How can parallel axis gearboxes improve the strength of reinforced concrete?
Cement, or reinforced concrete, is a mixture of Cement, Water, Sand and Gravel in specific proportions, to which additives are often added to improve its characteristics.
This mixture originated over 2,000 years ago with the Romans, who used lime as a binder, and for this reason it was less durable than today’s concrete.
But it was not until 1861, that Frenchman Joseph Monier invented reinforced concrete as we know it today, which is a cement mix with a skeleton of iron bars.
It was iron bars, or rather the need to standardize production, that necessitated the use of equipment and machinery, capable of speeding up the mass production of this essential component for making reinforced concrete.
Parallel axis gearboxes are a real competitive advantage for companies constantly seeking faster and more efficient ways to produce more, without reducing final quality.
This requires an advanced system capable of fulfilling the full range of workable sections of rebar and a mechanical gearbox capable of meeting different speeds and draw rates.
The research for this advanced system came about at the request of one of our customers who are in the field of manufacturing automated plants for processing rebar for reinforced concrete.
Reinforcing bar is essentially a carbon steel bar used as a tension device in reinforced concrete. The reinforcing bars have a circular cross section with an outer surface characterized by special ribbing called “knurling,” the function of which improves the bar’s adherence within the concrete structure.
Each ironworks has its own distinctive knurling design.
Until a few decades ago, regulations also required the use of smooth bars, and internal sliding in the concrete was prevented by making hooked bends at the ends of the bars themselves, which constituted true internal anchors.
The plants examined in this case study, are intended for straightening, drawing, shaping, cutting and welding of rebar for the subsequent creation of iron meshes, cages, lattice girders and pipes destined for the construction and civil works sector.
Parallel axis gearboxes: the driving function
How to combine the customer’s need for a drive function and the realization of parallel axis gearboxes.
With the realization of a new series of machines dedicated to straightening, drawing and plastic shaping of rebar, the customer also requested to be equipped with parallel axis gearboxes with the “driving” function of the system.
In the original design, the idea was that, thanks to the parallel axis reducers, the rebar would be uncoiled from its skein, straightened, reduced in section by drawing passes, and plastically deformed for the creation of the ribs useful for the anchoring function to the concrete.
The need that market big players fail to meet
At the product launch stage, technical requirements are often not compatible with the commercial solutions that large industrial groups propose. This is combined with the low quantity of units required.
Moreover, in this case the various customizations make the parallel axis gearboxes a mechanical solution designed ad-hoc for the specific requirement.
The customer was able to co-design and choose the various technical solutions designed and presented by OMME.
With a single parallel-axis gearbox model (3000 kg weight 1500x1000x1500mm), the customer was able to satisfy all drawing operations by covering the entire range of machinable sections of iron rod.
He was able to have a compact installation with a vertical input and output shaft, but what they appreciated most was the implementation of the mechanical gearbox to meet different drawing speed requirements.
The problems that often occur during the drawing process are:
- rod jamming
- softening of the structure
- fractures
For these reasons, it is necessary to vary the process speed and/or direction of rotation to achieve a continuous cycle.
The astute implementation of the OMME solution in automated rebar processing plants for reinforced concrete.
Close cooperation between the technical departments of both companies proved to be crucial.
On the one hand, OMME was able to understand exactly what the requirements were, on the customer side there was a great openness to unconventional testing and experimentation that allowed the companies to reach their final goal.
The process took place step by step through company visits, video calls and email exchange.
What has changed today thanks to the custom solution designed by OMME?
Thanks to the expertise of OMME’s engineering department, the customer saw all their requirements fully met resulting in a compact solution and a single model for all applications.
For example, find out the difference between cycloidal and planetary gearboxes by reading this article.
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