Average operating pressure for the pump a circuit

Assignment Help Physics

Reference no: EM131810837

Question: Design a circuit with correct contamination control for the machine in Problem.

Pump A Circuit Variable displacement axial piston pump Axial piston motor Operating pressure (average) 1600 psi Circuit is used to propel the machine in the forward and reverse directions.

Pump B Circuit Fixed displacement axial piston pump Axial piston motor Operating pressure (average) 3600 psi

The Pump B circuit is used to power a rotary mechanism that turns in one direction. Petroleum oil is the fluid for the system, and both pumps pull fluid from the same reservoir. The temperature control ensures that the fluid temperature does not exceed 140°F. The machine will not be operated where cold starts are required, and it will not be subjected to dynamic maneuvers where high shocks are required. 1. Select the cleanliness code required for both circuits.

2. Draw circuit diagrams for both circuits showing the completed circuit with filters in place.

Problem: A mobile machine has two hydrostatic transmissions. One hydrostatic transmission propels the machine, and the other transmission powers a rotary mechanism on the machine. A diesel engine drives a twin pump mount at 2000 rpm. Pump A (propel transmission) is mounted on the right side of the pump mount, and Pump B (rotary mechanism transmission) is mounted on the left side. These transmissions are specified as follows:

Pump A: Variable displacement pump 4.57 in3/rev maximum displacement Fixed displacement motor 4.57 in3/rev displacement Charge pump displacement 1.03 in3/rev Charge pump relief 350 psi Case pressure 40 psi

Pump B: Fixed displacement pump 2.56 in3/rev displacement Fixed displacement motor 2.56 in3/rev displacement Charge pump displacement 0.86 in3/rev Charge pump relief 290 psi Case pressure 40 psi

Average operating pressure for the Pump A circuit is estimated to be 1600 psi. Pump and motor overall efficiencies are estimated to be 93.5%, and volumetric efficiencies are estimated to be 97.5%. The pump will operate most of the time at 75% of maximum displacement. Average operating pressure for the Pump B circuit is estimated to be 3600 psi. Pump and motor overall efficiencies are estimated to be 92% and volumetric efficiencies are estimated to be 95.5%. Maximum ambient temperature is 95°F, and we must design for a maximum fluid temperature of 140°F. You may use the following assumptions:

1. The overall heat transfer coefficient for all heat transfer surfaces is U = 30 Btu/h⋅ft2⋅F.

2. 25% of the total heat generated is dissipated from the surface of the lines and components:

a. Calculate total heat generated by the two hydrostatic transmissions.

b. Design the reservoir with a capacity equal to four times the total reservoir flow (both circuits). You may use any shape you like. Calculate the total heat dissipated by the system (qsys) and reservoir (qres). If additional heat exchange is needed, write the specifications for a finned-tube oil cooler for the machine.

Reference no: EM131810837

Questions Cloud

How much will you have at the end of four years : If the account pays 4.00 percent annually, how much will you have at the end of four years

Taking the general inflation rate into account : Similarly, compute the after-tax rate of return for the owner, after taking the general inflation rate into account, assuming he sells the property 59 months

Calculate the gross margin return on inventory : Delroi, Inc. provided the following data for 2008 and 2009: Calculate the gross margin return on inventory investment for 2008 and 2009

Sandoval maintains an ending finished goods inventory : Sandoval has been following this inventory policy for several years

Average operating pressure for the pump a circuit : Average operating pressure for the Pump A circuit is estimated to be 1600 psi. Pump and motor overall efficiencies are estimated to be 93.5%.

Minimum attractive rate of return : The minimum attractive rate of return (MARR) is 7%. Use rate of return analysis to determine which alternative is preferable

Find the equivalent annual cost after taxes : Assume the real MARR is 8%, and the inflation rate is 5%. Find the equivalent annual cost after taxes. Does inflation increase or decrease the annual cost?

Annual loss of population and property values : Ruralville is suffering a 1% annual loss of population and property values. Even so, Ruralville must maintain its tax collections at a constant value

Record the issuance of bonds and warrants : Mickey Corp. issued 3,000 $1000 bonds at 105. Use the proportionate method to record the issuance of bonds and warrants

User Account

All Pages