A reconfigurable electric drive unit

Abstract

An electric drive unit (100) for powering driven equipment (600, 1100), the drive unit (100) comprising a base portion (150) that extends in a base plane (P), an electric machine, EM, (110), a battery support (130) arranged to releasably hold a battery (700) to power the EM (110), and a drive axle (D) extending out from the drive unit (100), where the EM (110), the battery support (130), and the drive axle (D) are arranged above the base portion (150) in use, where the drive unit (100) is arranged to be attached to and to power at least two different types of driven equipment (600, 1100), the drive unit (100) further comprising a control unit (120, 900) arranged to control an operation of the drive unit (100) based on configuration data, the control unit (120, 900) comprising a storage medium (930) arranged to store one or more software driver modules (935), where each software driver module (935) comprises configuration data adapted to configure the drive unit (100) to power a respective type of driven equipment (600, 1100) out of the at least two different types of driven equipment (600, 1100).

Description

[0001] TITLE

[0002] A RECONFIGURABLE ELECTRIC DRIVE UNIT

[0003] TECHNICAL FIELD

[0004] The present disclosure relates to electric drive units tor powering construction equipment and other types of machines.

[0005] BACKGROUND

[0006] Heavy-duty construction equipment such as floor saws, compactors, power trowels, scarifiers, wall saws and other tools have traditionally been powered by on-board combustion engines. However, there is an increasing demand for electrically powered construction equipment, and the combustion enginebased drive units are now being replaced by battery powered electric drive units.

[0007] It is desired to provide battery powered electric drive units that are cost efficient and easy to operate.

[0008] Stability is important in many types of construction equipment. It is important that the drive unit does not render the construction equipment unstable in use.

[0009] Serviceability is also important in a drive unit, i.e., that the drive unit does not have extensive service requirements, and also that the drive unit can be serviced in an efficient manner when required.

[0010] A drive unit is often used with more than one type of construction equipment. It is therefore desired to provide drive units which are versatile and that can be reconfigured in a convenient manner for use with different types of construction equipment having different operating characteristics.

[0011] To summarize, there is a need for improved more versatile electrical drive units. SUMMARY

[0012] It is an objective of the present disclosure to provide battery powered electric drive units suitable for use with different types of equipment such as floor saws, wall saws, compactors, power trowels, scarifiers, floor cleaning equipment, lawn mowers, and other machines.

[0013] This objective is at least in part obtained by equipment comprising an electric drive unit according to the appended claims.

[0014] Aspects of the present disclosure relate to an electric drive unit for powering driven equipment. The drive unit comprises a base portion that extends in a base plane, an electric machine (EM), a battery support arranged to releasably hold a battery to power the EM, and a drive axle extending out from the drive unit. The EM, the battery support, and the drive axle are arranged above the base portion in use, which allows the drive unit to be mounted onto different types of driven equipment in a straight-forward manner. The base portion may, e.g., comprise several different bolt hole patterns configured to match different types of equipment. Thus, the drive unit is arranged to be attached to and to power at least two different types of driven equipment. The drive unit further comprises a control unit that is arranged to control the operation of the drive unit based on configuration data, as discussed above. The control unit comprises a storage medium, preferably a digital storage medium, arranged to store one or more software driver modules, where each software driver module comprises configuration data adapted to configure the drive unit to power a respective type of driven equipment out of the different types of driven equipment. The control unit is, according to a preferred embodiment, arranged to interpret an operator input command to the drive unit by a selected software driver module out of the one or more software driver modules, and to control the EM according to the interpreted operator input command. This means that the software driver defines at least in part how the drive unit should respond to a given input command, such as a variable voltage on an input wire or a given control message received over a data communication bus. The software driver can thus be used to configure the behavior of the drive unit in dependence of the application of the drive unit, such as the type of equipment being powered by a given drive unit. In other words, the software driver module determines at least some of the operations of the drive unit and can therefore be used to customize the operation of the drive unit to fit different types of equipment. The same drive unit can therefore be used to power many different types of equipment, which is an advantage.

[0015] According to some aspects, the electric drive unit comprises a control unit arranged to be configured by a software driver module obtained from a storage medium of the control unit. This allows the drive unit to be reconfigured in a convenient and reliable manner depending on the intended use of the drive unit. The different applications in which the drive unit may be used vary in terms of requirements and limitations. One application may, e.g., be associated with a limitation on drive axle speed, while another application is associated with requirements on drive axle torque. The software driver module can be exchanged or selected from an assortment of software driver modules in a convenient manner. The software driver module may comprise criteria for when to intervene in the operation of the drive unit. Hazardous operating conditions may also vary between applications in which the drive unit can be used. The software driver module may comprise criteria for when to issue a warning signal.

[0016] Other aspects of the present disclosure relate to an electric drive unit that comprises an EM, a motor control unit (MCU) configured to control the EM, and a battery compartment arranged to releasably hold a battery to power the EM. The MCU may form part of the control unit discussed above in connection to the software driver or be realized as a separate control unit that is separate from the control unit associated with the software driver. A motor axle of the EM is arranged to transmit torque to a drive axle of the electric drive unit, which drive axle can then be connected to one or more active parts of the construction equipment to be powered, such as the saw blade of a floor saw or the trowels of a power trowel. The electric drive unit also comprises a frame structure arranged to at least partly enclose and to support the EM, the MCU, and the battery compartment. The frame structure comprises a base portion that extends in a base plane. A separating plane intersects the base portion and separates the battery compartment from the motor axle and from the drive axle of the drive unit. This means that the battery compartment and the part comprising the motor axle, and the drive axle are located side by side when viewed horizontally. It is an advantage that the relatively heavy battery is positioned close to the base plane, and not on top of the EM, since this improves stability of the drive unit. The drive unit is normally configured to be attached to the equipment to be powered at the base portion, e.g., by bolts or other fastening members.

[0017] The frame structure optionally comprises inner walls that at least partly delimit a battery compartment section from an EM section of the drive unit. This compartmentalization of the drive unit separates the heat generating EM and the MCU from the somewhat heat sensitive replaceable battery. The compartmentalization therefore reduces the cooling requirements of the battery. The EM section preferably comprises the EM and the MCU, and also a cooling fan arranged to generate a cooling air flow designed to transport heat away from the EM and from the MCU. The cooling air flow efficiently cools the EM and the MCU. The cooling air flow does not need to pass via the replaceable battery due to the compartmentalization of the drive unit interior, which is an advantage. The replaceable battery can instead be cooled passively, e.g., via a separate convection air flow.

[0018] According to a preferred implementation, the battery compartment extends out horizontally from the base portion in use. Phrased in geometric terms, a straight line or plane normal to the base plane and separated from the base portion intersects the battery compartment. This means that the battery compartment extends out from and is suspended from the rest of the drive unit, resulting in that the bottom part of the battery compartment is exposed to the ambient environment, which allows for more efficient passive cooling of the replaceable battery. At least one aperture facing the base plane can be formed in an external wall of the battery compartment to allow a vertical convection air flow to pass between the battery compartment and an external environment of the electric drive unit.

[0019] According to some aspects, at least a part of an external wall of the battery compartment facing the base plane is formed as a skid plate, in order to protect the replaceable battery which is positioned behind and above the skid plate.

[0020] The frame structure preferably also comprises inner walls that delimit a sealed drive axle section from the rest of the drive unit interior. The sealed drive axle section comprises the drive axle of the drive unit and is preferably ventilated by an axle housing vent. The sealed drive axle section protects the drive axle against dirt and other unwanted matter such as moisture. The sealed drive axle also reduces the need for lubricating and servicing the drive axle. The axle housing vent does not allow moisture to pass but regulates the air pressure inside the sealed drive axle section.

[0021] The drive units discussed herein are suitable for powering heavy-duty construction equipment which is operated in harsh environments. To increase the mechanical integrity of the drive unit, the frame structure is preferably formed at least in part as a cast metal structure. The cast metal structure adds weight to the drive unit, which is positive in many applications, such as in floor saws and in power trowels, where a certain minimum weight of the construction equipment is desired. The cast metal structure is also cost effective and suitable for mass production, which is an advantage. The cast metal structure may be formed with sturdy front and rear structures that extend out from the base portion.

[0022] The base portion of the drive unit may comprise mounts, i.e., feet, formed in a resilient material, in order to provide vibration suppression between the active part of the construction equipment, such as the excentre weight of a compactor or the saw drum of a scarifier, and the drive unit. By adding vibration suppressing mounts in this manner, the drive unit can be used also on equipment that generates significant vibration. The vibration suppressing mounts are advantageously combined with a vibration suppressing suspension of the battery compartment. The base portion optionally comprises a planar surface extending in the base plane. At least one bolt hole pattern can be formed in the base portion. A particular advantage is obtained if more than one bolt hole pattern is formed in the base portion, since this allows the drive unit to be fitted on different types of equipment comprising different bolt hole patterns. One or more of the bolt hole patterns may be formed so as to comply with a bolt hole pattern of a combustion-engine based drive unit. This allows the electric drive units described herein to replace legacy combustion-engine based drive units in a straight-forward manner.

[0023] According to some aspects, the drive axle and the motor axle are connected via a transmission arrangement that is arranged external to the frame structure, i.e., on the outside of the frame structure. This allows easy access to the transmission arrangement for, e.g., inspection and for servicing purposes. The transmission arrangement may, for instance, comprise a toothed belt. A toothed belt does not slip as much as a regular V-belt does and can support transfer of higher torques. A more powerful electric machine can therefore be used in the drive unit compared to if a normal V-belt had been used in the transmission, which is an advantage. It is appreciated that the drive unit can be fitted with different types of electric machines depending on the intended application. Sometimes a stronger electric motor is required and sometimes a less powerful motor is enough. The motor to be mounted onto a given drive unit can be selected to satisfy the requirements of the intended application. A software driver module selected based on the intended application and / or based on the type of fitted motor, can be used to configure the various control functions of the drive unit, as will be discussed in more detail below.

[0024] The gear ratio of the transmission arrangement can be adapted to suit the intended application in a convenient manner. The transmission arrangement may for instance be configured to have a gear ratio of between 2.5:1 and 3.1 :1 , and preferably about 2.8:1. The transmission arrangement optionally comprises a replaceable lower pulley connected to the drive axle and / or a replaceable upper pulley connected to the motor axle. The replaceable pulleys allow reconfiguration of the sizes of the pulleys, and thus also reconfiguration of the gear ratio of the transmission in a convenient manner. Transmission gear ratios from 2:1 up to 4:1 can be considered for various applications of the drive unit.

[0025] According to some aspects, the electric drive unit comprises a removable side housing portion that is arranged to cover the transmission arrangement. The side housing portion is arranged on an opposite side of the drive unit compared to the drive axle. The removable side housing portion allows easy access to the transmission arrangement of the drive unit. The transmission arrangement is therefore easily inspected and serviced without disassembling the drive unit.

[0026] According to some aspects, the battery compartment of the drive unit is configured as a through-hole battery compartment with first and second oppositely arranged openings. This type of battery compartment is easily accessible by an operator wishing to replace the battery. The through-hole battery compartment also allows for efficient passive cooling of the replaceable battery.

[0027] The battery compartment preferably has a battery insertion opening located on an opposite side of the drive unit compared to the side the drive axle protrudes from. In other words, the replaceable battery is inserted into the drive unit on one side, and the drive axle extends out from the other side. This way the drive axle and the torque transmission arrangement attached to the drive axle does not interfere with the battery as it is inserted and removed from the drive unit.

[0028] The battery compartment may, as mentioned above, be suspended from the frame structure by at least one resilient support member such as a rubber bushing or a metal spring arrangement. This way the replaceable battery is protected from strong vibration which may otherwise damage the battery. The suspension of the battery compartment in this manner allows use of the drive unit also on equipment which generate significant vibration, such as compactors and scarifiers. An air gap is optionally formed between the battery compartment and the frame structure of the electric drive unit. This gap prevents vibrations from propagating between, e.g., the bottom portion of the frame structure and the battery compartment. The air gap also promotes cooling of a replaceable battery held in the battery compartment.

[0029] According to some aspects, the battery compartment comprises upper and lower grates arranged to allow a vertical convection air flow to traverse the battery compartment. The grates prevent dirt from entering the battery compartment. The replaceable battery may be designed to have grates or apertures matching the upper and lower grates of the battery compartment, in order to allow a cooling air flow to traverse the interior of the replaceable battery when received in the battery compartment.

[0030] The electric drive unit optionally comprises two or more separate battery compartments arranged side-by-side and supported by the frame structure. This way an increased energy storage capacity can be obtained, which results in a prolonged operating time, which is an advantage. The drive unit may be configured to draw electrical power from one or both batteries.

