When employing an appropriate de-
sign, it is possible to transmit very high
spring loads in space critical environ-
ments. If spring deflection must achieve
a certain length, it is possible to stack
several disc springs as a disc spring
nest.
This has the disadvantage that a cer-
tain amount of friction arises at the
bearing surfaces which is displayed in
the spring characteristic as hysteresis.
As with wave springs, production
processes which increase the service
life and improve relaxation can be ap-
plied.
Sleeve springs
The sleeve spring is a relatively new
product in the field of compression-
loaded spring elements. As such, there
are several terms (e.g. piezo-injection
stamping parts, tube spring) for this
type of spring. Basically, it is spring
steel formed into a tube and punched to
achieve precisely defined contours. The
round sleeve springs are usually pro-
duced from flat material with the spring
either being welded at the joint or in-
serted as an open spring type.
Thanks to the punch pattern, the axial
load can be transmitted with zero trans-
verse force even by an unwelded
sleeve spring. This type of spring is
particularly suitable when very thin
spring elements are required and the
necessary travel is relatively small.
These springs are commonly used for
piezo injection technology.
Evaluation matrix
The table below is used to display and
analyse the advantages and disadvan-
tages of various spring types. It is, how-
ever, quite clear that the correct solu-
tion is always based on the specific ap-
plication. One of SCHERDELʼs key
tasks is to design and provide cus-
tomers with the best possible spring so-
lution in terms of its performance and
costs. The table is intended as a basic
reference tool, as it cannot display all
the possible applications. Applications
enginnering at SCHERDEL should al-
ways be contacted in order to develop
the ideal spring solution.
(
hmr/dk)
5
MECHANICAL ENGINEERING – MANAGEMENT –
TECHNOLOGY & PRODUCT DEVELOPMENT
–
NEWS AND INFORMATION
Application of a sleeve spring in a
piezo injector
Strength-weakness analysis of the
technical product solutions
