CN116771763A - Thermal management systems for hydraulic systems and electric powertrain components - Google Patents

Abstract

Thermal management systems for hydraulic systems and electric powertrain components. A thermal management system for an electric working machine having at least one working device hydraulically powered by a hydraulic system is disclosed. The thermal management system includes: one or more electric powertrain components; a bi-directional fan; and a first heat exchanger including a hydraulic oil cooler in fluid communication with the hydraulic system. The bidirectional fan is operable in a first mode in which air is forced by the bidirectional fan along a first airflow path across the heat exchange surface of the hydraulic oil cooler or in a second mode. and toward the powertrain components; in the second mode, air is forced by the bidirectional fan to flow along a second airflow path past the heat exchange surface of the hydraulic oil cooler and away from the electric powertrain into parts.

Description

Thermal management systems for hydraulic systems and electric powertrain components

Technical field

The present disclosure relates to thermal management systems for electric working machines, and more particularly to electric working machines having at least one work device hydraulically powered by a hydraulic system. The present disclosure also relates to associated methods of heating and cooling components, and more particularly to electric powertrain components and hydraulic systems of electric work machines using thermal management systems.

Background technique

Electro-hydraulic construction machinery has replaced models previously powered by diesel engines in order to reduce emissions. Such electro-hydraulic construction/off-highway equipment and machinery include, for example, excavators, telehandlers, forklifts, and the like having electro-hydraulic powertrain architectures. Such machinery can be collectively referred to as working machines. Electro-hydraulic work machines need to be able to operate in all types of weather and extreme temperatures. Their batteries (also called energy storage devices) have optimal operating temperatures for charging and discharging. If the battery is operated outside of the optimal temperature range, the battery life may be affected. Furthermore, the maximum charging rate can only be achieved when the battery is at optimal temperature. In extreme cases, the battery may not operate at all if it is too cold.

Solutions have been devised for warming batteries when ambient temperatures are very low. Existing solutions for heating batteries include internal cell heaters. However, these solutions cannot be used when the battery is completely depleted, and existing solutions have slow heating rates. Internal resistive heaters in the cells of air-cooled batteries also have the disadvantage that they create temperature gradients. Other solutions include applying external heating pads to the battery. However, this has disadvantages as it requires additional manual steps to insert the heating pad, additional equipment needs to be stored when not being used for heating, and the heating process is slow, thereby defeating the main purpose of the machine. Space within electro-hydraulic work machines is often limited, so there is often minimal room for other specialized liquid cooling/heating equipment such as coolant reservoirs, heaters, pumps, pipes and radiators.

Accordingly, it is desirable to provide improved systems for thermal management of electric powertrain components of electrohydraulic working machines, such as batteries.

Contents of the invention

According to one aspect of the present disclosure, there is provided a thermal management system for an electric working machine having at least one working device hydraulically powered by a hydraulic system, the thermal management system comprising: one or more electric powertrain components; a bidirectional fan; and a first heat exchanger including a hydraulic oil cooler in fluid communication with the hydraulic system, the hydraulic oil cooler having at least a first a heat exchange surface; the bi-directional fan, the electric powertrain component and the hydraulic oil cooler are arranged such that the bi-directional fan is operable in a first mode or is operable in a second mode, in the first In the first mode, air is forced by the bidirectional fan along a first airflow path across the heat exchange surface of the hydraulic oil cooler and toward the electric powertrain components; in the second mode, the air is forced by The bi-directional fan forces flow along a second airflow path across the heat exchange surface of the hydraulic oil cooler and away from the electric powertrain components.

The arrangement of the bi-directional fan, electric powertrain components and hydraulic oil cooler allows the system to be selectively operated such that hot air is drawn away from the electric powertrain components in order to cool the electric powertrain components, or alternatively Operates to cause hot air to be directed from the hydraulic oil cooler to the electric powertrain components in order to heat the electric powertrain components. Operation of the system in these two alternative modes can be achieved using a single fan, allowing a single fan to be operated to cool or heat electric powertrain components, depending on the selected operating mode. In other embodiments, operation of the system in two alternative modes may be accomplished with a single fan system including one or more bi-directional fans, each of the bi-directional fans of the fan system being operable in a first mode or Operable in a second mode in which air is forced by a bi-directional fan to flow along a first airflow path over the heat exchange surface of the hydraulic oil cooler and toward the electric powertrain components; The bi-directional fan forces flow along a second airflow path across the heat exchange surface of the hydraulic oil cooler and away from the electric powertrain components. Operation of the system in two alternative modes can be achieved by using the same fan to selectively heat or cool electric powertrain components. The bi-directional fan, electric powertrain components, and hydraulic oil cooler are suitably arranged such that when the bi-directional fan is operated in its first mode, air is forced by the bi-directional fan along the first airflow path both past the heat of the hydraulic oil cooler and The exchange surface in turn faces the electric powertrain components, and when the bi-directional fan is operated in its second mode, air is forced by the bi-directional fan along a second airflow path both past the heat exchange surface of the hydraulic oil cooler and away from the electric powertrain components .

A reversible fan is a reversible fan, meaning it can force air toward or away from the first side of the fan. For example, where the bi-directional fan includes a propeller fan, the propeller will be rotatable in a first direction and an opposite direction. The hydraulic oil cooler may be a fluid-to-air type heat exchanger. Through the arrangement of bidirectional fans, hydraulic oil coolers, and electric powertrain components, air can be used as a heat exchange medium to heat or cool electric powertrain components through forced convection. Advantageously, the system can use waste heat from the hydraulic system to warm the battery during cold start warm-up. The same components may alternatively be used to cool the battery without the need for additional components.