[0031] The electric drive unit may furthermore comprise a top cover attached to the frame structure on a side opposite to the base portion, i.e., on top of the drive unit in use. The top cover preferably comprises an air intake with a dust trap. The top cover can be removed from the frame structure to allow access to the internal volume of the frame structure, for inspection and maintenance purposes. It is an advantage that the air intake is situated on top of the drive unit, since then less dust and unwanted matter enters the air intake compared to if the air intake would have been located closer to the bottom portion of the drive unit, or on a side of the drive unit. The dust trap also reduces the amount of unwanted matter that enters the air intake. This air intake design allows the drive unit to be used on heavy-duty construction equipment that is operated in harsh environments with ample dirt and moisture which may otherwise have entered into the air intake. According to a preferred embodiment, the top cover comprises an air intake part with a lid that is separable from the air intake part to allow access to the dust trap. The lid can be easily removed by an operator of the drive unit in order to allow access to the dust trap, such that dust can be removed from the dust trap in an efficient manner.

[0032] The EM of the drive unit is optionally comprised in an EM section of the drive unit. The drive unit may then comprise an air pressure sensor arranged in the EM section, and a control unit that is configured to detect a restriction or blockage of a cooling air flow of the EM based on an output signal from the air pressure sensor. Thus, the drive unit is able to automatically detect when the cooling air flow has been restricted or blocked, allowing an operator to investigate the reason for the restriction or blockage. The electric drive unit may also comprise an air pressure sensor arranged in the top cover of the drive unit, and a control unit configured to detect a restriction or blockage of a cooling air flow of the EM based on an output signal from the air pressure sensor arranged in the top cover.

[0033] According to a preferred embodiment, the electric drive unit comprises a human-machine interface (HMI) and a control unit that is configured to display a status message of the electric drive unit via the HMI and / or to obtain a configuration parameter from a user via the HMI. The HMI can be used to inform an operator about events, such as current EM load, cooling air flow blockage, and various other error events. The HMI can also be used to allow an operator to input configuration commands directly to the drive unit. It is an advantage that the drive unit implements an HMI, since then equipment specific HMIs are not necessary. This contributes to cost efficiency of the equipment powered by the drive unit. The drive unit HMI can be reconfigured for different applications and for different types of equipment powered by the drive unit.

[0034] An HMI harness preferably extends between the frame structure, i.e., the body portion of the electric drive unit, and the HMI. This HMI harness optionally comprises communication bus wires arranged to support digital communication to and from the HMI, such as via a controller area network (CAN) bus or Ethernet bus. The HMI harness comprises a number of wires grouped together in a common wire cable. The HMI harness wires may carry electrical power, a common ground of the electric drive unit, and also one or more hardware signal wires. The HMI harness may for instance comprise a power on wire that is separate from the communication bus wires. This way the electric drive unit can be configured with a redundant power on system where a first power on signal is communicated via the power on wire and a second power on signal is communicated via the communication bus wires.

[0035] The HMI harness optionally comprises a hardware trigger wire which is a separate wire that allows the motor control unit of the electric drive unit to adapt an operation of the EM in dependence of a configuration of the hardware trigger wire. The hardware trigger wire can for instance be connected to ground, connected to a fixed potential, connected to a variable potential, or connected to a variable resistance. This allows for a reliable communication between the HMI and the different control units of the electric drive unit, such as the MCU.

[0036] According to some aspects, the HMI harness comprises a metal braided cable sleeve which covers at least a part of the HMI harness. This metal braided cable sleeve provides electromagnetic shielding for the covered part and also protects the harness from mechanical damage.

[0037] According to a preferred embodiment, the HMI harness comprises an auxiliary power interface that is arranged to power one or more auxiliary components of the electric drive unit. The auxiliary power interface can be controlled from the HMI and / or from a control unit on the electric drive unit body, such as by the MCU or the control unit associated with the software driver discussed above. The auxiliary power interface can be a 12V interface, a 24V interface, or some other type of power interface, such as a universal serial bus 5V power interface. The auxiliary power interface can be implemented as a branch cable that extends out from the HMI harness main cable.

[0038] According to some aspects, the electric drive unit comprises a control unit arranged to obtain an applied torque by the EM on the drive axle, to compare the applied torque to at least one predetermined torque level, and to trigger an action in case the applied torque exceeds the predetermined torque level. The control unit can for instance be arranged to store data indicative of the applied torque in a digital record which can then be read out to learn how the drive unit has been used, i.e. , what loads the drive unit has been subject to. The control unit can also trigger a warning to an operator of the drive unit in case the operator subjects the drive unit to excessive load.

[0039] The control unit can furthermore also be arranged to monitor the motor current of the EM and to detect an anomaly in the motor current, i.e., a motor current which deviates from an expected motor current in terms of phase, amplitude, or the like. Here, monitoring motor current preferably means that the motor current on three motor winding feed wires are monitored in terms of current, voltage and relative phase. The control unit can be configured to trigger an action in response to detecting the anomaly, such as an inactivation of the drive unit in response to detecting the anomaly, or the triggering of a warning signal. The control unit may also store detected anomaly events in a storage medium of the control unit. The detection can, e.g., be based on a comparison between a power consumption or current consumption of the EM and an acceptance or a warning criterion, such as a threshold or a range of expected current consumption or power consumption by the EM. The detection can also be implemented using more advanced techniques, such as techniques based on machine learning and artificial intelligence, as will be explained in more detail below.

[0040] The electric drive unit may furthermore comprise a control unit that is arranged to monitor a usage pattern of the drive unit, and to determine a suitable transmission gear ratio based on the usage pattern. The transmission gear ratio can then be reconfigured, e.g., by replacement of the drive pulleys of the transmission arrangement, in order to optimize the operation of the drive unit for a given application.

[0041] According to some aspects, the electric drive unit comprises a control unit arranged to activate the drive unit in response to receiving a user code that meets a predetermined acceptance criterion, and to inactivate the drive unit otherwise. This way unauthorized operation of the drive unit and the equipment powered by the drive unit can be prevented.

[0042] According to some other aspects, the electric drive unit comprises a control unit arranged to receive a wireless inactivation signal from a remote unit, and to inactivate the drive unit in response to receiving the wireless inactivation signal. This way the drive unit can be inactivated, e.g., in the case of theft, or if it is deemed that the drive unit cannot be operated safely for some reason.

[0043] According to some further aspects, the electric drive unit comprises a control unit arranged to configure the drive unit in a generator mode of operation or in a drive mode of operation. This means that the drive unit can be used to power equipment, and that the drive unit can be used to generate electrical energy from an input torque applied to the drive axle. Thus, a more versatile drive unit is obtained which can be used as power source as well as for power generation purposes.

[0044] Several methods related to electric drive units are also disclosed herein. For instance, there is disclosed a computer-implemented method, performed by a control unit in an electric drive unit. The method comprises obtaining access to a storage medium of the electric drive unit, where the storage medium comprises one or more software driver modules, obtaining information related to an intended application of the electric drive unit, selecting a software driver module in dependence of the intended application of the electric drive unit, and operating an EM of the electric drive unit according to one or more parameters comprised in the software driver module. This type of software driver module was discussed above. By using a software driver module to configure the control unit, and thus also the drive unit, a more versatile drive unit is obtained which can be easily reconfigured to suit several different use cases and equipment types.

[0045] Aspects of the present disclosure also relate to a computer-implemented method, performed by a control unit in an electric drive unit comprising an EM. The method comprises monitoring an applied motor axle torque of the EM and displaying the applied motor axle torque on a display device of the electric drive unit. This way an operator can adjust the way the drive unit is used, so as to not overload the drive unit. According to an optional example, the method also comprises obtaining information related to a desired operating point of the EM, where the desired operating point comprises a desired motor axle speed and a desired motor axle torque, monitoring a current operating point of the EM comprising a motor axle speed of the EM and the applied motor axle torque of the EM, comparing the current operating point of the EM to the desired operating point of the EM, and displaying an efficiency metric of the electric drive unit on the display device of the electric drive unit.

[0046] Other aspects of the present disclosure relate to a computer-implemented method, performed by a control unit in an electric drive unit. The method comprises obtaining a user code from an operator of the electric drive unit, comparing the obtained user code to a predetermined acceptance criterion, and determining if the obtained user code satisfies the acceptance criterion, and also activating the drive unit in case the obtained user code satisfies the acceptance criterion. According to an optional example, the method also comprises receiving a wireless inactivation signal from a remote unit and inactivating the drive unit in response to receiving the wireless inactivation signal. This way both authentication and remote inactivation of, e.g., stolen equipment, may be provided. It is an advantage that these functions are provided by the drive unit, i.e., that the functionality is integrated with the drive unit functions, since this reduces the need for intelligence and advanced processing circuitry in the equipment that is powered by the drive unit. By centralizing processing power to the drive unit in construction equipment powered by the drive unit, a more cost effective solution that can be used in more than one type of equipment is obtained.

[0047] It is appreciated that several of the technical features and functions discussed herein are applicable as stand-alone features. These features are not inextricably linked to the other features of the present disclosure.

[0048] There is disclosed herein an electric drive unit for powering construction equipment. The drive unit comprises an EM arranged to generate a drive torque, a control unit configured to control the EM, and a battery compartment arranged to releasably hold a battery to power the EM. The electric drive unit further comprises a frame structure arranged to at least partly enclose and to support the EM, the MCU and the battery compartment. The frame structure comprises a base portion that extends in a base plane, where the frame structure comprises inner walls that at least partly delimit a battery compartment section from an EM section of the drive unit.

[0049] There is disclosed herein an electric drive unit for powering construction equipment. The drive unit comprises an EM arranged to generate a drive torque, a control unit configured to control the EM, and a battery compartment arranged to releasably hold a battery to power the EM. The electric drive unit further comprises a frame structure arranged to at least partly enclose and to support the EM, the MCU and the battery compartment. The frame structure comprises a base portion that extends in a base plane, where the frame structure comprises inner walls that delimit a sealed drive axle section, where the sealed drive axle section is ventilated by an axle housing vent.

[0050] There is disclosed herein an electric drive unit for powering construction equipment. The drive unit comprises an EM arranged to generate a drive torque, a control unit configured to control the EM, and a battery compartment arranged to releasably hold a battery to power the EM. The electric drive unit further comprises a frame structure arranged to at least partly enclose and to support the EM, the MCU and the battery compartment. The frame structure comprises a base portion that extends in a base plane, where the drive axle and the motor axle are connected via a transmission arrangement external to the frame structure.

[0051] There is disclosed herein an electric drive unit for powering construction equipment. The drive unit comprises an EM arranged to generate a drive torque, a control unit configured to control the EM, and a battery compartment arranged to releasably hold a battery to power the EM. The electric drive unit further comprises a frame structure arranged to at least partly enclose and to support the EM, the MCU and the battery compartment. The frame structure comprises a base portion that extends in a base plane, where the battery compartment is configured as a through-hole battery compartment with first and second oppositely arranged openings.

[0052] There is disclosed herein an electric drive unit for powering construction equipment. The drive unit comprises an EM arranged to generate a drive torque, a control unit configured to control the EM, and a battery compartment arranged to releasably hold a battery to power the EM. The electric drive unit further comprises a frame structure arranged to at least partly enclose and to support the EM, the MCU and the battery compartment. The frame structure comprises a base portion that extends in a base plane, where a gap is formed between the battery compartment and the frame structure of the electric drive unit.

[0053] There is disclosed herein an electric drive unit for powering construction equipment. The drive unit comprises an EM arranged to generate a drive torque, a control unit configured to control the EM, and a battery compartment arranged to releasably hold a battery to power the EM. The electric drive unit further comprises a frame structure arranged to at least partly enclose and to support the EM, the MCU and the battery compartment. The frame structure comprises a base portion that extends in a base plane. The electric drive unit also comprises a top cover attached to the frame structure opposite to the base portion, where the top cover comprises an air intake with a dust trap.

[0054] There is disclosed herein an electric drive unit for powering construction equipment. The drive unit comprises an EM arranged to generate a drive torque, a control unit configured to control the EM, and a battery compartment arranged to releasably hold a battery to power the EM. The electric drive unit further comprises a frame structure arranged to at least partly enclose and to support the EM, the MCU and the battery compartment. The EM is comprised in an EM section of the drive unit. The drive unit comprises an air pressure sensor arranged in the EM section, and a control unit configured to detect a restriction or blockage of a cooling air flow of the EM based on an output signal from the air pressure sensor. There is disclosed herein an electric drive unit for powering construction equipment. The drive unit comprises an EM arranged to generate a drive torque, a control unit configured to control the EM, and a battery compartment arranged to releasably hold a battery to power the EM. The electric drive unit further comprises a frame structure arranged to at least partly enclose and to support the EM, the MCU and the battery compartment. The control unit is arranged to obtain an applied torque by the EM on the drive axle, to compare the applied torque to at least one predetermined torque level, and to trigger an action in case the applied torque exceeds the predetermined torque level.

