Precisely aligned, friction welded spiral bevel or hypoid ring gear and differential case assembly

Patent metadata

Field	Value
Publication number	US-10738869-B2
Application number	US-201815892867-A
Country	US
Kind code	B2
Filing date	Feb 9, 2018
Priority date	Nov 30, 2015
Publication date	Aug 11, 2020
Grant date	Aug 11, 2020

Abstract

A method for manufacturing a case-hardened ring gear/differential case assembly includes attaching a ring gear to a differential case. The case-hardened ring gear and the differential case are fabricated of materials each having differing properties of at least carbon content and melting temperature. The attaching includes placing a flange of the case-hardened ring gear in intimate contact with a flange of the differential case whereby a predetermined gap is defined between a remainder of the ring gear and a remainder of the differential case. The ring gear flange is attached to the differential case flange by a friction welding process. The predetermined gap defines an outflow channel that receives a carburized portion of the case-hardened ring gear as overflow material created by an upset forging step of the friction welding process. Differential assemblies and vehicles including such are described.

First claim

What is claimed:

1. A method for manufacturing a case-hardened ring gear/differential case assembly, comprising:
attaching a case-hardened ring gear to a differential case whereby the case-hardened ring gear will align and operatively interface with a hypoid pinion gear of the differential assembly, the attaching including placing a ring gear flange in intimate contact with a differential case flange wherein the ring gear flange and differential case flange are configured and dimensioned whereby a predetermined gap is defined between a remainder of the ring gear and a remainder of the differential case; and
attaching the ring gear flange to the differential case flange by a friction welding process whereby a carburized portion of the case-hardened ring gear passes into the predetermined gap as overflow during the friction welding process wherein the case-hardened ring gear is fabricated of a first material having a carbon content of at least 0.8% and the differential case is fabricated from a second material having a carbon content of at least 2%.

2. The method of claim 1 , wherein the predetermined gap defines an outflow channel for receiving the carburized portion created by an upset forging step of the friction welding process.

3. The method of claim 2 , wherein the predetermined gap is at least 0.03 cm.

4. The method of claim 1 , wherein the aligning comprises orienting a center line axis of the ring gear in a substantially perpendicular relationship to a center line axis of the hypoid pinion gear prior to the friction welding process.

5. The method of claim 1 , wherein the first material and the second material differ at least in a melting temperature property.

6. The method of claim 5 , wherein the first material is steel or a steel alloy and the second material is a nodular ductile iron.

7. The case-hardened ring gear/differential case assembly manufactured by the method of claim 1 .

8. A vehicle including the case-hardened ring gear/differential case assembly manufactured by the method of claim 1 .

9. A case-hardened ring gear/differential case assembly, comprising:
a differential case fabricated from a steel or a steel alloy having a carburized layer having a carbon content of at least 0.8%; and
a case-hardened ring gear, fabricated from a nodular ductile iron having a carbon content of at least 2%, attached to the differential case whereby the case-hardened ring gear will align and operatively interface with a hypoid pinion gear of the differential assembly;
the case-hardened ring gear including a ring gear flange and the differential case including a differential case flange each configured and dimensioned to abut one another to define a predetermined gap between a remainder of the case-hardened ring gear and a remainder of the differential case;
the predetermined gap being positioned to receive a carburized portion of the case-hardened ring gear as overflow material created during a friction welding process.

10. The assembly of claim 9 , wherein the predetermined gap defines an outflow channel for receiving the carburized portion created by an upset forging step of the friction welding process.

11. The assembly of claim 10 , wherein the predetermined gap is at least 0.03 CM.

12. The assembly of claim 9 , wherein a center line axis of the case-hardened ring gear is oriented in a substantially perpendicular relationship to a center line axis of the hypoid pinion gear prior to the friction welding process.

13. A vehicle including the assembly according to claim 9 .

14. A method for manufacturing a ring gear/differential case assembly comprising at least a case-hardened ring gear, a hypoid pinion gear, and a differential case, the method comprising:
positioning a ring gear flange, fabricated from a steel or a steel alloy having a carburized layer having a carbon content of at least 0.8%, adjacent to a differential case flange, fabricated from a nodular ductile iron having a carbon content of at least 2%, to align and operatively interface the ring gear with the hypoid pinion gear in the assembled differential assembly, the ring gear flange and differential case flange being configured and dimensioned to, when aligned and abutted, define a predetermined gap providing an outflow channel; and
friction welding the ring gear flange directly to the differential case flange;
wherein the outflow channel is dimensioned to receive and remove overflow created by an upset forging step of the friction welding, the overflow comprising a carburized portion of the case-hardened ring gear.

15. The method of claim 14 , wherein the outflow channel is at least 0.03 cm wide.

Assignees

• Ford Global Tech Llc

Inventors

• Bojanowski Paul John
• Perakes Andreas Evangelos
• Neumann Thomas Gerard
• Briscoe Mark E

Classifications

• F16H2048/382

  Methods for manufacturing differential gearings · CPC title

• B23K20/129

  specially adapted for particular articles or work · CPC title

• F16H2048/385

  of the ring or crown gear · CPC title

• B23K2101/006

  Vehicles · CPC title

• F16H48/40 Primary

  characterised by features of the rotating cases · CPC title