Rotor for a turbine or a compressor or a turbine/compressor geometry

A supercharging device, comprising:

• a housing and a rotor arranged therein, the rotor including:
• a shaft defining an axis of rotation and at least one impeller, the shaft including a first thread arranged coaxially to the axis of rotation and the at least one impeller including a complementary second thread arranged coaxially to the axis of rotation, wherein one of the first thread and the second thread includes an external thread arranged on a threaded pin and the other of the first thread and the second thread includes an internal thread arranged in a bore, wherein the first thread of the shaft is secured to the second thread of the impeller;
• a first contact surface arranged on the shaft at least partially contacting a second contact surface arranged on the at least one impeller;
• and
• a solder reservoir arranged between the first contact surface of the shaft and the second contact surface of the at least one impeller, wherein the solder reservoir is defined by at least one of a first annular groove in the first contact surface and a second annular groove in the second contact surface, wherein the first contact surface is fixedly secured to the second contact surface via at least one of a welded connection, a soldered connection and an adhesive connection.

A method for producing a rotor of a supercharging device, comprising:

• providing a shaft defining an axis of rotation and at least one impeller;
• forming a first thread on the shaft coaxially to the axis of rotation and a second thread on the at least one impeller coaxially to the axis of rotation, wherein one of the first thread and the second thread includes an external thread arranged on a threaded pin and the other of the first thread and the second thread includes an internal thread arranged in a bore;
• screwing the first thread of the shaft together with the second thread of the at least one impeller;
• wherein prior to screwing the first thread of shaft together with the second thread of the at least one impeller, the method includes at least one of the following steps:
• (i) inserting a solder platelet into a receiving region formed between a first contact surface of the shaft and a second contact surface of the at least one impeller and melting the solder platelet to connect the first contact surface with the second contact surface via at least a local heating in a region of the solder platelet;
• (ii) applying an adhesive to an adhesive surface disposed on at least one of the first thread of the shaft and the second thread of the at least one impeller;
• (iii) introducing a clamping element into at least one groove running in at least one of the first thread of the shaft and the second thread of the impeller;
• (iv) applying a layer of coating onto at least one of the first thread of the shaft and the second thread of the at least one impeller, the coating increasing a surface pressure between the first thread of the shaft and the second thread of the at least one impeller;
• and
• (v) wetting at least one of the first thread of the shaft and the second thread of the at least one impeller with a liquid containing a ceramic;
• wherein melting the solder platelet includes at least one of induction heating and heating with a beam.

A rotor for at least one of a turbine and a compressor of a supercharging device, comprising:

• a shaft defining an axis of rotation and at least one impeller;
• the at least one impeller including a first thread arranged coaxially to the axis of rotation;
• the shaft including a second thread complementary to the first thread arranged coaxially to the axis of rotation;
• the shaft and the at least one impeller being secured together via the first thread and the second thread;
• the first thread of the at least one impeller including one of an external thread arranged on a threaded pin and an internal thread arranged in a bore, and the second thread of the shaft including the other of the external thread arranged on the threaded pin and the internal thread arranged in the bore;
• wherein the threaded pin includes a centring portion defining a diameter and the bore includes a centring portion defining a complementary diameter that together with the centring portion of the threaded pin facilitates radial guidance and radial centring of the at least one impeller and the shaft relative to one another;
• and
• wherein the shaft and the at least one impeller are fixed with respect to one another via at least one of a soldered connection, a welded connection, an adhesive bond, a clamped connection and a crystallization connection.