[0055] There is disclosed herein an electric drive unit for powering construction equipment. The drive unit comprises an EM arranged to generate a drive torque, a control unit configured to control the EM, and a battery compartment arranged to releasably hold a battery to power the EM. The electric drive unit further comprises a frame structure arranged to at least partly enclose and to support the EM, the MCU and the battery compartment. The electric drive unit comprises a control unit arranged to monitor a motor current of the EM and to detect an anomaly in the motor current, and to trigger an action in response to detecting the anomaly.

[0056] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / an / the element, apparatus, component, means, step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated. Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. The skilled person realizes that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The present disclosure will now be described in more detail with reference to the appended drawings, where

[0058] Figure 1 shows parts of an interior of a battery powered drive unit;

[0059] Figure 2 is a cross-sectional view of an example drive unit;

[0060] Figures 3-4 illustrate an example battery powered drive unit;

[0061] Figure 5 shows parts of an interior of a battery powered drive unit;

[0062] Figures 6A-B show views of example construction equipment;

[0063] Figure 7 shows an example replaceable battery for a drive unit;

[0064] Figures 8A-C are flow charts illustrating methods;

[0065] Figure 9 shows a control unit comprising processing circuitry;

[0066] Figure 10 is a graph illustrating an example efficiency map;

[0067] Figure 11 shows example construction equipment;

[0068] Figure 12 schematically illustrates an electric machine with a drive unit;

[0069] Figure 13 shows an HMI harness arranged as HMI interface; and

[0070] Figure 14 illustrates details of an example HMI harness.

[0071] DETAILED DESCRIPTION

[0072] The invention will now be described more fully hereinafter with reference to the accompanying drawings, in which certain aspects of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments and aspects set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout the description. It is to be understood that the present invention is not limited to the embodiments described herein and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.

[0073] A drive unit is a power source with an output drive axle that can be connected to various types of equipment in order to power the equipment. A drive unit can, for instance, be used to drive the saw blade on a floor saw or a wall saw, the vibrating element on a compactor, or the screeds of a power trowel. It is common that several different types of construction equipment use the same drive unit model, in order to increase production volumes and reduce cost of the drive unit.

[0074] Figure 1 illustrates an electric drive unit 100 for powering construction equipment such as floor saws, wall saws, compactors, power trowels, scarifiers, and so on. The drive unit 100 may also be used to power other types of equipment, such as floor cleaners, lawn mowers, and other machines. An example floor saw 600 powered by the electric drive unit 100 is illustrated in Figures 6A-B. An example power trowel 1100 powered by the electric drive unit 100 is illustrated in Figure 1 1 . These two example pieces of construction equipment will be discussed in more detail below.

[0075] The drive units described herein can be used with a wide variety of different types of equipment and machinery. Equipment powered in some way by a drive unit according to the present disclosure can generally be referred to as driven equipment.

[0076] The drive unit 100 comprises an electric machine (EM) 110 with a motor axle M that is coupled to a drive axle D via a transmission. The motor axle M and the drive axle D are two separate axles physically separated from each other and connected by a transmission. The motor axle is preferably located above the drive axle in use. Hence, the drive axle extends out from the drive unit at a point close to the base of the drive unit. In some examples a vertical plane separates the motor axle from the drive axle and intersects the battery compartment 130 of the drive unit 100. Power from the EM 110 is transmitted to the drive axle D and onwards to the actuator of the construction equipment that is to be powered by the drive unit 100.

[0077] Some of the drive units 100 described herein may comprise other forms of battery supports, such as rails and battery receiving cavities.

[0078] The motor axle is separate from the drive axle, i.e., the motor axle and the drive axle are two physically separate axles.

[0079] According to an example embodiment, the motor axle constitutes the main power output of the drive unit. In this case there may not be any drive axle.

[0080] According to an example embodiment, there are two or more drive axles connected to the motor axle.

[0081] The EM 1 10 drives a fan which generates a cooling air flow that cools the EM 110 and the MCU 120. An example fan 560 is illustrated in Figure 5. The fan 560 draws air in via the air inlet 1 11 and pushes air out via the aperture 112 towards the MCU 120. The air inlet 111 can be connected to an air intake portion in a top cover of the drive unit 100. This air intake portion will be discussed in more detail below in connection to Figure 4. The cooling air flow exits the drive unit via the exhaust 280 that can be seen in, e.g., Figure 2.

[0082] The EM 110 is the main power source of the drive unit 100. A motor control unit (MCU) 120 controls the EM 110. The MCU 120 will be referred to generally herein as a control unit. It is appreciated that the drive unit 100 may comprise one or more physical control units. The control unit 120 controls the operation of the EM 110 and may also control other functions of the drive unit, such as the human machine interface (HMI) 610 exemplified in Figure 6 and one or more wireless communication transceiver circuits that can be used to communicate with external units such as auxiliary equipment 160 or a central server 170 used for fleet management purposes. It is appreciated that the drive unit may comprise a single control unit or a plurality of control units separated from each other. An example control unit will be discussed in more detail below in connection to Figure 9. The auxiliary equipment 160 may comprise, e.g., a dust extractor, a water tank, or other equipment configured to operate in combination with the equipment powered by the drive unit. The wireless radio link between the drive unit 100 and the auxiliary equipment can be used to control the auxiliary equipment in dependence of an operating state of the drive unit, such as activating the dust extractor when the drive unit is subject to load on the drive axle, indicating that the construction equipment is performing dust generating work.

[0083] The central server 170 may be accessed directly from the drive unit 100 via a short range communication link such as a Bluetooth radio link or the like, or indirectly via, e.g., a cellular communication network or a Wi-Fi network. The central server 170 may implement various monitoring functions that keep track of the status of the drive unit 100, how much the drive unit 100 is used, and perhaps also what loads the drive axle of the drive unit 100 is subject to in use.

[0084] The EM 1 10 is configured to draw power from a replaceable battery held in a battery compartment 130. To be replaceable means that a battery can be replaced by another battery without the use of specialized tools, and without first dismantling parts of the drive unit 100. An operator can easily remove a depleted battery and replace it with a fully charged battery in order to continue using the construction equipment powered by the drive unit 100. The control unit 120 may be configured to transmit a wireless signal to auxiliary equipment such as a remote control device, a smart phone device or a tablet, indicating the state of charge (SoC) of a battery 700 held in the battery compartment 130.

[0085] An example battery 700 is illustrated in Figure 7. The battery compartment 130 is arranged to receive the battery 700 in an insertion direction 710 which extends transversally across the drive unit 100, in alignment with the motor axle M. The battery 700 may be a relatively heavy battery having a weight between 3-7 kg. The battery 700 comprises an upper ridge structure 720 and a lower ridge structure 730, for mating with corresponding dove-tail grooves 132 of the battery compartment 130. A groove on the battery 700 opposite to the ridge structures 720, 730 is configured to mate with a corresponding heel 135 formed in the battery compartment 130. The heel 135 extends in the insertion direction 710 inside the battery compartment, on a side wall ot the compartment, as can be seen in Figure 2. This heel 135 supports the heavy battery in a robust manner. The battery 700 also comprises one or more electrical connectors 740 arranged protected in slots extending in the insertion direction to mate with a corresponding contact strip 131 arranged in the battery compartment 130. The one or more electrical connectors normally extend in a vertical direction when the drive unit 100 is mounted to construction equipment.

[0086] A handle portion 750 allows one-handed gripping and holding of the battery 700. To promote cooling of the battery cells inside the battery housing, there is an air inlet 760 arranged on a bottom side of the battery which is in fluid communication with an air outlet 770 arranged on the upper side of the battery. Thus, air can flow 270, 275 through the battery in use as illustrated in Figure 2. The air inlet 760 and the air outlet 770 are configured to align with lower and upper grates 330, 335 formed in the battery compartment. These grates can be seen in Figure 3 and in Figure 5. The lower and upper grates 330, 335 of the battery compartment are arranged to allow a vertical convection air flow 275 to traverse the battery compartment 130.

[0087] The battery 700 is, according to an example, arranged to deliver between 90V and 100V, and preferably about 94V. The battery 700 may be arranged to hold around 6Ah to 10Ah of electrical energy, and preferably about 8Ah.

[0088] The battery compartment 130 on the drive unit 100 is configured as a through- hole battery compartment with first and second oppositely arranged openings. The replaceable battery 700 is inserted into this through-hole battery compartment in the insertion direction 710, which is preferably aligned with the motor axle M and the drive axle D in use. More generally, a straight line parallel to the motor axle M may in some cases intersect the first and second oppositely arranged openings. The battery 700 can be inserted into the battery compartment 130 from a side of the drive unit 100 opposite to the side where the drive axle D extends out from the drive unit 100. In other words, the battery compartment 130 has a battery insertion opening located on an opposite side of the drive axle D on the drive unit 100, i.e., the battery insertion direction 710 points into the battery compartment, and this is essentially the same direction as the drive axle protrudes from the drive unit on the other side. This way there is more space to handle the battery, since the drive axle side of the drive unit 100 normally comprises the construction equipment actuator, such as the saw blade of a floor saw.

[0089] The battery insertion direction 710 is, according to some aspects, substantially aligned with or parallel with the drive axle D.

[0090] According to some aspects, the contact strips 131 arranged in the battery compartment 130 faces away from the drive axle side of the drive unit 100.

[0091] The battery compartment 130 is preferably suspended from the frame structure 140 by at least one resilient support member 570, as exemplified in Figure 5. The resilient support members may comprise springs or resilient bushings such as rubber or a soft polymer in order to prevent or at least suppress vibration from the construction equipment to propagate to the battery compartment 130 where it may damage the battery 700. An air gap is preferably formed between the battery compartment 130 and the frame structure 140 of the electric drive unit 100, in order to prevent vibration from the construction equipment driven by the drive unit 100 to propagate to the replaceable battery supported in the battery compartment 130.

[0092] It is appreciated that the electric drive units discussed herein can comprise two separate battery compartments arranged side-by-side and supported by the frame structure. According to an option, the drive unit then comprises an extra weight mounted on an opposite side of the drive unit compared to the extra battery compartment, in order to balance the weight of the additional replaceable battery.

[0093] With reference also to Figure 2 and to Figure 5, the motor axle M of the EM 110 is arranged to transmit torque to the drive axle D of the electric drive unit 100 via a transmission arrangement 510. The drive axle D and the motor axle M are connected via a transmission arrangement 510 external to the frame structure 140 of the drive unit 100, i.e., on the outside of the frame structure where it is more easily accessible. A service technician can easily access the components of the transmission arrangement 510 by removing the side housing portion 390 of the drive unit 100 to expose the transmission arrangement 510.

[0094] The motor axle M is connected to a motor axle pulley 520 which is connected to a drive axle pulley 530 via an endless belt 540. The transmission arrangement 510 preferably comprises a toothed belt, i.e., a synchronous belt or timing belt, although V-belts or chains can also be used. A belt tensioning member 550 is arranged to provide a desired amount of belt tension to the drive belt 540. Note that the motor axle M has a preferred direction of rotation, which is the direction where the belt tensioning member 550 engages the slack part. The preferred direction of rotation is indicated by the dashed arrow 535 in Figure 5. The motor axle M may, however, be driven in both clockwise and counter-clockwise direction.

[0095] The transmission arrangement 510 may be configured to have a gear ratio of between 2.5:1 and 3.5:1 , and preferably about 3:1 , such as 2.8:1. The gear ratio of the transmission arrangement 510 can be adapted to the intended use case of the drive unit 100 in a convenient manner. Other gear ratios may also be considered, such as between 2:1 and 4:1 .

[0096] According to some aspects, the transmission arrangement 510 comprises a replaceable lower pulley 530 connected to the drive axle D and / or a replaceable upper pulley 520 connected to the motor axle M. This means that the drive torque gear ratio of the drive unit can be reconfigured by a service technician or even by an operator engaged in using equipment powered by the drive unit 100.

[0097] Figure 10 shows an example efficiency map 1000 for a general electric machine. There is a peak output torque 1010 which can be output from the EM as function of output axle speed, and also an optimum operating point 1020. The optimal efficiency operating point 1020 is normally the desired operating point, but the desired operating point can also be some other point, if other aspects are also factored in, such as total driveline efficiency, floor saw component wear, saw blade wear, service intervals, and so on.

