Hydraulic motor mounting standards for gearboxes
Hydraulic motor mounting standards for gearboxes
(OP)
I am considering designing a system that uses a hydraulic motor mounted to a gear box. This is outside of my normal experience, so perhaps I am doing something that is not viable, or simply not normally done this way. I have found a hydraulic motor with the low speed, and high torque that I need, but I am looking for cheaper options. A smaller hydraulic motor with a gearbox would seem to be one.
I know about the NEMA electric motor mount standards, and of course, most gear boxes are used with electric motors. However, the few hydraulic motors I have looked at do not seem to match any standard NEMA specs. I have asked a couple of dealers and they didn't know the answer, saying only that they have never seen a hydraulic motor mated with a gearbox.
Is there a standard I should look for when trying to mate a hydraulic motor and a gearbox? Of course, I would prefer not to have to make an adapter.
Thanks for any recommendations,
-Joe
I know about the NEMA electric motor mount standards, and of course, most gear boxes are used with electric motors. However, the few hydraulic motors I have looked at do not seem to match any standard NEMA specs. I have asked a couple of dealers and they didn't know the answer, saying only that they have never seen a hydraulic motor mated with a gearbox.
Is there a standard I should look for when trying to mate a hydraulic motor and a gearbox? Of course, I would prefer not to have to make an adapter.
Thanks for any recommendations,
-Joe





RE: Hydraulic motor mounting standards for gearboxes
Ted
RE: Hydraulic motor mounting standards for gearboxes
David
RE: Hydraulic motor mounting standards for gearboxes
The device will be attached to a forklift, and rotation will be controlled by the operator using the hydraulic valve on his forklift. I actually want a fair amount of play in the positioning. I will add some item to the gripper assembly to insure at least a few degrees of movement, so that when the panel is put in place, the operator does not have to be as accurate.
Since this device will only be used a few days out of a month, I suspect maintenance will not be an issue.
Thank you all for the very valuable comments.
-Joe
RE: Hydraulic motor mounting standards for gearboxes
-Joe
RE: Hydraulic motor mounting standards for gearboxes
We have done hydraulic motors attached to our gearboxes using NEMA C-face in the smaller sizes (1/2hp - 2?hp) NEMA 56TC for example.
David
Where did you get your hydraulic motor? Did the manufacturer specify the NEMA C-face type, or did you just deduce by looking a the dimensions for the motor.
-Joe
RE: Hydraulic motor mounting standards for gearboxes
A quick skim over Parker, Eaton, and White Industries suggests that SAE mounts are a popular option. The shafts are larger diameter than the 5/8" of a 56C NEMA, and the pilots are a little smaller than the 4.5" of a 56C NEMA, but it seems like a straightforward custom.
David
RE: Hydraulic motor mounting standards for gearboxes
RE: Hydraulic motor mounting standards for gearboxes
Ted
RE: Hydraulic motor mounting standards for gearboxes
Regardless, you will get better efficiency by driving a larger flow hydraulic pump at lower speed directly off the electric motor, than you will by driving a lower flow hydraulic pump thru a gearbox and motor at higher speed. And the small flow, high-speed pump and gearbox combination will also cost more.
RE: Hydraulic motor mounting standards for gearboxes
I was investigating if I could get a lower overall cost, since the hydraulic motor with the specs I needed, especially the overhung load, was around $5,000. My actual torque needs are rather small, in terms of what hydraulic motors can handle. But, the overhung load was the issue. Also, since the item I am grabbing with my mechanism is rather long, I don't want to rotate it very fast. So if I use a small hydraulic motor with a gearbox, that would easily meet my needs. But, finding a gearbox that can handle my overhung load is not that cheap either.
The main motivation is seeing if there is a cost savings while, still keeping the power train simple. So far it has not. I can go cheaper if I use a hydraulic motor for only the torque needs, and then a pair of pillow blocks to handle the overhung load.
I think my lack of experience designing hydraulic systems means I didn't already have a feel for pricing of the various approaches. I have not heard back from Funk yet about their systems, but I the $5,000 Helac Rotary Actuator L30 series is looking like a decent price when you consider the entire system. It is a nice, all-in-one solution that can easily handle all my needs.
Thank you all for your comments. I hope you all had a good Christmas, wishing you all a great New Year.
-Joe
RE: Hydraulic motor mounting standards for gearboxes
Thanks for the clarification. Looking at your duplicate posting I would suggest that the Helac Rotary Actuator (with its coaxial helical spline mechanism that converts an axial input force to a rotary output force) is much better suited for the application you describe than a conventional hydraulic motor coupled to a reduction gearbox. For a lifting device that also must provide fairly precise positioning based on manual control of the hydraulic fluid flow, I think you will get better resolution and feedback with the Helac actuator that performs all functions in a single unit.
Happy New Year to you and good luck with your project.
Terry