A fluid pump device, in particular for a medical application, is described having a compressible pump housing and rotor, as well as with a drive shaft which runs in a sleeve and on whose end the fluid pump is arranged. In order to utilize all possibilities of a space-saving arrangement of the respective pump housing of the rotor, which is compressible per se, and as the case a bearing arrangement, the mentioned elements are displaceable to one another in the axial direction compared to an operation position. In particular these elements may be end-configured by way of an axial movement of the drive shaft after the assembly.