In certain embodiments, the electric powertrain components include energy storage devices. The electric powertrain components may alternatively include other components of the electric powertrain, such as motors or inverters.

In some embodiments, the bi-directional fan and the hydraulic oil cooler are arranged such that the hydraulic oil cooler is downstream of the bi-directional fan in the first airflow path. In such embodiments, the hydraulic oil cooler is located upstream of the bi-directional fan in the second air flow path.

In other embodiments, the bi-directional fan and the hydraulic oil cooler are arranged such that the hydraulic oil cooler is upstream of the bi-directional fan in the first airflow path. In such embodiments, the hydraulic oil cooler is located downstream of the bi-directional fan in the second air flow path.

The energy storage device may be contained within a housing having a first opening that allows air to pass therethrough via the first airflow path and the second airflow path. The hydraulic oil cooler and bi-directional fan can be located outside the energy storage device housing.

In some embodiments, the hydraulic oil cooler or the bi-directional fan is disposed adjacent the first opening of the housing. In other embodiments, the system further includes a duct disposed between the first opening of the housing and the hydraulic oil cooler or the bi-directional fan.

The bidirectional fan may be a variable speed fan. In such embodiments, the bi-directional fan may operate at variable speeds. A control system may be provided to vary the speed of the bi-directional fan based on the temperature of the electric powertrain component.

In some embodiments, the housing further includes one or more controllable louvers. Each blind can be moved between a closed and open position, and each blind can be controlled remotely. Providing one or more louvers allows further control of heating/cooling of the energy storage device.

The system may also include an energy storage device chargeable by an Electric Vehicle Supply Equipment (EVSE) unit, and the bi-directional fan may optionally be powered by the energy storage device or EVSE unit. The system can be configured so that the bi-directional fan can be selectively powered by an energy storage device or EVSE unit. The option to use an external power source to power the bidirectional fan during the stationary charge of the energy storage device conserves stored energy compared to using the energy storage device to power the fan. In cold ambient conditions, the electric powertrain components can be preheated while the electric work machine is being charged. The system uses waste heat from the hydraulic system to heat the electric powertrain components, such as energy storage devices, from a cold start. In other cases, the system can utilize heat from the hydraulic system during cold starts, which is generated by a hydraulic oil heater specifically designed to heat the hydraulic system, so the system can utilize heat from the hydraulic system rather than waste heat. The system may also include a hydraulic oil heater for heating the hydraulic oil of the hydraulic system, which hydraulic oil heater is optionally powered by the EVSE unit when the energy storage device of the electric working machine is charged, as will be discussed below regarding other implementations The method is described in more detail.

According to another aspect of the present disclosure, a thermal management system is provided for an electric working machine having at least one working device hydraulically powered by a hydraulic system, the thermal management system comprising: a or more electric powertrain components and one or more heat exchanger plates adjacent the electric powertrain components and configured in fluid communication with the hydraulic system. The thermal management system may include any other features of the thermal management system described above.

This provides another improved way in which electric powertrain components such as energy storage devices can be selectively heated and cooled to assist in the temperature management of electric powertrain components. Thermal management systems incorporating heat exchanger plates utilize hydraulic oil as a heat transfer medium to heat/cool electric powertrain components such as energy storage devices. Advantageously, the system can utilize waste heat from the hydraulic system to preheat electric powertrain components. Additionally, in some embodiments, hydraulic oil can be used as the primary fluid transfer medium for heating/cooling electric powertrain components (instead of, for example, water), thereby eliminating the need for space to accommodate additional equipment for heat transfer fluid storage and distribution. need.

In certain embodiments, the electric powertrain components include energy storage devices. The electric powertrain components may alternatively include other components of the electric powertrain, such as motors or inverters.

Not only can heat exchanger plates be positioned adjacent to energy storage devices, but the plates can be positioned adjacent to any electric powertrain component that can benefit from thermal management. For example, a heat exchanger plate in fluid communication with a hydraulic system may be positioned adjacent a motor, inverter, or other components that operate at temperatures higher than the hydraulic fluid in order to cool these components. Apart from a different placement of the heat exchanger plates, the system may otherwise have the same characteristics as the system described herein for heating and cooling energy storage devices.

The electric powertrain component may include an energy storage device, and the heat exchanger plate is configured to exchange heat between hydraulic fluid of the hydraulic system and a plurality of different surfaces of the energy storage device. Multi-surface heating of energy storage devices can be achieved using multiple heat exchanger plates.

The thermal management system may further include a hydraulic system including a primary fluid circuit for hydraulically powering the at least one working device of the electric working machine and an auxiliary fluid circuit in parallel with the primary fluid circuit. Fluid circuit, the heat exchanger plates are in the secondary fluid circuit.

The secondary fluid circuit may also include an auxiliary pump assembly for pumping hydraulic oil through the secondary fluid circuit. The auxiliary pump assembly may be a low pressure hydraulic pump assembly. The main fluid circuit has a main hydraulic pump assembly for pumping hydraulic fluid to drive the at least one working device, and the low pressure pump assembly is configured to pump fluid at a lower pressure than the main hydraulic pump assembly to protect the heat exchanger plate from damage. Receives high pressure within the main fluid circuit.

