Produkte / TPMS
Remote pneumatic shaft pressure monitoring — detect air loss before it costs a roll
A pneumatic expandable shaft is inflated once and then nobody looks at it again. Air loss shows up later as a winding defect and wasted material. Wireless pressure monitoring turns that into an early warning — no slip ring, no cable through a rotating part.
Compliance: CE in progress, expected to be held in November.
The failure mode this page is about
The shaft is inflated to grip the core, the inflator is disconnected, and the shaft runs. A slow leak does not announce itself: grip relaxes slightly, the roll is not wound as tightly as it should be, and the defect is found downstream — at the customer, or at the next process. Early detection of air loss is the whole value.
Why wireless monitoring on a rotating shaft
Reading pressure on a shaft that turns has always been the awkward part: a slip ring is maintenance, and a cable through a rotating part is a failure waiting to happen. A battery-powered wireless transmitter on the shaft, with a fixed receiver on the machine, removes both. That is the same platform we use for vehicle pressure monitoring, applied to a fixed machine.
Specification
| Item | Value |
|---|---|
| Typical working pressure | 7 bar (pneumatic shaft air circuit) |
| Medium | Gas — compressed air only |
| Wireless | Battery-powered radio transmitter on the shaft; fixed receiver on the machine. No slip ring |
| Output | RS232 or CAN 2.0B, one interface per unit, fixed at the factory |
| Alarm logic | Pressure decay over an agreed window, reported as an event rather than a number to watch |
| Remote data collection | Optional: receiver to a 4G gateway, so pressure history is available off-machine |
The mounting question we ask first
A shaft is a closed steel body, and radio does not pass through steel. So the first question is not the pressure range, it is where the measuring point physically sits:
- if the air chamber is inside the shaft body (a chamber smaller than the shaft diameter), a valve-mounted transmitter cannot go inside it — an internal, strap-mounted sensor or a modified port is the realistic route;
- if the measuring point can sit outside the shaft end, the radio path is short and the installation is simple;
- if the inflator coupling is removed after inflation, the sensor cannot use it as a permanent mount — it needs its own port.
Send a photo of the shaft end and the air connection and we will answer in writing before quoting anything.
What we will not claim
Gas only, around 7 bar. If your circuit runs at 100-300 bar, or the medium is oil or water rather than air, it is out of scope and we will say so instead of stretching a specification.
Send us the application
FAQ
- Do we have to modify the shaft?
- Depends where the measuring point can sit. Outside the shaft end, usually no. Internal and small, then a modification or an internal sensor is the honest answer.
- Can it also monitor a pneumatic cylinder?
- Yes, within the same gas range — same sensing part. Tell us the stroke cycle and where the port is.
- Will it tell us the leak rate?
- It reports pressure over time, which is what a leak rate is derived from. We agree the window and the threshold with you rather than hard-code them.
- Can the alarms reach a control room?
- Yes — the receiver goes to RS232 or CAN, and optionally to a 4G gateway for remote data collection.
Tell us the application
Send the vehicle, wheel count and where the data must end up. We answer in writing.