • Volvo diesel breakthrough Mother Nature knows best What can the automotive industry learn from nature • Driveline software when it comes to weight saving? Ryan Borroff has 20 been finding out • Four-way cat for petrol engines 20 Fuel injection systems Building up the pressure 11 Tony Lewin reports on the growing trend towards even The Columnist higher line pressures in injection systems.
    [Show full text]
  • Design and Modification of Cam Operated Spring-Less Valve System in IC Engine
    IOSR Journal of Engineering (IOSR JEN) www.iosrjen.org ISSN (e): 2250-3021, ISSN (p): 2278-8719, || Special Issue || June-2019, || PP 04-09 || Design and Modification of Cam Operated Spring-less Valve System in IC Engine D. V. Bhise1, Aishwarya R. Kulkarni2, Omkar S. Khaire3, Prasad S. Darekar4, Shubham R. Kochale5, Sunny R. Dhadve6 1(D. V. Bhise, Associate Professor, Dept. of Mechanical Engineering, JSPM Narhe Technical Campus, Pune, Maharashtra, India) 2,3,4,5,6(Students,Department of Mechanical Engineering, S.P.P.U. University, J.S.P.M. Narhe Technical Campus, Pune, Maharashtra, India) Abstract: This project presents the spring less valve system used in the IC engines.This mechanism has a closing cam which does not allow cam jump as conventional valve system. It has helped us to find out how spring less valve system is better than conventional valve system. We have found out the real importance of this spring less system at higher rpm of engine and need of this system at higher rpm. This system improves the performance of IC engine by reducing power consumption for overcoming spring stiffness and avoid cam jump at high speed. Keyword: Springless valve system, closing cam, cam jump, IC Engine, Stiffness I. Introduction 1.1 Introduction to conventional Spring System IC Engine uses valves to handle charge in and out of the cylinder for their operation. There are intake valves and exhaust valves which are to be spring operated at right time when needed and remains close to seal the cylinder when compression and combustion is occurred.
    [Show full text]
  • The Development of the Single Sleeve Valve Two-Stroke Engine Over the Last 110 Years
    energies Review The Silent Path: The Development of the Single Sleeve Valve Two-Stroke Engine over the Last 110 Years Robert Head * and James Turner Mechanical Engineering, Faculty of Engineering and Design, University of Bath, Bath BA2 7AY, UK; [email protected] * Correspondence: [email protected]; Tel.: +44-0789-561-7437 Abstract: At the beginning of the 20th century the operational issues of the Otto engine had not been fully resolved. The work presented here seeks to chronicle the development of one of the alternative design pathways, namely the replacement for the gas exchange mechanism of the more conventional poppet valve arrangement with that of a sleeve valve. There have been several successful engines built with these devices, which have a number of attractive features superior to poppet valves. This review moves from the initial work of Charles Knight, Peter Burt, and James McCollum, in the first decade of the 20th century, through the work of others to develop a two-stroke version of the sleeve- valve engine, which climaxed in the construction of one of the most powerful piston aeroengines ever built, the Rolls-Royce Crecy. After that period of high activity in the 1940s, there have been limited further developments. The patent efforts changed over time from design of two-stroke sleeve-drive mechanisms through to cylinder head cooling and improvements in the control of the thermal expansion of the relative components to improve durability. These documents provide a foundation for a design of an internal combustion engine with potentially high thermal efficiency. Keywords: two-stroke; sleeve valves; patents Citation: Head, R.; Turner, J.
    [Show full text]
  • Ducati's Desmo
    rfptesW&v'K* : OLDTIMERWORKSHOP.COM What is there about this last true production cafe racer that Three thousand kilometres ago it had been new; the product of an honors it with immortality? We might have believed its Italian factory that understood the qualities were all Italian idiosyncrasies the average owner real meaning of a solo seat, clip-ons, might not be prepared to tolerate until JOE BLAKE presented rearsets and a megaphone with a detachable muffler. this 13,000 kilometre report. The glint of the stunning metal- The single-cylinder bike is not dead, he says. Nor does its flake silver beckoned me closer. strength lie only in soppy memories of yesteryear. That paint was nearly two years old and it still looked half an inch deep. It took a Desmo to make this experienced rider realise it! “DUCATI”. White decals on a silver flake fibreglass tank. Only the IT WAS love at first sight. But here was a CAFE RACER — Italians could do that. But they But for a very difficult-to- one of the street-legal roadracer switched colors for the sidepanels. explain reason. It wasn’t logical for breed beloved by British enthusiasts “Desmo” screamed the writing . a man who already owned a who cling tenaciously to their what the hell did Desmo really well-used Norton roadster ahd re­ memories of the late Velocette mean? cently relinquished his hold on a Thruxton and like to pretend that I didn’t buy it on the spot. I little Kawasaki 100 to fall quite so N orton’s production racer is as went away and thought about it, heavily.
    [Show full text]