ACTUATOR FOR MOVING A BLADE UNIT RELATIVE TO A FRAME OF A CONSTRUCTION MACHINE AND ASSOCIATED CONSTRUCTION MACHINE

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims foreign priority to European Application No. 24207581.0 filed on Oct. 18, 2024, the disclosure and content of which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

The disclosure relates generally to an actuator used in construction equipment. In a particular aspect, the disclosure relates to an electric actuator for moving a blade relative to a frame of a construction machine. The disclosure can be applied to heavy-duty vehicles, such as construction equipment, among other vehicle types. Although the disclosure may be described with respect to a particular vehicle, the disclosure is not restricted to any particular vehicle.

BACKGROUND

In construction equipment, such as excavators, it is known to use a mobile blade attached to the front of the frame of the construction machine.

This blade is used to push and leverage materials on the ground, such as rocks. In addition, during use of the excavator, for example when digging, the blade engages in the ground, providing the machine additional stability.

On conventional machines with thermal engine, a hydraulic cylinder is generally used to move the blade relative to the frame of the construction machine.

Although the use of a hydraulic cylinder is a cost-effective solution, such hydraulic cylinder cannot be used on full electric machines, since a full electric machine does not have any embedded hydraulic system.

To drive the blade on full electric machines,, it is known to use an electric cylinder.

However, such electric cylinders are not entirely satisfactory, since they are expensive and comprise sensitive components, which may be damaged by mud or rocks during operation.

The invention aims to provide a robust and cost-effective alternative to the electric cylinder for operating the blade of a construction machine, in particular of a full electric machine.

SUMMARY

According to a first aspect of the disclosure, the invention concerns an actuator, for moving a blade unit relative to a frame of a construction machine, comprising:

• • a motor configured to generate a rotating torque;
  • a drive unit comprising a pushing rod, the drive unit being configured to transform the rotating torque of the motor into a translation movement of the pushing rod; and
  • a bar comprising a first extremity, connected to the pushing rod by a first joint, and a second extremity, connected to the blade unit by a second joint;
    the motor and the drive unit being arranged at least partly in a housing defined in the frame of the construction machine.

The first aspect of the disclosure may seek to provide a robust alternative to the electric cylinders for operating the blade.

A technical benefit of the actuator may include that the sensitive components of the actuator, such as the motor and the drive unit, are protected from the muds and the rocks in the housing defined in the frame. Furthermore, the actuator is also easy to implement and cost-effective.

Optionally in some examples, including in at least one preferred example, the motor is an electric motor.

A technical benefit may include that the activation of the blade unit is electrified, which is particularly advantageous for fully electrified machine.

Optionally in some examples, including in at least one preferred example, the drive unit is a screw jack, the pushing rod being a screw.

A technical benefit may include that such a drive unit is easy to implement. Furthermore, due to the poor efficiency of the screw jack, the need of a brake to lock the motion when some load is applied on the blade is eliminated.

Optionally in some examples, including in at least one preferred example, the drive unit comprises a conic gear set.

A technical benefit may include that such a conic gear set offers a simple solution to transform the rotating movement of the motor into a translation movement of the pushing rod.

Optionally in some examples, including in at least one preferred example, wherein the first joint is a pivot joint.

A technical benefit may include that such pivot joint allows a rotation of the bar according to the pushing rod, thus simplifying the pushing of the bar by the pushing rod.

Optionally in some examples, including in at least one preferred example, the first joint is a yoke.

A technical benefit may include that a yoke is easy to implement.

Optionally in some examples, including in at least one preferred example, the actuator comprises a guiding mean configured to guide the movement of the first joint. A technical benefit may include that the guiding of the first joint improves the reliability of the actuator.

Optionally in some examples, including in at least one preferred example, the guiding mean comprises at least one sliding element arranged on the pushing rod configured to slide on rails.

A technical benefit may include that such a guiding mean is easy to implement and cost-effective. Furthermore, such a guiding mean is robust.

