Jan 10, 1995 this invention relates to automotive air conditioning compressors in general, and specifically to a swash plate type compressor with an improved and simplified bearing mechanism joining the swash plate to the pistons. Simulation and performance analysis of control mechanism. All the necessary components to operate a semirigid helicopter main rotor with swashplates are fabricated and assembled. Simulation and performance analysis of control mechanism in variable displacement swash plate compressor. Deriving a simple degree of freedom model, we propose a dimensionless arm length to. A study on the variable displacement mechanism of swash. Swash plate in a singlepiston, isothermal axial piston. Us3333478a us57261866a us3333478a us 3333478 a us3333478 a us 3333478a us 57261866 a us57261866 a us 57261866a us 3333478 a us3333478 a us 3333478a authority us united states prior art keywords swash plate wobble ring ring bearing prior art date 19620910 legal status the legal status is an assumption and is not a legal conclusion. The dynamics of the swashplate mechanism of the cl327, anunmanned aerial vehicle uav with a vertical takeoffandlandingvtol ability is discussed in this paper, the underlying kinematicshaving been discussed in an earlier paper. Swashplate type axial piston pumps for open circuits in.
The working principles is similar to crankshaft, scotch yoke, or wobblenutatorzcrank drives, in engine designs. The antitorque mechanism generally includes an antitorque shaft and a compound bearing mounted thereto to provide fivedegreesoffreedom sphericallinearelastomeric so as to permit a swashplate attachment point to move axially in response to pitch input. Swash plate compressor with unitary bearing mechanism. Swash plate oscillation in a variable displacement floating cup pump p. In order to verify the mathematical model, a test bench of control mechanism and test system of vdsc are established, and the simulated results. Us3333478a swashplate mechanism for internal combustion. The pistons suck in fluid during half a revolution and push fluid out during the other half. This design has resulted in a pump with high reliability and long service life. How could the flat swash plate cam be modified to produce an even more interesting movement of the followers. The fixed swash plate is held between the opposing ends of the double piston by a pair of shoes and two steel balls. Author links open overlay panel changqing tian a hongbo xu a. The swash plate assembly consists of two parts the upper and lower swash plates. Helicopter swashplate design and analysis using semi.
This mechanism enables the swashplate to tilt in all directions and move vertically as one unit. Shown on edge on the far right in the animation is a dark stationary disk. This motion can be simulated by placing a cd on a ball bearing at its centre and pressing down at progressive places around. Modeling a helicopter swashplate mechanism comsol blog. The swashplate of a model helicopter consists of stationary and rotating plates separated by ball bearings. Variablestoke swash plate mechanisms are widely used for compressors in automotive airconditioning systems, but the dynamics of the system has not been investigated sufficiently. An antitorque mechanism which permits a full range of swashplate assembly motion. Long life a long life is obtained by adopting main bearings of large capacity and the pistonreturn mechanism that compensates for the wear of the shoe. This mechanism enables the swashplate to tilt in all directions and move vertically as. This paper is an extension of a previous research effort utilizing the rssp mechanism 7 and considers the influence of geometric proportions of a device on stroke size, velocity fluctuation, and force transmission effectiveness. Servos and swash plate, understanding rc helicopters. In the present study, we derived a dynamic equation based on the lagrangian mechanics for the mechanism and solved it numerically. The swashplate mechanism is used to transfer rotational motion into translational motion and vice versa. This mechanism would be applied to the helicopter directional control where the plate in the pitchroll mechanism would serve as the swash plate of the helicopter.
Dec 14, 1993 a swash plate mechanism, for coverting linear motion into notary motion and vice versa is disclosed, which overcomes the main difficulties with older arrangements of swash plate drives. C079, page 1 a study on the variable displacement mechanism of swash plate type compressor for automotive air conditioning system geon ho lee1, tae jin lee2 1 department of refrigeration and air conditioning, doowon technical college. Helicopter swashplate design and analysis using semi compliant. Based on the theory of elastic fluid dynamic lubrication, this work establishes a fluidsolid coupling model of a swash plate axial piston pump and solves the governing equations of the lubrication with respect to the port plate pair. Jun 14, 20 the connections in a swashplate mechanism are positioned in such a way that components form a closed loop the swashplate mechanism is thereby a good example of a closed loop multibody system. The upper swash plate connects to the mast, or rotor shaft, through special linkages. A spring pushes the pistons against a stationary swash plate, which sits at an angle to the cylinder. In particular, the double pump with its tandem arrangement, has eliminated a power divider, has an increased transmission efficiency, and is lighter. Several studies have been carried out to study the characteristics of such novel pump mechanism. The mathematical model of the control mechanism used in a variable displacement swash plate compressor vdsc is developed based on the force balance equation, mass and energy conservation equation. Homebuilt helicopter swashplate plans suitable for one seat or two seat helicopters. As they cut through air, air flows faster on the top side of the rotor blade compared to the air flowing on the bottom side.
