Hydraulic cycle Essay

Introduction: The design project, time restraints forced the Chinless Challenge team to design and build their competition bicycles without acquiring a good understanding of the dynamic nature of the system. It usually includes the quality, cost, and performance of the existing technologies. It Is desired that a human powered vehicle be designed that does not utilize a direct chain and sprocket system. Replacing this power train with a hydraulic one presents various problems. These Include reduced efficiency, pedal and pump rotational speed discrepancies, and increased overall weight.

In order to offset the drawbacks of efficiency loss, the team added value to the design by creatively using hydraulic components In various Requirement For Hydraulic Cycle Hydraulic Pump Hydraulic Gear Motor Hydraulic Fluid Hydraulic Hose Tank Frame Seat Wheels Tires Tire Tubes Disc Brakes Smooth Elbow Hydraulic Flutings Flow Control Valve Check Valve Accumulator Function Of The Parts Accumulator The accumulator Is the sole energy storage device In the system and Is sizes and energy storage capacities. The energy storage is determined by the accumulator’s maximum internal pressure.

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On long rides, the added weight of an accumulator is a hindrance. Gear System : The gearing system can either use a gear set, a chain and sprocket, or a combination of these systems. The gear system depends greatly on the type of pump and motor used. These systems must efficiently transfer rotational energy to the pump. The gear system must also be able to withstand the stresses associated with the power delivery Pump and Motors – The pump choice is a crucial decision for the design of the rest of the bicycle. Pumps can be classified as non-positive displacement, fixed displacement, and variable displacement.

The optimal operating speed of the pump will greatly affect the gearing system design. Higher optimal operating speeds translate into higher gear ratios. Gear System – The gearing system can either use a gear set, a chain and sprocket, or with the power delivery. Pipe Fittings, Valves, and Tubing – These pieces should allow for flexible design around the bicycle frame. Also, they must withstand the thermal, fatigue, and pressure stresses from the system. Low friction coefficients that allow good fluid flow are crucial.

The system was designed to avoid any type of leaks. Working Fluid : Hydraulic fluid is nearly incompressible and is used to transfer energy through the system. The fluid has good lubricity, low volatility, moderately low viscosity, and is incompressible. Valves : Valves control the fluid flow within the hydraulic circuit. Flow restricts, directional flow controls, and shutoff valves can be used. Frame : The frame is primarily composed of hollow steel tubing, which supports the other components and systems. All Junctions in the tubing are Joined using DIG welding.

The frame takes advantage of the excellent ductile properties of steel; it can elastically deform to absorb vibrations while riding. Through. The high pressure hoses are steel braided and have high strength. The fittings serve as Junctions between the hoses, pumps and the accumulator. Fixed Displacement Pump: The upright bike features an axially piston pump. The fluid in the recumbent bike’s hydraulic system is driven by a fixed displacement gear- rotor pump. Variable-Displacement Pump A hydraulic pump that can be adjusted to increase or decreases the amount of liquid that is moved in one pump cycle.

In this pump, pumping-chamber sizes can be changed. The GEM delivery can be changed by moving the displacement control, changing the drive speed, or doing both. The pump can be used in a closed-center system-?a pump continues to operate against a load in the neutral condition. In this type, the axial reciprocating motion of the pistons is obtained by a swash plate that is either fixed or variable in its degree of angle. The cylinder block and the drive shaft in this pump are located on the same centerline.

As the piston barrel assembly rotates, the pistons rotate around the shaft, with the piston shoes in contact with and lading along the swash plate surface. The pistons are connected through shoes and a shoe plate that bears against the swash plate. Since there is no reciprocating motion when the swash plate is in vertical position, no displacement occurs. As there is an increase in the swash plate angle, the pistons move in and out of the barrel as they follow the angle of the swash plate surface. The swash plate angle can easily be controlled remotely with the help of a separate hydraulic cylinder.

The pistons move out of the cylinder barrel during one half of the cycle of rotation thereby generating n increasing volume, while during the other half of the rotating cycle, the pistons move into the cylinder barrel generating a decreasing volume. This reciprocating motion results in the drawing in and pumping out of the fluid. Pump capacity can easily be controlled by altering the swash plate angle, larger the angle, greater being the pump capacity. The outlet and the inlet ports are located in the valve plate so that the pistons pass the inlet as they are being pulled out and pass the outlet as they are being forced back in.

As the cylinder rotates, the pistons reciprocate due to he piston shoes following the angled surface of the swash plate. The outlet and the inlet ports are located in the valve plate so that the pistons pass the inlet as they are being pulled out and pass the outlet as they are being forced back in. These types of pumps can also be designed to have a variable displacement capability. In such a design, the swash plate is mounted in a movable yoke. The swash plate angle can be changed by pivoting the yoke on pointless. The positioning of the yoke can be accomplished by manual operation, servo control or a compressor control and the Gear Motor

A gear motor (external gear) consists of two gears, the driven gear (attached to the output shaft by way of a key, etc) and the Dillinger Fluid enters where the gears mesh together. High pressure oil is ported into one side of the gears, where it flows around the periphery of the gears, between the gear tips and the wall housings in which it resides, to the outlet port. The gears then mesh, not allowing the oil from the outlet side to flow back to the inlet side Both gears rotate, although only one gear is connected to the output shaft.

The gears then rotate in the direction of the arrows, as he greatest pressure drop is around the outside of the housing (if the gears rotated the other direction then they would be pushing against system pressure). Also, by putting the input port where the gears mesh together puts the effective area of 2 gear teeth against the resisting pressure acting on 1 gear tooth. The efficiency of gear motor is lower at low speeds and increases (gets better) at high speeds. Gear motors are generally very compact relative to their displacement and are able to operate at high speed. Gear motors can be operated in a reversible (bi-directional) manner.

Operation Of The Cycle Here we are using the hydraulic pump and hydraulic gear motor to drive a bicycle The hydraulic pump is connected with pedal The hydraulic pump is used to pressurized the low pressure fluid and it passes to hydraulic gear motor The gear motor is fitted to the rear wheel hub Hydraulic gear motor is used to convert the hydraulic power into mechanical power An hydraulic passage which connects hydraulic pump and hydraulic motor While peddling the hydraulic fluid gets pressurized by the pump and passed through the hydraulic passage to gear motor The gear motor consists two spur gear which rotates n opposite together.

The gears have a very close clearance with casing. One gear is driver gear and other’s is driven gear. Driven gear is connected to the output shaft. When the pressurized fluid enters into the gear motor it strikes the driver gear and makes them rotate. This rotation is followed by the driven gear and the output shaft rotate along with it. This makes the rear wheel to rotate. This is the mechanism of the hydraulic bicycle Advantages of the bicycle Shifting, through valves and displacement, provides either continuously variable rearing or more steps than traditional bicycles.

Shifts smoothly under full power. Drive transmits power while peddling forward and backward. Thus racers can power bicycle through turns by alternating short forward and backward pedal strokes. No slack or backlash occurs, in either direction. Ability to coast is maintained. Sealed systems require less maintenance than open chain system. Front-wheel drive and two-wheel drive systems can be implemented. The hydraulic (hydrostatic) transmission could be useful for recumbent bicycles because the hoses may be easier to route than a long chain.

Energy recuperation, storage and power assist could be added. Though some of the components in a sealed hydraulic system maintain constant efficiency upwards of 95% in all conditions Conclusion Based on the information collected and reviewed that the bicycle can make an new revolutionary in the environment. Therefore, the project focus was on creating a simulation model to evaluate performance in different configurations. Persons or organizations choosing to use any information associated with this project should do so at their own risk.

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