Optionally in some examples, including in at least one preferred example, the sliding element is a block with chamfers.

A technical benefit may include that such a shape of the pad facilitates its sliding.

Optionally in some examples, including in at least one preferred example, the guiding mean comprises a splined rod.

A technical benefit may include that such a guiding mean is an alternative equivalent solution to the guiding means with a pad.

Optionally in some examples, including in at least one preferred example, the second joint is a pivot joint.

A technical benefit may include that such pivot joint allows a rotation of the bar according to the blade unit, thus simplifying the pushing of the blade by the bar.

According to a second aspect of the disclosure, the invention concerns a construction machine comprising:

• • a frame comprising an housing,
  • a blade unit comprising a blade and an arm connected to the frame by a pivot joint,
  • an actuator as previously defined,
    the second extremity of the bar being connected to the blade unit by the second joint, and the motor and the drive unit being arranged at least partly in the housing.

Optionally in some examples, including in at least one preferred example, wherein the second joint is connected to the arm of the blade unit.

A technical benefit may include that this arrangement of the second joint improves the efficiency of the transmission of movement from the bar to the blade unit.

Optionally in some examples, including in at least one preferred example, the machine is an excavator.

The disclosed aspects, examples (including any preferred examples), and/or accompanying claims may be suitably combined with each other as would be apparent to anyone of ordinary skill in the art. Additional features and advantages are disclosed in the following description, claims, and drawings, and in part will be readily apparent therefrom to those skilled in the art or recognized by practicing the disclosure as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples are described in more detail below with reference to the appended drawings.

FIG. 1 is a schematic view of an exemplary construction machine according to the invention.

FIG. 2 is a schematic perspective view of an exemplary part of a construction machine comprising an actuator according to an example of the invention.

FIG. 3 and FIG. 4 are detailed views of the actuator and the blade unit of FIG. 2.

FIG. 5 is a schematic perspective view of an exemplary part of a construction machine comprising an actuator according to another example of the invention.

DETAILED DESCRIPTION

The detailed description set forth below provides information and examples of the disclosed technology with sufficient detail to enable those skilled in the art to practice the disclosure.

FIG. 1 shows a construction machine 10.

In some examples, the construction machine 10 is more particularly an excavator.

As visible in FIG. 1, the construction machine 10 comprises a frame 12, a blade unit 14 and an actuator 16 for moving the blade unit 14 relative to the frame 12.

In the particular example shown in FIG. 1, the construction machine 10 also comprises a cab 18 fitted to the frame 12. The cab 18 may be rotatable relative to the frame 12.

In some examples, the construction machine 10 also comprises a driving unit, for example comprising wheels and/or tracks 20 attached to the frame 12.

In some examples, the construction machine 10 also comprises a working device 22, for example including a boom 24 linked to the cab 18, an arm 26 and a bucket 28.

The frame 12 comprises a housing 30.

In some examples, as visible on FIG. 2, the frame 12 comprises two longitudinal members 32 connected by a cross-member 34.

In particular, the two longitudinal members 32 are parallel to each other, and extend for example according to a longitudinal direction X.

The longitudinal direction X corresponds for example to the circulation direction of the construction machine 10 and defines for example the front and the back of the construction machine 10.

More precisely, the driving unit 20 are for example fixed to the longitudinal members 32.

For example, the cross-member 34 extends between the two longitudinal members 32, and in particular according to a transversal direction Y perpendicular to the longitudinal direction X.

In some examples, the cross-member 34 defines the support of the cab 18.

In the particular example shown on FIG. 2, the cross-member 34 is hollow and defines the housing 30.

The housing 30 defines more particularly an inner volume 31 adapted to receive components.

The blade unit 14 comprises an arm 36 and a blade 38.

The arm 36 of the blade unit 14 is preferably connected to the frame 12 by a pivot joint 40.

More precisely, the arm 36 of the blade unit 14 is connected to the cross-member 34 of the frame 12, and in particular to the front face of said cross-member 34.

