Construction Machine

This application claims foreign priority to European Application No. 24168770.6 filed on Apr. 5, 2024, the disclosure and content of which is incorporated by reference herein in its entirety.

The disclosure relates generally to construction machines. In particular aspects, the disclosure relates to construction machines who rotate around a center axis. The disclosure can be applied to vehicle types like excavators, telehandlers, forestry machines or the like, but is not limited to that. Although the disclosure may be described with respect to a particular vehicle, the disclosure is not restricted to any particular vehicle.

Excavators and similar structurally pivoting machines generate or store energy mostly in either lower or upper carriage, rising the need for power transfer from one part of machine to the other. In case of hydraulic power, transfer from upper to mostly lower carriage for propulsion purpose is done via a slip ring connection. In case of an electric or electro-hydraulic or hybrid machine, electric energy will be transferred via electric high voltage slip-rings. All these solutions have a high space claim and contribute to transfer losses, limiting efficiency and/or travel range.

According to a first aspect of the disclosure, the disclosure relates to a construction machine with a power transfer system. The power transfer system comprises: a rotor shaft arranged partly in an upper carriage and partly in a lower carriage of the construction machine, wherein the rotor shaft is partly arranged within a main bearing of the construction machine and/or in a center of rotation of the construction machine and at least one stator arranged in the upper carriage and/or in the lower carriage of the construction machine.

The first aspect of the disclosure may seek to provide a more compact, less susceptible to wear and efficient solution for power transfer from the upper carriage to the lower carriage and/or vice versa. According to the invention a central shaft along the center of rotation of the machine and/or in the main bearing is used to provide rotation and torque to lower and upper carriage. The invention is based on the recognition that by this arrangement the transfer of power becomes a direct mechanical and therefore lossless drive.

Optionally in some examples, including in at least one preferred example, the power transfer system further comprises at least one output shaft connected to the rotor shaft.

Using at least one output shaft connected to the rotor shaft allows to provide rotation and torque to lower and upper carriage.

In further examples a first output shaft is arranged in the upper carriage and a second output shaft is arranged in the lower carriage.

Optionally in some examples, including in at least one preferred example at least one consumer, preferably a differential, a hydraulic pump, a coupling and/or a generator is connected to the at least one output shaft or directly to the rotor shaft. It is further preferred if the differential is driving at least one propeller shaft.

A technical benefit may include that a modular approach is thus enabled, e.g. using an electric motor in the upper carriage connected via the rotor shaft to a differential in the lower carriage in order to enable an efficient travel function in wheeled excavator. Using an electric motor with two output shafts, the same motor could also drive a hydraulic pump in upper carriage, saving on cost, and a generator in lower carriage to power auxiliary functions.

Optionally in some examples, including in at least one preferred example, one elongated stator extends in the upper and in the lower carriage.

Optionally in some examples, including in at least one preferred example, the rotor shaft is a hollow shaft. A technical benefit may include that a hollow rotor shaft enables electrical or optical data transfer between upper and lower frame, e.g. to control functions.

This can be realized in some examples, including in at least one preferred example, in that at least one cable, preferably at least one electrical cable or at least one optical fiber arrangement is arranged in the hollow shaft

Furthermore in some examples, including in at least one preferred example, the hollow shaft is able and arranged to be used as light guide.

Compared to known solutions with slip rings the use of a hollow rotor shaft within a main bearing of the construction machine and/or in a center of rotation of the construction machine allows for transfer of power as well data transmission between upper and lower carriage with less disturbing effects in the data transmission.

Optionally in some examples, including in at least one preferred example, the construction machine comprises exactly one electric motor, preferably coupled to the power transfer system or comprising the rotor shaft. A technical benefit may include that the exact one electric motor together with the power transfer allows for a more compact realization of the power system of the construction machine with only one electric motor.

Optionally in some examples, including in at least one preferred example, the exact one electric motor is arranged in the upper carriage or in the lower carriage.

It is further preferred if the exactly one electric motor is a propulsion unit of the construction machine, preferably the sole propulsion unit. Thus a technical benefit may include that the only electric motor provides the necessary mechanical power supply for the whole construction machine. Especially in the case of mobile (wheeled) excavator the main power need in lower carriage will be used for propulsion, whereas in the upper carriage further working functions have to be powered. In this embodiment clutches can be foreseen to for example disengage a differential, in cases when only hydraulic power is needed.

Optionally in some examples, including in at least one preferred example, the construction machine is an excavator or a telehandler, or a forestry machine.

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.

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.

is an exemplary a construction machine, herein an excavator, according to an example. The construction machinehas a power transfer system. The power transfer systemcomprises a rotor shaftand two stators. The rotor shaftis arranged partly in an upper carriageand partly in a lower carriageof the construction machine. Furthermore the rotor shaftis partly arranged within a main bearingof the construction machine and in a center of rotation of the construction machine. In the shown example one statoris arranged in the upper carriageand a further statoris arranged in the lower carriageof the construction machine.

The construction machinefurther comprises two consumers, which are directly connected to the rotor shaft, one of them arranged in the upper carriage, the other one in the lower carriage. The consumersmay be a differential, a hydraulic pump, a coupling or a generator. In not shown alternative the power transfer system may further comprise a first output shaft arranged in the upper carriage and a second output shaft arranged in the lower carriage, each of which is connected to a consumer.

While in the shown example two stators are used, alternatively also only one elongated stator extending in the upper and in the lower carriage could be used. The rotor shaft is preferably a hollow shaft, in which at least one cable, preferably at least one electrical cable or at least one optical fiber arrangement is arranged in the hollow shaft.

The construction machine comprises exactly one electric motor (comprising the rotor shaftand the statorin the upper carriage. The exactly one electric motor is a propulsion unit of the construction machine, herein the sole propulsion unit.

Example 1: A construction machine with a power transfer system, the power transfer system comprising:

Example 2: Construction machine according to claim, the power transfer system further comprising at least one output shaft connected to the rotor shaft.

Example 3: Construction machine according to claim, wherein a first output shaft is arranged in the upper carriage and a second output shaft is arranged in the lower carriage.

Example 4: Construction machine according to claimsto, wherein at least one consumer, preferably a differential, a hydraulic pump, a coupling and/or a generator, is connected to the at least one output shaft.

Example 5: Construction machine according to one of the preceding claims, wherein one elongated stator extends in the upper and in the lower carriage.

Example 6: Construction machine according to one of the preceding claims, wherein the rotor shaft is a hollow shaft.

Example 7: Construction machine according to claim, wherein at least one cable, preferably at least one electrical cable or at least one optical fiber arrangement is arranged in the hollow shaft.

Example 8: Construction machine according to claim, wherein the hollow shaft is able and arranged to be used as light guide.

Example 9: Construction machine according to one of the preceding claims comprising exactly one electric motor, preferably coupled to the power transfer system or comprising the rotor shaft.

Example 10: Construction machine according to claim, wherein the exact one electric motor is arranged in the upper carriage or in the lower carriage.

Example 11: Construction machine according to one of claimor, wherein the exactly one electric motor is a propulsion unit of the construction machine, preferably the sole propulsion unit.

Example 12: Construction machine according to one of the preceding claims, wherein the construction machine is an excavator or a telehandler, or a forestry machine.

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.