[0098] Efficiency maps such as the efficiency maps 1000 can be stored in a memory of the control unit 120 and used to control the drive unit 100 in order to improve the overall efficiency of the construction equipment being powered by the drive unit 100. An efficiency map can be stored as a look-up table (LUT) or in some other format that can be accessed and read by the control unit 120. The efficiency data can be preconfigured, i.e., stored in a memory device accessible by the control unit 120.

[0099] According to some aspects, the control unit 120 monitors the operation of the drive unit in terms of motor axle speed and motor axle torque and compares this to a desired operating point of the EM 1 10 in terms of axle speed and axle torque. The EM has an optimal operating point 1020 where efficiency is at a maximum. This optimal operating point is often known a-priori from design and / or from practical experimentation. The control unit 120 may determine, based on the monitored operation of the EM 1 10, that a different gear ratio would be beneficial in terms of operating efficiency, since the gear ration will move the operating point of the EM 110. A higher gear ratio will mean less torque and higher speed, while a reduced gear ration will mean more torque and less speed. The control unit 120 can be configured to indicate to a user of the drive unit 100, to a service technician or to some other person or system that a change in gear ratio of the transmission arrangement is desired in order to increase the efficiency of the construction equipment. The drive unit can thus be reconfigured to achieve improved operating efficiency, which in turn may lead to extended battery operating time. In other words, the control unit 120, 900 can, according to some examples, be arranged to monitor a usage pattern of the drive unit 100, and to determine a suitable transmission gear ratio based on the usage pattern.

[0100] The term electric machine is used herein to indicate that the device 110 can, in some versions of the drive unit 100, be used as an electrical generator for generating electrical power in addition to operating as an electric motor. The EM 110 is according to some aspects configured to generate both positive and negative torque by the motor axle M. During generation of negative torque, the EM 1 10 applies a load to the drive axle (brakes the drive axle by the EM) which allows the EM to generate electrical power to, e.g., charge a battery of the drive unit 100 or provide electrical power to some other device.

[0101] When the drive unit 100 is used as generator, i.e., operating as a genset, it is connected to an external power source via the drive axle D or via the motor axle M. The external power source provides an input torque which is then converted into electrical energy by the EM 110. The external power source could, e.g., be a power take-off (PTO) axle of a vehicle or another drive unit, possibly a combustion engine-based drive unit.

[0102] The drive unit 100 may comprise an integrated inverter module configured to output alternating current (AC) via a socket, such as a 110V socket or a 220V socket. The inverter module draws direct current (DC) electrical power from the replaceable battery 700 and converts this DC current into AC. The AC can be used to operate auxiliary equipment such as corded powertools and the like.

[0103] The control unit 120 may be arranged to configure the drive unit 100 in a generator mode of operation or in a drive mode of operation. When the drive unit is configured in the generator mode of operation it outputs electrical power to, e.g., a battery charger or an inverter. When the drive unit is configured in the drive mode of operation it provides a positive torque on the output drive axle.

[0104] As mentioned above it is important that the drive unit is mechanically robust and able to withstand the forces acting on it during use. The electric drive unit 100 comprises a frame structure 140 that is arranged to at least partly enclose and to support the EM 110, the MCU 120 and the battery compartment 130. The frame structure 140 forms a robust structural skeleton of the drive unit 100 making it sturdy enough to withstand severe mechanical stress and impact. The frame structure 140 may, for instance, be formed at least in part as a cast metal structure, such as a cast iron structure. The frame structure 140 comprises a base portion 150 that extends in a base plane B. The base portion may form an interface with respect to the construction equipment to be powered by the drive unit 100. Thus, the base portion may comprise a planar surface extending in the base plane B. At least one bolt hole pattern is formed in the base portion 150. The bolt holes are configured to secure the drive unit 100 to the construction equipment to be powered by the drive unit. The base portion 150 optionally comprises mounts, i.e., feet, formed in a resilient material in order to provide some measure of vibration damping between the drive unit and the construction equipment. The resilient material mounts may advantageously be combined with vibration suppressing suspension of the battery compartment, such that the replaceable battery is protected by two stages of vibration suppression. One between the equipment and the bottom portion of the drive unit, and one between the frame structure and the battery compartment.

[0105] It is important that the drive unit is stable with a low mass center so as to not introduce instability in the construction equipment it powers. A notable feature of the example drive unit 100 illustrated in, e.g., the Figure 2, is that a separating plane, exemplified in Figure 2 by the example dash-dotted planes P1 and V, intersect the base portion 150 and separates the battery compartment 130 from the motor axle M and from the drive axle D of the drive unit 100, meaning that the battery compartment and the EM are arranged side by side. In case the drive axle extends out from the drive unit 100 in a lateral direction, then the battery compartment 130 extends in a longitudinal direction of the drive unit. The longitudinal direction 620 and the lateral direction 630 of the drive unit 100 are indicated in Figure 6B. Note that the drive axle D in Figure 2 is optional, the geometry illustrated in, e.g., Figure 2, is also applicable to drive units where the motor axle constitutes the main power outtake of the drive unit.

[0106] According to an example, the motor axle M and the drive axle D lie in an axle plane P2 that is parallel to the separating plane P1 . However, the separating T1 plane and the base plane B may also be orthogonal planes, as illustrated by the example plane V in Figure 2.

[0107] The battery compartment 130 supports a heavy battery in use, at least in part by the heel 135. It is an advantage that this weight is located close to the base portion 150 since this makes the drive unit more stable and less likely to tip over. The build height of the drive unit 100, i.e., the vertical height of a bounding box containing the drive unit 100 in use, is also reduced thanks to the placement of the battery compartment side-by-side with the EM 1 10 and the MCU 120, as opposed to, e.g., placing the battery at the top of the drive unit 100.

[0108] It is noted that the battery compartment 130 may be formed so as to extend out over the base portion 150 by a distance, i.e., to be suspended by the frame structure 140 above the base plane B. A straight line 155 normal to the base plane B and separated from the base portion 150 then intersects the battery compartment 130. At least one aperture facing the base plane B can be formed in an external wall 240 of the battery compartment 130 to allow a vertical convection air flow 275 to pass between the battery compartment 130 and an external environment of the electric drive unit 100, in order to cool a battery received in the battery compartment 130.

[0109] At least a part of an external wall 240 of the battery compartment 130 facing the base plane B can also be formed as a skid plate, to protect a battery received in the battery compartment in use. The skid plate may be located in connection to a bottom of the battery compartment, and / or in connection to a wall of the battery compartment facing forward in use. The skid plate will protect the drive unit 100, and in particular the battery received in the battery compartment in case the drive unit 100 bumps into an external object.

[0110] The frame structure 140 comprises inner walls that at least partly delimit a battery compartment section 210 from an EM section 220 of the drive unit 100. This means that the EM 1 10 is located in a compartment which is at least partly separated from the battery compartment 130. Thus, the heat generated by the EM 1 10 in use will not heat up the battery 700 received in the battery compartment 130, which is an advantage. The EM section 220 comprises the EM 110 and the MCU 120, and also a cooling fan 560 arranged to generate a cooling air flow 270 which transports heat away from the EM 110 and from the MCU 120, as illustrated in Figure 2. The air flow 270 exits the drive unit 100 via the exhaust 280, which preferably comprises an exhaust grate and is located in the bottom portion of the EM section 220, close to the MCU 120.

[0111] The frame structure 140 also comprises inner walls that delimit a sealed drive axle section 250, which is ventilated by an axle housing vent 230. The sealed drive axle section protects the drive axle of the drive unit 100 from moisture and dirt at the work site and reduces the need for servicing the drive axle.

[0112] With reference to Figure 3 and to Figure 4, the electric drive unit 100 comprises a top cover 260 attached to the frame structure 140 opposite to the base portion 150. The top cover prevents dirt and moisture from entering into the frame structure interior from above.

[0113] The top cover 260 also forms an air intake 310 with a dust trap 340 shown in Figure 4. The flow of cooling air generated by the fan 560 inside the EM section 220 is illustrated by the dashed line 350 in Figure 4. The top cover 260 comprises a lid 320 that is separable from the top cover 260 to allow access to the dust trap 340 and the interior of the air intake.

[0114] The air intake flow 350 extends from a grate 360 formed in the lid 320 on a longitudinally facing part of the top cover 260 via a labyrinth 370 to vanes 380 that guide the air flow into the interior of the drive unit 100 to the cooling fan 560 in the EM section 220. The design of the air intake 310 prevents dust and water from entering into the interior of the drive unit 100, which is an advantage.

[0115] A removable side housing portion 390 is arranged to cover the transmission arrangement 510 in order to protect the transmission from moisture, dirt, and also from impact damage. The side housing portion 390 is arranged on an opposite side of the drive unit 100 compared to the side from which the drive axle D extends. Consequently, a service technician or operator of the drive unit 100 can access the transmission arrangement 510 even though the drive unit is mounted on construction equipment.

[0116] The drive unit 100 optionally comprises an air pressure sensor arranged in the EM section 220, and a control unit 120 configured to detect a restriction or blockage of a cooling air flow of the EM 110 based on an output signal from the air pressure sensor. If the air intake 310 is obstructed such that the flow of cooling air 350 is restricted, then the air pressure inside the EM section will drop compared to a standard operating air pressure. The pressure inside the EM section 220 can be measured as an absolute pressure or as a relative pressure compared to, e.g., ambient air pressure. A control unit 120 monitoring the air pressure level inside the EM section 220 may detect blockage of the air intake using the pressure sensor and indicate the blockage to an operator by triggering a warning signal such as a visual indication in the form of, e.g., a light emitting diode (LED) or an audible warning signal such as a buzzer signal or the like.

[0117] The electric drive unit 100 may also comprise an air pressure sensor arranged in the top cover 260 of the drive unit 100, e.g., along the air flow path 350, and a control unit configured to detect a restriction or blockage of a cooling air flow of the EM 110 based on an output signal from the air pressure sensor.

[0118] According to some aspects, the electric drive unit 100 comprises a humanmachine interface (HMI) 610 and a control unit 120, 900 configured to display a status message of the electric drive unit 100 via the HMI and to obtain a configuration parameter from a user via the HMI.

[0119] The HMI may be connected to the control unit or control units of the drive unit 100 via wired or wireless link. The HMI may also be integrally formed with one or more control units of the drive unit 100. The processing circuitry used to provide the various control functions and interface functions discussed generally herein can also at least to some extent be integrated with the MCU 120. The control unit 120, 900 can for instance be arranged to obtain an applied torque by the EM 110 on the drive axle D, and to display the currently applied torque via the HMI. This way a load indicator can be created which displays the current load experienced by the drive unit. The load indicator can be used by an operator guiding the construction equipment in order to optimize performance of the construction equipment work task. The operator can also avoid operating the drive unit at too high loads, which may overload the drive unit. The load indicator may comprise an LED bar, perhaps with variation in color. An example load indicator 665 is schematically illustrated in Figure 6B.

[0120] The signal that indicates the current load can be communicated between the MCU 120 and the HMI via the HMI harness 1400, which will be discussed in more detail below in connection to Figure 13 and Figure 14. The HMI discussed in connection to the HMI harness may be the same HMI harness 610 discussed in connection to, e.g., Figure 6, or some other HMI associated with the electric drive unit.

[0121] The control unit 120, 900 may be configured to store a record of load, i.e., drive axle or motor axle torque, which can be read out later in order to determine if the drive unit 100 has been subject to excessive load, i.e., load that does not satisfy a predetermined acceptance criteria, and if so how often and perhaps also when the overload condition occurred. The predetermined acceptance criteria may comprise both thresholds and ranges. The predetermined acceptance criteria may also comprise time limits. The drive unit may, e.g., be allowed to operate with a given load as long as the load does not persist for too long.

[0122] The record may comprise time of day and / or date along with data indicative of the applied torque by the EM 1 10. Maximum applied torque over a predetermined time window may also be recorded.

[0123] The control unit 120, 900 may be arranged to monitor the operation of the EM 110 and / or the operation of the MCU 120, such as the motor winding currents, to detect faults in the drive unit 100. A sudden decrease in load may for instance be indicative of a ruptured drive belt. This event can be communicated to the operator via the HMI and / or recorded in a storage medium 930, possibly together with additional information such as a time stamp or a date, for later analysis.

[0124] The motor currents can also be used as a virtual “dead man's grip”, i.e., a function which detects when an operator no longer has control over the construction equipment, e.g., since he or she has lost hold of a guiding handle portion 670, 1140 of the construction equipment 600, 1100. In this case the control unit 120, 900 monitors the operation of the EM 110 and / or the MCU in order to detect anomalies and may inactivate the construction equipment or trigger a warning signal if an anomaly is detected. An inertial measurement unit (IMU) may also be arranged integrated with or in connection to the control unit 120, 900 to detect sudden unexpected movements by the construction equipment.