In some examples, thanks to the pivot joint 40, the arm 36 of the blade unit 14 is movable in rotation relative to the frame 12 around the transversal direction Y, for example upwards or downwards as visible by the arrow on FIG. 1.

In the particular example shown on FIG. 2, the arm 36 comprises two legs 42, each leg 42 being connected to the cross-member 34 of the frame 12 by a pin defining the pivot joint 40.

The blade 38 is preferably fixed to the extremity of the arm 36 opposed to the pivot joint 40.

More precisely, the blade 38 is integral with the arm 36.

In some example, the blade 38 is welded on the arm 36.

In some examples, the blade 38 is a plate, in particular a metallic plate, with a concavity. The concavity is on the side of the plate opposite to the arm 36, i.e. outwards.

The actuator 16 is configured to move the blade unit 14 relative to the frame 12.

The actuator 16 comprises a motor 44, a drive unit 46 and a bar 48.

Optionally, in some examples, the actuator 16 also comprises a guiding mean 50.

As visible on FIGS. 1 and 2, the motor 44 is arranged in the housing 30 defined in the frame 12, and more particularly inside the inner volume 31.

The motor 44 is adapted to generate a rotating torque.

In some examples, the motor 44 is an electric motor.

In particular, as visible on FIG. 4, the motor 44 comprises a rotating output shaft 52.

In some examples, as shown for example on FIG. 2, the motor 44 is arranged according to the transversal direction Y. More particularly, the motor rotating output shaft 52 extends parallel to the transversal direction Y.

As visible on FIGS. 1 and 2, the drive unit 46 is arranged at least partly in the housing 30 defined in the frame 12, and more particularly inside the inner volume 31.

The drive unit 46 comprises a pushing rod 54.

In some examples, the pushing rod 54 is configured to translate according to the longitudinal direction X, for example frontwards or backwards as shown on FIG. 1.

In some examples, the pushing rod 54 is perpendicular to the output shaft 52 of the motor 44.

The drive unit 46 is configured to transform the rotating torque of the motor 44 into the translation movement of the pushing rod 54.

To this end, in some examples, the drive unit 46 is a screw jack.

In particular, the pushing rod 54 is a screw, i.e. an at least partly threaded rod.

More particularly, the drive unit 46 further comprises for example a conic gear set 56 configured to transform the rotating torque of the motor 44 into a translation movement of the pushing rod 54.

More precisely, in some examples, as visible on FIG. 4, the gear set 56 is arranged between the motor output shaft 52 of the motor 44 and the pushing rod 54.

In particular, the conic gear set 56 cooperates with threads defined on the motor output shaft 52, so that a rotation of the motor output shat 52 leads to a rotation of the gear set 56.

Likewise, the gear set 56 cooperates with the threaded part of pushing rod 54, so that rotation of the gear set 56 leads to a translation movement of the pushing rod 54.

The bar 48 extends between a first extremity 58 and a second extremity 60.

The first extremity 58 is connected to the pushing rod 54 of the drive unit 46 by a first joint 62.

In some examples, the first joint 62 is a pivot joint, and in particular configured to allow a rotation of the bar 48 according to the pushing rod 54 around the transversal direction Y.

In an advantageous manner, the first joint 62 is a yoke.

As visible on FIGS. 1 and 2, the second extremity 60 of the bar 48 is connected to the blade unit 14 by a second joint 64.

More precisely, in some examples, the second extremity 60 of the bar 48 is connected to the arm 36 of the blade unit 14 by the second joint 64.

The second joint 64 is preferably a pivot joint, and in particular configured to allow a rotation of the bar 48 according to the blade unit 14 around the transversal direction Y.

In a preferred manner, the first joint 62 and the second joint 64 are configured so that a translation movement of the pushing rod 54 of the drive unit 46 leads to a rotation movement of the blade unit 14, and in particular of the blade 38, around the transversal direction Y, and more precisely upwards or downwards.

In some example, the guiding mean 50 is configured to guide the movement of the first joint 62.

