HYDRAULIC MACHINES VIVA QUESTIONS AND ANSWERS

What is a hydraulic machine?

Ans: A hydraulic machine is a machine that uses pressurized fluid to transmit force and energy from one place to another.

What are the components of a hydraulic system?

Ans: The components of a hydraulic system are a pump, a motor, a valve, an actuator, and a fluid.

What is a hydraulic pump?

Ans: A hydraulic pump is a mechanical device that converts mechanical power into hydraulic energy by pressurizing fluid.

What is a hydraulic motor?

Ans: A hydraulic motor is a mechanical device that converts hydraulic energy into mechanical power.

What is a hydraulic valve?

Ans: A hydraulic valve is a control element that regulates the flow of fluid in a hydraulic system.

What is an actuator?

Ans: An actuator is a hydraulic component that converts hydraulic energy into linear or rotary motion.

What is a fluid?

Ans: A fluid is a substance that flows and changes its shape to conform to its container. In hydraulic systems, fluid is typically oil or water.

What are the advantages of hydraulic systems?

Ans: The advantages of hydraulic systems include high power density, high efficiency, and low maintenance requirements.

What are the disadvantages of hydraulic systems?

Ans: The disadvantages of hydraulic systems include high cost, large size, and a tendency to leak.

What is the purpose of a hydraulic accumulator?

Ans: The purpose of a hydraulic accumulator is to store energy in a hydraulic system, so that it can be used when needed.

What is hydraulic transmission?

Ans: Hydraulic transmission refers to the transfer of power from a hydraulic pump to a hydraulic motor through pressurized fluid.

How does a hydraulic pump work?

Ans: A hydraulic pump works by pressurizing fluid in a closed system and forcing it through pipes and hoses to a hydraulic motor or actuator. The pressure generated by the pump is proportional to its speed and the displacement of its pistons or rotors.

What is the difference between a hydraulic pump and a hydraulic motor?

Ans: A hydraulic pump is a device that converts mechanical energy into hydraulic energy by pressurizing fluid, while a hydraulic motor is a device that converts hydraulic energy into mechanical energy.

What is the function of a hydraulic valve?

Ans: The function of a hydraulic valve is to control the flow of fluid in a hydraulic system. This can be achieved by blocking, redirecting, or regulating the flow of fluid.

What are the different types of hydraulic valves?

Ans: The different types of hydraulic valves include pressure control valves, flow control valves, directional control valves, and check valves.

What is a hydraulic cylinder?

Ans: A hydraulic cylinder is a hydraulic component that converts hydraulic energy into linear motion. It consists of a cylindrical casing, a piston, and a rod.

What is a hydraulic ram?

Ans: A hydraulic ram is a hydraulic component that uses the pressure of a fluid to generate linear motion. It consists of a piston and a cylinder, and works by pressurizing fluid in one chamber to create a force that moves the piston.

What is the principle of a hydraulic press?

Ans: The principle of a hydraulic press is to use the pressure of a fluid to generate a force that is proportional to the area of the pressurized fluid. This force can be used to shape or compress materials.

What is the purpose of a hydraulic accumulator?

Ans: The purpose of a hydraulic accumulator is to store energy in a hydraulic system, so that it can be used when needed. This helps to ensure that the system has sufficient energy to perform its functions, even if the source of hydraulic energy (e.g. the pump) is not available.

What is hydraulic fluid?

Ans: Hydraulic fluid is a substance that is used in hydraulic systems to transmit energy and force. It is typically a type of oil or water, and must have certain properties such as high viscosity and low compressibility in order to function effectively.

What is hydraulic oil?

Ans: Hydraulic oil is a type of fluid that is used in hydraulic systems. It is typically a mineral oil or synthetic oil, and must have certain properties such as high viscosity and low compressibility in order to function effectively.

What is the difference between hydraulic oil and hydraulic fluid?

Ans: Hydraulic oil and hydraulic fluid are often used interchangeably to refer to the substance that is used in hydraulic systems. However, hydraulic fluid is a more general term that can refer to any type of fluid used in a hydraulic system, while hydraulic oil specifically refers to a type of fluid that is commonly used in such systems.

What are the factors that affect the performance of a hydraulic system?

Ans: The factors that affect the performance of a hydraulic system include the properties of the fluid, the size and design of the components, the pressure and flow rate of the fluid, and the efficiency of the components.