[0125] The EM 110 may be a permanent magnet synchronous motor (PMSM) which is an alternating current (AC) synchronous motor whose field excitation is provided by permanent magnets, and which has a sinusoidal counterelectromotive force (counter EMF) waveform, also known as back electromotive force (back EMF) waveform. PMSM motors are known in general and will therefore not be discussed in more detail herein. For instance, similar electrical motors including associated control methods are discussed in “Electric Motors and Drives” (Fifth Edition), Elsevier, ISBN 978-0-08-102615- 1 , 2019, by Austin Hughes and Bill Drury.

[0126] The EM 110 may be fed by current of three phases as schematically shown in Figure 12, which shows a set-up where the control unit 120 controls an inverter 121 which in turn controls current over the motor interface 125. However, any number of feed currents can be used. In this particular example the motor interface 125 comprises three wires for energizing the motor windings. The inverter 121 is normally controlled by a current command from the control unit 120. An inverter is a module which generates one or more phases of alternating current, normally from a DC feed. By controlling the frequency and voltage of the phases over the motor interface 125, the electromagnetic field in the motor can be brought into a controlled rotation to generate a positive torque by the motor shaft, which then can be used to power the equipment. The electric motor can also be used to provide negative torque to the motor shaft, i.e., to brake the drive axle in order to generate electrical energy or to slow down the active part of the equipment.

[0127] It has been realized that the control signals by which the control unit controls the electric motor, i.e., the currents drawn by the electric motor 110 over the three-phase motor interface 125, and the state variables of the control unit 120 for the motor control comprise valuable information which can be used for realtime fault detection of the above-mentioned fault states as well as other fault states. It has also been realized that the currents drawn by the electric motor 110 over the three-phase motor interface 125, and the state variables of the control unit 120 for the motor control can be used for predicting imminent fault states, i.e., fault states which have not yet occurred, but which are likely to occur in the near term, such as a worn or ruptured drive belt 540 or a bearing that is about to seize. Thus, advantageously, the methods disclosed herein may be configured to not only detect fault states after they have occurred but also to indicate a fault state about to occur, i.e., a fault state associated with an increased risk of occurring in the near future.

[0128] The control signals and internal parameters of the electric machine and its control system can be monitored, and different types of classification algorithms can be used to detect when the control signals are indicative of a fault state, as opposed to when the power tool is operating normally. For instance, the currents over the three-phase motor interface 125 can be used to detect one or more of the above-mentioned fault states. Internal regulator variables, such as internal state variables of a PID regulator or the like, executed by the control unit 120, can also be used to indicate fault states.

[0129] The detection mechanisms are advantageously based on machine learning techniques, sometimes referred to as artificial intelligence techniques. Different types of machine learning techniques have been applied with success, but it has been found that algorithms based on random forest techniques are particularly effective and provide robust prediction of fault events. Various types of neural networks may also be applied with success to this classification task.

[0130] Random forests or random decision forests represent an ensemble learning method for classification, regression and other tasks that operate by constructing a multitude of decision trees at training time and outputting the class that is the mode of the classes (classification) or mean / average prediction (regression) of the individual trees. Random decision forests are associated with the advantage of being able to correct for decision trees' habit of overfitting to their training set. Random forests generally outperform decision tree-based algorithms.

[0131] As an alternative to random forest classification methods, a less complex decision tree algorithm can be used, often referred to as regression tree algorithms, which is basically a single tree random forest algorithm.

[0132] The machine learning techniques used herein comprise the construction of a fault model which can be configured, i.e., “trained”, using a plurality of examples of construction equipment which have experienced various fault states. Measurement data of one or more parameters related to the operation of the electric motor of the drive unit 100 and / or of equipment powered by the drive unit 100 is stored and tagged with a respective fault state, which data is then used to train the fault model in a training phase. The thus configured fault model can then be fed by measurement data in real-time during operation of a drive unit 100 and / or of equipment powered by a drive unit 100. If the drive unit 100 and / or the equipment powered by the drive unit 100 experiences a fault state similar to one or more of the training examples, then the fault model is likely to classify the drive unit 100 and / or the equipment powered by the drive unit 100 as being associated with a fault state. The fault model is not only able to determine that the drive unit experiences a fault state, but it may also be configured to determine which fault state out of a pre-determined number of fault states that has occurred. Training of a machine learning model for fault state classification is advantageously done using a hold-out dataset, where one part of the data set is used to train the model, and another part is used for verification of the trained model.

[0133] For example, data of normal use of the power trowel exemplified in Figure 11 can be recorded, and also data of use cases where the operator releases the handle portion 1 140 of the power trowel. These two data sets can be used to train the machine learning structure to recognize when the operator has let go of the handle portion 1140. The machine learning structure can then be used in a virtual dead man grip function, which will quickly detect when the operator lets go of the handle portion and inactivate the drive unit 100 as a result.

[0134] To summarize, there is disclosed a method performed in a control unit of a drive unit 100 driven by an electric motor 1 10, for detecting a fault condition in the drive unit 100, wherein the electric motor 1 10 is associated with a motor current drawn over a motor interface 125. The method comprises monitoring a parameter of the electric motor 110 during operation of the drive unit 100, wherein the parameter is indicative of the motor current. The method also comprises obtaining a fault model, wherein the fault model is configured to classify a state of the drive unit 100 into a pre-determined number of drive unit states comprising one or more fault states, based on a series of electric motor parameter values, and classifying a state of the drive unit 100 into the predetermined number of states based on the fault model and on one or more values of the monitored electric motor 1 10 parameter. The method also comprises triggering an action by the drive unit 100 in case the state of the drive unit 100 is classified as a fault state.

[0135] Thus, advantageously, fault conditions in the drive unit 100 and / or in the equipment powered by the drive unit 100 can be automatically detected, and a suitable response action can be triggered by the control unit. It is an advantage that the detection mechanisms are based primarily on the motor current and does not need other sensor systems. According to aspects, the method further comprises initially training the fault model using recorded values of monitored electric motor 110 parameters corresponding to the one or more fault states. Thus, the fault model is adjusted to the specific type of use case of interest, i.e. , to a specific tool or work task. This enables a more efficient and accurate fault detection mechanism.

[0136] According to aspects, the monitored parameter of the electric motor 110 comprises a D-Q transformed motor current over the motor interface 125. This parameter is easily measured and is often already conveniently available in existing electric motor control systems. Thus, the methods disclosed herein can be implemented as a software add-on in existing drive unit 100 control units.

[0137] According to aspects, the method further comprises monitoring meta data associated with the D-Q transformed motor current, wherein the meta data comprises any of frequency width of a sub-band, relative magnitude in a subband, a frequency sub-band power, and a frequency sub-band entropy of a Fourier transformed representation (1 100) of the D-Q transformed motor current. This type of meta-data can be determined without prohibitive computational complexity and has been shown to provide accurate fault detection and state classification.

[0138] According to aspects, the method further comprises adjusting a sample or window size of the Fourier transform in dependence of a motor speed. This means that the Fourier transform is at least partly compensated for changes in motor speed. For instance, a homogenous frequency curve is obtained independent of the motor speed, which is an advantage since it simplifies further processing and fault state classification.

[0139] According to aspects, the monitored parameter of the electric motor 110 comprises one or more state variables of an electric motor 110 regulator module. These state variables are normally already available internally in the control unit, thus, detection based on such internal state variables can be conveniently implemented in most control units. According to aspects, the monitored parameter of the electric motor 110 comprises an estimated rotor angle of the electric motor 1 10. This estimated rotor angle has been shown to comprise significant amounts of relevant information for the detection of fault conditions in drive unit 100s such as cutoff tools and other types of concrete processing equipment.

[0140] According to aspects, the method further comprises monitoring an output from any of an inertial measurement unit (IMU) a temperature sensor, a dust sensor, and / or a vision-based sensor. This additional sensor data acts as a complement which further increases the performance of the proposed methods in terms of detection performance.

[0141] Figure 6B shows an example HMI module 610. The HMI module 610 comprises an on / off button 650 and a user interface 660 for communicating information to an operator of the drive unit 100, such as the load indicator discussed above. The HMI module may comprise one or more of the control units 120 discussed herein. The HMI module may also comprise one or more wireless transceivers configured to communicate with external units, such as the auxiliary equipment 160 and the central server 170. The HMI module 610 can be connected to the control unit or control units of the drive unit 100 via a cable harness. An example cable harness will be discussed in more detail below in connection to Figure 13 and Figure 14.

[0142] The HMI module 610 comprises an example load bar, which indicates the current load in terms of torque on the drive axle or on the motor axle. This load bar may be color coded, e.g., such that low loads are indicated by green color, medium loads are indicated by yellow color, and high loads in breach of an acceptance criterion are indicated by red color.

[0143] Different types of construction equipment have different operating characteristics and therefore subject the drive unit 100 to different types of load on the drive axle and to different axle speeds. The use cases of the drive unit 100 may vary substantially between the different types of equipment that can be powered by the drive unit 100. Some types of equipment may have restrictions on the amount of drive torque that can be handled without risk of damaging the active part ot the equipment. Similarly, some types of equipment may have restrictions on the drive axle speeds that can be handled safely and without jeopardizing a given work task to be performed by the equipment.

[0144] The control unit 120, 900 is optionally arranged to be configured by a software driver module 935 obtained from a storage medium 930 of the control unit 120, 900. A storage medium 930 of the control unit 120 may be arranged to receive a software driver module 935 from an external device, and / or to store a plurality of different software driver modules 935, where each software driver module comprises operating parameters suitable for a given piece of equipment or for a given type of equipment.

[0145] A software driver module may comprise operating parameters for the EM 1 10, such as a mapping between operator control inputs and operating points in a drive axle speed vs drive axle torque map 1000. Thus, an operator fully depressing the trigger 640 of the floor saw shown in Figure 6B may get a different response from the drive unit 100 in terms of acceleration, speed or torque compared to an operator of some other construction equipment having a similar trigger, such as a lawn mower or a power trowel. The mapping between control input to the HMI and the control of the EM 110 is governed at least in part by the parameters in the software driver module 935, which can be selected differently for different types of construction equipment.

[0146] The operating parameters may also comprise limitations on output drive axle torque 1030 and / or limitations on output drive axle speed 1040, as exemplified in Figure 10.

[0147] According to some aspects, the software driver module 935 defines an allowable operating region 1050 in the drive axle speed vs drive axle torque map 1000. A suitable software driver module 935 can be selected and used for operating the drive unit 100 in dependence of the construction equipment that is being powered by the drive unit 100. This way a construction equipment specific optimization of the drive unit operation can be performed in a straightforward manner, which is an advantage. The software driver module 935 may be configured to determine the appearance of the HMI, and to govern the functions implemented by the HMI. This way different types of construction equipment can be conveniently configured with different types of HMIs, by adapting the software driver module 935. Certain LEDs and other components on the HMI can be assigned different functions in accordance with the instantiation of the software driver module 935.

[0148] To summarize, there is disclosed an electric drive unit 100 for powering driven equipment 600, 1100. The drive unit 100 comprises a base portion 150 that extends in a base plane P, an electric machine, EM, 110, a battery support 130 arranged to releasably hold a battery 700 to power the EM 110, and a drive axle D extending out from the drive unit 100. The EM 110, the battery support 130, and the drive axle D are arranged above the base portion 150 in use, which allows the drive unit to be mounted onto different types of driven equipment in a straight-forward manner. The base portion may, e.g., comprise several different bolt hole patterns configured to match different types of equipment. Thus, the drive unit 100 is arranged to be attached to and to power at least two different types of driven equipment 600, 1100. The drive unit 100 further comprises a control unit 120, 900 arranged to control an operation of the drive unit 100 based on configuration data, as discussed above. The control unit 120, 900 comprises a storage medium 930 arranged to store one or more software driver modules 935, where each software driver module 935 comprises configuration data adapted to configure the drive unit 100 to power a respective type of driven equipment 600, 1100 out of the at least two different types of driven equipment 600, 1100.

[0149] The control unit 120, 900 may also be arranged to activate the drive unit 100 in response to receiving a user code that meets a predetermined acceptance criterion, and to inactivate the drive unit 100 otherwise. An operator having a user code that meets the predetermined acceptance criterion may use the drive unit 100, i.e., may operate the construction equipment powered by the drive unit 100. The acceptance criteria may comprise a usage time period and / or a date of use configured, e.g., by a rental agency or the like. The user code may also be a personal user code assigned to operators that are allowed to use a given type of construction equipment. The predetermined acceptance criterion may, according to an example, be communicated to the drive unit 100 from a central server 170 or from a configuration device that communicates directly with the control unit 120 on the drive unit 100.

