Sealed micropump

A cardiac support system comprising:

• a sealed micropump, the sealed micropump comprising:
• a housing comprising:
• an outer wall, and
• a spider bearing comprising:
• one or more radial arms extending radially inward from an inner surface of the outer wall;
• and
• an annular wall positioned at a radially inward end of the one or more radial arms, the annular wall having a continuous support surface;
• an integrated motor;
• at least one impeller operatively coupled to the integrated motor for generating a fluid flow inside the housing of the micropump, wherein the at least one impeller comprises an impeller pin;
• and
• a sheathing disposed about and fixedly coupled to the impeller pin, the sheathing having an axial length greater than an axial length of the annular wall;
• wherein:
• the sheathing is comprised of a material different from a material of the spider bearing;
• the sheathing is positioned radially between the continuous surface of the annular wall and the impeller pin such that the annular wall surrounds a portion of the sheathing and is configured to support the impeller pin;
• and
• an interaction between a radially inward surface of the annular wall and a radial outward surface of the sheathing forms a radial sliding bearing.