JPH018641Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a rotor shaft connection device for connecting a metal shaft to a rotor shaft of a centrifugal supercharger mainly used in an internal combustion engine.

Since the turbine side of conventional centrifugal superchargers used in internal combustion engines is heated to a high temperature by exhaust gas, some use turbine rotors made of highly heat-resistant ceramic. However, since ceramic is inferior in strength to metal, some metal shafts are connected to the rotor shaft, which requires strength.
Furthermore, the rotor shaft made of ceramic and the metal shaft are bonded together using organic or inorganic adhesives or brazing, but it is difficult to select an adhesive that is suitable for both materials, and problems such as peeling occur during use. It was hot.

This invention was made for the purpose of improving this inconvenience, and in a device that connects a rotor shaft made of ceramic and a metal shaft in a tapered manner, a groove is formed in the circumferential direction in at least one tapered portion, and the groove is The present invention provides a rotor shaft connection device for a centrifugal supercharger in which a portion of the adhesive enters into the rotor shaft, thereby greatly improving the adhesive force between the rotor shaft and the metal shaft.

This invention will be described in detail below with reference to one embodiment shown in the drawings. In the drawing, 1 is a turbine rotor of a centrifugal supercharger (not shown), and an impeller portion 1a and a rotor shaft 1b are integrally formed of ceramic.
The tip side of the rotor shaft 1b has a tapered shape that gradually becomes smaller in diameter toward the tip, and this tapered portion 1c
A plurality of concave grooves 1d each having a semicircular cross section are formed in the circumferential direction on the outer periphery of the groove.

Further, 2 is a metal shaft connected to the rotor shaft 1b, and a tapered recessed hole 2a into which the tapered portion 1c of the rotor shaft 1b fits is bored in the connecting portion.
A plurality of grooves 2b having a triangular cross section are formed in the circumferential direction on the inner peripheral surface of the groove 2a.
These grooves 2b are positioned between the grooves 1d of the tapered portion 1c when the shafts 1b and 2 are combined.

On the other hand, the rotor shaft 1b and the metal shaft 2 are joined by adhesive or brazing, and at this time, a part of the adhesive or solder enters the grooves 1d and 2b and hardens. Even if a force acts in the direction of peeling off the adhesive between the shaft 1b and the metal shaft 2, the hardened adhesive enters the grooves 1d and 2b and opposes it, greatly strengthening the adhesive force. be done.

In the above embodiment, the grooves 1d and 2b are provided on both the rotor shaft 1b and the metal shaft 2, but it is also effective to use either one of them.

As described above, this invention is a device in which a rotor shaft 1b made of ceramic and a metal shaft 2 are joined in a tapered manner, and grooves 1d and 2b each having a substantially wedge-shaped cross section are formed in the tapered surface of at least one of both shafts in the circumferential direction. Since the grooves 1d and 2b are provided so that a part of the adhesive for bonding each shaft enters the grooves 1d and 2b, the area of the bonding surface is increased by the grooves 1d and 2b, and the wedge-shaped grooves 1d and 2b are Since the adhesive that has entered 2b faces the force in the peeling direction, the adhesive force can be greatly improved. Therefore, the risk of separation between the rotor shaft 1b and the metal shaft 2 during operation can be reduced, and if the concave groove 1d on the rotor shaft 1b side is made into an arc shape,
It is easy to mold, and there is less worry about the corners being damaged.

[Brief explanation of the drawing]

The drawings show an embodiment of this invention, with FIG. 1 being a partially cutaway side view, and FIG. 2 being an enlarged view of the circle in FIG. 1. 1b is a rotor shaft, 1d and 2b are grooves, and 2 is a metal shaft.

Claims (1)

[Scope of utility model registration request] In a device in which a rotor shaft 1b made of ceramic and a metal shaft 2 are tapered coupled, the rotor shaft 1b is
Grooves 1d and 2d having a substantially wedge-shaped cross section are formed in the circumferential direction on at least one tapered surface of the metal shaft 2, and a portion of the adhesive for bonding both tapered surfaces is formed in the groove 1d. , 2b, a rotor shaft connection device for a centrifugal supercharger.