# Hydrolics, Forces and flow rate.

#### GuitarWill88

Hi, I'm currently trying to work out the forces involved in raising a traffic barrier.

It works using hydrolics.

It has a motor that has a speed of 1400 rpm and 1/3 hp. the torque of the motor is 200Nm

the pump is a lobe pump and has a delivery of 1.5 l/min.

The pump will move the hydrolic oil through a hose 50mm2 and then into a piston of 1320mm2

I need to work out the force that the pump/ motor is exerting on the fluid. However i am not sure how i can do this only using the mass flow rate.

If anyone can tell me if this can be done/ how to do it would be great. If there is any additional information needed to solve this problem i can probably provide it.,

Thank, Will.

Related Mechanical Engineering News on Phys.org

#### nucleus

By traffic barrier do you mean one of those arms that drop down by railway lines? They have a counterweight opposite the arm that basically cancels the weight of arm so you don’t have to lift very much. For the hydraulics you must decide how fast you want it to operate as well as the force needed. Here are some formulas to get you started:
http://www.hydraulic-systems.com/pages/ref_formulas.htm

#### GuitarWill88

Thanks, those formulas have been quite useful.

By parking barrier i meant the type of barrier use in car parks to let you in/ out. The are usually powered using an electric motor or a hydrolic pump. The is no counter balance

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving