Patent Application
20220294315
This disclosure relates generally to electrical machines and more particularly to diode mounting rings for rotating rectifier assemblies for generators.
The rotating rectifier assembly (RRA) is mounted in the rotor shaft of a variable frequency generator (VFG). It is used to convert alternating current to direct current using a full bridge rectifier configuration.
Two mounting rings are located in the RRA. Each one is connected to the AC (alternating current) power source through three diodes. The diodes the convert the alternating current to direct current, which is then transmitted from the body of the mounting ring to the contact band connected to the DC (direct current) pins. The DC pins connect the RRA to the resistor assembly and to the main field winding of the VFG.
In traditional configurations, the RRA uses two mounting rings with brazed pins to make the DC connections. The braze joints can weaken the material. The mounting rings are traditionally made of Beryllium Copper (BeCu), which is a potential health hazard when machined.
The conventional techniques have been considered satisfactory for their intended purpose. However, there is an ever present need for improved systems and methods for mounting diode pins within a generator. This disclosure provides a solution for this need.
An assembly comprises a mounting ring for a rotating rectifier assembly (RRA) having a pin bore defined in the mounting ring oriented in an axial direction and at least one contact band seated in a the pin bore of the mounting ring for mounting a direct current (DC) pin to the mounting ring.
A respective joining interface can be formed between each of the at least one contact bands and the mounting ring, wherein the joining interface can be free of braze and each respective joining interface of the at least one contact bands can be an interference fit. The at least one contact band can include a first contact band and a second contact band. The first contact band can be axially stacked with the second contact band within the pin bore. The contact bands can be spring type contact bands. The mounting ring can be of Aluminum, the at least one contact band can be of a metallic material, and both the mounting ring and at least one contact band can be free of BeCu.
At least one axial channel can be included on a radially outer surface of the mounting ring for accommodating a DC pin of another mounting ring in the RRA. At least one circumferential coolant channel can be defined on an outward surface of the mounting ring. A DC pin can be seated in the at least one contact band.
The mounting ring can be a first mounting ring, and the DC pin can be a first DC pin. A second mounting ring for an RRA having a pin bore defined in the second mounting ring oriented in the axial direction can be included. At least one contact band seated in a the pin bore of the second mounting ring and a second DC pin can be seated in the at least one contact band of the second mounting ring. The second DC pin can pass through an axial channel on a radially outer surface of the first mounting ring. The first and second mounting rings can be assembled into the RRA of a variable frequency generator (VFG). The first and second DC pins can electrically connect between diodes and a field winding of the VFG for rectifying alternating current (AC) to DC in the RRA.
A method includes forming a mounting ring for a rotating rectifier assembly (RRA) and forming a pin bore in the mounting ring oriented in an axial direction. The method also includes installing at least one contact band into a the pin bore of the mounting ring.
The method can include mounting a direct current (DC) pin to the mounting ring by seating the DC pin in the at least one contact band. The method can also include assembling the mounting ring into an RRA, wherein mounting ring is a first mounting ring, and the DC pin is a first DC pin. The method can include assembling a second a mounting ring to the RRA can be included, wherein a pin bore can be defined in the second mounting ring oriented in the axial direction, and at least one contact band can be seated in a the pin bore of the second mounting ring. The method can include mounting a second DC pin seated in the at least one contact band of the second mounting ring, wherein the second DC pin can pass through an axial channel on a radially outer surface of the first mounting ring.
The contact bands can be spring type contact bands and are assembled with interference fits into the respective first and second mounting rings without braze. The first and second mounting rings can be assembled into the RRA of a variable frequency generator (VFG). The method can also include electrically connecting the first and second DC pins between diodes and a field winding of the VFG for rectifying AC to DC in the RRA.
These and other features of the systems and methods of the subject disclosure will become more readily apparent to those skilled in the art from the following detailed description taken in conjunction with the drawings.
So that those skilled in the art to which the subject disclosure appertains will readily understand how to make and use the devices and methods of the subject disclosure without undue experimentation, embodiments thereof will be described in detail herein below with reference to certain figures, wherein:
Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure. For purposes of explanation and illustration, and not limitation, a partial view of an embodiment of an assembly in accordance with the disclosure is shown in
Shown in
At least one contact band 106 can be seated in the pin bore 104 of the mounting ring 102 for mounting a direct current (DC) pin 108 to the mounting ring 102. The at least one contact band 106 can allow for precise, durable positioning of the DC pin 108 within the mounting ring 102. The at least one contact band 106 can be of a metallic material, for example a material that allows the DC pin 108 to electrically connect between diodes 110 and a field winding 112 of the VFG 1 for rectifying alternating current (AC) to DC in the RRA 10. Both the mounting ring 102 and at least one contact band 106 can be free of BeCu, however it is contemplated that the entire assembly 100 as described herein can be free of BeCu.
A respective joining interface 114 can be formed between each of the at least one contact bands 106 and the mounting ring 102. Brazing the DC pin 108 to the mounting ring 102 can weaken the assembly 100, therefore the joining interface 114 can be free of braze. Each respective joining interface 114 of the at least one contact band 106 can be an interference fit, for example, the at least one contact band 106 can be spring type contact band. The at least one contact band 106 can include a first contact band 106a and a second contact band 106b. The first contact band 106a can be axially stacked with the second contact band 106b within the pin bore 104.
At least one axial channel 116 can be included on a radially outer surface 118 of the mounting ring 102 for accommodating a DC pin 108 of another mounting ring 102 in the RRA10. For example, the mounting ring 102 can be a first mounting ring 102a and the assembly 100 can include a second mounting ring 102b, and the DC pin 108 can be a first DC pin 108. The second a mounting ring 102b can also have a pin bore 104b defined therein in the axial direction, as described for the mounting ring 102a. The second mounting ring 102b can also include at least one contact band 120a,b seated within the pin bore 104b The second DC pin 108b can pass through the axial channel 116 of the first mounting ring 102a, and through the pin bore 104b of the second mounting ring 102b, as shown in
Shown in
Assembling 210 a second a mounting ring 102b to the RRA 10 can be included in the method 200, wherein a pin bore 104b can be defined in the second mounting ring 102b oriented in the axial direction, and at least one contact band 120a,b can be seated in the pin bore 104b of the second mounting ring 102b. The method 200 can further include mounting 212 a second DC pin 108b seated in the at least one contact band 120a,b of the second mounting ring 102b, wherein the second DC pin 108b can pass through an axial channel 116 on a radially outer surface 118 of the first mounting ring 102a.
The methods and systems of the present disclosure, as described above and shown in the drawings, provide for decreased complexity in assembly, reduced manufacturing cost and compliance requirements, improved cooling and thermal conductivity, and improved conductivity. While the apparatus and methods of the subject disclosure have been shown and described, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the scope of the subject disclosure.
