Brake-assist system assembly

What was the context and the client's desired application?‍

The client was a tier 1 international parts manufacturer who undertook a project in 2017 to develop a brake-assist system for electric vehicles. The client had various challenges to reckon with, such as cleanliness, on-board electronics and the creation of a gearbox coupled to an electric motor.

Our client wanted LGC's expertise on fastening a bearing and gear coupling on a special screw with a head. Since we had already contributed to the development of several other innovative projects, our client decided to put us to the test.

‍

What fasteners did the client have in mind before talking to us?

Initially, the customer contacted us to design an M8 screw with a 12mm diameter head that was to receive a bearing requiring X-micron precision, X surface hardness, X cylindricity and X roughness.

In the one-piece version, we could start with a 22” diameter piece and then, by turning, make a rough outline of the 12” diameter raceway before induction treatment. Finally, we put it through a plunge grinding process.

The cost price of a component produced via multiple industrial processes made it a very complex and inefficient part.

‍

What studies did we conduct?

The client requested requested a grooved pin-based solution. No other suggestion was given as the client had no better solution.

For this piece, we saw how inefficient the existing process was and came up with a completely new one! Our analysis focused on an assembly rather than turning, with less material removal, more automation and a drastic reduction in costs.

‍

What was our advice to the client?

We offered our client a two-body version composed of a headshaft and a spacer fastened onto the shaft by automated assembly.

- Headshaft with an M8 head made through cold heading, complete with precision grooving carried out by us. Cold heading has the advantage of sustaining extremely competitive rates.

- The spacer which, after batch heat treatment, will be ground to precision on the diameter as well as the roughness.

- An automated assembly of the spacer on the grooves on the M8 shaft, making it possible to maintain the required precision (X-micron cylindricity, X roughness) for the bearing thanks to large-batch grooving. Evaluations are carried out during assembly - presence and position of the spacer, minimum and maximum holding force of the spacer on the grooved shaft, etc.

- Packaging is carried out by a robot; assembly island driven by an operator

‍

What were the quantifiable benefits for our customer?

Most notably, the price of the part - with a cost reduction of 40% at peak production.

Carbon footprint was reduced by over 50% because no turning takes place. This brought about a considerable reduction in the energy used in the manufacturing process and in material waste.

Reduced investments accompanying the development of the project since 2017 since we relied on techniques mastered internally such as grooving (our specialty), manufacturing a semi-standard spacer and an M8 shaft obtained by cold heading on a standard machine in 5 stations.