Hydraulic soft-close hinge from Megatrade increases the safety of wind turbines

Operators of offshore wind turbines can look forward to greater safety at work when Siemens Gamesa in future equips access hatches and machine covers with Megatrade’s unique self-closing soft-close hinge.

ODH Hinge

It is associated with personal danger, as well as the risk of material damage, if a hatch does not close, but also if heavy hatches slam too hard. This is a problem that the wind turbine manufacturer Siemens Gamesa Renewable Energy is well aware of, and so they approached the wholesaler, Megatrade for a solution.

– It is a requirement for our offshore turbines that the hatches between the sections close automatically, and at the same time also close in a soft and controlled manner. It has been a great challenge to find a hinge that could solve that task in a saltwater environment, says Kim Gade Nielsen, Modular Mechanical Lead Offshore DD Platform, at Siemens Gamesa Renewable Energy.

The task of finding such a hinge led to just one possible candidate, from a Japanese manufacturer. Anders Melgaard, Senior Key Account Manager at Megatrade says:

– Within the requirements that Siemens Gamesa made for such a hinge, we actually only had one option, from a Japanese supplier, and we were not even completely satisfied with it. It was both expensive and did not meet the requirements we set for the product. We could see that this was a problem that we could solve in a better way. Therefore, our technical department teamed up with one of our gas spring manufacturers to develop the optimum soft-close hinge.

Even better and cheaper

In co-operation between Megatrade’s technical department and their gas spring supplier, Megatrade was able to present Siemens Gamesa with a new and improved hinge which was a little out of the ordinary.

– Without us asking for it, Megatrade itself has continued to work with the hinge, together with one of their suppliers, so the new version is even better and cheaper. Not many wholesalers unsolicitedly create such a new product, even cheaper, and come back to offer it, says Kim Gade Nielsen and continues:

– I have tested the new hinge myself, and it can really withstand a great deal. It is a solid construction that can handle a heavier hatch, entailing that fewer hinges will be needed in the turbines. In addition, then they even fit directly over the old hinges. 

The success is palpable

At Megatrade, we are proud to be able to deliver professional solutions that are tailored to the customer, and the investment in the new product has already paid off, as the hinge will be installed in all of Siemens’ future offshore wind turbines.

– The hinge is already gaining acceptance, as we have sold it to both Vestas and Siemens, and we have mounted it on some Ørsted turbines which are being retrofitted. It shows us that the extra service in developing such a hinge not only pays off for our customers, but also for us, says Anders Melgaard from Megatrade.

The hinge, called ODH, can withstand a load of 15Nm, closes even at opening angles of less than 90°, is made of acid-proof steel, so that it is suitable for use in corrosion category C5-M, and is available for both top and inside mounting. Megatrade expects that the hinge will also be used in the offshore and shipping industries.

Functional principle

The hinge is filled with oil and the damping works by moving the oil from one chamber to another when the hinge is moved. The oil passes through some small holes on its way to the second chamber, and the viscosity of the oil makes this movement soft and slow. When the hinge is moved back, the oil can return through a larger number of holes, and thus the damping does not work in the opposite direction.

Mounting

The hinge is available for both top and inside mounting.

Specifications

Material: AISI316
Max load: 15Nm
Closing speed: ≈ 9° i sekundet*

Variants

The hinge is also available in die-cast zinc/ with stainless steel parts, in either 5Nm or 10Nm

*at maximum load in own test setup