Electric machine

Patent metadata

Field	Value
Publication number	US-2018175697-A1
Application number	US-201515128979-A
Country	US
Kind code	A1
Filing date	Mar 24, 2015
Priority date	Mar 26, 2014
Publication date	Jun 21, 2018
Grant date	—

Abstract

Electric machine comprises a rotor and a stator surrounding the rotor. The stator comprises a cylindrical stator core having a laminated structure and slots for a stator winding and a stator frame surrounding the stator core. The stator core is attached with fastening brackets by means of fastening means based on a compression joint to the stator frame. The stator frame comprises two opposite end constructions and a frame plate located between the end constructions. Back beams extending in the axial direction of the stator are attached to an outer surface of the stator core. Each fastening bracket comprises two perpendicular branches, a first branch attached to the stator frame plate and a second branch attached to the back beam by fastening means based on a compression joint. The fastening means passes through openings in each branch. The openings are allow a small movement of the fastening means in the openings so that the stator core can be centralized in a radial direction and in an axial direction in relation to the stator frame before the fastening means are tightened in order to lock the stator core to the stator frame.

First claim

1 . An electric machine comprises a rotor and a stator surrounding the rotor, said stator having a longitudinal centre axis, a radial direction being perpendicular to the centre axis, a horizontal centre plane passing through the centre axis of the stator, and a vertical centre plane passing through the centre axis of the stator, said stator comprising a cylindrical stator core having a laminated structure and slots for a stator winding and a stator frame being attached with fastening brackets by means of fastening means based on a compression joint to the stator frame, said stator frame comprising two opposite end constructions located at an axial distance from each other and at least one frame plate located between the end constructions, back beams extending in the axial direction of the stator being attached to an outer surface of the stator core,
wherein: the fastening brackets comprises two branches that are perpendicular to each other, each branch having at least one opening, whereby a first branch is attached to the stator frame plate and a second branch is attached to the back beam by fastening means based on a compression joint, said fastening means passing through the openings in each branch of the fastening bracket, the openings in the two branches of the fastening bracket are dimensioned to allow a small movement of the fastening means in the openings so that the stator core can be centralized in the radial direction and the axial direction in relation to the stator frame before the fastening means are tightened in order to lock the stator core to the stator frame.

2 . An electric machine according to claim 1 , wherein the fastening brackets are positioned on both sides of the back beams and on both sides of the frame plate so that the second branch of the fastening bracket rests on the outer surface of the stator core and the first branch of the fastening bracket rests on the frame plate, whereby
the first branches of two opposite fastening brackets on both sides of the frame plate are attached to the frame plate with a fastening means based on a compression joint, the second branches of two opposite fastening brackets on both sides of the back beam are attached to the back beam with fastening means based on a compression joint.

3 . An electric machine according to claim 1 , wherein the fastening means is based on a bolt and a nut.

4 . An electric machine according to claim 3 , wherein the nut is provided with friction increasing means in order to further secure that the nut does not open due to vibrations.

5 . An electric machine according to claim 1 , wherein the stator comprises support elements being located symmetrically on opposite sides of the vertical centre plane between the end constructions of the stator frame, said support elements being made of cast iron and being attached to the end constructions of the stator frame and to a support structure of the electric machine with fastening means based on a compression joint.

6 . An electric machine according to claim 1 , wherein each frame plate is formed of four separate frame plate sectors so that two frame plate sectors are located symmetrically on both sides of the vertical centre line in upper corners of the stator frame and two frame plate sectors are located symmetrically on both sides of the vertical centre line in lower corners of the stator frame, whereby
the two frame plate sectors of frame plates in the upper corners of the stator frame are connected to each other with a connection part in order to form a first frame plate package.

7 . An electric machine according to claim 6 , wherein the support elements and the frame plates in each lower corner of the stator frame are attached to each other in order to form a support element package, whereby each end of the support element package is attached to a respective end construction of the stator frame.

8 . An electric machine according to claim 7 , wherein the stator frame comprises further first intermediate parts located symmetrically at opposite sides of the vertical centre plane in lowermost corners of the stator frame, the first intermediate parts being located between the end constructions.

9 . An electric machine according to claim 7 , wherein the four frame plate sectors are expanded so that their edges attach each other forming a continuous annular frame plate surrounding the stator core.

10 . An electric machine according to claim 9 , wherein a support element is located between each end construction and the adjacent frame plate and between adjacent frame plates.

11 . An electric machine according to claim 9 , wherein the stator frame comprises further first intermediate parts located symmetrically on opposite sides of the vertical centre plane in lowermost corners of the stator, a first intermediate part being located between each end construction and the adjacent frame plate and between adjacent frame plates.

12 . An electric machine according to claim 9 , wherein the stator frame comprises further second intermediate parts located symmetrically on opposite sides of the vertical centre plane in upper corners of the stator, a second intermediate part being located between each end construction and the adjacent frame plate and between adjacent frame plates.

13 . An electric machine according to claim 2 , wherein the fastening means is based on a bolt and a nut.

14 . An electric machine according to claim 13 , wherein the nut is provided with friction increasing means in order to further secure that the nut does not open due to vibrations.

15 . An electric machine according to claim 14 , wherein the stator comprises support elements located symmetrically on opposite sides of the vertical centre plane between the end constructions of the stator frame, said support elements being made of cast iron and being attached to the end constructions of the stator frame and to a support structure of the electric machine with fastening means based on a compression joint.

16 . An electric machine according to claim 2 , wherein the stator comprises support elements located symmetrically on opposite sides of the vertical centre plane between the end constructions of the stator frame, said support elements being made of cast iron and being attached to the end constructions of the stator frame and to a support structure of the electric machine with fastening means based on a compression joint.

17 . An electric machine according to claim 2 , wherein each frame plate is formed of four separate frame plate sectors so that two frame plate sectors are located symmetrically on both sides of the vertical centre line in upper corners of the stator frame and two frame plate sectors are located symmetrically on both sides of the vertical centre line in lower corners of the stator frame, whereby
the two frame plate sectors of frame plates in the upper corners of the stator frame are connected to each other with a connection part in order to form a first frame plate package.

18 . An electric machine according to claim 5 , wherein each frame plate is formed of four separate frame plate sectors so that two frame plate sectors are located symmetrically on both sides of the vertical centre line in upper corners of the stator frame and two frame plate sectors are located symmetrically on both sides of the vertical centre line in lower corners of the stator frame, whereby
the two frame plate sectors of frame plates in the upper corners of the stator frame are connected to each other with a connection part in order to form a first frame plate packa

Assignees

• Abb Schweiz Ag

Inventors

• Helander Joonas
• Grün Moritz
• Vartiainen Ari
• Pulkkinen Risto

Classifications

• H02K5/04

  Casings or enclosures characterised by the shape, form or construction thereof · CPC title

• H02K1/185 Primary

  to outer stators · CPC title

• H02K5/26

  Means for adjusting casings relative to their supports · CPC title

• H02K5/24 Primary

  specially adapted for suppression or reduction of noise or vibrations · CPC title

• H02K2213/12

  Machines characterised by the modularity of some components · CPC title