Torsional isolation of a drive system

• US 9,233,723 B1
• Filed: 07/31/2014
• Issued: 01/12/2016
• Est. Priority Date: 07/31/2014
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Metzger, Rustin, Speichinger, Justin
• Primary Examiner(s): Hurley, Kevin
• Application Number:
  US14/447,925
• Publication Number:
  US 20160031499A1
• Time in Patent Office: 530 Days
• US Class Current: 1/1
• CPC Class Codes: B62D 55/06 with tracks without ground wheels
• CPC Class Codes: B62D 55/12 Arrangement, location, or adaptation of driving sprockets

Abstract

A hydraulic drive system may include a hydraulic motor and a drive sprocket. The hydraulic drive system may also include a torsional isolation member that is operably connected between the hydraulic motor and the drive sprocket. The torsional isolation member may be configured to operably disconnect the hydraulic motor from the drive sprocket when the drive sprocket reaches a predetermined torque load.

Claims

1. A drive system, comprising:

a motor;

a drivetrain having at least one shaft operably connected to the motor, wherein the motor is configured to rotate the drivetrain;

a drive sprocket operably connected to the drivetrain such that rotation of the drivetrain rotates the drive sprocket, wherein the drive sprocket is arranged and configured to move a drive track; and

a torsional isolation member operably connected between the motor and the drive sprocket, wherein the torsional isolation member is arranged and configured to operably disconnect the motor from the drive sprocket when the drive sprocket reaches a predetermined torque load,

wherein the drive sprocket defines a plurality of teeth that are arranged around 360-degrees of a periphery of the drive sprocket and arranged and configured to engage the drive track, the drive track is movably connected to the drive sprocket and includes a plurality of teeth engaging portions that are arranged and configured to engage a portion of the plurality of teeth of the drive sprocket, and the portion of the plurality of teeth of the drive sprocket is less than 180 degrees of the periphery of the drive sprocket.

2. The drive system of claim 1, wherein the torsional isolation member is a slip-clutch.

3. The drive system of claim 2, wherein the slip-clutch is biased to a locked position.

4. The drive system of claim 1, wherein the portion of the plurality of teeth of the drive sprocket is less than or equal to 90 degrees of the periphery of the drive sprocket.

5. The drive system of claim 4, wherein when the portion of the plurality of teeth of the drive sprocket disengage from the drive track and then reengage the drive track, the torsional isolation member disengages the drive sprocket from the motor.

6. The drive system of claim 5, wherein when the portion of the plurality of teeth of the drive sprocket have been engaged with the corresponding plurality of teeth engaging portions of the drive track for at least five seconds, the drive system operates within an operating torque range, and wherein the predetermined torque load is equal to four times a maximum of the operating torque range.

7. The drive system of claim 6, further comprising a hydraulic pump operably connected to an engine that is configured to actuate the hydraulic pump, wherein the motor is a hydraulic motor that is actuated by the hydraulic pump, and wherein the drivetrain includes:

a motor shaft having a first end and a second end opposite the first end, wherein the first end of the motor shaft is operably connected to the hydraulic motor;

a drive shaft having a first end and a second end opposite the first end, wherein the first end of the drive shaft is operably connected to the second end of the motor shaft; and

a pair of planetary gears operably connected between the second end of the drive shaft and the drive sprocket, and wherein when the slip-clutch disconnects the hydraulic motor from the drive sprocket upon the drive sprocket reaching a predetermined torque load, the slip-clutch disconnects the second end of the motor shaft from the first end of the drive shaft, the drive system further comprising a brake pack operably connected to the drivetrain, wherein the brake pack is configured to impede the rotation of the drivetrain.

