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11 votes
Accepted

Is there a mechanism that can turn circular motion into alternating circular motion?

What about a crank-rocker mechanism? (source: udec.cl) When I am looking for inspiration for mechanisms, I have a look in the book Mechanisms and mechanical devices, by Neil Sclater.
jos's user avatar
  • 393
5 votes

Is there a mechanism that can turn circular motion into alternating circular motion?

One solution is to use a system with a ring gear that only has teeth on half of its inner circumference, like conceptually shown in the following image: There are three gears: Ring gear (red) ...
Involute's user avatar
  • 1,327
4 votes

Calculating piston force for pneumatic vs hydraulic

The formula is valid independant of the fluid. The force in an hydraulic system is based on pressure and area - a height difference between pistons is usually small compared to the acting pressure ...
Solar Mike's user avatar
  • 15.8k
3 votes

Why do high pressure multistage air compressor have different piston diameter sizes?

There is a simple reason and a useful added benefit. As you compress air of a fixed mass it occupies less volume. If you give it more space again, it will immediatly decompress and the multiple ...
totalynotanoob's user avatar
3 votes
Accepted

Purpose of the piston ring in an engine

The piston rings perform two functions: they seal the piston tightly in the cylinder bore, so the piston can compress the inlet gases and also develop power without leakage (called blow-by) when the ...
niels nielsen's user avatar
2 votes

Design Input: Rotary motion to Linear motion, What system should I choose?

Obviously cranks and pistons have been used for hundreds of years for this. Your other option would be fast-acting motors or hydraulic rams. But a 500N (or is it 600?) force isn't what happens when ...
Tiger Guy's user avatar
  • 6,901
2 votes

Cylinder's surface condition of gas springs (gas struts)

Designed a 7 ton press cylinder for my son's project in his machining apprenticeship. The inner cylinder finish was far above what you would get with a plug draw... If you don't have a suitable ...
Solar Mike's user avatar
  • 15.8k
2 votes
Accepted

Is there any mechanical engineering solution that employs 'ankling', as per a cyclist's ankle/foot/pedal setup?

This answer covers the disadvantages, as I am unable to find any advantages. Your answer is something you've written into the question. "It uses the fewest simplest parts to enable the linear ...
fred_dot_u's user avatar
  • 7,122
1 vote

Functioning of compression rings

The pistons that i had to replace rings on in a v8 had 3 rings. Each ring was a different design based on its position AND function. The bottom or lowest ring was actually 3 pieces as it had two ...
Solar Mike's user avatar
  • 15.8k
1 vote

Different connecting rod designs for diesel vs gasoline engines?

It's for clearance. Getting the longer conrod/piston into the longer stroke cylinder and past the camshaft is the reason.
Tiger Guy's user avatar
  • 6,901
1 vote

Clarification of a piston and crank dynamics question

I don't think there is a problem. As C moves up and down the shape of triangle ABC will change and therefore θ will change too. You do seem to be missing one more measurement though. You haven't got ...
Transistor's user avatar
  • 10.8k
1 vote

Is there any mechanical engineering solution that employs 'ankling', as per a cyclist's ankle/foot/pedal setup?

Ankling is to make up for the inefficiencies of turning a crank with a device designed to walk/run. So unless you have a stupid designer who make the input power inefficient (thanks, evolution), there ...
Tiger Guy's user avatar
  • 6,901
1 vote
Accepted

Circuit to provide position control for double action hydraulic actuator

The pneumatic circuit in your question provides simple start / stop control of the piston. While the 5-port valve is opened you have full flow in either forward / reverse directions. Your control ...
jrbe228's user avatar
  • 376
1 vote

Cylinder's surface condition of gas springs (gas struts)

As I under stand you expect a one-time pressurization ,not a continuous gas supply.I then believe you will need a honed ID surface for seal to hold pressure for an extended time. Look at the surface ...
blacksmith37's user avatar
  • 6,134
1 vote

How can I make inside a LSAW pipe uniform and smooth?