This module enables simulation of an assembly of flexible and rigid bodies, together with. A static equilibrium condition for the steadystate analysis. This animation shows the relation between pitch angle of two opposite blades as function of swashplate position. A swashplate mechanism, used in a helicopter to control the pitch of the rotor blades, can be easily simulated using the multibody dynamics module available in comsol multiphysics. Helicopter swashplate mechanism comsol multiphysics. The cl327 guardianis currently under production by bombardier servicesdefence, and isconsidered the worlds most versatile and advanced vtol system. The slipper pad is an improvement on the swash plate which provides higher pressure. Buy your copy today of the homemade helicopter swashplate plans.
Pitch angle of main blades of helicopter is a function of swahplate. Toyota industries corporation was founded in 1926 by sakichi toyoda to manufacture and sell the automatic looms which he had invented. Out of a wide variety of our swash plate type axial piston pumps. The fixed swashplate is held between the opposing ends of the double piston by a pair of shoes and two steel balls.
It was originally invented to replace a crankshaft, and. This system includes blade grips, which connect the blades to a hub. These are the high friction of most drives or the high complexity of efforts to overcome the friction effects. If you were to model all the components as rigid, the mechanism would become overly constrained and difficult to simulate. Because the main rotor blades are spinning, the swashplate is used to transmit three of the pilots commands from the nonrotating fuselage to the rotating rotor hub and mainblades. Dynamic behavior of variable stroke swash plate mechanism. The driving shaft rotates the cylinder barrel, swash plate and pistons.
The mechanism of a variable wobble plate compressor the preferred configuration for a piston compressor soon moved to a double acting swashplate design of which the harrison delphi hd6 is typical. When i saw this i almost jumped in my chair, but its just an illusion of two simple wheels. Electrically controlled swash plate axial piston pumps with conical cylinder blocks are recently used in the industry in view of their superior performance. The cam mechanism would normally be boxed in for safety reasons. A swashplate or swash plate is a component which can be used to convert circular motion into reciprocating motion, and vice versa. Swash plate pumps have a rotating cylinder containing pistons. Swash plate oscillation in a variable displacement floating. The device is shown to have significant kinematic advantages over the traditional form of the swash plate mechanism. A study on the variable displacement mechanism of swash plate. A swashplate also known as slant disk was invented by anthony george maldon michell in 1917. Initially pencilpaper drawings and wooden structure have done to fix the correct dimensions for swash plate components and structural members. If you know how aerofoils work, you know half of the answer.
Btrt nt nl f hplt hn n trnfrtn tr b dvd dr vn th hplt hn d t trnfr rttnl tn nt trnltnl tn nd v vr. Dynamics of the swash plate mechanism semantic scholar. Pdf dynamic behavior of variable stroke swash plate mechanism. The cylinder block is rotated by means of the pump driving shaft, and is held tightly against the valve plate under the effect of the supply pressure and the force of the cylinder block. The swashplate engine also sometimes called axial engine or barrel engine is a type of reciprocating engine that replaces the common crankshaft with a circular plate the swashplate. Swash plate in a singlepiston, isothermal axial piston pump. The swash plate block models a single, pistonactuated swash plate within an axialpiston pump. A swash plate drive mechanism for an axial piston machine is disclosed comprising a pair of yokes with intersecting longitudinal axes and intersecting crossaxes and a swash plate drivingly connected with the pistons and pivotally connected between the yokes for pivotal movement about their crossaxes whereby the swash plate is caused to oscillate and effect double frequency drive between the. The mechanism is a combination of a cylinder block or rotor, with the piston fitted inside, and an. Flushing should be provided using an off line filtration system. Swash plate oscillation in a variable displacement floating cup pump.
Figure 1 shows schematically the pumping mechanism of the investigated swash plate axial piston pump, which has an odd number of pistons nested in a circular array within the block at equal intervals. Swashplates can be used in a variety of settings, with one of the most famous applications being the helicopter swashplate, which is used by the pilot to adjust the blades of a helicopter in order to achieve lift and control the position of the helicopter. Simulation and performance analysis of control mechanism in. Miloslavich, project engineer abstract several mechanisms have been used to con vert the motion of a rotating shaft to the reciprocating motion needed to drive the pistons of a conventional compressor. All the necessary components to operate a semirigid helicopter main rotor with swash plates are fabricated and assembled. Modeling of swash plate axial piston pumps with conical. The pistons 24 are driven by swash plate 22 through a mechanism that consists only of a socket 26 machined centrally in piston 24, and a bearing member in the form of a ball.
However, on the drawing below the front has been removed so that the mechanism can be clearly seen. Servo valves have been designed and built into the pump. Internal combustion engines and stirling engines have been built using this mechanism. In the present study, we derived a dynamic equation based on the lagrangian mechanics for the mechanism and solved it.
In these studies, partial mathematical modeling is conducted relevant to the points discussed. Duke engines has been working on such a platform since 1993. Pdf load and stress analysis for the swash plate of an axial. Swash plate free download as powerpoint presentation. The mechanism of a variable wobble plate compressor the preferred configuration for a piston compressor soon moved to a double acting swash plate design of which the harrison delphi hd6 is typical. Homebuilt helicopter swashplate plans build a helicopter. Feb 16, 2014 this video will help you understand what servos are and what a swash plate is and how they work together. Pdf dynamic behavior of a variable stroke swash plate mechanism is analytically and numerically investigated. An improved alternative to the threedimensional, swash plate. Kpm swash plate type axial piston pumps programs for industrial vehicles. The swashplate engine uses a swashplate in place of a crankshaft to translate the motion of a piston into rotary motion. Since then toyota industries has diversified and expanded the scope of its business domains to include textile machinery, automobiles vehicles, engines, car airconditioning compressors, etc. An arrangement of a swash plate pump is shown in figure 6. A static equilibrium condition for the steadystate.
Types of compressor and structure oneway swash plate type. A swashplate is a device that translates input via the helicopter flight controls into motion of the main rotor blades. Low noise even less noise has been achieved because of the op. Swash plate oscillation in a variable displacement. An improved alternative to the threedimensional, swash. It is a mechanical engineering device used to translate the motion of a rotating shaft into reciprocating motion, or vice versa. It had five or seven cylinders and a variable compression ratio, altered by changing the wobble plate angle and hence the length of piston stroke. Paper presents measured data of ilx27 helicopter test in hover condition.
High efficiency and large selfpriming capability the spherical valve plate and improved hydraulic balance provide stable cylinder rotation, thus achieving. The mechanism is a combination of a cylinder block or rotor, with the piston fitted inside, and an angled swash plate. Pumping mechanism of swash plate axial piston pump with conical cylinder block. New for 2016 homebuilt helicopter swashplate plans ebook download. May 20, 2014 pitch angle of main blades of helicopter is a function of swahplate. Pdf performance analysis on a variable capacity swash plate. Multidisciplinary design optimization of a swashplate axial. In an axial piston pump design, the swash plate plays an important role in controlling the displacement of the pump, especially in a closed loop system. Lownoise the unique, compact and rigid housing construction in addition to the semicylindrical pillow type swashplate and its antivibration supporting. Mar 04, 2020 a swashplate or swash plate is a component which can be used to convert circular motion into reciprocating motion, and vice versa.
As the engine turns the rotor shaft, it also turns the upper swash plate and the rotor blade system. Noise considerations presented by viral mehta a candidate for the degree of doctor of philosophy and hereby certify that in their opinion it is worthy of acceptance. The swash plate, another mechanism, produces recipro cating motion in a direction parallel to the centerline of the rotating driveshaft. A numerical study on the performance of a variable capacity swash plate compressor for an automotive airconditioning system was carried out. One of the most elusive parts of building your own homemeade helicopter is now available to the public. When a swash plate axial piston pump operates under highpressure conditions, the valve plate will undergo warping deformation. This model illustrates the operation of a swashplate mechanism used in helicopters to translate the input of helicopter flight control into the motion of the rotor blades, and hence controls the orientation of the rotor blades. C079, page 1 a study on the variable displacement mechanism of swash plate type compressor for automotive air conditioning system geon ho lee1, tae jin lee2 1 department of refrigeration and air conditioning, doowon. Pistons press down on the plate in sequence, forcing it to nutate around its center. The rotation of the barrel plates and the cups is synchronised with the main shaft by means of a pin and slot mechanism.
Torque ripple attenuation for an axil piston swash plate. It translates linear actuation into rotational motion that, when connected to the valve plate orifice il block, periodically connects the piston with the pump intake and discharge. Dynamic behavior of a variable stroke swash plate mechanism is analytically and numerically investigated. Micheli also gave a complete description of swashplate drive kinematics 2. The swash plate block is a model of a swash plate mechanism used in axialpiston hydraulic pumps and motors to convert translational motion of a piston into rotational motion of a drive shaft. Servos and swash plate, understanding rc helicopters lesson. Lownoise the unique, compact and rigid housing construction in addition to the semicylindrical pillow type swash plate and its antivibration supporting mechanism has significantly reduced noise levels.
It had five or seven cylinders and a variable compression ratio, altered by changing the wobbleplate angle and hence the length of piston stroke. Using transformation matrices to describe each joint. The cl327 guardianis currently under production by bombardier servicesdefence, and isconsidered the worlds most versatile and advanced vtol. Volume 27, issues 1112, august 2007, pages 18681875. The compressor under investigation had six cylinders and capacity regulation was made by changing the swash. The swash plate and slipper pad designs are both axial cylinder pumps. A minimum flow return line filter of 10 micron nominal should be utilized to prevent contaminant. A swash plate mechanism, for coverting linear motion into notary motion and vice versa is disclosed, which overcomes the main difficulties with older arrangements of swash plate drives.