FluidPower.Pro

SUN Hydraulics – delivery time issue

SUN delivery issueWorking on the design of new projects I like to involve SUN Hydraulics valves and use them a lot. They are not expensive, pretty reliable and have uncredible understandable paper and online catalogs.

All these major benefits coming to naught as soon delivery time even of very wonderfull products makes impossible to use them in projects. This is exactly what going on these days.

Today I got a quotation from a local vendor for the valve FDEA-LAN with delivery time 31 weeks!!! It is longer than my project needs to be completed!

Helios Technologies (formerly known as Sun Hydraulics) has three facilities in the Americas, two in Europe and already three in Asia-Pacific (one more plant in China has been opened this year). But this fact doesn’t help to provide SUN valves faster.

Because the company, where I’m working now, has fillies in Europe we know the issue with the SUN product delivery time is currently common for the whole world. There no any comments from SUN and its parent Helios at their websites and I see the delivery time is increasing every month.

Therefore, I’m seriously starting to think about solutions on how to proceed. Problem is a lot of manifolds that have already been designed in our projects use SUN cavities. And to re-design of these manifolds is a pain, you know why. I’m seriously thinking to use SUN clones to cover these positions. Currently, I dug the next manufacturers:

  • Winner Hydraulic. This is a manufacturer from Taiwan, but they do not have distributors in North America.
  • PressureBoss Hydraulics Inc. From their website is not clear what country their plant is physically situated. They have distributors in the US but not in Canada.

For new projects, I’m starting to look at Parker and Eaton cartridges. They have a pretty good assortment and actually last months I already used some of their valves as quick replacement options.

How you are dealing with SUN Hydraulic delivery issue?

Mounting flanges and shafts of pumps and motors

Just to determine what flange and shaft of pump or motor you have, please see below excerpts from the next standards:
SAE J744. “Hydraulic Pump and Motor Mounting and Drive Dimensions”.
ISO 3019-1. “Dimensions and identification code for mounting flanges and shaft ends of displacement pumps and motors”.

 

Two bolts mounting flange

Two bolts mounting

Two bolts mounting

Temperature-Viscosity Chart

The interpolation calculator provided below is used to determine:

  • the kinematic viscosity values, depends from temperature, calculated by the formulas specified in ASTM D341 – (‘Standard Practice for Viscosity-Temperature Charts for Liquid Petroleum Products’);
  • the Viscosity Index (VI) by the formulas specified in ASTM D2270 (`Standard Practice for Calculating Viscosity Index from Kinematic Viscosity at 40 and 100°C 1`) or in ISO 2909 (`Standard Practice for Calculating Viscosity Index from Kinematic Viscosity at 40 and 100°C 1`) or in ГОСТ 25371-2018 (`Нефтепродукты. Расчёт индекса вязкости по кинематической вязкости`)

Annotation.

Any mineral oil is supplied with the specification of kinematic viscosity values at two different temperatures, usually at 40°C and at 100°C (or at 100°F and at 210°F). These data is enough to determine kinematic viscosity at any other values of temperature and as well Viscosity Index.

You can calculate pre-filled values of oil classified by ISO 3448 with grades VG22, VG32, VG46 or VG68 (at viscosity Index = 100) or enter specific values for any other oils.

The issue with Danfoss H1P pumps for fan drive

Danfoss H1P issue

I like H1P close-loop pumps for mobile applications: they are very compact, have a small weight, pretty reliable and very easy in an adjustment of any its settings.

But I met one undocumented issue during the experience with these pumps: the max work pressure at fan drive applications. These small displacement pumps (45cc, 53cc and 60cc) can not produce full flow and work stable at the high-pressure range. I made a request about this to Danfoss and got the next responses:

We’ve had experience running these smaller frame H1 pumps on fan drives at full working pressure in the past. What we’ve found is, the pump swashplate sometime is unable to overcome the forces necessary to keep itself at full stroke. Even though the pump control is commanding full stroke, it may not go all the way (the 53cc frame size is the worst size for this).

The reason the pumps can’t reach their rated pressure in these applications is due to the nature of the H1 fan drive control. It is a non-feedback control, meaning there is no link between the position of the swashplate and the pump control. Thus, the swashplate position is susceptible to changing based on the system pressure.

The challenging part is, this isn’t consistent across all pumps. Depending on how the tolerances stack up on an individual pump, one batch of pumps may work perfectly fine at the high working pressure and another may not. Based on our previous experience, we wouldn’t support a fan drive application at full rated working pressure.

Therefore I asked about max work pressure these pumps can provide full flow and got these data:

  • 60cc pump can work stable up to 350 bar
  • 45cc/53cc pumps can work stable up to 280 bar

Again, this issue is only for fan drive control system (FDC) where swashplate goes to full displacement upon loss of the control signal. The simple EDC control system does not have this operating pressure issue.

Therefore, like options, we can either select bigger displacement pump or different brand. Good to know for system design, right? But you can not find this info in Danfoss pumps catalogue.