Date Published:Aug. 03. 2020


Muilti-Functional Machined Slotted Springs

● Flexus are multi-functional parts made of various materials (not only spring materials) with slits; the portion between the slits works as a spring.

● Flexus products enable various spring properties such as compressing, tensioning, shearing, and bending.

● Due to its cutting process, exact spring constants can be obtained for use in instruments where precision and reliability are required.

● The shape and dimensions are flexible. Polygonal shapes as well as cylinders can be manufactured.

● The shape of the hub (end portion for mounting) can also be manufactured according to individual needs. One can reduce the number of parts required by making the spring and its attachments as an integral construction.  

● Flexus products can be designed with suitable materials such as aluminum alloys, stainless steels, engineering plastics, copper alloys, and more thereby matching customer’s needs.

Flexible Spring Functions

Spiral Slits

 NBK can make any spring function by arranging the slit shape, number, depth, and more. Furthermore, Single Start or Multiple Start spiral slits are possible. Coil springs, as they are manufactured from one-piece spring material, cannot have multiple start spiral slits.
 Single start springs receive rotational force when compressed: axial loads are added to single start slit springs but the multiple start slit springs do not rotate. (Fig. 1)

●Fig. 1- Axial factor and rotational factors, as in single start slit springs

 In addition, repellent forces and moment occur when compressed or tensile loads are added in single start spiral slit springs. That is to say, the loading is unbalanced and single start springs are easily bent. However, the bending moment does not occur in multiple start spiral slits which allows high precision spring function. (Fig. 2)

 ●Fig. 2- Moment difference between single and double start springs


Straight Slits

 NBK can design an approximate quadratic curve by inserting irregular pitch slits. This is a good way to increase the spring loads when the deflection eclipses a specific value, such as when assembling equipment. (Fig. 3)

●Fig. 3- An example of a Flexus product with a spring property made to approximate quadratic curve by inserting irregular pitch slits

Specific Example

 The following Pic. 1 shows three different Flexus products that have 30mm outside diameters and 40mm lengths.
 NBK can control various spring functions even in products with the same outline dimensions by changing the slit shapes, numbers, inner diameters and more.
 NBK can design the loads flexibly for each customer’s needs, applications and requirements by controlling the slits patterns. (Fig. 4)

●Pic. 1- Three slit pattern examples

●Fig. 4- Each spring’s characteristics

You can reduce the number of the parts required with one piece construction

 Typically, one needs to use some attachments (accessories) such as spring posts when installing a common spring coil but Flexus products can be designed with one piece construction including those parts.
 Doing so, will enable one to reduce the number of needed parts and enable one to save assembly procedure and reduce space.

Example of part reduction.

Examples of Integrated Structures

Flexus with integrated structure of female thread

Flexus with integrated structure of flange

Flexus with integrated structure of male thread

Other Usage examples

Flexus with DD motors

 Flexus products have a heat dissipation function that causes the surface area to become bigger by machining the slits. Furthermore, it absorbs the head expansion and contraction. 

Flexus for Vibration Absorption

 If one replaces some rubber parts with Flexus products for absorbing vibration, one can improve the life cycle or one can use high-temperature conditions that the rubber cannot endure. 

To Request a Quotation or Designing

Flexus products are fully customized products.

Please let NBK know the following. 

・Intended Usage machine, equipment

・Illustration or Drawing, Image

・Usage Quantity

・Materials and Surface Treatment

・Spring Characteristics: Spring constant, Deflection

・Maximum Size 

Customization Technical Data Vibration prevention/high precision Customization Heat resistance/corrosion resistance Elegant functionality/design Cleanroom/vacuum/non-magnetic Automation/robots/motorization Machine Tools Semiconductor Manufacturing Equipment Food Machinery Automotive Manufacturing Process Medical equipment FA Devices Technical Data Couplings