ELECTRIC CLUTCH

Abstract

An electric clutch (196) is disclosed. The electric clutch (196) comprises: a clutch assembly (214) with clutch elements (260, 262) which transmit a torque when engaged; an input mechanism (216) comprising: a pinion (220) designed to receive a rotational input from an electric machine (172); and a cam gear (290) which meshes with the pinion (220) to rotate about a reference axis (192); and an actuating arrangement (218) comprising: an actuating spring (234); a cam disk (230) which is arranged around the reference axis (192) and engages in the cam gear (290) on a cam ramp (302), so that a change in the timing position of the cam gear (290) around the reference axis (192) causes a translation of the cam disk (230) along the reference axis (192) to move the actuating spring (234);and an actuating piston (232) which is moved by the actuating spring (234) in response to the translation of the cam disc (230) to engage the clutch elements (260, 262) of the clutch pack (214).

Description

AREA OF REVELATION

[0001] This disclosure relates generally to an electric clutch for a transmission system of a work vehicle. BACKGROUND OF THE REVELATION

[0002] Heavy-duty work vehicles, such as those used in agriculture, construction, forestry, and mining, may be electric vehicles powered by an electric motor. The drive system of these heavy-duty work vehicles can benefit from powershift transmission, where the clutch engages slowly and slips slightly before fully engaging to allow for smooth shifting. Hydraulically operated pneumatic clutches can perform powershift transmission smoothly, where two clutches share the torque for part of the time between shifts; however, these clutches require a hydraulic pump and hydraulic fluid to operate.Electric clutches work well when you can stop and shift gears or perform a 100% synchronous shift, but electric clutches are inadequate when performing a load shift, as they are designed more as an on / off clutch system. SUMMARY OF THE REVELATION

[0003] An electric clutch comprises a clutch pack with clutch elements that transmit torque when engaged, an input mechanism, and an actuating assembly. The input mechanism includes a pinion gear designed to receive a rotary input from an electric machine and a cam gear that meshes with the pinion to rotate about a reference axis. The actuating assembly includes an actuating spring, a cam disk, and an actuating piston. The cam disk is arranged around the reference axis and engages the cam gear via a cam ramp, such that a change in the timing position of the cam gear about the reference axis causes a translation of the cam disk along the reference axis to move the actuating spring. The actuating piston is moved by the actuating spring in response to the translation of the cam disk to engage the clutch elements of the clutch pack.

[0004] In one example of an electric clutch, the pinion drives the cam gear within a range of cycle angles around the reference axis, corresponding to a range of translational positions of the cam disc along the reference axis. In another example of an electric clutch, the actuating spring is dimensioned and designed in a first translational position of the cam disc such that it positions the actuating piston in engagement with the clutch elements, and in a second translational position of the cam disc, the actuating spring is dimensioned and designed such that it does not position the actuating piston in engagement with the clutch elements.

[0005] In another example of the electric clutch, the actuating spring is designed to bias the actuating piston toward the clutch pack. In another example of the electric clutch, the cam disc defines the cam ramp, and the cam gear has a cam tappet that engages the cam ramp to cause translation of the cam disc along the reference axis. In yet another example of the electric clutch, the cam disc has an annular circumferential flange extending around the reference axis and featuring a toothed circumference that fixes a timing position of the cam disc, and the cam ramp is a radially raised surface that tapers along the annular circumferential flange of the cam disc.In another example of the electric clutch, the cam gear is a ring gear formed by an annular body that extends around the reference axis and has an inner and an outer circumference, wherein the outer circumference has a plurality of teeth meshing with the pinion and the inner circumference has the cam tappet. In yet another example of the electric clutch, the cam disk defines pulse limiters at opposite ends of the cam ramp that engage with the cam tappet to restrain rotation about the reference axis.

[0006] In another example of the electric clutch, the pinion is a worm gear and the cam gear is a ring gear with a toothed outer circumference that meshes with the worm gear to change the indexing position of the ring gear about the reference axis. In yet another example of the electric clutch, the actuating spring is arranged concentrically around the actuating piston, the cam disc is arranged concentrically around the actuating spring, and the cam gear is arranged concentrically around the cam disc.

[0007] In another example of the electric clutch, the actuating arrangement further comprises a return spring dimensioned and designed to provide a return spring force that biases the actuating piston away from the clutch pack, and wherein the actuating spring dimensioned and designed to provide an actuating spring force that overcomes the return spring force in at least one translational position of the cam disk in order to move the actuating piston toward the clutch pack. In another example of the electric clutch, the input mechanism comprises the electric machine that drives the pinion.

