Wet Filament Winding rings for starter motors and commutators are among our bestsellers. As market leader, we produce millions of pieces per year to be delivered in JIT or E-Kanban to the most important global players all over the world, who acknowledge our premium quality.

The technique we use is comparable to that of Filament-Winding that was modified and enriched with other technologies to better suit technical needs and product cost. We designed the most strategic machineries and equipments. Our production and products are constantly checked by computerized systems that keep process parameters and traceability monitored.

Our service starts with initial customer contact that focuses on gaining an understanding of technical and business needs, along with environment and operating conditions where the product will be in use. “Our collaboration does not end with the installation of the ring, but continues through a team working together with the customer to explore all possible further optimizations.

Saver is experienced at coordinating the functional and business requirements to provide the product with specific quality documentation (PPAP, FMEA, etc.) and we have our own technological laboratories for testing, inspecting and improving the product and its performance. Specialized equipment is used to test the product for mechanical and thermal stress.

Lab tests ensure that our product fulfills the client’s requests. Data is then collected and analyzed to form graphs, reports, FMEA, PPAP, etc. From every lot of delivered products we keep a sample for a certain number of years in to be able to do ex post verifications. Saver uses SPC statistical techniques and computerized visual checks to determine and monitor the PPM parameters of our process, and relate causes and effects.

For years we have been supplying our products with a quality warranty all over the world, from the UE, to Japan, to Korea, to USA, to Central and South America (in many cases due to our reliability when the product enters the client’s production lines it does not need to be checked).

For high performance applications we can produce rings for a lighter, more compact, faster, reliable new generation of armatures that requires high resistance to centrifugal force and high temperatures: BK Ring. Millions of armatures already mount this higher performing quality.

Some advantages of our rings:

  • Electric Insulator
  • Completely insulating bandage
  • Non-magnetic bandage
  • No risk of contaminating the motor with metal parts
  • Compatibility with impregnation resins
  • Improved resistance to mechanical stress due to better compatibility with armature impregnation resins
  • Resistance to high centrifugal loads
  • Resistance to centrifugal force
  • Reduced vibration during engine operation

  • Thermal Properties
    • Rings are made of thermosetting resin for high temperature reinforced by long glass fibers
    • The glass transition according to ASTM E 1545 is higher than 240 and 290°C
    • For short periods of time it can endure up to 350°C
    • The thermal expansion coefficient is 2/3 of that of steel
  • Electrical Properties
    • Highly insulating
    • Does not absorb humidity
    • High dielectric rigidity resistance, both perpendicular and parallel to stratification
    • Highly anti-tracking
  • Mechanical Properties
    • Resists to radial traction more than structural steel
    • Non-permanent deformation prior breakage (no stretching)
    • Very good compatibility with impregnating resins: a tighter grip on the armature improves rotation velocity performances
  • Dimensional Properties
    • Precise sizes, very small tolerance
  • Ease of Installation and Economy
    • Ease of installation with simple automatic lines
    • Preparing samples and prototypes is fast and cheap
    • No rejected material due to short circuit. Insulating checks on conductors are not needed.

Rings for starter motors:

Rings for starter motors are used in the automotive industry: lighter components are used to produce lighter cars with lower consumption at a lower price. Starters’ designers are developing new generations of starting motors much lighter and with improved performances compared to the past.
They reduce the volume and the quantity of material, increasing considerably the spin velocity and applying a reduction gear to increase the torque. These motors required a choice of materials with higher performances to resist greater mechanical stress and thermal shock.
The last generation of “start and stop” cars reducing pollution emissions has even more increased the necessity to have rings with higher and higher performances, both mechanical and thermal in automatic armaturing.
Several million cars are equipped with Saver products all over the world.

Rings for commutators:

Rings in insulating composite material have replaced the steel rings inside bar commutators, eliminating asbestos fibers from molding thermosetting.
Due to this necessity, many commutators had to be redesigned in the past.
In some specific applications, the commutator system (commutator+brush+brush holder) produced by electric motors producers requires higher and higher performances.

The commutator has to endure:

  • Very high revolving speed (over 40-50.000 revolutions)
  • lower step bar than a few micron
  • Even at high speed, it has to maintain its geometric roundness
  • Good performance at high temperatures and welding thermal stress.

Because of this commutator producers keep researching new technologies that satisfy their customers’ requests.
The composite rings are essential to improve performances, allowing an easier automation.
Glass fibers, impregnated with resins for high temperatures and with the correct orientation, guarantee a resistance to radial tensile stress higher than steel.
Moreover, being insulating, they do not cause any short circuits when assembled against the bars.
Commutator designers could have higher speed performance and higher precision. Several million commutators are equipped with Saver products.