Mechanical system, injection pump and valve actuator comprising such a mechanical system and manufacturing method

An injection pump for a motor vehicle comprising:

• a mechanical system including:
• a support element made of a first material and having an outer surface adapted to slide in a housing receiving the mechanical system,
• a pin extending along a first axis and comprising two opposite ends, each adapted to be fitted in the support element for radial and/or axial retention of the pin relative to the first axis, and
• a roller element movable in rotation relative to the pin around the first axis,
• wherein the mechanical system comprises at least one outer insert having at least a partially annular shape and positioned at the outer surface of the support element such that the at least one outer insert is configured to contact the housing, the outer insert being spaced from and not contacting the pin, wherein the at least one outer insert is formed of a second material having a hardness greater than that of the first material, the second material being a steel, the at least one outer insert having a constant outer diameter,
• wherein the mechanical system is a subassembly integrated into the injection pump.

A valve actuator for a motor vehicle comprising:

• a mechanical system including:
• a support element made of a first material and having an outer surface adapted to slide in a housing receiving the mechanical system,
• a pin extending along a first axis and comprising two opposite ends, each adapted to be fitted in the support element for radial and/or axial retention of the pin relative to the first axis, and
• a roller element movable in rotation relative to the pin around the first axis,
• wherein the mechanical system comprises at least one outer insert having at least a partially annular shape and positioned at the outer surface of the support element such that the at least one outer insert is configured to contact the housing, the outer insert being spaced from and not contacting the pin, wherein the at least one outer insert is formed of a second material having a hardness greater than that of the first material, the second material being a steel, the at least one outer insert having a constant outer diameter,
• wherein the mechanical system is a subassembly integrated into the valve actuator.

A method for manufacturing a mechanical system comprising steps of:

• obtaining components of the mechanical system, the components including:
• a support element made of a first material and having an outer surface adapted to slide in a housing receiving the mechanical system,
• a pin extending along a first axis and comprising two opposite ends, each adapted to be fitted in the support element for at least one of radial retention and axial retention of the pin relative to the first axis, and
• a roller element,
• wherein the mechanical system comprises at least one outer insert having at least a partially annular shape and positioned at the outer surface of the support element such that the at least one outer insert is configured to contact the housing, the outer insert being spaced from and not contacting the pin, wherein the at least one outer insert is formed of a second material having a hardness greater than that of the first material, the second material being a steel, the at least one outer insert having a constant outer diameter;
• assembling the roller element to be movable in rotation relative to the pin around the first axis, and
• assembling the support element onto the at least one outer insert by one of:
• overmolding the support element onto the at least one outer insert or snapping the at least one outer insert in a groove formed in the support element.