Work vehicle

Patent metadata

Field	Value
Publication number	US-11697402-B2
Application number	US-202217744989-A
Country	US
Kind code	B2
Filing date	May 16, 2022
Priority date	Sep 7, 2021
Publication date	Jul 11, 2023
Grant date	Jul 11, 2023

Abstract

A diff-lock operation shaft 50 is supported by a case 11 in such a manner as to be rotatable around an axis P 1 of the diff-lock operation shaft 50 and operates a diff-lock section 48 to a lock position A 2 by being rotated, and a first coil spring 51 is wound around the outer surface of the diff-lock operation shaft 50 concentrically with the diff-lock operation shaft 50 , and is linked at one end portion 51 b to the diff-lock operation shaft 50 and at another end portion 51 a to linking members 55 and 56 . The first coil spring 51 is twisted around the axis P 1 via the linking members 55 and 56 by the manual operation tool 58 being operated, and the diff-lock operation shaft 50 is rotated via the first coil spring 51.

First claim

What is claimed is:

1. A work vehicle comprising:
right and left travel devices;
a differential configured to distribute power from a motor section to the right and left travel devices;
a diff-lock section operable to an operating position in which the differential is operational and a diff-lock position in which the differential is locked;
a diff-lock device configured to operate the diff-lock section to the operating position and the diff-lock position;
a case housing the differential, the diff-lock section and the diff-lock device;
a diff-lock operation tool configured to be manually operated;
a linking member connected between the diff-lock device and the diff-lock operation tool,
a parking brake provided in a transmission system from the motor section to the differential;
a brake operation tool configured to operate the parking brake to a braking state by being manually operated and
a flexible spring connected between the linking member and the brake operation tool,
wherein-the diff-lock device includes:
a diff-lock operation shaft supported by the case in such a manner as to be rotatable around an axis of the diff-lock operation shaft, and configured to operate the diff-lock section to the diff-lock position by being rotated; and
a first coil spring wound around an outer surface of the diff-lock operation shaft concentrically with the diff-lock operation shaft, and linked at one end portion to the diff-lock operation shaft and at another end portion to the linking member, and
the first coil spring is wound around the outer surface of a portion of the diff-lock operation shaft protruding externally from the case,
the one end portion and the other end portion of the first coil spring are respectively linked to the diff-lock operation shaft, outside the case,
due to the diff-lock operation tool being operated, the first coil spring is twisted around the axis via the linking member, and the diff-lock operation shaft is rotated via the first coil spring, and
due to the brake operation tool being operated, the first coil spring is twisted around the axis via the flexible spring and the linking member, and the diff-lock operation shaft is rotated via the first coil spring.

2. The work vehicle according to claim 1 ,
wherein, in at least one of a portion where the one end portion of the first coil spring is linked to the diff-lock operation shaft and a portion where the other end portion of the first coil spring is linked to the linking member, the linked sections become separated from each other in response to the diff-lock operation shaft being rotated by the one of the diff-lock operation tool and the brake operation tool being operated.

3. The work vehicle according to claim 1 ,
wherein the diff-lock operation shaft extends to one of left and right sides and to another of the left and right sides with respect to a left-right center of the differential, and
wherein a portion of the diff-lock operation shaft on the one of the left and right sides and a portion of the diff-lock operation shaft on the other of the left and right sides are rotatably supported by the case.

4. The work vehicle according to claim 3 ,
wherein the diff-lock device comprises:
a fork section attached to the portion of the diff-lock operation shaft on the one of the left and right sides in such a manner as to be movable along the axis, and engaging with the diff-lock section;
a cam section configured to, in response to the diff-lock operation shaft being rotated, transmit the rotation of the diff-lock operation shaft to the fork section and move the fork section such that the diff-lock section is operated to the diff-lock position; and
a second coil spring wound around the outer surface of the diff-lock operation shaft concentrically with the diff-lock operation shaft to span from the fork section to the portion on the other of the left and right sides of the diff-lock operation shaft, and biasing the fork section such that the diff-lock section is operated to the operating position.

Assignees

• Kubota Kk

Inventors

• Yasuda Toshifumi
• Takami Akihiro

Classifications

• F16H48/24

  using positive clutches or brakes · CPC title

• F16H63/3416

  Parking lock mechanisms or brakes in the transmission · CPC title

• B60T1/005 Primary

  by locking of wheel or transmission rotation · CPC title

• F16H2063/3089

  Spring assisted shift, e.g. springs for accumulating energy of shift movement and release it when clutch teeth are aligned · CPC title

• F16H2048/305

  using manual actuators · CPC title