Impeller with protection elements and centrifugal compressor

[0029]The following description of exemplary embodiments refers to the accompanying drawings.

[0030]The following description does not limit embodiments of the present invention. Instead, the scope of the invention is defined by the appended claims.

[0031]Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification is not necessarily referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

[0032]The impeller of FIG. 1 (see also FIG. 2) is a closed-type centrifugal impeller and has a main body with a root 1, a shroud 2 and a plurality of blades 3; the blades 3 connect th