The system may also include an energy storage device chargeable by an electric vehicle supply equipment (EVSE) unit, and the auxiliary pump assembly may optionally be powered by the energy storage device or EVSE unit. Powering the electric motor of the auxiliary pump assembly with the charging current advantageously conserves stored energy.

In extreme cold temperatures, the viscosity of hydraulic oil increases, which causes damage to hydraulic system equipment unless the hydraulic oil is preheated. Existing solutions for heating hydraulic oil include the use of external heating pads, which are slow to heat and require manual installation and removal from the working machine.

According to another aspect of the present disclosure, there is provided a thermal management system for an electric working machine having at least one working device hydraulically powered by a hydraulic system, the thermal management system comprising: Hydraulic oil heater for heating the hydraulic oil of the hydraulic system. The thermal management system may include any other features of the thermal management system described above.

The hydraulic oil heater may be an electric heater, and the system further includes an energy storage device that can be charged by an electric vehicle supply equipment (EVSE) unit, and the hydraulic oil heater can optionally be charged by the energy storage device or Electric Vehicle Supply Equipment (EVSE) unit supplies power. Powering the hydraulic oil heater and auxiliary pump assembly with charging current helps conserve stored energy.

In some embodiments, the hydraulic oil heater is configured to be located in the hydraulic tank.

In other embodiments, the thermal management system further includes a hydraulic system including a primary fluid circuit for hydraulically powering the at least one working device of the electric working machine and an interface with the primary fluid circuit. The main circuit is connected in parallel with the auxiliary fluid circuit, and the hydraulic oil heater is in the auxiliary fluid circuit. In such an embodiment, the system effectively has an in-line oil heater.

The secondary fluid circuit may also include an auxiliary pump assembly for pumping hydraulic oil through the secondary fluid circuit.

Thermal management systems including hydraulic oil heaters as described above may be combined with any of the previously disclosed aspects.

According to another aspect of the present disclosure, there is provided an electric working machine having at least one working device hydraulically powered by a hydraulic system, the electric working machine including a thermal management system, the thermal management system The system includes: one or more electric powertrain components; a bidirectional fan; and a first heat exchanger including a hydraulic oil cooler in fluid communication with the hydraulic system, the hydraulic oil cooling the device has at least a first heat exchange surface; the bi-directional fan, the electric powertrain component and the hydraulic oil cooler are arranged such that the bi-directional fan is operable in a first mode or is operable in a second mode, In the first mode, air is forced by the bidirectional fan along a first airflow path across the heat exchange surface of the hydraulic oil cooler and toward the electric powertrain components; in the second mode , air is forced by the bidirectional fan to flow along a second airflow path across the heat exchange surface of the hydraulic oil cooler and away from the electric powertrain components. The electric working machine may incorporate any other features of the thermal management system as described above.

According to another aspect of the present disclosure, a method of heating or cooling one or more electric powertrain components of an electric working machine having at least one workpiece hydraulically powered by a hydraulic system is provided. The method includes providing a thermal management system including: one or more electric powertrain components; a bi-directional fan; and a first heat exchanger including: A hydraulic oil cooler in fluid communication with the hydraulic system, the hydraulic oil cooler having at least a first heat exchange surface; the bidirectional fan, the electric powertrain component and the hydraulic oil cooler being arranged such that the bidirectional the fan is operable in a first mode in which air is forced by the bidirectional fan to flow along a first airflow path across the heat exchange surface of the hydraulic oil cooler and Towards the electric powertrain components; in the second mode, air is forced by the bi-directional fan to flow along a second airflow path past the heat exchange surface of the hydraulic oil cooler and away from the electric powertrain component; the method further includes operating the bidirectional fan in its first mode or its second mode. The method may be used to optionally heat or cool one or more electric powertrain components, such as energy storage devices. According to another aspect of the present disclosure, a method of thermal management of an electric working machine having any thermal management system as described above is provided.

As used herein, the terms "coupled," "attached," "connected," "mounted," and the like are intended to mean that two components are directly or indirectly engaged with each other. Such engagement may be fixed (eg permanent) or removable (eg removable or releasable).

Description of drawings

Features of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic diagram showing elements of a thermal management system of an electro-hydraulic working machine using forced convection for thermal management;

Figures 2-5 each show a schematic cross-sectional view of an example of an energy storage system (ESS) component that may be employed in the system of Figure 1;

6A to 6C are schematic diagrams, each showing an alternative arrangement of elements of a thermal management system of an electrohydraulic working machine employing at least one heat exchanger plate;

7A and 7B are schematic diagrams each showing an alternative arrangement of elements of a thermal management system of an electrohydraulic working machine including a heater for heating hydraulic oil;

Figure 8 is an electrical schematic diagram of any of the systems of Figures 1 to 7B.

Detailed ways

The embodiments of the disclosure described herein are not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Rather, the embodiments were chosen to be described in order to enable those skilled in the art to practice the disclosure.

Thermal management via forced convection

Referring now to the drawings, in which like reference numerals refer to like features throughout the several figures, FIG. 1 is a schematic diagram illustrating certain components of a thermal management system 10 for an electro-hydraulic work machine in accordance with the disclosed embodiments, The system uses forced convection for thermal management. Thermal management system 10 may be used with electro-hydraulic work machines, such as excavators or other construction equipment. An electrohydraulic work machine has a hydraulic system that hydraulically powers the work device, such as a boom and arm assembly with a bucket. The thermal management system 10 may be housed in the superstructure of the excavator machine.

