Hydraulic Motors

[Carl Wilson 4Participant @carlwilson4]

Hello,

In the middle of a thought experiment that might lead to my building an hydraulic motor.

Seem to remember a few years back seeing an article in either ME or EiM in which the author described construction of petrol/hydraulic loco. Think bent axis hydraulic motors had been made. Can anyone shed any light on this?

Thanks,

Carl.

[Carl Wilson 4Participant @carlwilson4]

[Ady1Participant @ady1]

Put "petrol hydraulic" into the searchbox

Linky

There's a few returns with ME numbers

5"g.petrol-hydraulic by Mr Faulkes

petrol-hydraulic locomotive by C.Faulkes

Mr Smith's petrol hydraulic locomotive

G.T.Harris' 5"g. petrol/hydraulic loco

etc

[Ady1Participant @ady1]

"Oilie", J.Harlow's petrol-hydraulic, issue 3526 page 1171

and Oily is about right

If you do take this route be prepared for a messy system which drips oily pollution everywhere

The only hydraulic systems I've ever come across which didn't spew oil out all over the place are car jacks and fully enclosed automatic transmissions

(I worked with hyd. pumps and cranes at sea. Bottom line is if it needs any pipes then it's going to get messy and smelly)

Edited By Ady1 on 05/09/2013 06:40:07

[Hi Speed ScrapParticipant @hispeedscrap]

Hi Carl,

something like this may interest you, google, varspe.com, and

download brochure.

I made a few tiny ones similiar to these many years ago, they worked

very well. (no connection to this company)

Dave.

[Carl Wilson 4Participant @carlwilson4]

Hello,

Thanks for all your contributions. I've also worked with hydraulics over many years both in aviation and marine settings.

I'm looking at the feasibility of either trying to produce a gerotor type motor or a radial piston type. The gerotor would probably not be a true gerotor motor but rather an internal gear type motor. Similar to the more familiar external gear pump/motor but with an internal ring gear and smaller planet gear. A crescent shaped lobe seals the intake and outlet areas between the two gears. I'm trying to source some internal gear rings as I think it'll be easier to buy these than to make them. Anyone know of a source?

The radial piston idea could be like a "Staffa" motor. A number of radially mounted fixed pistons would bear against an eccentric on the output shaft. As each piston extends the shaft rotates.

Thanks again for all your help.

Carl.

[ChrisLHParticipant @chrislh]

Hello Carl,

Just noticed your enquiry and thought you may be thinking of Roy Amsbury's articles in Model Engineer some while back. He had a go at a 5 inch gauge Hymek locomotive and started of with a hydrostatic type transmission. This didn't work out in the end despite heroic efforts on Roy's part and he finished up with a mechanical transmission. It's all described in MEs for 17/06/88, 15/07/88, 19/08/88, 16/09/88, 21/10/88 and 18/11/88. Even if inapplicable or too late it's an interesting read.

Chris

[Brian WoodParticipant @brianwood45127]

Hello Carl,

I'm rubbish at adding links, they never seem to work for me, but internal ring gears are available from HPC Gears at Chesterfield Derbyshire

http://www.hpc-gears.co.uk phone 01246 268080 email sales@hpc-gears.co.uk

You may not like the price

Regards

Brian

Edited By Brian Wood on 09/11/2014 18:55:17

[Gordon WParticipant @gordonw]

I don't really understand what you are trying to do, build a motor and pump from scratch? If not there are a lot of small motors out there. Some garden tractors had all hydraulic drive, flail cutters, golf carts etc. May be worth a look.

[V8EngParticipant @v8eng]

I know next to nothing about Hydraulics but for many years motor vehicles have been fitted with compact hydraulics for power steering etc.

Some (I'm told) have battery powered pumps, it might be an idea to check if there are any scrappies in your area to have a friendly chat with.

Edited By V8Eng on 10/11/2014 10:56:22

[Carl Wilson 4Participant @carlwilson4]

Thank you for your replies and help gents. As you can see this post is a year old now. It was originally a thought experiment. What I was trying to do was to distract myself and get some respite from the most traumatising and tragic event that has ever happened to me, and which has left me utterly bereft.

No need to worry, I have all the info I need if I ever decide to go anywhere with it.

Thanks again.

Carl.

[MuzzerParticipant @muzzer]

There are quite a few cars nowadays with electrohydraulic power steering (EHPS), such as the BMW Mini and several Fords from memory. However, you won't find any hydrostatic motors in them, only the constant flow pump, control valve and rack (which contains the actuator piston). Even the smallest cars are going to have pretty large motors in them (about 1kW or so). I can't think of a smaller, commonplace application using hydraulics but they must surely exist.

Having worked with all of the major golf cart manufacturers, I can tell you that they all use electric drive (no hydraulics). Aerial work platforms, electric pallet trucks and small fork lifts might be a good place to look.

Murray

[Mark P.Participant @markp]

They have them on airliners known as HMG. hydraulic motor generator powered from the aircrafts main hydraulic system,used if the engine driven generators fail.

Mark P.

[Les Jones 1Participant @lesjones1]

Citroen cars with hydropneumatic suspension have an electriclly driven hydraulic pump that is used to raise the suspension to give different ride heights and suspension levelling.They normally only run for a short time so they may overheat if run continuously.

Les.

[Carl Wilson 4Participant @carlwilson4]

If I was going to do it I'd probably use something like a Danfoss OMM series motor. But I'm not so no worries.

[Ian S CParticipant @iansc]

Some ride on mowers use Hydraulic motors for the main drive (either 2 or 4 wheel drive) and one for each cutter, the one I'm thinking of has 3, It is powered by a 3 cylinder Komasu diesel, a lovely little motor, quite quiet.

Some of the machines we built for feeding out bails of hay were powered by a hydraulic motor from the tractor hydraulic system, the motor we used was about 4" dia x 5" long. This system replaced the wheel driven method used on most of our machines. Both systems have plenty of power, with 2 heavy bails on the deck they could weigh nearly 2 tons. Ian S C This is a hydraulic drive machine with an extra long deck to carry 3 bails of hay. Plenty of power in a motor that size for a small loco, and no leaks.

[Carl Wilson 4Participant @carlwilson4]

Gents,

If I was going to do this then I would probably use something as shown in the photographs below. This is also a good example of the type of thing I have to deal with on a regular basis. You are looking at a subsea ROV operated milling machine with hydraulic motor drive to the leadscrews for the XYZ axis and the spindle. This machine is designed for a specific task in the process of removing old spool pieces from a subsea vertical riser. So I'll be doing some milling at 1300 metres. There'll be a plentiful supply of coolant.

This shows an OML series Danfoss motor driving one of the leadscrews. Other pictures show the same motors driving other leadscrews on the unit.

The gearbox and hydraulic drive to the cutter.

[Chris Gibson 1Participant @chrisgibson1]

I would like to build a small, radio controlled model (say 20th of full size) of a JCB with backhoe. I am trying to find details/drawings/information of cylinders, pistons and hydraulic pumps at suitable size. Can anybody suggest sources of books or drawings please?

[Neil WyattModerator @neilwyatt]

Hello Chris,

Glad you were able to find us!

neil

[Author]

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