US-12617479-B2 - Work vehicle

US12617479B2US 12617479 B2US12617479 B2US 12617479B2US-12617479-B2

Abstract

A work vehicle includes a body 1 ; a plurality of travel wheels 2 at front and back portions of the body 1 on each of left and right sides; a plurality of holder mechanisms A held by the body 1 and holding the respective travel wheels 2 in such a manner as to be capable of moving the travel wheels 2 independently of one another relative to the body 1 ; and a plurality of crawler travel devices E attachable to and detachable from the respective holder mechanisms A.

Inventors

Minoru Hiraoka
Tomoyoshi Sakano
Junichi Ishikawa

Assignees

KUBOTA CORPORATION

Dates

Publication Date: 20260505
Application Date: 20211201
Priority Date: 20201211

Claims (7)

1 . A work vehicle, comprising: a body; a plurality of travel wheels at front and back portions of the body on each of left and right sides; a plurality of holder mechanisms held by the body and holding the respective travel wheels in such a manner as to be capable of moving the travel wheels independently of one another relative to the body; a plurality of auxiliary wheels disposed at front and back portions of the body on each of the left and right sides and held by the respective holder mechanisms; and a plurality of crawler travel devices attachable to and detachable from the respective holder mechanisms, each of the crawler travel devices comprising a driving sprocket, a driven sprocket, and a belt wound around the driving sprocket and the driven sprocket, wherein with each crawler travel device attached to a corresponding one of the holder mechanisms, the driven sprocket is coaxial with a corresponding one of the auxiliary wheels.
2 . The work vehicle according to claim 1 , wherein: the holder mechanisms each comprise a hydraulic motor configured to drive a corresponding one of the travel wheels, and the crawler travel devices are each drivable by a corresponding one of the hydraulic motors while the crawler travel device is attached to a corresponding one of the holder mechanisms.
3 . The work vehicle according to claim 2 , wherein: with each crawler travel device attached to a corresponding one of the holder mechanisms, the driving sprocket is coaxial with a corresponding one of the travel wheels and drivable by a corresponding one of the hydraulic motors.
4 . The work vehicle according to claim 1 , wherein: the driving sprocket has an axis apart from an outer surface of the belt by a first distance, whereas a corresponding one of the travel wheels has an axis apart from an outer surface of the corresponding travel wheel by a second distance, the first distance is equal to or smaller than the second distance.
5 . The work vehicle according to claim 1 , wherein: the holder mechanisms each comprise: a bendable link mechanism; and an orientation changer configured to change an orientation of the bendable link mechanism independently, and the bendable link mechanism has a leading end provided with a corresponding one of the travel wheels.
6 . The work vehicle according to claim 5 , wherein: the orientation changer is a hydraulic cylinder.
7 . The work vehicle according to claim 1 , wherein: the body comprises: a back body section; and a front body section swingable in a left-right direction of the body relative to the back body section, the front body section holds each holder mechanism holding a front one of the travel wheels, and the back body section holds each holder mechanism holding a rear one of the travel wheels.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is the United States national phase of International Application No. PCT/JP2021/044091 filed Dec. 1, 2021, and claims priority to Japanese Patent Application No. 2020-206227 filed Dec. 11, 2020, the disclosures of which are hereby incorporated by reference in their entireties. BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a work vehicle. Description of Related Art Patent Literature 1 discloses a rover designed to travel on rough terrain. The rover includes a body and four travel wheels each held by the body with a link mechanism in-between. The link mechanism is provided with an electric motor, and is drivable by means of the driving force from the electric motor to bend and stretch. Patent Literature 1 Japanese Unexamined Patent Application Publication, Tokukaihei, No. H9-142347 The rover disclosed in Patent Literature 1, which includes travel wheels, is only capable of traveling on a travel surface on which a vehicle is capable of traveling with use of travel wheels. SUMMARY OF THE INVENTION It is an object of the present invention to provide a work vehicle capable of traveling on various travel surfaces. To attain the above object, a work vehicle of the present invention includes: a body; a plurality of travel wheels at front and back portions of the body on each of left and right sides; a plurality of holder mechanisms held by the body and holding the respective travel wheels in such a manner as to be capable of moving the travel wheels independently of one another relative to the body; and a plurality of crawler travel devices attachable to and detachable from the respective holder mechanisms. With the above configuration, the work vehicle includes crawler travel devices attachable to and detachable from the respective holder mechanisms, and is thereby capable of traveling on various travel surfaces. The work vehicle is, for instance, capable of traveling on a smooth travel surface with use of travel wheels and on an uneven or soft travel surface with use of crawler travel devices. The work machine may preferably further include: the holder mechanisms each include a hydraulic motor configured to drive a corresponding one of the travel wheels, and the crawler travel devices are each drivable by a corresponding one of the hydraulic motors while the crawler travel device is attached to a corresponding one of the holder mechanisms. The above configuration allows use of hydraulic motors to drive both the travel wheels and the crawler travel devices. This simplifies the structure of the work vehicle, as compared to a work vehicle including separate driving sources for travel wheels and crawler travel devices. The work machine may preferably further include: the crawler travel devices each include: a driving sprocket; a driven sprocket; and a belt wound around the driving sprocket and the driven sprocket, and with each crawler travel device attached to a corresponding one of the holder mechanisms, the driving sprocket is coaxial with a corresponding one of the travel wheels and drivable by a corresponding one of the hydraulic motors. With the above configuration, each driving sprocket is coaxial with the corresponding travel wheel and is drivable by the corresponding hydraulic motor. This simplifies the mechanism for transmitting the driving force from the hydraulic motor to the driving sprocket. The work machine may preferably further include: a plurality of auxiliary wheels disposed at front and back portions of the body on each of the left and right sides and held by the respective holder mechanisms, wherein with each crawler travel device attached to a corresponding one of the holder mechanisms, the driven sprocket is coaxial with a corresponding one of the auxiliary wheels. With the above configuration, each driven sprocket is coaxial with the corresponding auxiliary wheel. This downsizes the holder mechanisms, the auxiliary wheels, and the entire crawler travel devices for a simple structure. The work machine may preferably further include: the driving sprocket has an axis apart from an outer surface of the belt by a first distance, whereas a corresponding one of the travel wheels has an axis apart from an outer surface of the corresponding travel wheel by a second distance, the first distance being equal to or smaller than the second distance. The above configuration allows the work vehicle to have its travel wheels in contact with a travel surface and travel with use of the travel wheels even with the crawler travel devices attached to the respective holder mechanisms, with the result of improved convenience. The work machine may preferably further include: the holder mechanisms each include: a bendable link mechanism; and an orientation changer configured to change an orientation of the bendable link mechanism independently, wherein the bendable link mechanism has a leading end provided with a corresponding