[0008] A transmission for a work vehicle comprises an output shaft, a gear providing a transmission ratio, and an electric clutch that, when engaged, couples the gear to the output shaft. The electric clutch comprises a clutch pack with clutch elements that transmit torque when engaged, an input mechanism, and an actuating assembly. The input mechanism includes a pinion gear designed to receive a rotary input from an electric motor and a cam gear that meshes with the pinion gear to rotate about a reference axis. The actuating assembly includes an actuating spring, a cam disc, and an actuating piston.The cam disc is arranged around the reference axis and engages with the cam gear via a cam ramp, such that a change in the timing position of the cam gear around the reference axis causes a translation of the cam disc along the reference axis to move the actuating spring. The actuating piston is moved by the actuating spring in response to the translation of the cam disc to engage the clutch elements of the clutch pack.

[0009] In one example of the transmission, the input mechanism comprises the electric motor that drives the pinion. In another example of the transmission, the pinion drives the cam gear between a range of stroke angles around the reference axis, corresponding to a range of translational positions of the cam disk along the reference axis. In yet another example of the transmission, the actuating spring is dimensioned and designed in a first translational position of the cam disk such that it positions the actuating piston in engagement with the clutch elements, and in a second translational position of the cam disk, the actuating spring is dimensioned and designed such that it does not position the actuating piston in engagement with the clutch elements.

[0010] In another example of the transmission, the cam disk defines the cam ramp, and the cam gear has a cam tappet that engages the cam ramp to cause translation of the cam disk along the reference axis. In yet another example of the transmission, the cam gear is a ring gear formed by an annular body extending around the reference axis and having an inner and an outer circumference, the outer circumference having a plurality of teeth meshing with the pinion and the inner circumference having the cam tappet.The cam disk has an annular circumferential flange extending around the reference axis and a toothed circumference that fixes a timing position of the cam disk; the cam ramp is a radially raised surface that tapers along the annular circumferential flange of the cam disk; and the cam disk defines timing limiters at opposite ends of the cam ramp that engage in the cam tappet to inhibit rotation around the reference axis.

[0011] In another example of the transmission, where the actuating spring is arranged concentrically around the actuating piston, the cam disc is arranged concentrically around the actuating spring, and the cam gear is arranged concentrically around the cam disc. In yet another example of the transmission, the actuating arrangement further comprises a return spring dimensioned and designed to provide a return spring force that biases the actuating piston away from the clutch pack, and the actuating spring dimensioned and designed to provide an actuating spring force that overcomes the return spring force in at least one translational position of the cam disc in order to move the actuating piston toward the clutch pack.

[0012] Further features and aspects become apparent when considering the detailed description, the claims and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an exemplary work vehicle in the form of a wheel loader, which has a drive arrangement with an electric clutch according to the present disclosure; Fig. Figure 2 is a schematic representation of an exemplary control system of the work vehicle of Fig. 1; Fig. Figure 3 is a perspective view of an exemplary drive arrangement of the work vehicle of Fig. 1; Fig. Figure 4 is another perspective view of the same with one or more distant housings; Fig. 4A is a side view of the same; Fig. 5 is a cross-sectional view along line 5-5 from Fig. 4; Fig. 6A is an enlarged detail view showing the area 6A-6A from Fig. 5; Fig. 6B is an enlarged detail view showing the area 6B-6B from Fig. 5; Fig. Figure 7 is a cross-sectional view along line 7-7 from Fig. 4; Fig. Figure 8 is a perspective view of an exemplary electrical coupling arrangement of the drive arrangement of Fig. 3; Fig. 9 is an exploded view of the same; Fig. Figure 10 is a side view of a cam disc coupled to a ring gear of the exemplary electrical coupling arrangement of Fig. 8 is coupled; and Fig. 11 is a cross-sectional view along line 11-11 of Fig. 4.

[0013] In all drawings, identical reference symbols denote the same element. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more accurately illustrate the example shown. Furthermore, the drawings provide examples and / or implementations that correspond to the description; however, the description is not limited to the examples and / or implementations provided in the drawings. DETAILED DESCRIPTION

[0014] The following disclosure describes one or more exemplary embodiments of the disclosed electric coupling for a work vehicle, as shown in the accompanying figures of the drawings briefly described above. Various modifications of the exemplary embodiments are conceivable for a person skilled in the art. The discussion here focuses on an electric coupling for a gear transmission of a work vehicle, such as a wheel loader, although the electric coupling disclosed herein can be used in other contexts, such as in other work vehicle platforms in agriculture, construction, forestry, mining, and other industries. OVERVIEW

[0015] When operating heavy-duty work vehicles, a powershift transmission may be desirable to enable a smooth transition from one gear ratio to another without stopping the vehicle. To achieve this powershift, a currently engaged first clutch must begin to disengage and may slip, while a disengaged second clutch begins to engage and may also slip. At this point, a specific torque is transmitted intermittently or simultaneously through both clutches to propel the vehicle until one clutch is fully engaged and the other is fully disengaged. This process is typically accomplished by a hydraulic system.