8. A machine, comprising:

a motor;

a drivetrain having at least one shaft operably connected to the motor, wherein the motor is arranged and configured to rotate the drivetrain;

a drive sprocket operably connected to the drivetrain such that rotation of the drivetrain rotates the drive sprocket;

a drive track movably connected to the drive sprocket; and

a torsional isolation member operably connected between the motor and the drive sprocket, the torsional isolation member arranged and configured to operably disconnect the motor from the drive sprocket when the drive sprocket reaches a predetermined torque load, wherein the torsional isolation member is a slip-clutch that is biased to a locked position.

9. The machine of claim 8, further comprising first and second idlers rotatably connected to the drive track and spaced from each other along a horizontal direction, wherein the drive sprocket is mounted above the first and second idlers along a vertical direction that is perpendicular to the horizontal direction.

10. The machine of claim 9, wherein the drive sprocket defines a plurality of teeth that are arranged around 360-degrees of a periphery of the drive sprocket and arranged and configured to engage the drive track, and wherein the drive track defines a plurality of teeth engaging portions that are arranged and configured to engage a portion of the plurality of teeth of the drive sprocket.

11. The machine of claim 10, wherein the portion of the plurality of teeth of the drive sprocket is less than or equal to 90 degrees of the periphery of the drive sprocket, wherein when the plurality of teeth of the drive sprocket have been engaged with the corresponding plurality of teeth engaging portions of the drive track for at least five seconds, the drive system operates within an operating torque range, and wherein the predetermined torque load is equal to four times a maximum of the operating torque range.

12. The machine of claim 11, wherein the motor is a hydraulic motor, and wherein the drivetrain includes:

a motor shaft having a first end and a second end opposite the first end, wherein the first end of the motor shaft is operably connected to the hydraulic motor;

a drive shaft having a first end and a second end opposite the first end, wherein the first end of the drive shaft is operably connected to the second end of the motor shaft; and

a pair of planetary gears operably connected between the second end of the drive shaft and the drive sprocket, and wherein when the slip-clutch disconnects the hydraulic motor from the drive sprocket upon the drive sprocket reaching a predetermined torque load, the slip-clutch disconnects the second end of the motor shaft from the first end of the drive shaft, the drive system further comprising a brake pack operably connected to the drivetrain, wherein the brake pack is configured to impede the rotation of the drivetrain.

13. A method of manufacturing a drive system, comprising:

connecting a drivetrain having at least one shaft to a motor, wherein the motor is arranged and configured to rotate the drivetrain;

connecting a drive sprocket to the drivetrain such that the rotation of the drivetrain rotates the drive sprocket, wherein the drive sprocket defines a plurality of teeth that are arranged around 360-degrees of a periphery of the drive sprocket;

connecting a drive track to the drive sprocket, wherein the drive sprocket is arranged and configured to move the drive track, wherein the drive track has a plurality of teeth engaging portions that are arranged and configured to engage a portion of the plurality of teeth of the drive sprocket, the portion of the plurality of teeth of the drive sprocket is less than 180 degrees of the periphery of the drive sprocket; and

connecting a torsional isolation member between the motor and the drive sprocket, wherein the torsional isolation member is arranged and configured to operably disconnect the motor from the drive sprocket when the drive sprocket reaches a predetermined torque load.

14. The method of claim 13, wherein the drive track moves around a first idler, a second idler, wherein the first and second idlers are spaced from each other along a horizontal direction, and the drive sprocket that is arranged between the first and second idlers along the horizontal direction and above the first and second idlers along a vertical direction that is perpendicular to the horizontal direction.

15. The method of claim 14, further comprising arranging and configuring the drive sprocket such that the portion of the plurality of teeth of the drive sprocket is less than or equal to 90 degrees of the periphery of the drive sprocket.

16. The method of claim 15, wherein the motor is a hydraulic motor and the torsional isolation member is a slip-clutch that is biased to a locked position, wherein when the plurality of teeth of the drive sprocket have been engaged with the corresponding plurality of teeth engaging portions of the drive track for at least five seconds, the drive system operates within an operating torque range, and wherein the predetermined torque load is equal to four times a maximum of the operating torque range.