In order to have an internal surface of sufficient surface finish for a piston to seal properly, the cylinder must be internally machined. Properly, it should be bored and honed. To speed up the ...
Corey's user avatar
  • 404
1 vote

Work required to push an object inside a pressurized dome by using a piston

If the pressure in the dome stays constant at 2 atm this implies there is some pressure relief mechanism so the volume is not fixed. Therefore there is no work needed to compress the air in the system ...
jko's user avatar
  • 2,347
1 vote

Design Input: Rotary motion to Linear motion, What system should I choose?

Use a screw press mechanism and reducing gearbox. Then it becomes an issue of calculating the force multiplication of the screw and gearbox mechanism to get 500 newtons. It won't be fast, but it ...
henradrie's user avatar
1 vote

Design Input: Rotary motion to Linear motion, What system should I choose?

If budget was not an issue you could design a crank / piston assembly from scratch... As it is an issue then consider re-purposing a small single cylinder engine - lawnmower or chainsaw perhaps. ...
Solar Mike's user avatar
  • 15.8k
1 vote

Real life example of motor/piston involving an isoterm process?

We assume isothermal as having to include all the heat gains and losses to the gas during the cycle would be too onerous and add little to the accuracy of the result.
Solar Mike's user avatar
  • 15.8k
1 vote

How to calculate the speed and force of the piston in a vacuum syringe?

I think you're dismissing friction far too easily. Frictionless Since you asked for it here it is: The forces on the piston are pressure (from the atmosphere on the back of the piston) and friction. ...
Rick's user avatar
  • 1,335
1 vote
Accepted

How to calculate the speed and force of the piston in a vacuum syringe?

If we ignore the friction and assume total vacuum ( both unrealistic) the force on the piston with the larger diameter increases. But it is reasonable to assume the mass of the piston increases by ...
kamran's user avatar
  • 22.4k
1 vote
Accepted

What practically is constant volume heat addition in SI piston engine?

the rate at which heat is added is so fast that the piston has no opportunity to move during the process. Furthermore, when the piston is at the top of its stroke (which is where the heat is added) ...
niels nielsen's user avatar
1 vote

how are these radial piston rotors machined

That part is likely two different parts, one of them pressed inside the other. Each part could be made in many different ways. How they were produced highly depends on what material they were made ...
DrMrstheMonarch's user avatar
1 vote

What is this part called, and where could I get one?

What is it called? Your name of "screw piston" sounds good to me. Where are you going to get one? That is harder. If that is the way you want to go, you are going to have to have it made yourself. ...
user1683793's user avatar
  • 1,020
1 vote

How Can You Calculate Force to Overcome Friction From an O-Ring Seal?

We know that friction formulas only depend on the coefficient of friction and the normal force. It does not depend the area of contact; it doesn't depend on the sliding speed. So, the crux of this is ...
monkey's user avatar
  • 196
1 vote
Accepted

Thermodynamic, ideal gas problem

The solution for this problem relies upon the fact that the process is reversible, that is every state undergone by the system is in equilibrium. Consider the initial state. Now the pressure inside ...
Pranav's user avatar
  • 349
1 vote

Can an electric motor use reciprocating pistons like an internal combustion engine does?

Every time you convert energy from one form to another, the conversion is not 100%, there is some loss. For example: electrical energy to mechanical energy (motor), chemical energy to mechanical ...
Daniel K's user avatar
  • 2,646
1 vote

Can an electric motor use reciprocating pistons like an internal combustion engine does?

Linear electric motors exist, and are used in applications where you want a linear motion. As Solar Mike said, using a linear motor to drive a crank is pointless.
Hobbes's user avatar
  • 746
1 vote

How can a car can be lifted using hydraulic press?(Pascal's Law)

The main idea of the hydraulic press is that we use a piston for which we have to apply a small force $F_1$ and small area $A_1$ to displace a specific volume of the incompressible fluid. Imagine we ...
MrYouMath's user avatar
  • 1,036

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