problem operating 2 geared motors at the same time with one hyd pump 1

• Apr 17, 2010

1
• #2

hydtools

Mechanical

Apr 4, 2007

3,265

US

You are using bypassing flow controls. When the shaker motor control is set to low flow excess flow from the fixed displacement pump is being dumped back to tank and little flow is avaialble for the lift motor.
When you increase the flow to the shaker motor the pressure rises also pushing more flow to the lift motor.
Where are the flow controls in the circuit? Before or after the directional valves?
You would be better off with a tandem pump. One side for the shaker and one side for the lift. Split the pump, not the flow.

Ted

 

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• Apr 17, 2010

• #3

kiran21

Mechanical

Apr 17, 2010

7

AE

It seems you have connected both the Motors in Parallel Connection through control Valve.

Parallel Connections are more efficient only when load on each motor is same. Raising the pressure on one motor cause the other one less efficient & may disrupt the speed relation. you can increase the system pressure to increase torque of highest pressure motor. How about connecting both the motors in series. speed of the motors can be controlled by bleed-off flow contol valve & torque can be adjusted by relief valves.

 

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• Apr 17, 2010

• #4

hydtools

Mechanical

Apr 4, 2007

3,265

US

Do not connect the motors in series. The motor shaft seals will not handle the pressure created by the downstream motor.
Do not manage motor torque with a relief valve. Permit the system to deliver what the motors require at the flows delivered to the motors.
Use relief valves only to protect system components.
Bleeding off flow from an upstream motor will deprive the downstream motor of flow that may be required to reach desired speed.

Ted

 

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• Apr 17, 2010

• Thread starter
• #5

ozzy3406

Mechanical

Apr 16, 2010

2

US

ted thankyou that makes sense the flowcontrols are after the spoolvalves. goes as such. from spoolvalve too in on flowcontrole then the controled flow goes to motor and from the motor back to spoolvalve the e flow on flowcontrole goes to tank. would it make any difference if i went straight to tank i wouldent think so since the return on the spool goes to tank anyways. is there anyway i can make this work or is there no way to?
kiran
these need to be independently controled the motors have two totally different loads and operate at different rpms so series is out of the question

 

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• Apr 17, 2010

• #6

hydtools

Mechanical

Apr 4, 2007

3,265

US

Change out your pump to a tandem pump, two pumps on a common drive shaft. Select each section to provide the maximum flow you want for each motor. You will have two separate motor circuits. Use separate directional valves. You can use the flow controls to control the speed of each motor.

Alternatively, you can use a rotary flow splitter between the single pump and separate directional valves. For about the same money as the rotary gear splitter you could just get a tandem pump to replace the single pump.

Ted

 

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