[0150] The control unit 120, 900 can furthermore be arranged to receive a wireless inactivation signal from a remote unit, and to inactivate the drive unit 100 in response to receiving the wireless inactivation signal. This way a remote operator can inactivate the drive unit 100, e.g., if a certain drive unit has gone missing or has been stolen or is in need of service.

[0151] Figures 8A-C are flow charts that illustrate methods which summarizes some of the operations and functions of the drive units described herein.

[0152] Figure 8A shows a computer-implemented method, performed by a control unit 120, 900 in an electric drive unit 100. The method comprises obtaining Sa1 access to a storage medium 930 of the electric drive unit 100, where the storage medium 930 comprises one or more software driver modules 935, obtaining Sa2 information related to an intended application of the electric drive unit 100, loading Sa3 a software driver module 935 in dependence of the intended application of the electric drive unit 100, and operating Sa4 an electric machine, EM, 1 10 of the electric drive unit 100 according to one or more parameters comprised in the software driver module 935. The software driver module 935 was discussed above. It allows a construction equipment specific optimization of the drive unit operation. To load a software driver module 935 means that configuration parameters of the control unit are read out and used to parameterize the control unit.

[0153] Figure 8B shows a computer-implemented method, performed by a control unit 120, 900 in an electric drive unit 100 comprising an electric machine, EM, 110. The method comprises monitoring Sb1 an applied motor axle torque of the EM 110 and displaying Sb2 the applied motor axle torque on a display device of the electric drive unit 100. This type of load indicator was discussed above. It allows the operator to monitor the operation of the drive unit 100 and the construction equipment being powered by the drive unit in an efficient manner.

[0154] According to some aspects, the method further comprises obtaining Sb3 information related to a desired operating point of an electric machine, EM, 110 of the electric drive unit 100, where the desired operating point comprises a desired motor axle speed and a desired motor axle torque, monitoring Sb4 a current operating point of the EM 110 comprising a motor axle speed of the EM 1 10 and the applied motor axle torque of the EM 110, comparing Sb5 the current operating point of the EM 110 to the desired operating point of the EM 110, and displaying Sb6 an efficiency metric of the electric drive unit 100 on the display device of the electric drive unit 100.

[0155] Figure 8C shows a computer-implemented method, performed by a control unit 120, 900 in an electric drive unit 100. The method comprises obtaining Sc1 a user code from an operator of the electric drive unit 100, comparing Sc2 the obtained user code to a predetermined acceptance criterion, and determining if the obtained user code satisfies the acceptance criterion, and activating Sc3 the drive unit 100 in case the obtained user code satisfies the acceptance criterion. This way access control to the drive unit 100 can be implemented in an efficient manner.

[0156] According to some aspects, the method also comprises receiving Sc4 a wireless inactivation signal from a remote unit 170, and inactivating Sc5 the drive unit 100 in response to receiving the wireless inactivation signal.

[0157] Figures 6A-B and Figure 11 show example construction equipment comprising respective drive units 100 according to the present disclosure. The two drive units 100 may, as discussed above, be configured by two different software driver modules 935.

[0158] Figures 6A-B illustrate an example floor saw 600 powered by the drive unit 100. A saw blade is connected to the drive axle D via a secondary transmission that normally comprises a belt drive but can also comprise a geared transmission or a direct connection between drive axle and saw blade. Figure 11 illustrates an example power trowel 1 100 comprising the drive unit 100. The drive axle of the drive unit 100 is connected to the active part 1 110 of the trowel, i.e., the trowel blades, via a transmission. The transmission is at least partly enclosed in a transmission housing 1120.

[0159] The drive unit 100 in Figure 1 1 also comprises a lifting eye 1130 which can be used to hoist the drive unit 100 or the construction equipment 1100. This lifting eye 1130 extends through the top cover 260 to the frame structure 140.

[0160] Many of the technical features discussed herein are not inextricably linked to each other, which means that they can be implemented separately to provide various advantages as stand-alone features. A list of example drive units will now be given to illustrate some of these independent technical features.

[0161] The description and figures describe and illustrate an example electric drive unit 100 for powering construction equipment 600, 1 100, the drive unit 100 comprising an electric machine, EM, 1 10 arranged to generate a drive torque, a motor control unit, MCU, 120 configured to control the EM 110, and a battery compartment 130 arranged to releasably hold a battery 700 to power the EM 110. The electric drive unit 100 further comprises a frame structure 140 arranged to at least partly enclose and to support the EM 110, the MCU 120 and the battery compartment 130, the frame structure 140 comprising a base portion 150 extending in a base plane B, where the frame structure 140 comprises inner walls that delimit a sealed drive axle section 250, where the sealed drive axle section 250 is ventilated by an axle housing vent 230.

[0162] The description and figures describe and illustrate an example electric drive unit 100 for powering construction equipment 600, 1 100, the drive unit 100 comprising an electric machine, EM, 1 10 arranged to generate a drive torque, a motor control unit, MCU, 120 configured to control the EM 110, and a battery compartment 130 arranged to releasably hold a battery 700 to power the EM 110. The electric drive unit 100 further comprises a frame structure 140 arranged to at least partly enclose and to support the EM 110, the MCU 120 and the battery compartment 130, the frame structure 140 comprising a base portion 150 extending in a base plane B, where the frame structure 140 is formed at least in part as a cast metal structure.

[0163] The description and figures describe and illustrate an example electric drive unit 100 for powering construction equipment 600, 1 100, the drive unit 100 comprising an electric machine, EM, 1 10, a motor control unit, MCU, 120 configured to control the EM 1 10, and a battery compartment 130 arranged to releasably hold a battery 700 to power the EM 1 10, where a motor axle M of the EM 110 is arranged to transmit torque to a drive axle D of the electric drive unit 100, the electric drive unit 100 further comprising a frame structure 140 arranged to at least partly enclose and to support the EM 110, the MCU 120 and the battery compartment 130, the frame structure 140 comprising a base portion 150 extending in a base plane B, where the drive axle D and the motor axle M are connected via a transmission arrangement 510 external to the frame structure 140.

[0164] The description and figures describe and illustrate an example electric drive unit 100 for powering construction equipment 600, 1 100, the drive unit 100 comprising an electric machine, EM, 1 10 arranged to generate a drive torque, a motor control unit, MCU, 120 configured to control the EM 110, and a battery compartment 130 arranged to releasably hold a battery 700 to power the EM 110. The electric drive unit 100 further comprises a frame structure 140 arranged to at least partly enclose and to support the EM 110, the MCU 120 and the battery compartment 130, the frame structure 140 comprising a base portion 150 extending in a base plane B, where the battery compartment 130 is configured as a through-hole battery compartment with first and second oppositely arranged openings.

[0165] The description and figures describe and illustrate an example electric drive unit 100 for powering construction equipment 600, 1 100, the drive unit 100 comprising an electric machine, EM, 1 10 arranged to generate a drive torque, a motor control unit, MCU, 120 configured to control the EM 110, and a battery compartment 130 arranged to releasably hold a battery 700 to power the EM 110. The electric drive unit 100 further comprises a frame structure 140 arranged to at least partly enclose and to support the EM 110, the MCU 120 and the battery compartment 130, the frame structure 140 comprising a base portion 150 extending in a base plane B, where an air gap is formed between the battery compartment 130 and the frame structure 140 of the electric drive unit 100.

[0166] The description and figures describe and illustrate an example electric drive unit 100 for powering construction equipment 600, 1 100, the drive unit 100 comprising an electric machine, EM, 1 10 arranged to generate a drive torque, a motor control unit, MCU, 120 configured to control the EM 110, and a battery compartment 130 arranged to releasably hold a battery 700 to power the EM 110. The electric drive unit 100 further comprises a frame structure 140 arranged to at least partly enclose and to support the EM 110, the MCU 120 and the battery compartment 130, the electric drive unit 100 comprising a top cover 260 attached to the frame structure 140 opposite to the base portion 150, where the top cover 260 comprises an air intake 310 with a dust trap 340.

[0167] The description and figures describe and illustrate an example electric drive unit 100 for powering construction equipment 600, 1 100, the drive unit 100 comprising an electric machine, EM, 1 10 arranged to generate a drive torque, a motor control unit, MCU, 120 configured to control the EM 110, and a battery compartment 130 arranged to releasably hold a battery 700 to power the EM 110. The electric drive unit 100 further comprises a frame structure 140 arranged to at least partly enclose and to support the EM 110, the MCU 120 and the battery compartment 130, where the EM 1 10 is comprised in an EM section 220 of the drive unit 100, the drive unit 100 comprising an air pressure sensor arranged in the EM section 220, and a control unit configured to detect a restriction or blockage of a cooling air flow 270 of the EM 110 based on an output signal from the air pressure sensor.

[0168] The description and figures describe and illustrate an example electric drive unit 100 for powering construction equipment 600, 1 100, the drive unit 100 comprising an electric machine, EM, 1 10 arranged to generate a drive torque, a motor control unit, MCU, 120 configured to control the EM 110, and a battery compartment 130 arranged to releasably hold a battery 700 to power the EM 110. The electric drive unit 100 further comprises a frame structure 140 arranged to at least partly enclose and to support the EM 110, the MCU 120 and the battery compartment 130, where the control unit 120, 900 is arranged to obtain an applied torque by the EM 110 on the drive axle D, to compare the applied torque to at least one predetermined torque level, and to trigger an action in case the applied torque exceeds the predetermined torque level.

[0169] The description and figures describe and illustrate an example electric drive unit 100 for powering construction equipment 600, 1 100, the drive unit 100 comprising an electric machine, EM, 1 10 arranged to generate a drive torque, a motor control unit, MCU, 120 configured to control the EM 110, and a battery compartment 130 arranged to releasably hold a battery 700 to power the EM 110. The electric drive unit 100 comprising a frame structure 140 arranged to at least partly enclose and to support the EM 110, the MCU 120 and the battery compartment 130, the electric drive unit 100 comprising a control unit 120, 900 arranged to monitor a motor current of the EM 1 10 and to detect an anomaly in the motor current, and to trigger an action in response to detecting the anomaly.

[0170] Figure 9 schematically illustrates, in terms of a number of functional units, the general components of a control unit 120, 900. Processing circuitry 910 is provided using any combination of one or more of a suitable central processing unit CPU, multiprocessor, microcontroller, digital signal processor DSP, etc., capable of executing software instructions stored in a computer program product, e.g., in the form of a storage medium 930. The processing circuitry 910 may further be provided as at least one application specific integrated circuit ASIC, or field programmable gate array FPGA.

[0171] Particularly, the processing circuitry 910 is configured to cause the control unit 120, 900, to perform a set of operations, or steps, such as the methods discussed herein. For example, the storage medium 930 may store the set of operations, and the processing circuitry 910 may be configured to retrieve the set of operations from the storage medium 930 to cause the device to perform the set of operations. The set of operations may be provided as a set of executable instructions. Thus, the processing circuitry 910 is thereby arranged to execute methods as herein disclosed.

[0172] The storage medium 930 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory.

[0173] The device 120, 900 may further comprise an interface 920 for communications with at least one external device, such as a wheel speed sensor 810 or a load sensor 820. As such the interface 920 may comprise one or more transmitters and receivers, comprising analogue and digital components and a suitable number of ports for wireline or wireless communication.

[0174] The processing circuitry 910 controls the general operation of the control unit 120, 900, e.g., by sending data and control signals to the interface 920 and the storage medium 930, by receiving data and reports from the interface 920, and by retrieving data and instructions from the storage medium 930.

[0175] According to some aspects the storage medium comprises a software driver module 935 for operating various functions of the drive unit 100. The configuration parameters comprised in this module may for instance comprise a configuration of drive torque limits, a configuration of motor axle or drive axle speed limits, or a configuration of applied torque and / or axle speed in response to a given control input signal. The software driver module 935 may be configured to store operating parameters of the drive unit 100 suitable for different types of equipment. A power trowel may, for instance, be associated with a given set of operating parameters that are different from the operating parameters suitable for a floor saw. The software driver module 935 consequently selects a set of configuration parameters to optimize performance of the drive unit 100 for a given use case and application. The software driver module 935 may also store different acceptance criteria against which one or more monitored parameters can be compared, e.g., in order to trigger suitable warning signals and determine when the drive unit 100 is to be inactivated for safety reasons.

[0176] To summarize, there is disclosed herein an electric drive unit 100 for powering construction equipment 600, 1100. The drive unit 100 comprises an EM 110, and a battery compartment 130 arranged to releasably hold a battery 700 to power the EM 110. The motor axle of the EM may be used as power output from the drive unit 100. Alternatively, a separate drive axle D connected to the motor axle M via a transmission can be used, as discussed above. The electric drive unit 100 comprises a control unit 120, 900 arranged to control at least an operation of the EM 110, such as an applied torque or speed in response to an input command. The control unit 120, 900 is arranged to be configured by a replaceable software driver module 935 obtained from a storage medium 930 of the control unit 120, 900.