Referring to FIG. 1 , thermal management system 10 includes an energy storage system (ESS) 12 (also referred to as an energy storage device or battery), a bidirectional fan 16 , and a first heat exchanger including a hydraulic oil cooler (HOC) 14 . The hydraulic oil cooler 14 is in fluid communication with the hydraulic system 20 of the electro-hydraulic working machine. Hydraulic system 20 includes a primary fluid circuit 22 that includes a hydraulic tank 24 for storing hydraulic oil and a primary hydraulic pump assembly 26 for pumping hydraulic oil to hydraulic actuators 28 to control machine functions. The hydraulic system 20 also includes a plurality of main control valves 29 that control the flow of hydraulic oil supplied from the main hydraulic pump assembly 26 to a plurality of hydraulic actuators 28 .

Referring to FIG. 2 , a schematic cross-sectional view of thermal management system 110 is shown according to some examples. Energy storage device 12 is contained within housing 30 . Energy storage device 12 includes electrochemical cells that can be grouped into modules. These modules may include support structures and battery management units to manage cell charging and discharging. In the embodiment shown in FIGS. 2 to 5 , the energy storage device 12 is shown with two modules 32 , however the energy storage device 12 may have one or more modules. Housing 30 may be any suitable housing for housing a battery module.

Hydraulic oil cooler 14 may be a fluid-to-air heat exchanger configured to exchange heat between hydraulic oil and air of the hydraulic system. As we all know, hydraulic oil coolers are used in hydraulic working machines to cool hydraulic oil (because hydraulic oil tends to increase in temperature during the control of hydraulic equipment, which can cause oil degradation and damage the seals of the fluid circuit). The hydraulic oil cooler 14 is connected to the main fluid circuit 22 and has at least a first heat exchange surface for heat exchange with the air surrounding the hydraulic oil cooler 14 in order to cool the hydraulic oil.

The bidirectional fan 16 is operable in a first mode in which air is forced in a first direction and a second mode in which air is forced in a second direction. The first direction may be opposite to the second direction. The bidirectional fan 16 , the hydraulic oil cooler 14 and the energy storage device 12 are arranged relative to each other such that when the bidirectional fan is operated in its first mode, air is forced to flow along the first airflow path A across the heat exchange surface of the hydraulic oil cooler. and toward the energy storage device, and such that when the bidirectional fan operates in its second mode, air is forced to flow along the second airflow path B through the heat exchange surface of the hydraulic oil cooler and away from the energy storage device. The fan 16 is schematically shown in Figures 2 to 5 as a propeller fan, however the fan may be of other suitable types for forced air.

Housing 30 may have openings 34 that allow air to flow therethrough between the interior and exterior of housing 30 . Openings 34 may be any suitable openings that allow air to pass through, such as holes, groups of holes, grilles, or the like. The bi-directional fan 16 is arranged relative to the opening 34 to allow air to flow through the opening 34 via the first airflow path A and the second airflow path B.

By positioning the hydraulic oil cooler 14 and the bi-directional fan 16 next to the energy storage device 12 , the hydraulic oil cooler 14 and the fan 16 are positioned to selectively draw hot air from the battery housing 30 in order to cool the energy storage device 12 , Or hot air is pushed into the battery housing 30 to heat the energy storage device 12 . When bi-directional fan 16 is operated in its first mode, heat from the hydraulic system may be used to compound the heating effect of an internal electric core heater within energy storage device 12 and achieve faster warm-up during cold starts, for example. The system uses waste heat from the hydraulic system to preheat the energy storage device 12 during cold start warm-up. The same system can be used to cool the energy storage device 12 simply by switching the direction of the bidirectional fan 16, thereby saving space in a working machine (where space is very limited) that might otherwise need to be occupied by additional cooling/heating devices.

In certain embodiments, the hydraulic oil cooler 14 or the bi-directional fan 16 is disposed adjacent the opening 34 of the battery housing 30 such that the bi-directional fan 16 can force air toward or via the first air flow path A or the second air flow path B, respectively. Flows away from the energy storage device 12 through the heat exchange surfaces of the hydraulic oil cooler 14 . The bidirectional fan 16 may be arranged so that it is downstream or upstream of the hydraulic oil cooler 14 when air is forced along the first airflow path A or the second airflow path B. For example, the hydraulic oil cooler 14 may be positioned adjacent the opening 34 and the bi-directional fan 16 adjacent the hydraulic oil cooler 14 as shown in FIG. 2 . Alternatively, the bi-directional fan 16 may be positioned adjacent the opening 34 and the hydraulic oil cooler 14 adjacent the bi-directional fan 16 as shown in FIG. 3 .

Hydraulic oil cooler 14 or bi-directional fan 16 need not be directly adjacent to battery housing 30 . As shown in FIGS. 4 and 5 , in the illustrated thermal management system 310 , 410 , a duct 36 is disposed between the battery housing 30 and the hydraulic oil cooler 14 or bidirectional fan 16 (depending on the HOC 14 or fan 16 Which one of is arranged closest to the energy storage device 12) in a particular arrangement. It should be understood that the energy storage device 12 , the hydraulic oil cooler 14 and the bidirectional fan can be arranged in various ways, as long as the air forced by the bidirectional fan 16 communicates with the interior of the battery housing 30 and flows through the hydraulic oil cooler 14 Just the heat exchange surface. Other arrangements are conceivable, such as including ducting between the bi-directional fan and the hydraulic oil cooler.

In some embodiments, the bi-directional fan is a variable speed fan. This allows the rate at which air flows into or out of the energy storage device 12 to be varied, thus allowing the selection of fan speeds that seek to maintain the energy storage device 12 at a target temperature.

