Sound Level Reducing Elements in Hydraulic Systems
Sound Level Reducing Elements in Hydraulic Systems
SOUND LEVEL REDUCING FACTORS IN HYDRAULIC SYSTEMS
With large surfaces and thin metal walls, oil tanks transmit sound well. It is possible to isolate the sound generated in the tank by using vibration damping materials.
The methods used in insulation are as follows;
- Placing the pump on a non-vibrating element,
-Using the pump with a vibration damping element,
- Use of rubber pipe rings (grommet),
-Installation of pipelines with fixing clamps with sound damper
- Vibrations in fluids are mainly caused by pressure pulses and a hydraulic battery that receives pressure pulses is usually used in the insulation.
Elements used to dampen vibrations and reduce sound;
1-VIBRATION DISTINCTION PUMP CARRIERS
The elastic pump carrier is used to connect the hydraulic pump and drive motor to each other so as to substantially prevent transmission of element vibrations and oscillations. The pump vibrations are sealed and damped by a rubber ring that transmits the force and is temperature and fluid resistant. By using a rotating elastic coupling, the metal connection between the pump and the motor is removed. This reduces the sound level of the hydraulic system considerably. (Figure 1.)
The level achieved in reducing the volume depends on many factors. (type of pump, working pressure, piping, design vs .vs) It is therefore not possible to obtain exact values. The damping material used in the pump carrier must be suitable for different motor-pump combinations. The main body (1) together with the connecting flange form a fixed unit connected to the pump flange (4) by a rubber ring (3) and holding ring (2). The shore hardness value and quality of the rubber ring are compatible with the pump type, drive power and fluid. (Figure 2)
2- VIBRATION ABSORBER AND PUMP CARRIER WITH OIL - AIR COOLER
In this model, the fluid returned from the system is cooled in the oil - air cooler. The air flow required for cooling is obtained by a fan connected to the shaft of the motor. (Figure 1.) Vibration damping The combination of pump carrier and oil-air cooler means simplicity and low cost in hydraulic power units. The heat exchanger pump is placed on the outside of the carrier so that it is easy to clean. The air distribution is designed so that the pump carrier can be mounted vertically or horizontally in the tank. According to the shape of the device, cooling power is limited to 1.8 kw. The leak oil in the system is cooled in many applications. In addition, the heat generated in systems operating for long periods or on hot summer days can be compensated.
Basic properties of oil-air coolers;
- Low installation cost
- Low operating cost
- Easy maintenance
- Fan driven by main drive motor
The main body (1) together with the connecting flange forms a fixed unit connected to the pump flange (4) by a rubber ring (3) and holding ring (2). (Figure 3.) The shore hardness value and quality of the rubber ring should be selected in accordance with pump type, drive power and fluid. The cooling elements (5) and the air supply housing are mounted in the main body and are designed to simplify assembly of the pump assembly. The fan (6) is connected to the motor shaft.
3- PIPE, HOSE AND CABLE CLAMPS
Shock absorber and vibration damping fasteners ensure fast, clean, tidy and aesthetic connection of pipes. Figure (4) These fasteners are used in the following connections.
- Main system piping
- Additional system (leak line, pilot line, pneumatic system line, etc.)
- In hoses
- Electrical installation
The fasteners shall have the following characteristics;
- Secure clamps, pipes or hoses (static and dynamic load)
- Vibration damping
- Sound insulation
- Shock absorption
- Length compensation due to temperature change in pipes
Particular attention should be paid not to press the hoses in sharp corners. The lines must be secured using clamps so that they do not bend. The vibration and sound insulation characteristics of the fasteners are extremely important in order to prevent the vibration of the elements from spreading to the whole system. The diameters of the pipes and hoses used determine the dimensions of the fasteners. In addition to the dynamic load, the internal pressure of the pipe determines the series of the fastening element. (light or heavy series) (Figure 5.)
4- HYDRAULIC ACCUMULATORS
The main task of a hydraulic accumulator is to take a certain amount of fluid from the pressurized hydraulic system and store it for return to the system when necessary.
Accumulators are used in hydraulic systems in different ways, for example;
- Energy storage
- Fluid storage
- Emergency applications
- Balancing of forces
- Absorption of mechanical shocks
- Absorption of pressure shocks
- Coverage of oil leaks
- Vibration damping
- Shock damping
- Vehicle suspension
- Sound insulation
5- HYDRAULIC OIL TANK DESIGN
Hydraulic oil tank design is very important for sound insulation and healthy operation of hydraulic systems.
When designing the hydraulic oil tank, considering the working conditions of the hydraulic system, an oil tank with a size of at least 5 times the hydraulic pump flow rate should be selected. ventilation caps must be installed to relieve air pressure.
6- SELECTION OF HYDRAULIC FITTINGS
There are many kinds of connection elements used in hydraulic systems and they have different sizes. When designing a new system, in order to ensure the quiet operation of the hydraulic system, to ensure the long life of the selected hydraulic elements and to use the performance of the hydraulic system efficiently, the design of the hydraulic system should be made considering the operating flow rate, working pressure and operating temperature of the hydraulic system, and the necessary parts should be selected unnecessarily. elbow use should be avoided.
POINTS TO BE CONSIDERED IN PIPE AND HOSE CONNECTION:
- Different pipe diameters should not be used in hydraulic systems.
- In corners used in hydraulic systems, sharp corners should be avoided.
- Excessively long and unnecessary pipes or hose lines should be avoided.
-To prevent vibration and cavitation in the system, the pipes should be fixed at regular intervals with the help of clamps.
- The suction pipe must be short.
- The return pipe must be short.
- Hose should be used in moving and vibrating places.
- Thermal expansion of pipe connections must be taken into account.
- Pipe diameters should be sufficient to provide desired flow and pressure.
- Pipe wall thickness and hose type must be selected to meet the operating pressure.
- Pipe and hose connections must be sealed.
- Pipe inner surfaces should be smooth.
- The innermost layer of the hose must be resistant to the fluid used in the system.