Device for operating a track tension wheel

Abstract

The invention relates to a device for operating a track tension wheel on a tracked vehicle. The device comprises two operating cylinders, a pivoting cylinder (38, 48) for pivoting a tension wheel arm (10) that carries a tension wheel, and a tensioning cylinder (28, 30) for changing the distance between the center (25) of the tension wheel and the center of rotation (12) of the tension wheel arm. The tensioning cylinder (28, 30) is pivotally connected to a pivoting link arm (36), which link arm is arranged to be stationary in a first phase of a pivoting upward movement of the tension wheel arm (10) from a lowered position and to pivot around its connection to the link arm (36). In a second phase of the upward pivoting movement, a lug (50) on the tension wheel arm (10) is arranged to engage with the link arm (36) to cause the tensioning cylinder (28, 30) to be pivoted around the connection of the link arm (36) to the attachment (18) during a continued upward pivoting movement of the tension wheel arm (10).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a tension wheel arm according to the invention in a fully lowered position and with the tension wheel projected maximally from the center of rotation;

FIG. 2 is a side view of the tension wheel arm according to the invention in a middle position;

FIG. 3 is a side view of the tension wheel arm according to the invention in a fully raised position;

FIG. 4 is a perspective view of the tension wheel arm according to the invention, viewed from the inside of the arm;

FIG. 5 is a side view of the tension wheel arm according to the invention in a partially sprung-inward position;

FIG. 6 is a side view of the tension wheel arm according to the invention in a maximally sprung-inward position;

FIG. 7 is a side view of the tension wheel arm according to the invention in a position in which the tension wheel is maximally retracted towards the center of rotation of the tension wheel arm; and

FIG. 8 is a side view of a tension wheel arm according to a second embodiment of the invention in a lowered position.

Claims

1. A device for operating a track tension wheel on a tracked vehicle, comprising: a tension wheel arm that has an axis of rotation at a first end, around which the arm can be pivoted in relation to the vehicle by means of a first drive member, and which tension wheel arm carries the tension wheel at its other end, via a rocker arm that is mounted on the tension wheel arm in such a way that it can pivot around a spindle; anda second drive member for changing the distance between the central axis of the tension wheel and the center of rotation of the tension wheel arm by pivoting the rocker arm in relation to the tension wheel arm, in order thereby to adjust the tension of, or alternatively to replace, a vehicle drive track that is running over the tension wheel,said first drive member having a first end that engages with the tension wheel arm at a distance from the center of rotation of the tension wheel arm in such a way that it can pivot, and a second end that is pivotally connected to a first attachment,said second drive member having a first end that is pivotally connected to a part that is connected to the rocker arm;wherein a second end of the second drive member is pivotally connected to a first pivoting link arm, which has a first end that is pivotally connected to a second attachment configured to be fixated to the vehicle, said first link arm being arranged, in a first position thereof, to engage with a retainer at the second attachment, in order to allow the second drive member to pivot around its connection to the first link arm in a first phase of the pivoting or springing upward movement of the tension wheel arm from a fully lowered position; and a lug on the tension wheel arm is arranged to engage with the first link arm in a second continued phase of the pivoting or springing upward movement of the tension wheel arm, to cause the second drive member to pivot around the connection of the first link arm to the second attachment during the continued pivoting or springing upward movement of the tension wheel arm.

2. The device according to claim 1, wherein the first end of the first link arm is pivotally connected to the second attachment at the axis of rotation of the tension wheel arm.

3. The device according to claim 2, wherein the second attachment is located inside a hub part of the tension wheel arm.

4. The device according to claim 1, wherein the first end of the second drive member is pivotally connected to a crank, which is rigidly connected to the spindle that carries the rocker arm.

5. The device according to claim 1, wherein the first drive member is arranged to allow an inward and outward springing movement of the tension wheel arm.

6. The device according to claim 5, wherein the first drive member is urged by a mechanical spring towards a first position in a non-rigid way, in which position the tension wheel arm assumes a lowered position, said first drive member being able be moved in its entirety and in a locked state towards a position that is displaced backward in relation to the first position, against the action of the tensioning force of the spring.

7. The device according to claim 6, wherein the second end of the first drive member is pivotally connected to the first attachment through a second pivoting link arm.

8. The device according to claim 7, wherein the second link arm has a first end that is pivotally connected to the second end of the first drive member, and a second end that is pivotally connected to the first attachment.

9. The device according to claim 8, wherein the mechanical spring consists of a torsion rod connected to the second end of the second link arm, which torsion rod is arranged to be attached to a fixed support on the vehicle.

10. The device according to claim 7, wherein the second link arm is designed in such a way that its two ends are located at essentially diametrically opposite sides of the axis of rotation of the tension wheel arm.

11. The device according to claim 1, wherein the first and second drive members consist of hydraulic compression cylinders.

12. The device according to claim 11, wherein the first drive member can be compressed in a non-rigid way by the action of a hydraulic or pneumatic spring unit, that comprises a pressure accumulator connected to the first drive member.

13. The device according to claim 1, wherein the first end of the first drive member is pivotally connected to the spindle.

14. The device according to claim 1, wherein the tension wheel arm is designed with a self-supporting housing in which the first and the second drive members are contained and arranged essentially overlapping each other.