Referring to Figure 2, battery housing 30 may also include one or more controllable blinds 38. Two louvres 38 are shown in Figure 2, but it should be understood that there may be one louvre or more than two louvres. Each shutter may include a flap covering an opening in the battery housing 30 that is movable between an open position and a closed position. The louvers 38 further help control the temperature of the energy storage device 12 . As the energy storage device 12 is cooling, in addition to operating the bi-directional fan in its second mode to draw hot air from the energy storage device 12 , one or more louvers 38 may be opened to allow a greater amount of air to be drawn through Battery housing 30. When energy storage device 12 is heated, in addition to operating the bidirectional fan in its first mode to push hot air into battery housing 30 , each louver may be closed to prevent heat loss during warm-up of energy storage device 12 . By placing a plurality of louvers 38 at certain positions relative to the energy storage device, control of the airflow used to heat or cool the energy storage device can be optimized. For example, one or more louvers may be opened and one or more other louvers may not be opened in order to force more air flow over specific surfaces of the energy storage device that require cooling.

Energy storage device 12 may be charged by an external source such as an electric vehicle supply equipment (EVSE) unit 39 (shown in FIG. 1 ). The bi-directional fan 16 may be electric. The bi-directional fan 16 may be configured such that it may optionally be powered by the EVSE unit. This means that when the energy storage device 12 is being charged by the EVSE unit (i.e., during stationary charging), if the bidirectional fan 16 is operating to heat or cool the energy storage device 12, the bidirectional fan may operate on the charging current to conserve storage energy of. Bidirectional fan 16 may be powered by energy storage device 12 when operating except during periods when the EVSE unit is charging energy storage device 12 .

The described thermal management system 10, 110, 210, 310, 410 provides various benefits to the working machine, such as extended battery life due to less time spent at non-optimal battery temperatures. Battery life is also improved due to reduced temperature gradients within each battery cell as more surface area is heated/cooled by forced air directed by bi-directional fans. The heating time required to bring the battery to a temperature suitable for operation in cold ambient temperatures can be reduced, thereby increasing efficiency when using the work machine. The ability to use a thermal management system to cool the battery in hot environments or when the battery reaches high temperatures from use makes higher battery charging rates possible.

The embodiment of Figures 1-5 illustrates a system for heating and cooling an energy storage device, however it should be understood that the same thermal management system can be employed to heat and cool other electric powertrain components, such as motors and inverters. .

Thermal management using heat exchanger plates

Further embodiments of a thermal management system for an electro-hydraulic working machine will now be described with reference to Figures 6A to 6C. 6A-6C are schematic diagrams, each illustrating certain components of a thermal management system 510A, 510B, 510C for a liquid heating/cooling electrohydraulic working machine employing energy storage devices, according to some examples.

Referring to FIG. 6A , thermal management system 510A includes energy storage device 12 and a heat exchanger including one or more heat exchanger plates 40 . The heat exchanger plate 40 is in fluid communication with the hydraulic system 20 of the electro-hydraulic working machine. Hydraulic system 20 includes a main fluid circuit 22 as described above with respect to FIG. 1 , which includes a hydraulic tank 24 and a main hydraulic pump assembly 26 for pumping hydraulic oil through a plurality of main control valves. 29 supplied to hydraulic actuator 28. The heat exchanger plate 40 is configured to exchange heat between the hydraulic oil of the hydraulic system 20 and the energy storage device 12 . The heat exchanger plate 40 may be a standard heat exchanger plate, such as a chiller plate or cooling plate, which is used to exchange heat between the heat exchange fluid (in this case hydraulic oil) flowing through the heat exchanger plate 40 and the adjacent heat exchanger plate 40 . Heat is transferred between the main bodies of the device board. The heat exchanger plate 40 may contain one or more conduits through which hydraulic oil is directed in use. Heat exchanger plate 40 is adjacent to energy storage device 12 . In some embodiments, heat exchanger plates 40 are attached to energy storage device 12 . The heat exchanger plate 40 is operable to heat or cool the energy storage device 12 by direct fluid conduction using hydraulic oil as the heat transfer fluid.

The heat exchanger plate 40 may be mounted to the housing of the energy storage device 12 . For example, the heat exchanger plate 40 may be mounted to or integrated with the base plate of the energy storage device.

In operation, if hydraulic oil that is cooler than the energy storage device 12 is directed through the heat exchanger plates 40 , this will act to cool the energy storage device 12 . If hydraulic oil that is hotter than the energy storage device 12 is conducted through the heat exchanger plates 40 , this will have the effect of heating the energy storage device 12 . Advantageously, this system allows waste heat from the hydraulic system 20 to be used to preheat the energy storage device 12 and also to cool the energy storage device 12 . Thermal management system 510A may be implemented to provide additional cooling/heating to pre-engineered air-cooled or liquid-cooled batteries. Thermal management system 510A can be used as the primary heat transfer medium for liquid-cooled energy storage devices, replacing standard coolants (e.g., instead of water) as the heat transfer medium, thereby saving time on the work machine that would otherwise be occupied to store and distribute additional heat transfer fluid. space.

System 510A may have valve 45 upstream of heat exchanger plate 40 to regulate the flow of hydraulic oil from main fluid circuit 22 to heat exchanger plate 40, and return oil check valve 46 downstream of heat exchanger plate 40 to prevent hydraulic Oil flows back. Valve 45 may have a solenoid operated valve. System 510A may also optionally include a hydraulic oil heater 50 located upstream of heat exchanger plate 40 or within hydraulic tank 24 . The hydraulic oil heater can be an electric heater. Further details regarding the hydraulic oil heater are provided below with respect to the embodiment of Figures 7A and 7B.

