CS241911B1 - Connecting the tacho to the shaft of a rotating electrical machine - Google Patents

Abstract

In the case of shafts of rotating electrical machines supported on three bearings and carrying a tachodynamo rotor on the front bearing, it is necessary to weaken the shaft section between the middle and front bearings, which leads to difficulties in machining the shaft and is associated with the risk of damage during production and transport. The invention solves this difficulty by dividing the shaft into two parts, connected outside the middle bearing and centered by an internal cone of the pit.

Description

BACKGROUND OF THE INVENTION The present invention relates to a tachodynamic coupling to a shaft of a rotating electric machine on three rolling bearings.

Such a design is used in rotary machines with foreign axial ventilation located around the shaft between the middle and front bearing. A certain compromise is required when selecting the diameter of the shaft between the middle and front bearings: a small diameter is preferable in terms of additional bearing stress, resulting in greater shaft compliance in this section. On the other hand, in terms of machining and handling, both the shaft and the entire armature, it is advantageous for the shaft to be as thin as possible in the region between the middle and front bearing.

The shaft weakened in the section between the middle and the front bearing is difficult to machine and requires great care in rotor manufacturing to avoid bending the weakened section. An undiluted shaft is of low yield, causing a large additional bearing load statically indefinitely; Such a bearing is more susceptible to vibration and has multiple resonant areas.

These disadvantages are overcome according to the invention in that outside the central bearing the shaft is extended by an extension screwed into the shaft and by a centered inner cone of its centering hole.

Splitting the shaft into two parts facilitates machining and reduces the risk of damage because the adapter is only screwed into the shaft when the machine is mounted.

241 911

An exemplary embodiment of the invention is a longitudinal cross-sectional view of a rotating electrical machine.

The shaft 1 of the electric machine is mounted in the central bearing 2. The outer ring of the central bearing 2 is mounted in the hub 3. of the bearing shield 4 and is supported on the retaining ring 5, in the shaft 1. 7 and a threaded bore 8. A threaded end 2 of the boss 10 with an outer cone 11 is screwed into the threaded bore 8, which fits into the inner cone 6 in the shaft 1. A cylindrical shoulder 12 is connected to the outer cone 11 of the boss 10. tightening key. On the opposite side of the extension 10, a cylindrical seat 14a is provided. A support ring 15 for the front roller bearing 16. The outer ring of the front roller bearing 16 is received in the intermediate flange 17 with bolts 18 tightened to the wall of the ventilation cover 19. the intermediate flange 17 is therefore radially adjustable so that even if the bore of the hub bore 3 and the wall of the ventilation cover wall are not aligned, the shaft is not bent and thus the bearing 2 is additionally loaded,

16. A tachodynamic stator 21 is attached to the intermediate flange. Tacho rotor is fitted on the free end 22 of the extension 10. In the shaft J _and a locking screw 23 screwed with spikard \ recessed in the adapter 10 between the outer cone 11 and the threaded end of the ninth

The diameter of the extension 10 at the point between the cylindrical shoulder 12 and the support collar 15 must be chosen such that the natural frequency of the extension 10 and of the whole assembly does not interfere with the output parameters of the tachodynamics. Because the bearing 2 can be on the shaft. 1. fitted before the attachment 10 is screwed on, the attachment 10 can have the same or even larger diameter up to the cylindrical seat 14; than the center bearing seat diameter 2 on shaft 1, ·

This arrangement also eliminates the difficulties of anchoring the anchor, where the weakened portion of the shaft between the middle and front bearings is very stressed by pulling the bandage tape. Though smaller forces are generated when the commutator is turned, the active surface of the commutator must be very smooth and, with small deviations, coaxial with the bearing seats.

Claims (1)

SUBJECT OF THE INVENTION 241 911 Coupling of the tochodynamic to the shaft of a rotating electric machine on three rolling bearings, and a front bearing carrying the tachodynamic rotor mounted in a radially adjustable intermediate flange, characterized in that outside the middle bearing (2) the shaft (1) is extended by an extension (10) screwed into the shaft and a centered inner cone (6) of the shaft pit (1).