What is the customer's context and application?
Our client is an international Tier 1 equipment manufacturer. In 2017, it undertook a project to develop a braking assistance system for electric vehicles. It faced a number of challenges, including cleanliness, on-board electronics, and the design of a gearbox coupled to an electric motor.
Our customer consulted us as an expert for the attachment of a bearing and gear pair to a special screw with head. LGC had already participated in the development of several innovation projects, so our customer challenged us.
What was the customer's fastening project before coming to see us?
Initially, the customer came to us to design an M8 head screw with a diameter 12 body to accommodate a bearing requiring XX micron precision, XX surface hardness, XX cylindricity and XX roughness.
In the monobloc version, we could start with a 22-diameter billet, then rough-turn the 12-diameter raceway before induction treatment. In the final operation, we performed plunge grinding.
The cost price of a component produced by multiple processes made it very complex and inefficient.
What study have we carried out?
The splined pin solution was requested by the customer. No other solution was proposed as a better proposal.
For this part, we were convinced that the existing process was inefficient, so we came up with a completely new one! The work focused on assembly rather than turning, with less material removal, more automation and a drastic reduction in costs.
What did we recommend?
We offered our customer a two-body version consisting of a spindle with a head and a spacer that fits onto the spindle by means of automated assembly.
- The cold-forged M8 head axle, on which we have just applied a precision spline. Cold heading has the advantage of supporting extremely competitive production rates.
- The pressed-in spacer, which, after heat treatment in a batch, will be ground to achieve precision in diameter and roughness.
- Automated assembly of the spacer on the spline of the M8 axle, enabling us to maintain the required precision (cylindricity of XX microns, roughness xxx ) for the bearing, thanks to our mastery of splining in mass production. During assembly, checks are carried out on the presence and position of the spacer, and on the minimum and maximum holding force of the spacer on the splined shaft.
- Packaging is carried out by a robot, and the assembly island is managed by an operator.
What are the quantifiable benefits for our customer?
The measured benefit is first and foremost on the cost of the part, with a 40% improvement in costs at peak production.
The carbon footprint is reduced by over 50%, as no bar turning operations are carried out, resulting in a considerable reduction in the energy used to produce and the material sacrificed.
Reduced investment has accompanied the development of the project since 2017, as we have relied on techniques mastered in-house with splining, which is our specialty, the manufacture of a semi-standard production spacer and an M8 pin obtained by cold heading on a standard machine in 5 stations.