Referring to Figure 6B, an alternative embodiment of a thermal management system 510B for liquid heating/cooling using energy storage devices is shown. For heat exchanger plates 40 operating at a lower pressure than required to drive the hydraulic actuator 28 in the primary fluid circuit 22 , the heat exchanger plate 40 may be located in a secondary fluid circuit 42 in parallel with the primary fluid circuit 22 , as shown in Figure 6B. The secondary fluid circuit 42 includes an auxiliary pump assembly 44 for pumping hydraulic oil around the secondary fluid circuit 42 at a lower pressure than the primary fluid circuit 22 (ie, the pump assembly 44 is an auxiliary low pressure hydraulic pump assembly). In the embodiment of FIG. 6B , the secondary fluid circuit 42 extends from the hydraulic tank 24 to the auxiliary pump assembly 44 to the heat exchanger plate 40 and back to the primary fluid circuit 22 , where hydraulic fluid flows through the hydraulic tank 24 before returning to the hydraulic tank 24 . Oil cooler14. System 510B may have an oil return check valve 46 downstream of heat exchanger plate 40 to prevent hydraulic oil from flowing back. Like system 510A, system 510B may also optionally include a hydraulic oil heater 50 located upstream of heat exchanger plate 40 or within hydraulic tank 24 .

Referring to Figure 6C, an alternative embodiment of a thermal management system 510C for liquid heating/cooling using energy storage devices is shown. System 510C is similar to system 510A, except that system 510C additionally includes flow control mechanism 47 . The flow control mechanism 47 is any mechanism that controls the flow level of hydraulic oil through the secondary fluid circuit 42, such as a flow control valve. The flow control mechanism 47 allows the flow rate of hydraulic oil through the heat exchanger plate 40 to vary according to the temperature of the energy storage device 12 . The flow control mechanism 47 may also enable the use of low pressure heat exchanger plates. The flow control mechanism 47 may be in the secondary fluid circuit 42 , for example upstream of the heat exchanger plate 40 .

In certain embodiments, multiple heat exchanger plates may be provided, each in communication with hydraulic system 20 to allow for multi-surface heating/cooling of the energy storage device. Therefore, the heat exchanger plate 40 in the schematic diagrams of Figures 6A-6C may represent a plurality of heat exchanger plates.

As with the embodiment of Figures 1 to 5, the energy storage device 12 may be charged by an external source such as an EVSE unit. The auxiliary pump assembly 44 may be configured such that it may optionally be powered by an EVSE unit (ie, by powering an electric motor that drives the auxiliary pump assembly 44). This means that while the energy storage device 12 is being charged by the EVSE unit, the auxiliary pump assembly 44 can be powered by the charging current during heating/cooling of the energy storage device 12 using the heat exchanger plate 40, thereby conserving stored energy. The auxiliary pump assembly 44 may be powered by the energy storage device 12 when the auxiliary pump assembly 44 is operated outside of the period during which the EVSE unit is charging the energy storage device 12 .

The space inside a working machine, such as a small excavator, is limited. Systems 510A, 510B, 510C provide space-saving advantages by eliminating the need for additional space for storage of separate heat transfer fluids, heaters, pumps, piping, radiator devices, etc.

Thermal management systems 510A, 510B, 510C for managing the temperature of the energy storage device may include forced air convection in combination with the hydraulic oil cooler 14 and bi-directional fan 16 shown in Figures 1-5 and the heat exchanger plate 40 to allow Use either heat exchange option depending on the temperature of the energy storage device, hydraulic oil, ambient temperature, etc.

The embodiment of Figures 6A-6C illustrates a system for heating and cooling an energy storage device, however it should be understood that the same thermal management system can be employed to heat and cool other electric powertrain components, such as motors and inverters. .

Charging current enabled hydraulic oil heating

A further thermal management system for an electro-hydraulic working machine will now be described with reference to Figures 7A and 7B according to some examples. In extremely cold temperatures, the viscosity of hydraulic oil increases, which can lead to improper lubrication and cavitation issues in hydraulic systems, leading to damage. Therefore, in cold environments, hydraulic oil needs to be preheated for optimal machine performance, resulting in work machine shutdowns. External heating pads can be used to heat hydraulic oil, however these are slower and require storage space when not in use.

Figure 7A is a schematic diagram illustrating certain components of a thermal management system 610A for an electro-hydraulic work machine employing charging current enabled hydraulic oil heating. Referring to FIG. 7A , thermal management system 610A includes a hydraulic oil heater 50 for heating hydraulic oil in hydraulic system 20 . The hydraulic oil heater 50 is in fluid communication with the hydraulic system 20 of the electro-hydraulic working machine. The hydraulic system 20 includes the main fluid circuit 22 described with respect to FIG. 1 , which includes a hydraulic tank 24 and a main hydraulic pump assembly 26 for pumping hydraulic oil to supply via a plurality of main control valves 29 Hydraulic actuator 28.

The hydraulic oil heater 50 may be an electric heater. The hydraulic oil heater 50 may be configured such that it may optionally be powered, for example, by an EVSE unit charging an energy storage device. This means that when the energy storage device 12 is charged by the EVSE unit, the hydraulic oil heater 50 can be powered by the charging current in order to heat the hydraulic oil in the hydraulic system 20, thereby saving stored energy. The hydraulic oil heater 50 may also be configured such that it may optionally be powered by an energy storage device of the working machine such that the hydraulic oil heater 50 may be operated to provide heating at times other than during charging of the energy storage device by the EVSE unit. Hydraulic oil.