[0177] The electric drive unit 100 optionally comprises a human-machine interface (HMI) 610, as discussed above. The control unit 120, 900 can then be configured to display a status message of the electric drive unit 100 via the HMI, where the status message is configured at least in part by the software driver module 935. Thus, the HMI may be configured display different types of information and different types of messages depending on the type of equipment it powers.

[0178] The control unit 120, 900 is optionally arranged to limit an operation by the EM 110 to an operating range, where the operating range is at least in part defined by the software driver module 935. The operating range can be an axle torque operating range or an axle speed operating range, as discussed above.

[0179] The control unit 120, 900 is optionally arranged to obtain an applied torque by the EM 110 on a drive axle D of the drive unit 100 or a motor axle M of the drive unit 100, to compare the applied torque to at least one predetermined torque level configured by the software driver module 935, and to trigger an action in case the applied torque exceeds the predetermined torque level. The control unit 120, 900 may also be arranged to store data indicative ot an applied torque by the EM 110 in a digital record.

[0180] The control unit 120, 900 is optionally arranged to monitor a motor current of the EM 110 and to detect an anomaly in the motor current, and to trigger an action in response to detecting the anomaly, as discussed above. The detection may be based on straight forward thresholding, or on more advanced machine learning techniques, as discussed above.

[0181] According to some aspects, the software driver module 935 comprises a mapping between input commands and operations by the drive unit 100, where the control unit 120, 900 is arranged to interpret an input command based on the mapping, and to control the EM 110 according to the interpreted input command. Consequently, the response by the drive unit 100 to a given input command, e.g., via the HMI discussed above, is determined by which software driver module 935 that has been selected.

[0182] The software driver module 935 optionally comprises one or more acceptance criteria associated with a motor axle torque and / or motor axle speed of the EM 110, where the control unit 120, 900 is arranged to trigger an action in case a current motor axle torque and / or a current motor axle speed does not satisfy the respective acceptance criteria. Thus, the operating range of the drive unit in terms of motor axle torque and / or motor axle speed is determined at least in part by the software driver module that has been selected. There is also disclosed herein a computer readable medium carrying a computer program comprising program code means for performing the methods discussed herein, when said program product is run on a computer. The computer readable medium and the code means may together form a computer program product.

[0183] Figure 13 illustrates an example drive unit 100 which comprises an HMI module 610 as discussed above that communicates with the main body of the drive unit, i.e., the parts associated with the frame structure 140, via an HMI harness 1400. The HMI harness 1400 extends between the frame structure 140 and the HMI 610. A harness is, generally, a collection of signal conduits, such as electrically conducting signal wires and perhaps also optical fibers configured to transport data.

[0184] The example HMI harness 1400 in Figure 14 comprises a main cable 1410 that extends between a drive unit side connector 1420 and an HMI side connector 1430. The HMI harness 1400 comprises a collection of wires 1440, some of which may be twisted together in order to reduce interference from external sources. The insert 1405 in Figure 14 shows an example wire layout, comprising a power on wire (POWER ON), a hardware trigger wire (HW TRIG), wires to support a controller area network (CAN) bus (CAN H, CAN L, BUS PWR), as well as a common electrical ground (GND). This example harness also comprises two auxiliary power wires which branch off from the main cable 1410.

[0185] The communication bus wires CAN H, CAN L, BUS PWR are generally arranged to support digital communication to and from the HMI 610, such as via a CAN bus. Other bus types, such as Ethernet, can also be supported.

[0186] The electric drive unit 100 preferably comprises a power on wire (POWER ON) that is physically separate from the communication bus wires (CAN H, CAN L, BUS PWR). Together with the digital communication bus wires, this allows for two separate start / stop communication channels, which increases reliability and robustness.

[0187] The HMI harness 1400 optionally implements a hardware trigger wire (HW TRIG). In this case the MCU 120 can be arranged to adapt an operation of the EM 110 in dependence of a configuration of the hardware trigger wire HW_TRIG. It is for instance possible to permanently connect this wire to ground, or to a high potential level in order to configure the MCU in a given mode of operation. It is also possible to connect a potentiometer between the hardware trigger wire and electrical ground, in order to allow analog control of, e.g., motor axle speed in a reliable manner. The example HMI harness 1400 comprises a metal braided cable sleeve 1470 which covers at least a part of the HMI harness 1400. This sleeve protects a part of the harness from mechanical wear and also from external interference.

[0188] According to some aspects, the HMI harness 1400 comprises an auxiliary power interface 1450 arranged to power one or more auxiliary components of the electric drive unit 100, such as a work light, a universal serial bus (USB) battery charger, or the like. This auxiliary power interface 1450 can be realized as a branch cable that extends out from the HMI harness 1400, as shown in Figure 14.

Claims

CLAIMS1 . An electric drive unit (100) for powering driven equipment (600, 1 100), the drive unit (100) comprising a base portion (150) that extends in a base plane (P), an electric machine, EM, (110), a battery support (130) arranged to releasably hold a battery (700) to power the EM (110), and a drive axle (D) extending out from the drive unit (100), where the EM (1 10), the battery support (130), and the drive axle (D) are arranged above the base portion (150) in use, where the drive unit (100) is arranged to be attached to and to power at least two different types of driven equipment (600, 1 100), the drive unit (100) further comprising a control unit (120, 900) arranged to control an operation of the drive unit (100) based on configuration data, the control unit (120, 900) comprising a storage medium (930) arranged to store one or more software driver modules (935), where each software driver module (935) comprises configuration data adapted to configure the drive unit (100) to power a respective type of driven equipment (600, 1 100) out of the at least two different types of driven equipment (600, 1 100), where the control unit (120, 900) is arranged to interpret an operator input command to the drive unit (100) by a selected software driver module (935) out of the one or more software driver modules (935), and to control the EM (1 10) according to the interpreted operator input command.

2. The electric drive unit (100) according to claim 1 , comprising a humanmachine interface, HMI, (610), where the control unit (120, 900) is configured to display a status message of the electric drive unit (100) via the HMI, where the status message is configured at least in part by the software driver module (935).

3. The electric drive unit (100) according to claim 1 or 2, where the control unit (120, 900) is arranged to limit an operation by the EM (1 10) to an operatingrange, where the operating range is at least in part defined by the software driver module (935).

4. The electric drive unit (100) according to any previous claim, where the control unit (120, 900) is arranged to obtain an applied torque by the EM (1 10) on a drive axle (D) of the drive unit (100), to compare the applied torque to at least one predetermined torque level configured by the software driver module (935), and to trigger an action in case the applied torque exceeds the predetermined torque level.

5. The electric drive unit (100) according to any previous claim, where the control unit (120, 900) is arranged to store data indicative of an applied torque by the EM (110) in a digital record.

6. The electric drive unit (100) according to any previous claim, where the control unit (120, 900) is arranged to monitor a motor current of the EM (1 10) and to detect an anomaly in the motor current, and to trigger an action in response to detecting the anomaly.

7. The electric drive unit (100) according to any previous claim, where the software driver module (935) comprises a mapping between operator input commands to the drive unit (100) and operations by the drive unit (100), where the control unit (120, 900) is arranged to interpret an operator input command based on the mapping, and to control the EM (110) according to the interpreted operator input command.

8. The electric drive unit (100) according to claim 7, comprising a control device (610) arranged to obtain the operator input commands, where the control device (610) comprises any of a wireless or wired remote control device, a wireless or wired HMI (610) configured to be attached to the driven equipment (600, 1100), and / or a control panel integrated with the drive unit (100).

9. The electric drive unit (100) according to any previous claim, where the software driver module (935) comprises one or more acceptance criteria associated with a motor axle torque and / or motor axle speed of the EM (1 10),where the control unit (120, 900) is arranged to trigger an action in case a current motor axle torque and / or a current motor axle speed does not satisfy the respective acceptance criteria.

10. The electric drive unit (100) according to any previous claim, comprising the HMI (610) and a frame structure (140), arranged to at least partly enclose and to support the EM (1 10) and the battery support (130), where an HMI harness (1400) extends between the frame structure (140) and the HMI (610).

11. The electric drive unit (100) according to claim 10, where the HMI harness (1400) comprises communication bus wires (CAN H, CAN L, BUS_PWR) arranged to support digital communication to and from the HMI (610), such as via a controller area network, CAN, bus or Ethernet bus.

12. The electric drive unit (100) according to claim 1 1 , comprising a power on wire (POWER ON) separate from the communication bus wires (CAN H, CAN_L, BUS_PWR).

13. The electric drive unit (100) according to any of claims 10-12, comprising a motor control unit, MCU, (120) configured to control the EM (110), where the MCU (120) is at least partly enclosed by the frame structure (140), where the HMI harness (1400) comprises a hardware trigger wire (HW_TRIG), where the MCU (120) is arranged to adapt an operation of the EM (110) in dependence of a configuration of the hardware trigger wire (HW TRIG).

14. The electric drive unit (100) according to claim 13, where the hardware trigger wire (HW_TRIG) is connected to ground, connected to a fixed potential, connected to a variable potential, or connected to a variable resistance.

15. The electric drive unit (100) according to any of claims 10-14, where the HMI harness (1400) comprises a metal braided cable sleeve (1470) which covers at least a part of the HMI harness (1400).

16. The electric drive unit (100) according to any of claims 10-15, where the HMI harness (1400) comprises an auxiliary power interface (1450) arranged to power one or more auxiliary components of the electric drive unit (100).

17. The electric drive unit (100) according to claim 16, where the auxiliary power interface (1450) is a branch cable that extends out from the HMI harness (1400).

18. A computer-implemented method, performed by a control unit (120, 900) in an electric drive unit (100), the method comprising obtaining (Sa1 ) access to a (930) of the electric drive unit (100), where the storage medium (930) comprises one or more software driver modules (935), obtaining (Sa2) information related to an intended application of the electric drive unit (100), loading (Sa3) a software driver module (935) from the storage medium (930) in dependence of the intended application of the electric drive unit (100), and operating (Sa4) an electric machine, EM, (110) of the electric drive unit (100) according to one or more parameters comprised in the software driver module (935).

19. An electric drive unit (100) for powering driven equipment (600, 1100), the drive unit (100) comprising an electric machine, EM, (110), a motor control unit, MCU, (120) configured to control the EM (1 10), and a battery compartment (130) arranged to releasably hold a battery (700) to power the EM (1 10), where a motor axle (M) of the EM (110) is arranged to transmit torque to a drive axle (D) of the electric drive unit (100), the electric drive unit (100) further comprising a frame structure (140) arranged to at least partly enclose and to support the EM (1 10), the MCU (120) and the battery compartment (130), the frame structure (140) comprising a base portion (150) extending in a base plane (B),where a separating plane (P1 , V) intersects the base portion (150) and separates the battery compartment (130) from the motor axle (M) and from the drive axle (D) of the drive unit (100).

20. The electric drive unit (100) according to claim 19, where the motor axle (M) and the drive axle (D) lie in an axle plane (P2) that is parallel to the separating plane (P1 ).

21. The electric drive unit (100) according to claim 19 or 20, where the separating plane (V) and the base plane (B) are orthogonal planes.

22. The electric drive unit (100) according to any of claims 19-21 , where the frame structure (140) comprises inner walls that at least partly delimit a battery compartment section (210) from an EM section (220) of the drive unit (100).

23. The electric drive unit (100) according to claim 22, where the EM section (220) comprises the EM (1 10) and the MCU (120), and a cooling fan (560) arranged to generate a cooling air flow (270) to transport heat away from the EM (1 10) and from the MCU (120).

24. The electric drive unit (100) according to claim 22 or 23, where a straight line (155) normal to the base plane (B) and separated from the base portion (150) intersects the battery compartment (130).

25. The electric drive unit (100) according to any of claims 22-24, where at least one aperture facing the base plane (B) is formed in an external wall (240) of the battery compartment (130) to allow a vertical convection air flow (275) to pass between the battery compartment (130) and an external environment of the electric drive unit (100).

26. The electric drive unit (100) according to any of claims 22-25, where at least a part of an external wall (240) of the battery compartment (130) facing the base plane (B) is formed as a skid plate.

27. The electric drive unit (100) according to any of claims 19-26, where the frame structure (140) comprises inner walls that delimit a sealed drive axlesection (250), where the sealed drive axle section (250) is ventilated by an axle housing vent (230).

