Axial piston variable pump. A10VSO series All-purpose medium pressure pump; Size 18 ; Nominal pressure bar; Maximum pressure bar. Axial Piston Variable Pump. A10VSO. Data sheet. Series Sizes 18 to Nominal pressure bar. Maximum pressure bar. Open circuit. Features. Sizes 18 to ▷ Nominal pressure bar. ▷ Maximum pressure bar. ▷ Open circuit. Axial piston variable pump. A10VSO Series RE
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Thank you for helping keep Eng-Tips Forums free z10vso inappropriate posts. The Eng-Tips staff will check this out and take appropriate action. Click Here to join Eng-Tips and talk with other members!
Join your peers on the Internet’s largest technical engineering professional community. It’s easy to join and it’s free. Register now while it’s still free! Close this window and log in. Are you an Engineering professional? By joining you are opting in to receive e-mail. Promoting, selling, recruiting, coursework and thesis posting is forbidden. I am maintaining a hydraulic press which is having a piston of mm. It works up to bars and creates a maximum force of Tons. It is coupled with a 35 HP electric motor.
Please find attached images of the pump and also the schematic of the hydraulic circuit. By looking at the schematic, it suggests the pump to be a power control pump i. But physically see the image attached it is NOT a power control pump. Practically, power control is taking place in the circuit – otherwise a pump delivering lpm of oil cannot go up to a pressure of bars with a 35 HP Motor.
My question is how power control is taking place in the circuit? Again, my question is how is it happening? If the flow is dynamically controlled, then power control can be achieved.
But, in this circuit, how is flow being dynamically reduced with the rise is pressure so as to achieve power control. Please help me out. It’s a load sensing pump and it senses the pressure difference across the, what looks to be, the 6. The one just to the right of the pressure cut off and LS compensators on the drawing. The proportional pressure relief valve Item 2 opens at the set pressure. When opening, the flow across the orifice increases, the pressure drop goes up, the LS compensator responds to the difference.
At this point, the pump will back off or increase its displacement to maintain the pressure drop over the orifice. In this respect, the pumps is dynamically controlling flow, against changing pressure, to give constant power control. Hello, You are right, the proportional valve 2 thus limits the maximum pressure force up to tons.
For me two solutions: The pressure relief valve designed on the pump rate decrease piston is it not a representation of a power control?
Bosch Rexroth Axial Piston Variable Pumps Type A10VSO series 31
It is not uncommon on a press or shears we spend 2 times the rated power of the electric motor for a short time. The pump part number and controller matches what is shown on the drawing.
The press manufacturer has simply adapted the control to make it more efficient and to allow a smaller motor. Is there a problem with the current operation or are you just trying to understand what’s happening? Please find document below pup Thanks for the replies friends. The pumps name plate says DRS. That means it is a flow control model with X to T line plugged.
Now as Adrian says, the manufacturer a10vwo adapted the control to a10vsl like a power control. This is what I am not quite clear. Power will be automatically controlled if we can control the flow dynamically. In a DRS control, the pumps entire flow passes through a variable oump which creates a pressure drop. When this happens, the flow controller shifts and gives oil to the back of the yoke piston. This in turn reduces the flow of the pump.
As a result the pressure drop pkmp also reduced. This keeps on happening the flow gets reduced until the pressure drop is equal to the spring setting of the DRS control.
The spring of the controller now again tries to increase the flow but the resultant pressure drop again reduces the flow. The spool modulates to maintain the flow at a required level, say 65 lpm. This is how flow control takes place in a DRS control. Correct me if I am wrong here Adrian. The actuator will move with different speeds. Now can you explain me just as I did in the DRS control how this is happening with a proportional relief valve.
How does the pump maintains is flow level. Waiting for your valuable suggestions please. Look at the orifice You can see that the pump load sense compensator is looking at pressures on either side of the orifice. When you first start the pump, the pressure at the outlet is what the load sense compensator is set to. The strategy of the pump controller is to always a10fso that pressure. It is usually around – kPa. The delta pressure at the compensator will be the same as a10vdo pressure drop across the orifice.
By opening the proportional valve, the flow rate at a particular pressure can be set. Remember that the pump a10vxo always trying to maintain the pressure drop across the orifice. In this case, rather than having a variable orifice, the flow is being varied instead. The result is the same, the pressure a1vso. So, in order maintain the pressure drop, the pump will increase or decrease the flow rate. This is done by supplying oil to the servo piston.
The pump a10bso the swash plate until it gets the pressure drop it needs.
The name plate on the pump is correct, it’s a DRS controller. The only difference is as I say, there is not variable orifice. To change the pressure drop, the proportional valve opens to change flow and pump responds accordingly to maintain flow. The flow from the pump is directed to the actuators, but the pump control remains independent of the load at the actuators.
In this way, you are able to maintain power control independent of load. It’s an elegant solution, it works and the pump name plate is correct. You’ll agree once you understand how a load sensing pump works. Just remember, the control strategy of the pump is to maintain the pressure drop across the orifice. If the proportional valve moves to change the pressure As always, if it’s not clear I am like simram, I do not understand the explanation.
Could you give us the signal values proportional pressure relief valve according to the desired flow rate at the pump?
I cannot give any values for command signals etc I can only explain the principle of operation with information available at this time. If we can confirm the diameter of the orifice, we can calculate the pressure drop when the pump is at full stroke, then start to look at what flow area would be needed through the proportional valve.
It would also help to know the stand by pressure of the pump Adrian. It’s a power limiting pump with a load sense compensator. However the LS compensator is only being used to enable the proportional relief valve to adjust the cut-off maximum pressure. The 1mm not 6. The power limiting is achieved with the pilot relief valve closest to the pump.
As the control piston extends to de-stroke the pump it also increases the pressure setting of this pilot relief usually a dual spring arrangement to approximate to a hyperbolic constant power curve. So with a reduced flow the pump is allowed to go to a higher pressure thus keeping within the power limit. The initial setting of this pilot relief thus determines the power limit and the setting of the proportional relief sets the normal cut-off pressure. The ultimate cut-off pressure can still be adjusted manually by means of the pressure limiting compensator spool the left hand one.
Thanks a lot for he replies. Sorry for such a late reply – just joined work again — was hospitalised. I agree with your explanation.
A10V(S)O variable piston pump – Rexroth
You said “It’s an elegant solution, it works and the pump name plate is correct. You’ll agree once you understand how a load sensing pump works”.
I found a document of Parker, explaining the same load sense control in each stage. Am sharing the pdf file pum.