In an example, the guiding mean 50 comprises an outer housing 66.

For example, as shown on FIG. 3, the outer housing 66 is fixed on the cross-member 34 of the frame 12, and is preferably connected to the inner volume 31 of the housing 30.

Advantageously, a part of the pushing rod 54 of the drive unit 46 and also the first joint 62 connecting the pushing rod 54 to the bar 48 are arranged inside said outer housing 66.

In some examples, the outer housing 66 comprises rails 68.

The guiding mean 50 comprises for example at least one sliding element 70 arranged on the pushing rod 54, as visible on FIGS. 3 and 4.

More precisely, the outer faces of the sliding element 70 are configured to slide on the rails 68 thus guiding the translation of the pushing rod 54 and thus guiding the movement of the first joint 62 pushed by the pushing rod 54.

In some example, the sliding element 70 is a block with chamfers and more precisely, defines a plurality of inclined outer faces configured to slide on corresponding inclined faces of the rails 68.

For example, as illustrated, the sliding element 70 defines two inclined outer faces. More precisely, the sliding element 70 defines two inclined outer lower faces sliding on corresponding inclined faces of the rails 68 and a flat upper face sliding on a corresponding upper flat rail 68, for example a plate.

Alternatively, the sliding element 70 defines four inclined outer faces.

In one example, the sliding element 70 is metallic and the inclined faces of the rails 68 are covered with a polymer coating, for example with a polytetrafluoroethylene (PTFE) coating, in particular with a Teflon™ coating. Alternatively, the sliding element 70 is a polymer pad, in particular a Teflon™ pad and the rails 68 are metallic.

An exemplar use of the actuator 16 to move the blade unit 14 relative to the frame 12 of the construction machine 10 will now be described.

The motor 44 is first activated to generate a rotating torque in a first direction, for example following a command of a user, for example seated in the cab 18.

In particular, the motor output shaft 52 of the motor 44 rotates in the first direction, for example counter-clockwise, along the transversal direction Y.

Then, the drive unit 46 transforms said rotating torque in the first direction in a translation of the pushing rod 54, for example frontwards.

In particular, the rotation of the motor output shaft 52 leads to a rotation of the gear set 56, thus leading to the translation of the pushing rod 54.

The translation of the pushing rod 54 leads to a translation of the first joint 62, in particular pushing the bar 48 for example frontwards.

In some examples, said translation of the pushing rod 54 and thus of the first joint 62 is guided by the guiding mean 50.

More precisely, the sliding element 70 fixed on the pushing rod 54 slides on the rails 68.

Then, the translation frontwards of the first joint 62 leads to a rotation of the bar 48 around the transversal direction Y by means of the second joint 64, in this case downwards, as illustrated on FIG. 1.

This movements thus leads to a downward rotation of the blade unit 14 along the transversal direction, and thus of the blade 38.

The same applies in the opposite direction when the motor is activated in the opposite rotating direction, i.e. clockwise, thus leading to an upward rotation of the blade unit 14.

The actuator 16 according to the invention offers a solution to electrify the activation of the blade unit 14 in an advantageous manner.

First, the actuator 16 is robust. Indeed, the sensitive components of the actuator 16, such as the motor 44 and the drive unit 46, are protected from the muds and the rocks in the housing 30 defined in the frame 12.

The actuator 16 is also easy to implement and cost-effective.

Moreover, the actuator 16 is low maintenance.

Furthermore, this actuator 16 eliminates the need of a brake to lock the motion when some load is applied on the blade 38. This is due to the poor efficiency of a screw jack, making it not reversible.

In another example illustrated on FIG. 5, the guiding mean 50 does not comprise a sliding element 70, nor an outer housing 66 with rails 68.

In this other example illustrated on FIG. 5, the guiding mean 50 comprises a splined rod 72, in particular fixed to the frame 12, and more precisely to the cross-member 34 of the frame 12.