[0016] The present disclosure provides an electric coupling arrangement that can replicate the functionality of a hydraulic system and a hydraulically actuated clutch during the power-shifting process. An electric coupling capable of performing this operation is desirable to eliminate the need for hydraulic hardware (e.g., hydraulic pump, hydraulic lines, and hydraulic fluid required to operate a hydraulic coupling). The electric coupling arrangement performs the operations of engaging the clutch by slipping it until fully engaged and disengaging it by slipping it until fully disengaged. This electric coupling can be used to enable power shifting between two gear transmissions.For example, one electric coupling arrangement can be used to engage / disengage one gear unit, and another electric coupling arrangement can be used to engage / disengage a different gear unit, enabling load switching between the gear units by actuating the electric couplings. The electric coupling arrangement can include a coupling pack, an input mechanism, and an actuating arrangement. The input mechanism includes an electric machine coupled to a gear unit. The gear unit is driven by the electric machine and drives the actuating arrangement to engage / disengage the coupling pack.

[0017] The gear drive comprises a pinion and a cam gear. The pinion receives a rotary input from the electric machine and drives the cam gear. In at least one aspect, the pinion is a worm gear and the cam gear is a ring gear. The ring gear may have teeth along its outer circumference that mesh with the worm gear. The ring gear may have an annular concave section along its outer circumference that meshes with the worm gear. The annular concave section may, for example, at least partially surround the worm gear. In an alternative aspect, a different gear drive may be used to drive the ring gear.

[0018] For example, a different type of gear (e.g., a spur gear, a helical gear, a sprocket, etc.) could drive the ring gear, or a belt wrapped around the ring gear could be used to drive it. Finally, the electric motor is mechanically coupled to the ring gear to set it in rotation. The rotation of the ring gear drives the actuating mechanism for engaging / disengaging the clutch pack.

[0019] The actuating assembly comprises a cam disc, an actuating spring, and an actuating piston. The actuating spring is arranged concentrically around the actuating piston, and the cam disc is also arranged concentrically around the actuating spring. The actuating piston is arranged along a reference axis. The translation of the cam disc along the reference axis changes the compression of the actuating spring. The actuating spring applies a preload force that causes the translation of the actuating piston along the reference axis and engages / disengages the clutch assembly. The actuating spring consists of one or more compression springs.

[0020] The ring gear is arranged concentrically around the cam disc. The ring gear can rotate about the reference axis and is otherwise stationary. The ring gear can be held in position, for example, by thrust washers placed on both sides of the ring gear, with the thrust washers being held in position by a housing of the working vehicle. The ring gear has at least one cam tappet arranged around its inner circumference. The one or more cam tappets engage a cam ramp on the cam disc. The cam ramp is a radially raised surface that tapers along an outer circumferential surface of the cam disc. The rotation of the ring gear moves the cam tappets along the cam ramp, which translates the cam disc along the reference axis to compress / decompress the actuating spring and thus engage / disengage the clutch pack.The ring gear can be designed such that a rotational movement moves the clutch assembly from a fully disengaged position to a fully engaged position. For example, a 120-degree rotation of the ring gear can cause the cam disc to move a predetermined distance along the reference axis. The translational movement of the cam disc can compress the actuating spring by a predetermined amount, applying a predetermined preload force to the actuating piston. The predetermined preload force is also applied to the cam disc, but the cam disc is engaged with the ring gear's cam tappets, preventing the cam disc from moving as a result of the predetermined preload force.The predetermined preload force causes the actuating piston to translate along the reference axis by a further predetermined distance in order to push the clutch pack from the fully disengaged position to the fully engaged position.

[0021] In at least one aspect, cam ramps can be arranged around the cam disk, and each cam ramp can engage a cam tappet of the ring gear. In at least one aspect, there are three cam ramps and three cam tappets. In an alternative aspect, there can be any number of cam ramps greater than zero. The cam ramp can be designed such that movement of the cam along the entire length of the cam ramp can move the clutch pack from the engaged / disengaged position to the disengaged / engaged position. The rotation of the ring gear required to move the cam along the entire length of the cam ramp can be related to the number of cam ramps. For example, three cam ramps could be distributed around the entire outer circumference of the cam disk. The rotation required to move a cam tappet along the entire length of the cam ramp would then be approximately 120 degrees.The maximum rotational amount is, for example, 360 divided by the number of cam ramps. If there are gaps between the cam ramps, the required rotational amount of the ring gear would be less than 360 divided by the number of cam ramps. The design of the cam ramps and the spacing between them determines the amount of rotation required to move the cam tappet along the entire length of the cam ramp.

