DD292860A5 - ARRANGEMENT FOR FIXING LONG HUB BODIES ON WAVES - Google Patents

Abstract

The invention relates to an arrangement for attachment of long Nabenkoerpern on waves, in particular of individual sheets combined rotor laminations of electrical machines. The object underlying the invention is to increase the torsional strength of the connection shaft / hub with a ratio Preszfugenlaenge / shaft diameter L / D1 in the Einfluszbereich of the torque to be transmitted. It is achieved according to the invention by the press connection on the torque introduction side having a zone of increased torsional strength, which consists of a ringing or a roughness depth of 0.001 D. Fig. 1 {electrical machine; Wave; Nabenkoerper; Preszverbindung; Torsional vibration load; Torque input side; Verdrehfestigkeitserhoehung; raised material; Raendelsitz}

Description

For this 1 page drawing Field of application of the invention

The invention relates to the attachment of long hub body, in particular of assembled from individual sheets rotor laminations electrical machines, expand, preferably for powered by internal combustion engine generators. However, they can also be used in drives in which high torsional vibration loads occur, the ratio of the hub length / shaft diameter is § 1 and in which, the yield strength of the hub material in the bore is at most at the shaft surface.

Characteristic of the known technical solutions

The attachment of the magnetic body on the shaft of the rotor of electrical machines can be easily by a

Press connection done. As criteria with regard to the claim of this bond are shown on the large Shaft diameter related hub lengths, relatively low grout pressures and high in special applications Alternating torques in stationary operation. Other special features result from the fact that the hubs are usually laminated and as a prefabricated magnetic body

inevitably have a layer offset between the individual slats, which adversely affects the Preßfugenstruktur.

The theoretical consideration of such a press connection shows that the emphasis in the calculation of the

transmittable torque not in the choice of the average joint pressure, but on the concrete assessment of the

Shaft rotation in the practically torsionally stiff hub on the side of the torque introduction is. As you know, the Relative resistance between shaft and hub, especially for thin and long waves, depending on the load of the shaft

Friction more or less in the hole and limit the slip-free length to a part of the total

Preßfugenlänge. The result is so-called local sliding in the Preßfuge with the largest values near the joint end on the

torsionsbeanspruchten side, which in extreme cases, the formation of fretting corrosion and subsequently progressive

Destruction of the press connection may result. The recommendations contained in the DDR standard TGL19361 for press connections for monolithic hubs are based on Ratios Preßfugenlänge to shaft diameter to L / D S 1.6.

Instructions for reducing local sliding and preventing fretting are included in the application

- higher average joint pressure

- Grading of stiffness of shaft and hub

- relief contours in the shaft as well

- Hardened mating surfaces and / or bonding to the

- Lubrication of the press joints with MoS ₂ oil paste or zinc diphosphate paste.

Furthermore, it is generally known to use with small units and low torque loads knurled seats for connecting hubs or laminated cores of Ε engines with the waves. However, the scope of application of this type of connection is limited in terms of both size and performance. It is not sufficient for torsionally vibrated waves. A similar type of attachment is described in DE-OS 3000589, Pat. Kl. B 23 P, 11/00. Herein, a method for connecting hub bodies with wave-like components is described, in which the shaft is provided with a circumferential groove whose groove bottom is knurled. The hub body, such as gear, is inserted with a smooth bore on the shaft and then pressed axially with the aid of a tool so that material flows from the hub body in the knurled groove. The transmission of the torque takes place solely via the knurled seat. Torsional vibration loads should not be equal to such a tight fit.

Object of the invention

The object of the invention is a press connection for the shaft and the magnetic body of an electric machine, the auc. ¹ »with a large ratio of Preßfugenlänge to WeMendurchmesser and exposure to strong torsional vibration loads a permanent sliding SiU of the magnetic body over its entire length guaranteed with minimal technical effort.

Essence of the invention

The technical problem underlying the invention to provide a rotationally fixed connection shaft / hub with a ratio Preßfugenlänge / shaft diameter, L / D S 1 is to increase the torsional strength of the press connection in the region of the inflow of the torque to be transmitted. According to the invention this object is achieved in that a part of the Preßfugenlänge on the side of the torque introduction a zone of increased torsional strength is mediated. This zone extends to a length of up to 0.25 × L. One possibility for forming such a zone consists in a uniformly distributed on the shaft circumference, provided parallel to the longitudinal axis material launch. According to a primary inventive idea knurling is provided for the zone of increased strength. The knurled seat is characterized in the event that the yield point of the hub material at the bore surface is at most equal to the corresponding shaft surface, characterized in that it causes a high proportion of play-free positive locking in addition to the following from the radial pressure friction and thus the relative movement between the shaft and hub knurled Beroich limited to one of the elasticity of the knurling corresponding value.

The inventive combination of press fit and knurled seat can in the case of a prefabricated hub both in one Querpreßverbindung or shrink connection and Längspreßverbindung be realized, both types of mating

require the cutting of the knurled profile into the hub bore at the end of the joining process. With appropriate

Dimonsionierung the knurling is also possible to provide a less hard press fit, so that preferred

energy-saving Längspreßverbindungen can be used. Furthermore, by hard layers of the sheets in

Partial packages directly onto the shaft and intermediate presses, especially in the area of knurling, the combined knurling Press connection are also used in larger machines in which the prefabrication of the magnetic body inappropriate

As a major technological advantage is to emphasize that the knurling can be easily classified in the process of wool production. This is especially true if further knurls to fix other assemblies, such. B.

Fans or exciter machine anchors on the shaft are required. A zone of increased strength in the context of the invention can also be achieved by this surface in a roughness depth of> 0.001 D

roughened.

embodiment The invention will be explained in more detail using an exemplary embodiment. In the diagram, provided with the reference numeral 1, a piece of a shaft of a torsionally vibrated machine

shown, on which a hub body 2 is arranged. The shaft 1 on the one hand has a nominal diameter D for

Hub body matching press fit 4 and also increased on the drive side of the zone according to the invention Verdrehfestigkeit 3, in the present example, a knurling in the width B, on. Both fixed seats form the length L, which corresponds almost to the hub length. A wave shoulder on the side of the introduction of the Torque m (t) serves as a stop for taking place from the opposite side joining process. The assembly can, depending on the structure of the hub body on the one hand by pressing the individual sheets up

to achieve the desired hub length, on the other hand, by pressing the complete hub, so vohl cold way as well as taking advantage of a heating expansion to be completed.

Claims (5)

1. Arrangement for attachment of long hub bodies on shafts, in particular of single sheets assembled rotor laminations of electrical machines, in which the ratio of Preßfugenlänge to the shaft diameter, L / D, ä 1, characterized in that a part of the Preßfugenlänge on the side of Dretjmomenteneinleitung a Zone has increased torsional strength. 2. Anoidnung for attachment of long hub bodies on waves according to claim 1, characterized in that extending the zone of increased torsional strength to about 0.25 x L. 3. Arrangement for fastening long hub bodies on shafts according to claims 1 and 2, CHARACTERIZED IN THAT the zone of increased torsional strength is formed by a material imparting evenly distributed on the shaft circumference. 4. Arrangement for fastening of long hub bodies on shafts according to claims 1 to 3, characterized in that the zone of increased strength has a knurling. 5. Arrangement for fastening long hub bodies on shafts according to claims 1 to 4, characterized in that the shaft is roughened in the zone of increased strength with a roughness depth> 0.001 D.