28. The electric drive unit (100) according to any of claims 19-27, where the frame structure (140) is formed at least in part as a cast metal structure.

29. The electric drive unit (100) according to any of claims 19-28, where the base portion (150) comprises mounts formed in a resilient material.

30. The electric drive unit (100) according to any of claims 19-29, where the base portion (150) comprises a planar surface extending in the base plane (B), where at least one bolt hole pattern is formed in the base portion (150).31 . The electric drive unit (100) according to any of claims 19-30, where the base portion (150) comprises at least one bolt hole pattern in compliance with a bolt hole pattern of a combustion engine based drive unit.

32. The electric drive unit (100) according to any of claims 19-31 , where the drive axle (D) and the motor axle (M) are connected via a transmission arrangement (510) external to the frame structure (140).

33. The electric drive unit (100) according to claim 32, where the transmission arrangement (510) comprises a toothed belt (540).

34. The electric drive unit (100) according to claim 32 or 33, where the transmission arrangement (510) has a gear ratio of between 2.5:1 and 3.1 :1 , and preferably about 2.8:1 .

35. The electric drive unit (100) according to any of claims 32-34, where the transmission arrangement (510) comprises a replaceable lower pulley (530) connected to the drive axle (D) and / or a replaceable upper pulley (520) connected to the motor axle (M).

36. The electric drive unit (100) according to any of claims 19-35, where the battery compartment (130) is configured as a through-hole battery compartment with first and second oppositely arranged openings.

37. The electric drive unit (100) according to claim 36, where a straight line parallel to the motor axle (M) intersects the first and second oppositely arranged openings.

38. The electric drive unit (100) according to any of claims 19-37, where the battery compartment (130) has a battery insertion opening located on an opposite side of the drive unit compared to a drive axle (D) side of the drive unit (100).

39. The electric drive unit (100) according to any of claims 19-38, where the battery compartment (130) is suspended from the frame structure (140) by at least one resilient support member (570).

40. The electric drive unit (100) according to any of claims 19-39, where an air gap is formed between the battery compartment (130) and the frame structure (140) of the electric drive unit (100).41 . The electric drive unit (100) according to any of claims 19-40, where the battery compartment (130) comprises upper and lower grates (330, 335) arranged to allow a vertical convection air flow (275) to traverse the battery compartment (130).

42. The electric drive unit (100) according to any of claims 19-41 , comprising two separate battery compartments arranged side-by-side and supported by the frame structure.

43. The electric drive unit (100) according to any of claims 19-42, comprising a top cover (260) attached to the frame structure (140) opposite to the base portion (150), where the top cover (260) comprises an air intake (310) with a dust trap (340).

44. The electric drive unit (100) according to claim 43, where the top cover (260) comprises an air intake part (310) with a lid (320) separable from the air intake part to allow access to the dust trap (340).

45. The electric drive unit (100) according to claim 32, comprising a removable side housing portion (390) arranged to cover the transmissionarrangement (510), where the side housing portion (390) is arranged on an opposite side of the drive unit (100) compared to the drive axle (D).

46. The electric drive unit (100) according to any of claims 19-45, where the EM (110) is comprised in an EM section (220) of the drive unit (100), the drive unit (100) comprising an air pressure sensor arranged in the EM section (220), and a control unit configured to detect a restriction or blockage of a cooling air flow (270) of the EM (110) based on an output signal from the air pressure sensor.

47. The electric drive unit (100) according to any of claims 19-46, comprising an air pressure sensor arranged in a top cover (260) of the drive unit (100), and a control unit configured to detect a restriction or blockage of a cooling air flow of the EM (1 10) based on an output signal from the air pressure sensor.

48. The electric drive unit (100) according to any of claims 19-47, comprising a human-machine interface, HMI, (610) and a control unit (120, 900) configured to display a status message of the electric drive unit (100) via the HMI and / or to obtain a configuration parameter from a user via the HMI.

49. The electric drive unit (100) according to any of claims 19-48, comprising a control unit (120, 900) arranged to obtain an applied torque by the EM (1 10) on the drive axle (D), to compare the applied torque to at least one predetermined torque level, and to trigger an action in case the applied torque exceeds the predetermined torque level.

50. The electric drive unit (100) according to claim 49, where the control unit (120, 900) is arranged to store data indicative of the applied torque in a digital record.51 . The electric drive unit (100) according to claim 49 or 50, where the control unit (120, 900) is arranged to monitor a motor current of the EM (1 10) and to detect an anomaly in the motor current, and to trigger an action in response to detecting the anomaly.

52. The electric drive unit (100) according to any of claims 19-51 , comprising a control unit (120, 900) arranged to be configured by a software driver module (935) obtained from a storage device (930) of the control unit (120, 900).

53. The electric drive unit (100) according to any of claims 19-52, comprising a control unit (120, 900) arranged to monitor a usage pattern of the drive unit (100), and to determine a suitable transmission gear ratio based on the usage pattern.

54. The electric drive unit (100) according to any of claims 19-53, comprising a control unit (120, 900) arranged to activate the drive unit (100) in response to receiving a user code that meets a predetermined acceptance criterion, and to inactivate the drive unit (100) otherwise.

55. The electric drive unit (100) according to any of claims 19-54, comprising a control unit (120, 900) arranged to receive a wireless inactivation signal from a remote unit, and to inactivate the drive unit (100) in response to receiving the wireless inactivation signal.

56. The electric drive unit (100) according to any of claims 19-55, comprising a control unit (120, 900) arranged to configure the drive unit (100) in a generator mode of operation or in a drive mode of operation.

57. A computer-implemented method, performed by a control unit (120, 900) in an electric drive unit (100) comprising an electric machine, EM, (1 10), the method comprising monitoring (Sb1 ) an applied motor axle torque of the EM (1 10), and displaying (Sb2) the applied motor axle torque on a display device of the electric drive unit (100).

58. The computer-implemented method according to claim 57, further comprising obtaining (Sb3) information related to a desired operating point of the EM (1 10), where the desired operating point comprises a desired motor axle speed and a desired motor axle torque,monitoring (Sb4) a current operating point of the EM (110) comprising a motor axle speed of the EM (110) and the applied motor axle torque of the EM (1 10), comparing (Sb5) the current operating point of the EM (110) to the desired operating point of the EM (110), and displaying (Sb6) an efficiency metric of the electric drive unit (100) on the display device of the electric drive unit (100).

59. A computer-implemented method, performed by a control unit (120, 900) in an electric drive unit (100), the method comprising obtaining (Sc1) a user code from an operator of the electric drive unit (100), comparing (Sc2) the obtained user code to a predetermined acceptance criterion, and determining if the obtained user code satisfies the acceptance criterion, and also activating (Sc3) the drive unit (100) in case the obtained user code satisfies the acceptance criterion.

60. The computer-implemented method according to claim 59, further comprising receiving (Sc4) a wireless inactivation signal from a remote unit (170), and inactivating (Sc5) the drive unit (100) in response to receiving the wireless inactivation signal.

61. An electric drive unit (100) for powering driven equipment (600, 1100), the drive unit (100) comprising an electric machine, EM, (110) arranged to generate a drive torque, a control unit (120, 900) configured to control the EM (1 10), and a battery compartment (130) arranged to releasably hold a battery (700) to power the EM (110), the electric drive unit (100) further comprising a frame structure (140) arranged to at least partly enclose and to support the EM (1 10), the MCU (120) and the battery compartment (130), the frame structure (140) comprising a base portion (150) extending in a base plane (B),where the frame structure (140) comprises inner walls that at least partly delimit a battery compartment section (210) from an EM section (220) of the drive unit (100).

62. An electric drive unit (100) for powering driven equipment (600, 1100), the drive unit (100) comprising an electric machine, EM, (110) arranged to generate a drive torque, a control unit (120, 900) configured to control the EM (1 10), and a battery compartment (130) arranged to releasably hold a battery (700) to power the EM (110), the electric drive unit (100) further comprising a frame structure (140) arranged to at least partly enclose and to support the EM (1 10), the MCU (120) and the battery compartment (130), the frame structure (140) comprising a base portion (150) extending in a base plane (B), where the frame structure (140) comprises inner walls that delimit a sealed drive axle section (250), where the sealed drive axle section (250) is ventilated by an axle housing vent (230).

63. An electric drive unit (100) for powering driven equipment (600, 1100), the drive unit (100) comprising an electric machine, EM, (1 10), a control unit (120, 900) configured to control the EM (110), and a battery compartment (130) arranged to releasably hold a battery (700) to power the EM (110), where a motor axle (M) of the EM (110) is arranged to transmit torque to a drive axle (D) of the electric drive unit (100), the electric drive unit (100) further comprising a frame structure (140) arranged to at least partly enclose and to support the EM (1 10), the MCU (120) and the battery compartment (130), the frame structure (140) comprising a base portion (150) extending in a base plane (B), where the drive axle (D) and the motor axle (M) are connected via a transmission arrangement (510) external to the frame structure (140).

64. An electric drive unit (100) for powering driven equipment (600, 1100), the drive unit (100) comprising an electric machine, EM, (110) arranged togenerate a drive torque, a control unit (120, 900) configured to control the EM (1 10), and a battery compartment (130) arranged to releasably hold a battery (700) to power the EM (110), the electric drive unit (100) further comprising a frame structure (140) arranged to at least partly enclose and to support the EM (1 10), the MCU (120) and the battery compartment (130), the frame structure (140) comprising a base portion (150) extending in a base plane (B), where the battery compartment (130) is configured as a through-hole battery compartment with first and second oppositely arranged openings.

65. An electric drive unit (100) for powering driven equipment (600, 1100), the drive unit (100) comprising an electric machine, EM, (110) arranged to generate a drive torque, a control unit (120, 900) configured to control the EM (1 10), and a battery compartment (130) arranged to releasably hold a battery (700) to power the EM (110), the electric drive unit (100) further comprising a frame structure (140) arranged to at least partly enclose and to support the EM (1 10), the MCU (120) and the battery compartment (130), the frame structure (140) comprising a base portion (150) extending in a base plane (B), where an air gap is formed between the battery compartment (130) and the frame structure (140) of the electric drive unit (100).

66. An electric drive unit (100) for powering driven equipment (600, 1100), the drive unit (100) comprising an electric machine, EM, (110) arranged to generate a drive torque, a control unit (120, 900) configured to control the EM (1 10), and a battery compartment (130) arranged to releasably hold a battery (700) to power the EM (110), the electric drive unit (100) further comprising a frame structure (140) arranged to at least partly enclose and to support the EM (1 10), the MCU (120) and the battery compartment (130),the electric drive unit (100) comprising a top cover (260) attached to the frame structure (140) opposite to the base portion (150), where the top cover (260) comprises an air intake (310) with a dust trap (340).

67. An electric drive unit (100) for powering driven equipment (600, 1100), the drive unit (100) comprising an electric machine, EM, (110) arranged to generate a drive torque, a control unit (120, 900) configured to control the EM (1 10), and a battery compartment (130) arranged to releasably hold a battery (700) to power the EM (110), the electric drive unit (100) further comprising a frame structure (140) arranged to at least partly enclose and to support the EM (1 10), the MCU (120) and the battery compartment (130), where the EM (110) is comprised in an EM section (220) of the drive unit (100), the drive unit (100) comprising an air pressure sensor arranged in the EM section (220), and a control unit configured to detect a restriction or blockage of a cooling air flow (270) of the EM (1 10) based on an output signal from the air pressure sensor.

68. An electric drive unit (100) for powering driven equipment (600, 1100), the drive unit (100) comprising an electric machine, EM, (110) arranged to generate a drive torque, a control unit (120, 900) configured to control the EM (1 10), and a battery compartment (130) arranged to releasably hold a battery (700) to power the EM (110), the electric drive unit (100) further comprising a frame structure (140) arranged to at least partly enclose and to support the EM (1 10), the MCU (120) and the battery compartment (130), where the control unit (120, 900) is arranged to obtain an applied torque by the EM (110) on the drive axle (D), to compare the applied torque to at least one predetermined torque level, and to trigger an action in case the applied torque exceeds the predetermined torque level.

69. An electric drive unit (100) for powering driven equipment (600, 1100), the drive unit (100) comprising an electric machine, EM, (110) arranged togenerate a drive torque, a control unit (120, 900) configured to control the EM (1 10), and a battery compartment (130) arranged to releasably hold a battery (700) to power the EM (110), the electric drive unit (100) comprising a frame structure (140) arranged to at least partly enclose and to support the EM (110), the MCU (120) and the battery compartment (130), the electric drive unit (100) comprising a control unit (120, 900) arranged to monitor a motor current of the EM (1 10) and to detect an anomaly in the motor current, and to trigger an action in response to detecting the anomaly.

Images