Manufacture method of bushing, bushing and excavator

Patent metadata

Field	Value
Publication number	US-2023166327-A1
Application number	US-202117917145-A
Country	US
Kind code	A1
Filing date	Dec 14, 2021
Priority date	Nov 11, 2021
Publication date	Jun 1, 2023
Grant date	—

Abstract

This disclosure relates to a manufacture method of a bushing, a bushing and an excavator to alleviate the problems of insufficient lubricity and wear resistance of the bushing. The bushing includes an inner ring and an outer ring. The manufacture method of the bushing includes the following steps: grinding a first mixed powder containing Fe, Al, Ti, Cr and V, nitriding the ground first mixed powder to form a nitrogen-rich stable compound powder, and then carrying out molding by pressing and sintering the nitrogen-rich stable compound powder to form the outer ring; grinding a second mixed powder containing Fe and Mo, sulfurizing the ground second mixed powder to form a sulfurized powder containing FeS and MoS2, and carrying out molding by pressing the sulfurized powder to form the inner ring; and placing the inner ring in the outer ring and carrying out sintering to obtain the bushing.

First claim

1 . A method of manufacturing a bushing, the bushing comprising an inner ring and an outer ring, the method comprising:
grinding a first mixed powder containing Fe, Al, Ti, Cr and V; nitriding the ground first mixed powder to form a nitrogen-rich stable compound powder, and molding the nitrogen-rich stable compound powder by pressing the nitrogen-rich stable compound powder and sintering the pressed nitrogen-rich stable compound powder to form the outer ring; grinding a second mixed powder containing Fe and Mo; sulfurizing the ground second mixed powder to form a sulfurized powder containing FeS and MoS 2 ; and molding the sulfurized powder by pressing the sulfurized powder to form the inner ring; placing the inner ring in the outer ring; and sintering the inner ring and the outer ring to obtain the bushing.

2 . The method according to claim 1 , wherein the first mixed powder containing Fe, Al, Ti, Cr and V comprises the following components in percentage by mass: 82% to 93% of Fe, 5.0% to 10.0% of Cr, 0.8% to 3.0% of Al, 1.0% to 3.0% of Ti, and 0.2% to 2.0% of V.

3 . The method according to claim 1 , wherein the second mixed powder containing Fe and Mo comprises the following components in percentage by mass: 85% to 97% of Fe and 3% to 15% of Mo.

4 . The method according to claim 1 , wherein the first mixed powder containing Fe, Al, Ti, Cr and V is ground for 1 h to 4 h.

5 . The method according to claim 1 , wherein the step of nitriding the ground first mixed powder comprises: nitriding the ground first mixed powder in an atmosphere of flowing NH 3 at 400° C. to 700° C. for 1 h to 4 h.

6 . The method according to claim 1 , wherein prior to the step of molding the nitrogen-rich stable compound powder, the method further comprises adding a third mixed powder containing Fe and Cu to the nitrogen-rich stable compound powder, mixing the third mixed powder and the nitrogen-rich stable compound powder, and ball milling the mixture including the third mixed powder for 4 h to 6 h.

7 . The method according to claim 6 , wherein the third mixed powder containing Fe and Cu comprises the following components in percentage by mass: 90% to 95% of Fe and 5% to 10% of Cu.

8 . The method according to claim 1 , wherein the step of molding the nitrogen-rich stable compound powder comprises: putting the nitrogen-rich stable compound powder into a bushing mold, and pressing and molding the nitrogen-rich stable compound powder with a pressure of 650 MPa to 800 MPa.

9 . The method according to claim 1 , wherein the second mixed powder containing Fe and Mo is ground for 1 h to 4 h.

10 . The method according to claim 1 , wherein the step of sulfurizing the ground second mixed powder comprises sulfurizing the ground second mixed powder in a sealed tank containing H 2 S gas at 540° C. to 600° C. for 1 h to 3 h.

11 . The method according to claim 1 , wherein the step of molding the sulfurized powder comprises: putting the sulfurized powder into the bushing mold, and pressing and molding the sulfurized powder with a pressure of 700 MPa to 850 MPa.

12 . The method according to claim 1 , wherein the step of placing the inner ring in the outer ring and sintering the inner ring and the outer ring to obtain the bushing comprises: assembling the inner ring and the outer ring and then carrying out sintering in a high-temperature furnace with a protective atmosphere of an inert gas at 1210° C. to 1260° C. for 1 h to 3 h.

13 . The method according to claim 1 , further comprising carrying out vacuum oil impregnating on the sintered bushing.

14 . The method according to claim 13 , wherein the step out vacuum oil impregnating on the sintered bushing comprises: cleaning the sintered bushing, placing the cleaned bushing in a vacuum chamber, sealing and vacuuming the vacuum chamber to -750 mmHg to -650 mmHg, feeding lubricating oil into the vacuum chamber, heating up the vacuum chamber to 80° C. to 90° C., and holding the temperature for 30 min to 50 min.

15 . A bushing prepared and formed by the method of claim 1 .

16 . An excavator comprising the bushing of claim 15 .

Assignees

• Jiangsu Xcmg Construction Machinery Res Institute Ltd

Inventors

• Xu Guo
• Chen Bo
• Feng Kun

Classifications

• C22C38/16

  containing copper · CPC title

• B22F7/062 Primary

  involving the connection or repairing of preformed parts · CPC title

• B22F3/26

  Impregnating {(making ferrous alloys by impregnation C22C33/0242)} · CPC title

• B22F9/16

  using chemical processes · CPC title

• B22F9/04

  starting from solid material, e.g. by crushing, grinding or milling ({C22C1/1084 takes precedence}; crushing, grinding or milling, in general, see the relevant subclasses, e.g. B02C) · CPC title