For example, the first joint 62 comprises an intermediary piece 74 linked on one side to the pushing rod 54, for example by a pivot with a pivot axis according to the vertical direction Z, and on the other side to the bar 48 by a pivot, for example with a pivot axis according to the transversal direction Y.

This intermediary piece 74 is advantageously mounted on the splined rod 72, such that it is adapted to slide on the splined rod 72.

In this example, the translation of the pushing rod 54 leads to a translation of the first joint 62 by the translation of intermediary piece 74 guided by the splined rod 72.

In some example, the actuator 16 comprises two bars 48 as for example shown on FIG. 5.

In some examples, as for example shown on FIG. 5, the motor 44 is arranged according to the longitudinal direction X.

Such an arrangement of the motor 44 reduces the width required to arrange the actuator 16 inside the housing 30.

In these examples, the actuator 16 preferably comprises a gear box 76 arranged between the motor 44 and the drive unit 46.

In an advantageous manner, the gear box 76 with its gear ratio, allows to have a smaller motor, with less torque but turning faster.

Example 1: An actuator 16, for moving a blade unit 14 relative to a frame 12 of a construction machine 10, comprising:

• • a motor 44 configured to generate a rotating torque;
  • a drive unit 46 comprising a pushing rod 54, the drive unit 46 being configured to transform the rotating torque of the motor 44 into a translation movement of the pushing rod 54; and
  • a bar 48 comprising a first extremity 58, connected to the pushing rod 54 by a first joint 62, and a second extremity 60, connected to the blade unit 14 by a second joint 64;
    the motor 44 and the drive unit 46 being arranged at least partly in a housing 30 defined in the frame 12 of the construction machine 10.

Example 2: The actuator 16 according to example 1, wherein the motor 44 is an electric motor.

Example 3: The actuator 16 according to any one of examples 1 or 2, wherein the drive unit 46 is a screw jack, the pushing rod 54 being a screw.

Example 4: The actuator 16 according to example 3, wherein the drive unit 46 comprises a conic gear set 56.

Example 5: The actuator 16 according to any one of examples 1 to 4, wherein the first joint 62 is a pivot joint.

Example 6: The actuator 16 according to example 5, wherein the first joint 62 is a yoke.

Example 7. The actuator 16 according to any one of examples 5 or 6, comprising a guiding mean 50 configured to guide the movement of the first joint 62.

Example 8. The actuator 16 according to example 7, wherein the guiding mean 50 comprises at least one sliding element 70 arranged on the pushing rod 54 configured to slide on rails 68.

Example 9. The actuator 16 according to example 8, wherein the sliding element 70 is a block with chamfers.

Example 10. The actuator 16 according to example 7, wherein the guiding mean 50 comprises a splined rod.

Example 11. The actuator 16 according to any one of examples 1 to 10, wherein the second joint 64 is a pivot joint.

Example 12. A construction machine 10 comprising:

• • a frame 12 comprising an housing 30,
  • a blade unit 14 comprising a blade 38 and an arm 36 connected to the frame 12 by a pivot joint 40,
  • an actuator 16 according to any one of examples 1 to 11,
    the second extremity 60 of the bar 48 being connected to the blade unit 14 by the second joint 64, and
    the motor 44 and the drive unit 46 being arranged at least partly in the housing 30.

Example 13. The construction machine 10 according to example 12, wherein the second joint 64 is connected to the arm 36 of the blade unit 14.

Example 14. The construction machine 10 according to any one of examples 12 or 13, wherein the machine is an excavator.

The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including” when used herein specify the presence of stated features, integers, actions, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, actions, steps, operations, elements, components, and/or groups thereof.

It will be understood that, although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the present disclosure.

Relative terms such as “below” or “above” or “upper” or “lower” or “horizontal” or “vertical” may be used herein to describe a relationship of one element to another element as illustrated in the Figures. It will be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It is to be understood that the present disclosure is not limited to the aspects described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present disclosure and appended claims. In the drawings and specification, there have been disclosed aspects for purposes of illustration only and not for purposes of limitation, the scope of the disclosure being set forth in the following claims.