Hydraulic oil heaters can be in-tube heaters or tank heaters. Figure 7A shows an embodiment employing an in-tube heater 50, which will now be described. In this embodiment, the hydraulic oil heater 50 is in the secondary fluid circuit 42 in parallel with the primary fluid circuit 22 . The secondary fluid circuit 42 is similar to the secondary fluid circuit 42 of Figures 6A-6C. The secondary fluid circuit 42 optionally includes an auxiliary pump assembly 44 for pumping hydraulic oil around the secondary fluid circuit 42 at a lower pressure than the primary fluid circuit 22 . In the embodiment of FIG. 7A , the secondary fluid circuit 42 extends from the hydraulic tank 24 to the auxiliary pump assembly 44 to the hydraulic oil heater 50 , such as back to the primary fluid circuit 22 via the hydraulic tank 24 .

In the embodiment of FIG. 7A , there is an oil return check valve 46 downstream of the hydraulic oil heater 50 to prevent the hydraulic oil from flowing back.

The secondary fluid circuit 42 includes a temperature sensor 54 for sensing the temperature of the hydraulic oil. The control system may be used to turn the hydraulic oil heater 50 on and off based on the sensed oil temperature.

The auxiliary pump assembly 44 may be coupled to an electric motor to drive the hydraulic auxiliary pump assembly. When the energy storage device 12 is being charged by the EVSE unit, not only the hydraulic oil heater 50 may be powered by the charging current, but also the electric motor for the auxiliary pump assembly 44 may be powered by the charging current, thereby conserving stored energy. The electric motor may also be constructed so that it may optionally be powered by the energy storage device of the work machine, such that the auxiliary pump assembly 44 may be operated at times other than during periods when the EVSE unit is charging the energy storage device.

The secondary fluid circuit 42 of FIGS. 6A-6C may be modified to include an in-line hydraulic oil heater as shown in FIG. 7A to include heating the hydraulic oil and/or using heat based on the temperature of the energy storage device, hydraulic oil, ambient temperature, etc. Options for switch board 40.

Referring to Figure 7B, an alternative embodiment of a thermal management system 610B is shown that utilizes charging current enabled hydraulic oil heating. System 610B is similar to system 610A except that it does not include an auxiliary low pressure pump assembly in secondary fluid circuit 42 . System 610B has a valve 48 upstream of the primary hydraulic pump assembly 26 that is operable to direct hydraulic fluid through a secondary fluid circuit 42 in parallel with the primary fluid circuit 22 . The auxiliary fluid circuit 42 has a hydraulic oil heater 50, and downstream of it is an oil return check valve 46 that prevents the reverse flow of hydraulic oil. A secondary fluid circuit 42 extends from valve 48 to hydraulic tank 24 . Valve 48 may be a three-way valve. Like system 610A, system 610B includes a temperature sensor 54 for sensing the temperature of the hydraulic oil. The control system may be used to turn the hydraulic oil heater 50 on and off based on the sensed oil temperature.

As mentioned above, instead of an in-line hydraulic oil heater, the system may include an in-tank hydraulic oil heater (eg, as shown in Figure 6A). In such embodiments, the hydraulic oil heater is located inside the hydraulic tank 24 and heats the hydraulic oil from within the tank. Like the in-line hydraulic oil heater, the in-tank hydraulic oil heater can optionally be powered by the EVSE unit during stationary charging or by an energy storage device.

Electrical schematic diagram

Figure 8 shows an electrical schematic showing the arrangement of the main elements of the system according to any previous embodiment or example. It can be seen that the energy storage device 12, the motor 26A for the main hydraulic pump assembly 26, the motor 44A for driving the auxiliary pump assembly 44, the hydraulic oil heater 50, the bidirectional fan 16 and the charging unit 39 can all be electrically connected. The charging unit 39 may be an on-board AC charger or an off-board EVSE (DC charger).

By structuring the hydraulic oil heater (in-tube or in-tank) so that it can be powered by the EVSE unit during stationary charging, this avoids wasting stored energy from the energy storage device to power the hydraulic oil heater, thus saving energy to run the working machine key feature, which means more can be done between charges.

It is to be understood that the embodiments of the present disclosure have been described above by way of example only and that detailed modifications within the scope of the appended claims will be apparent to the skilled person. Embodiments of the present disclosure are described above by way of example only. Features of one embodiment may be used with any other embodiment. Other modifications will be apparent to those skilled in the art, within the scope of the claims.

In particular, with respect to the various functions performed by the above-described components, devices, circuits, systems, etc., unless otherwise stated, the terms used to describe such components (including references to "means") are intended to correspond to performing the described Any component (eg, a functional equivalent) of a specified function of a component, even if not structurally equivalent to the structure disclosed for performing the function in the exemplary aspects illustrated herein of the claimed subject matter.

Claims (22)

1. A thermal management system for an electric work machine having at least one work device hydraulically powered by a hydraulic system, the thermal management system comprising:

one or more electric powertrain components;

A bidirectional fan; and

a first heat exchanger comprising a hydraulic oil cooler in fluid communication with the hydraulic system, the hydraulic oil cooler having at least a first heat exchange surface;

the bi-directional fan, the one or more electric powertrain components, and the hydraulic oil cooler are arranged such that the bi-directional fan is operable in a first mode in which air is forced by the bi-directional fan along a first airflow path across the heat exchange surface of the hydraulic oil cooler and toward the one or more electric powertrain components or is operable in a second mode; in the second mode, air is forced by the bi-directional fan to flow along a second airflow path over the heat exchange surface of the hydraulic oil cooler and away from the one or more electric powertrain components.

