Retightenable wedge system for tightening coil in slot of generator stator

• US 10,340,764 B2
• Filed: 03/30/2017
• Issued: 07/02/2019
• Est. Priority Date: 03/30/2017
• Status: Active Grant

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Energy Incorporated (Siemens AG)
• Inventors: Sanjuan, Xabier A., Vindler, Michael R., Hall, Michael A., Garner, Timothy J.
• Primary Examiner(s): Desai, Naishadh N
• Application Number:
  US15/474,324
• Publication Number:
  US 20180287448A1
• Time in Patent Office: 824 Days
• Field of Search: 310214, 310215
• CPC Class Codes: H02K 15/0018 Applying slot closure means in the core; Manufacture of slot closure means
• CPC Class Codes: H02K 2213/09 Machines characterised by the presence of elements which are subject to variation, e.g. adjustable bearings, reconfigurable windings, variable pitch ventilators
• CPC Class Codes: H02K 3/487 Slot-closing devices

Abstract

A retightenable wedge system for tightening a coil in a slot of a generator stator bar is presented. The retightenable wedge system includes a first filler layer, a spring member, a second filler layer and a retightenable wedge assembly. The retightenable wedge assembly includes a slot wedge having an aperture, a tightening member having form fit feature and a locking member having mating form fit feature. The tightening member is tightenable in the aperture such that a radial load is applied on the second filler layer for tightening the coil in the slot. The tightening member is locked in place in the aperture by an engagement between the form fit feature of the tightening member and the mating form fit feature of the locking member such that the tightening member is restrained from backing out of the slot wedge.

Claims

1. A retightenable wedge system for tightening a coil in a slot of a generator stator comprising:

a first filler layer placed on the coil;

a spring member placed on the first filler layer;

a second filler layer placed on the spring member;

a retightenable wedge assembly placed on the second filler layer, wherein the retightenable wedge assembly comprises;

a slot wedge comprising an aperture;

a tightening member comprising a form fit feature, wherein the tightening member is configured to be tightenable in the aperture for applying a radial load on the second filler layer, wherein the second filler layer is configured to evenly distribute the radial load on the spring member, and wherein the spring member is configured to apply the evenly distributed radial load onto the coil for tightening the coil in the slot; and

a locking member comprising a mating form fit feature configured to engage with the form fit feature of the tightening member to lock the tightening member in place in the aperture such that the tightening member is able to be restrained from backing out of the slot wedge.

2. The retightenable wedge system as claimed in claim 1, wherein the form fit feature of the tightening member comprises a pawl located on outer side surface of head of the tightening member.

3. The retightenable wedge system as claimed in claim 1, wherein the form fit feature of the tightening member comprises a radially extended serrated outer side surface of head of the tightening member.

4. The retightenable wedge system as claimed in claim 1, wherein the mating form fit feature of the locking member comprises a radially extended serrated inner side surface of the locking member.

5. The retightenable wedge system as claimed in claim 1, wherein the mating form fit feature of the locking member comprises a pawl located on inner side surface of the locking member.

6. The retightenable wedge system as claimed in claim 1, wherein the mating form fit feature of the locking member comprises a locking pin.

7. The retightenable wedge system as claimed in claim 1, wherein the locking member is embedded in the aperture.

8. The retightenable wedge system as claimed in claim 1, wherein the locking member is an integral part of the aperture.

9. A method for tightening a coil in a slot of a generator stator comprising:

placing a first filler layer on the coil;

placing a spring member on the first filler layer;

placing a second filler layer on the spring member;

placing a retightenable wedge assembly on the second filler layer, wherein the retightenable wedge assembly comprises;

a slot wedge comprising an aperture,

a tightening member comprising a form fit feature, and

a locking member comprising a mating form fit feature,

tightening the tightening member in the aperture for applying a radial load on the second filler layer, wherein the second filler layer is configured to evenly distribute the radial load on the spring member, and wherein the spring member is configured to apply the evenly distributed radial load onto the coil for tightening the coil in the slot; and

locking the tightening member in place in the aperture by an engagement between the form fit feature of the tightening member and the mating form fit feature of the locking member such that the tightening member is able to be restrained from backing out of the slot wedge.