What is hydraulic power?

Ans: Hydraulic power is the power that is transmitted through a hydraulic system using pressurized fluid. It is expressed in units of work per unit of time, such as watts or horsepower.

What is a hydraulic circuit?

Ans: A hydraulic circuit is a closed system of pipes, hoses, and components that is used to transmit hydraulic power. It typically includes a pump, a motor, a valve, and an actuator, as well as the fluid that is used to transmit the power.

What is a hydraulic system?

Ans: A hydraulic system is a machine that uses pressurized fluid to transmit force and energy from one place to another. It typically includes components such as a pump, a motor, a valve, and an actuator, as well as the fluid that is used to transmit the power.

What is the purpose of a hydraulic system?

Ans: The purpose of a hydraulic system is to transmit energy and force from one place to another using pressurized fluid. This can be used to perform tasks such as lifting, lowering, or moving heavy objects, as well as to provide power to a wide range of industrial and agricultural machines.

What is the advantage of using a hydraulic system over other systems?

Ans: The advantage of using a hydraulic system over other systems is that hydraulic fluid can transmit energy and force over long distances with minimal energy loss, making it ideal for use in applications where large forces or heavy loads need to be moved. Additionally, hydraulic systems are typically more efficient and reliable than mechanical or electrical systems.

What are the factors that influence the selection of hydraulic components?

Ans: The factors that influence the selection of hydraulic components include the type of hydraulic system, the size and weight of the loads that need to be moved, the pressure and flow rate requirements, the available space and power supply, and the cost and maintenance requirements.

What is the function of a hydraulic accumulator?

Ans: The function of a hydraulic accumulator is to store energy in a hydraulic system. This stored energy can then be used when needed, which helps to ensure that the system has sufficient energy to perform its functions even if the source of hydraulic energy (such as a pump) is not available.

What is the role of a hydraulic filter in a hydraulic system?

Ans: The role of a hydraulic filter in a hydraulic system is to remove contaminants from the fluid, such as dirt, rust, and other particles. This helps to ensure that the fluid is clean and free of debris, which can cause damage to the components and reduce the efficiency of the system.

What are the common causes of hydraulic system failures?

Ans: The common causes of hydraulic system failures include contamination of the fluid, wear and damage to components, incorrect sizing or selection of components, improper installation, and incorrect maintenance.

What is hydraulic shock and how can it be prevented?

Ans: Hydraulic shock is a sudden and excessive pressure surge in a hydraulic system. It can be caused by rapid changes in fluid flow or pressure, and can cause damage to the components and reduce the efficiency of the system. To prevent hydraulic shock, it is important to have proper system design, correct sizing and selection of components, and proper installation and maintenance practices.

What is cavitation in a hydraulic system?

Ans: Cavitation in a hydraulic system is the formation of vapor pockets in the fluid. This can occur when the pressure in the system drops below the vapor pressure of the fluid, and can cause damage to the components and reduce the efficiency of the system. To prevent cavitation, it is important to have proper system design and to choose a hydraulic fluid with the appropriate vapor pressure.

What is the importance of having a properly designed hydraulic system?

Ans: A properly designed hydraulic system is important because it helps to ensure that the system will perform efficiently and reliably, while also reducing the risk of failure and damage to the components. A well-designed hydraulic system takes into account factors such as the type of fluid used, the size and weight of the loads, the pressure and flow rate requirements, and the space and power supply available.

What are the types of hydraulic pumps and what are their applications?

Ans: There are several types of hydraulic pumps, including gear pumps, vane pumps, piston pumps, and screw pumps. The choice of pump will depend on the application, and factors such as the size and weight of the load, the pressure and flow rate requirements, and the available space and power supply.

What is the difference between open-center and closed-center hydraulic systems?

Ans: Open-center hydraulic systems are systems where the pump does not generate any pressure when the actuator is not in use, while closed-center hydraulic systems are systems where the pump generates pressure even when the actuator is not in use. The choice of open-center or closed-center hydraulic system will depend on the specific application and the requirements for pressure control.

What are the components of a hydraulic system and what are their functions?

Ans: The components of a hydraulic system typically include a pump, a motor, a valve, an actuator, and the fluid used to transmit energy and force. The pump is used to pressurize the fluid, the motor is used to convert hydraulic energy into mechanical energy, the valve is used to control the flow of fluid, the actuator is used to convert hydraulic energy into linear or rotary motion, and the fluid is used to transmit energy and force throughout the system.

