Conversion of a power machine between wheeled and endless track tractive elements

Patent metadata

Field	Value
Publication number	US-12409901-B2
Application number	US-202017613562-A
Country	US
Kind code	B2
Filing date	May 26, 2020
Priority date	May 24, 2019
Publication date	Sep 9, 2025
Grant date	Sep 9, 2025

Abstract

A kit and corresponding method can be used to convert wheels of a power machine to track assemblies, such as to convert a four-wheeled power machine to a quad track power machine. A stub shaft ( 346 ) can be secured to an axle ( 328 ) of a power machine ( 300 ) and can be configured to support a track frame ( 366 ) of a track assembly in place of a wheel ( 319 ). A bearing ( 368 ) can be secured to the stub shaft ( 346 ) and a bushing ( 376 ) can engage the axle ( 328 ) to rotatably support the track assembly relative to the axle ( 328 ). Pieces of a segmented sprocket ( 378, 380 ) can be separately secured to a hub ( 306 ) of a power machine ( 300 ) to help install and drive a track of a track assembly.

First claim

What is claimed is:

1. A kit for converting a wheeled power machine to a tracked power machine, the wheeled power machine including an axle with a rotating axle shaft, a hub secured to the axle shaft inboard of an outboard end of the axle shaft, and a wheel secured to the hub, the kit comprising:
a stub shaft positionable outboard of the hub when the wheel is removed from the hub, the stub shaft configured to be secured at the outboard end of the axle shaft;
a track frame configured to be operably coupled to the axle at the stub shaft; and
a sprocket configured to be secured to the hub in place of the wheel to move a track about the track frame upon rotation of the axle shaft.

2. The kit of claim 1 , with the axle further including a non-rotating axle tube that surrounds the axle shaft, the kit further comprising:
a first bearing configured to engage the stub shaft and the track frame to operably couple the track frame to the axle shaft; and
a second bearing configured to engage the axle tube and to rotatably support the track frame relative to the axle opposite and inboard the hub from the first bearing.

3. The kit of claim 2 , wherein at least part of the second bearing is integrally formed with the track frame.

4. The kit of claim 1 , wherein the stub shaft has an engagement feature configured to engage a complementary feature on the axle to position and support the stub shaft relative to the axle.

5. The kit of claim 4 , wherein the engagement feature includes a boss configured to extend into a corresponding recess on the outboard end of the axle shaft of the axle.

6. The kit of claim 1 , wherein the stub shaft is one of four substantially identical stub shafts, each configured to rotatably support a corresponding track frame relative to a corresponding axle of the wheeled power machine, to convert the wheeled power machine to a quad track power machine.

7. The kit of claim 1 , wherein the sprocket includes a segmented sprocket with at least three sprocket pieces configured to collectively define a substantially circular sprocket profile;
the at least three sprocket pieces being configured to be separately secured to the hub to be engaged with the track.

8. The kit of claim 7 , wherein the segmented sprocket includes one of the following configurations:
a first of the sprocket pieces is a semi-circular sprocket piece and a second and a third of the sprocket pieces are quarter-circular sprocket pieces; and
each of the at least three sprocket pieces is a third-circular sprocket piece.

9. A method of converting a power machine from using wheeled tractive elements to tractive elements that each include an endless track, the method comprising:
removing a wheel from a hub of an axle of the wheeled power machine;
attaching a stub shaft to an outboard end of an axle shaft of the axle;
rotatably securing a track frame to the stub shaft;
supporting the stub shaft on the track frame with a first bearing outboard of the hub;
supporting the axle on the track frame with a second bearing inboard of the hub;
aligning a track on the track frame;
attaching a sprocket to the hub inboard of the stub shaft; and
rotating the hub to tension the track with the sprocket.

10. The method of claim 9 , wherein the sprocket is a segmented sprocket including at least two sprocket pieces; and
wherein a first of the sprocket pieces is attached to the hub and rotated to engage the track before a second sprocket piece is attached to the hub.