2. The thermal management system of claim 1, wherein the one or more electric powertrain components comprise an energy storage device.

3. The thermal management system of claim 1, wherein the bi-directional fan and the hydraulic oil cooler are arranged such that the hydraulic oil cooler is downstream of the bi-directional fan in the first airflow path.

4. The thermal management system of claim 1, wherein the bi-directional fan and the hydraulic oil cooler are arranged such that the hydraulic oil cooler is upstream of the bi-directional fan in the first airflow path.

5. The thermal management system of claim 2, wherein the energy storage device is housed within a housing having a first opening that allows air to pass therethrough via the first and second airflow paths.

6. The thermal management system of claim 5, wherein the hydraulic oil cooler or the bi-directional fan is disposed adjacent to the first opening of the housing.

7. The thermal management system of claim 5, further comprising a conduit disposed between the first opening of the housing and the hydraulic oil cooler or the bi-directional fan.

8. The thermal management system of claim 1, wherein the bi-directional fan is a variable speed fan.

9. The thermal management system of claim 5, wherein the housing comprises one or more controllable louvers.

10. The thermal management system of claim 1, wherein the thermal management system further comprises an energy storage device chargeable by an electric vehicle supply equipment, EVSE, unit, the bi-directional fan being energizable by the energy storage device or EVSE unit.

11. The thermal management system of claim 1, further comprising a second heat exchanger comprising one or more heat exchanger plates adjacent to the one or more electric powertrain components and configured to be in fluid communication with a hydraulic system.

12. The thermal management system of claim 11, wherein the one or more electric powertrain components comprise an energy storage device, the heat exchanger plates configured to exchange heat between hydraulic oil of the hydraulic system and a plurality of different surfaces of the energy storage device.

13. The thermal management system of claim 11, further comprising a hydraulic system including a primary fluid circuit for hydraulically powering the at least one work device of the electric work machine and a secondary fluid circuit in parallel with the primary fluid circuit, the heat exchanger plate being in the secondary fluid circuit.

14. The thermal management system of claim 13, wherein the secondary fluid circuit further comprises an auxiliary pump assembly for pumping hydraulic oil through the secondary fluid circuit.

15. The thermal management system of claim 14, wherein the thermal management system further comprises an energy storage device chargeable by an electric vehicle supply equipment, EVSE, unit, the auxiliary pump assembly being electrically chargeable by the energy storage device or EVSE unit.

16. The thermal management system of claim 1, wherein the thermal management system further comprises a hydraulic oil heater for heating hydraulic oil of the hydraulic system.

17. The thermal management system of claim 16, wherein the hydraulic oil heater is an electric heater, the thermal management system further comprising an energy storage device chargeable by an electric vehicle power plant EVSE unit, the hydraulic oil heater being electrically powered by the energy storage device or EVSE unit.

18. The thermal management system of claim 16, wherein the hydraulic oil heater is configured to be located in a hydraulic tank.

19. The thermal management system of claim 16, further comprising a hydraulic system including a primary fluid circuit for hydraulically powering the at least one work device of the electric work machine and a secondary fluid circuit in parallel with the primary fluid circuit, the hydraulic oil heater being in the secondary fluid circuit.

20. The thermal management system of claim 17, wherein the secondary fluid circuit further comprises an auxiliary pump assembly for pumping hydraulic oil through the secondary fluid circuit.

21. An electric working machine having at least one working device hydraulically powered by a hydraulic system, the electric working machine comprising a thermal management system comprising:

one or more electric powertrain components;

a bidirectional fan; and

a first heat exchanger comprising a hydraulic oil cooler in fluid communication with the hydraulic system, the hydraulic oil cooler having at least a first heat exchange surface;

the bi-directional fan, the one or more electric powertrain components, and the hydraulic oil cooler are arranged such that the bi-directional fan is operable in a first mode in which air is forced by the bi-directional fan along a first airflow path across the heat exchange surface of the hydraulic oil cooler and toward the one or more electric powertrain components or is operable in a second mode; in the second mode, air is forced by the bi-directional fan to flow along a second airflow path over the heat exchange surface of the hydraulic oil cooler and away from the one or more electric powertrain components.

22. A method of heating or cooling one or more electric powertrain components of an electric work machine having at least one work device hydraulically powered by a hydraulic system, the method comprising:

providing a thermal management system, the thermal management system comprising: one or more electric powertrain components; a bidirectional fan; and a first heat exchanger comprising a hydraulic oil cooler in fluid communication with the hydraulic system, the hydraulic oil cooler having at least a first heat exchange surface;

arranging the bi-directional fan, the one or more electric powertrain components, and the hydraulic oil cooler such that the bi-directional fan is operable in a first mode in which air is forced by the bi-directional fan to flow along a first airflow path over the heat exchange surface of the hydraulic oil cooler and toward the one or more electric powertrain components or is operable in a second mode; in the second mode, air is forced by the bi-directional fan to flow along a second airflow path over the heat exchange surface of the hydraulic oil cooler and away from the one or more electric powertrain components; and

The bi-directional fan is operated in either the first mode or the second mode.