What is the difference between a hydraulic motor and a hydraulic pump?

Ans: A hydraulic motor is a component that converts hydraulic energy into mechanical energy, while a hydraulic pump is a component that pressurizes the fluid in a hydraulic system. In other words, a hydraulic motor takes in fluid at a given pressure and converts it into rotary motion, while a hydraulic pump takes in fluid at low pressure and increases the pressure to a higher level.

What is the importance of proper maintenance in a hydraulic system?

Ans: Proper maintenance is important in a hydraulic system because it helps to ensure that the system continues to perform efficiently and reliably. This includes tasks such as regularly checking and replacing the fluid, cleaning and checking the components for wear or damage, and making any necessary repairs or replacements. Regular maintenance can also help to extend the lifespan of the components and reduce the risk of system failures.

What are the common causes of failure in hydraulic systems?

Ans: Some common causes of failure in hydraulic systems include leaks or cracks in the components, incorrect fluid viscosity, air in the fluid, incorrect installation or connection of components, incorrect pressure settings, and contamination of the fluid.

How does fluid contamination affect the performance of a hydraulic system?

Ans: Fluid contamination can have a significant impact on the performance of a hydraulic system. Contaminants such as water, dirt, and other impurities can cause corrosion, wear, and damage to the components, reduce the efficiency of the system, and increase the risk of system failures. To minimize the impact of fluid contamination, it is important to regularly check the fluid for impurities and replace it as needed.

How can you improve the efficiency of a hydraulic system?

Ans: To improve the efficiency of a hydraulic system, you can consider several factors, including selecting the right components, reducing fluid leaks and wastage, using high-quality fluid, reducing pressure drop in the system, and optimizing the size and design of the components.

What is the role of fluid in a hydraulic system?

Ans: Fluid plays a crucial role in a hydraulic system as it is responsible for transmitting energy and force throughout the system. The fluid used in a hydraulic system must have the appropriate properties, such as viscosity, to ensure that it performs efficiently and reliably.

What is cavitation and how does it affect hydraulic systems?

Ans: Cavitation is a phenomenon that occurs when the pressure in a hydraulic system drops below the vapor pressure of the fluid, causing bubbles to form and collapse. Cavitation can cause damage to the components, reduce the efficiency of the system, and increase the risk of system failures. To minimize the impact of cavitation, it is important to design the system to maintain a minimum pressure and to avoid sharp pressure drops.

What are the safety precautions that should be taken when working with hydraulic systems?

Ans: Some safety precautions that should be taken when working with hydraulic systems include wearing protective equipment, such as gloves and safety glasses, to protect against fluid exposure and injuries, following the manufacturer's instructions and guidelines, avoiding overloading the system, and being aware of the hazards associated with high pressure fluids.

What is the difference between a hydraulic cylinder and a hydraulic motor?

Ans: A hydraulic cylinder is an actuator that converts hydraulic energy into linear motion, while a hydraulic motor is an actuator that converts hydraulic energy into rotary motion. In other words, a hydraulic cylinder is used to generate linear force and motion, while a hydraulic motor is used to generate rotary force and motion.

What is the importance of using the correct fluid in a hydraulic system?

Ans: The correct fluid is important in a hydraulic system because it plays a crucial role in transmitting energy and force throughout the system. The fluid must have the appropriate properties, such as viscosity, to ensure that it performs efficiently and reliably. Using the incorrect fluid can cause damage to the components, reduce the efficiency of the system, and increase the risk of system failures.

What is the difference between a hydraulic pump and a hydraulic motor?

Ans: A hydraulic pump is a component that pressurizes the fluid in a hydraulic system, while a hydraulic motor is a component that converts hydraulic energy into mechanical energy. In other words, a hydraulic pump takes in fluid at low pressure and increases the pressure to a higher level, while a hydraulic motor takes in fluid at a given pressure and converts it into rotary motion.

What are the advantages of using hydraulic systems over mechanical systems?

Ans: Some advantages of using hydraulic systems over mechanical systems include increased efficiency, improved precision, reduced maintenance requirements, and increased safety. Hydraulic systems can also handle higher loads and generate greater forces compared to mechanical systems, making them ideal for heavy-duty applications.