11. The method of claim 10 , wherein the segmented sprocket includes one of the following sets of sprocket pieces:
a semi-circular sprocket piece and two quarter-circular sprocket pieces; and
three third-circular sprocket pieces.

12. The method of claim 9 , wherein aligning the track, attaching the sprocket, and rotating the hub include:
securing a first sprocket piece of a segmented sprocket to the hub;
placing a track in alignment with the first sprocket piece;
rotating the hub to tension the track with the first sprocket piece; and
after tensioning the track with the first sprocket piece, securing second and third sprocket pieces of the segmented sprocket to the hub.

13. The method of claim 12 , wherein the first sprocket piece is a semi-circular sprocket piece and the second and third sprocket pieces are quarter-circular sprocket pieces.

14. The method of claim 12 , wherein each of the first, second, and third sprocket pieces are third-circular sprocket pieces.

15. The method of claim 9 , further comprising:
removing an end cap from the outboard end of the axle shaft of the axle;
wherein the stub shaft is attached to the outboard end of the axle shaft in place of the end cap.

16. A kit for converting a wheeled power machine to a tracked power machine, the wheeled power machine including an axle with an axle shaft, a hub supported by the axle shaft, a wheel secured to the hub, and an end cap secured to fastener holes at an outboard end of the axle shaft, with a track frame being provided to replace the wheel, the kit comprising:
a stub shaft configured to be secured at the fastener holes at the outboard end of the axle shaft, spaced outboard of the hub, in place of the end cap, the stub shaft including a support shaft and a cylindrical flange that extends radially outward from an inboard end of the support shaft, the support shaft having one or more fastener holes extending axially through the support shaft;
the stub shaft being further configured to rotatably support the track frame relative to the axle and to be secured at the fastener holes at the outboard end of the axle using the one or more fastener holes.

17. The kit of claim 16 , further comprising:
a segmented socket configured to be secured to the hub to rotate relative to the track frame.

18. A method of converting a power machine from using wheeled tractive elements to tractive elements that each include an endless track, the method comprising:
removing a wheel from a hub of an axle of the wheeled power machine;
removing an end cap from an outboard end of an axle shaft of the axle;
attaching a stub shaft to the outboard end of the axle shaft in place of the end cap;
rotatably securing a track frame to the stub shaft;
aligning a track on the track frame;
attaching a sprocket to the hub inboard of the stub shaft; and
rotating the hub to tension the track with the sprocket.

19. A method of converting a power machine from using wheeled tractive elements to tractive elements that each include an endless track, the method comprising:
removing a wheel from a hub of an axle of the wheeled power machine;
attaching a stub shaft to an outboard end of an axle shaft of the axle;
rotatably securing a track frame to the stub shaft;
aligning a track on the track frame;
attaching a sprocket to the hub inboard of the stub shaft; and
rotating the hub to tension the track with the first sprocket piece;
wherein aligning the track, attaching the sprocket, and rotating the hub include:
securing a first sprocket piece of a segmented sprocket to the hub;
placing a track in alignment with the first sprocket piece;
rotating the hub to tension the track with the first sprocket piece; and
after tensioning the track with the first sprocket piece, securing second and third sprocket pieces of the segmented sprocket to the hub.

Assignees

• Doosan Bobcat North America Inc

Inventors

• Agnew Dennis

Classifications

• B62D55/13

  readily interchangeable modular type · CPC title

• B62D55/065

  Multi-track vehicles, i.e. more than two tracks {(soil-shifting machines E02F; mining machines E21C)} · CPC title

• B62D55/04 Primary

  with tracks and alternative ground wheels, e.g. changeable from endless track vehicle into wheeled vehicle and vice versa {(for multi-purpose tractors B62D49/0635)} · CPC title

• B62D55/12

  Arrangement, location, or adaptation of driving sprockets · CPC title

• B62D55/084 Primary

  Endless-track units or carriages mounted separably, adjustably or extensibly on vehicles, e.g. portable track units (B62D55/07 takes precedence) · CPC title