Is the machinery where you have installed one or more Vivoil flow dividers generating excessive noise? You may be wondering what the cause could be. Usually, when a machine produces abnormal noise, the first thought is that one of its components is malfunctioning.
In fact, phenomena such as wear, cavitation, pressure oscillations, oil contamination or incorrect fastening can generate vibrations and increase the noise level of the machinery. We have discussed these and other common issues in our guide to selecting and using Vivoil flow dividers.
Sometimes, however, the problem originates much earlier, during the machinery design stage or in the definition of certain construction details, and only becomes apparent once the system is put into operation.
This is exactly what happened to one of our Customers, a company manufacturing hydraulic systems.
The flow dividers were generating abnormal noise
The Customer contacted us regarding an issue identified during the testing phase of an application they had designed: a system equipped with two Vivoil flow dividers (RV-1D/7.8×3 – 9RD033), Group 1, with three elements and a displacement of 7.8 cm³/rev.
He had noticed an anomaly: although the system had been correctly sized, during testing both flow dividers generated particularly intense noise. The phenomenon only decreased when the flow rate was gradually reduced, but reappeared during normal machine operation.
Unable to identify the source of the problem, the Customer contacted our Technical Department and sent us all the available documentation: the project data, the main operating parameters and a short video of the machinery in operation.
We immediately investigated the case.
The issue was not the Vivoil flow dividers
It is important to point out that Vivoil flow dividers are tested to verify the absence of operating anomalies, including abnormal noise. However, it is not possible to reproduce during testing every operating condition that a component may encounter in real applications once installed on a machine.
In fact, noise depends on many factors related to the specific application.
Our Technical Department carefully analysed the Customer’s documentation, but the review of the technical data revealed no anomalies that could justify the level of noise reported.
The video, however, proved to be decisive.
After carefully watching it, we noticed that all the connections had been made exclusively using metallic components, without any element capable of absorbing or damping vibrations. As a result, the entire machine structure was extremely rigid.
In a configuration of this kind, resonance phenomena are very likely to occur: the vibrations generated by the system are transmitted and amplified, significantly increasing the perceived noise level and, in the most severe cases, even causing damage to the components.
In other words, the problem was not the operation of the flow dividers, but some of the construction choices adopted for the machinery.
The solution: introduce anti-vibration elements
Once the likely cause of the problem had been identified, we suggested two modifications:
- Install rubber anti-vibration elements between the flow divider mounting brackets and the machine structure.
- Install small rubber elastic elements in the hydraulic lines connected to the flow dividers.
These measures interrupt the transmission of vibrations and significantly reduce resonance phenomena.
As an additional solution, we also recommended installing two larger flow dividers.
A larger flow divider operates at a lower rotational speed and can help reduce system noise, with only a slight reduction in accuracy, which is generally negligible above 1500 rpm. Sometimes, choosing the most suitable flow divider is all that is needed.
In this case, however, neither the hydraulic circuit nor the flow dividers had to be modified. Installing the anti-vibration elements recommended by our Technical Department was enough to eliminate the noise.
Construction details also make the difference
The case we have just presented demonstrates that, even with a correctly designed system and properly sized components, construction details can significantly influence the behaviour of the entire machinery.
For this reason, whenever an anomaly occurs, it is important to analyse not only the component involved, but also the way it has been integrated into the machinery and the characteristics of the overall structure.
Are you designing a machine using one or more Vivoil flow dividers and wondering what measures you should adopt to prevent excessive noise and keep your components in perfect condition?
Contact us. We are here to help!