[0022] The actuating piston is arranged concentrically on a clutch hub. The clutch hub can be mounted on a drive shaft and mesh with it, so that the rotation of the drive shaft rotates the clutch hub. A gear for engaging / disengaging the clutch assembly can be positioned concentrically around the clutch hub, with the clutch assembly located between the clutch hub and the gear. The clutch assembly can comprise first elements that engage an outer circumferential surface of the clutch hub and second elements that engage an inner circumferential surface of the gear. The first and second elements can be alternately distributed within the clutch assembly such that each first element bears against at least one second element.Compressing the clutch pack engages it, forcing the first elements against the second elements to generate friction between them. With the buildup of this friction, torque is transmitted either from the gear to the drive shaft or vice versa. The first and second elements may slip past each other at the beginning of the compression process, but once the clutch pack is sufficiently compressed, it is fully engaged and the first and second clutch elements rotate together. When the clutch pack is fully engaged, full torque is available between the drive shaft and the gear.The disengagement of the clutch pack is similar, but reversed in that the clutch pack is fully engaged, begins to disengage, and allows slippage between the first and second elements until the clutch pack is fully disengaged.

[0023] To assist in the retraction and complete disengagement of the actuating piston from the clutch pack, a return spring is arranged concentrically around the clutch hub to apply a preload force to the actuating piston and move it away from the clutch pack. The return spring consists of one or more compression springs. The preload force of the actuating spring must overcome the preload force of the return spring to move the actuating piston into the clutch pack.

[0024] The speed required for the clutch assembly to engage and disengage can depend on the type of vehicle and the tasks it is intended to perform. The compression rate of the clutch assembly depends on the translational movement of the actuating piston. This translational movement is determined by the amount of preload force generated by the actuating spring. The engagement speed of the clutch assembly can be modified by changing the rotational speed of the electric motor driving the pinion, by changing the cam ramp angle, and / or by changing the actuating spring to a different spring constant, thus affecting the generated preload force.The speed at which the pinion rotates influences the rotational speed of the cam gear, which in turn affects the translational speed of the cam disc. The cam ramp angle changes the translational speed of the cam disc depending on the rotation of the cam gear. Changing the actuating spring to a higher spring constant causes the actuating spring to generate a greater preload force from a smaller movement and can result in a greater translation of the actuating piston with a smaller translational movement of the cam disc.

[0025] One or more exemplary embodiments of an electric coupling for a work vehicle are provided in the figures of this disclosure. The following description should be understood merely as providing a non-restrictive exemplary context in which embodiments of this disclosure are more readily understood. EXEMPLARY ELECTRIC CLUTCH FOR A WORK VEHICLE

[0026] As in Fig. 1 and Fig. Figure 2 shows a work vehicle 100 realized as a wheel loader or other heavy-duty work vehicle, such as those used in agriculture, construction, forestry, and mining. The work vehicle 100 comprises a chassis 102, which supports a plurality of ground engagement elements 104, such as wheels or tracks, that hold the chassis 102 above the ground. Mounted on the chassis 22 are an engine compartment housing 106 and an operator's cab 108, to be occupied by an operator of the work vehicle 100. It is understood that the present disclosure can also refer to autonomous work vehicles, in which case the operator's cab can be omitted. The work vehicle further comprises a front bucket 110, which is mechanically connected to a front part of the chassis 102 via a boom assembly 112.

[0027] The operator cabin 108 can include one or more display devices 122 and one of several operator interfaces 124 connected to a control system 120. In addition to the display devices 122, the operator interface devices 124 can include various video and audio devices for providing video and audio information, haptic devices that provide haptic feedback, levers, joysticks, steering wheels, pedals, buttons, etc. The operator interface devices 124 can also be a set of input elements displayed on the display devices 122, such as links, icons, or other mechanisms operable by the user. Additionally or alternatively, part of the operator interfaces 124 can be integrated into the display devices 122, so that the operator interfaces 124 include physical input elements (for example, pushbuttons, switches, dials, etc.).The display devices 122 may include a touchscreen module integrated into the display devices 122 or a cursor input device (for example, joystick, trackball, or mouse) for positioning a cursor to select GUI elements generated on the display devices 122. The display devices 122 may be any imaging device designed for operation in the operator cabin 108, comprising one or more dedicated display consoles and various heads-up display projectors.

[0028] The display devices 122 and operator interfaces 124 are operationally connected to the control system 120, with various data connections between these components being represented by a number of signal lines representing wired and / or wireless data connections. The control system 120 comprises one or more control units or other control architecture, which may take any suitable form for performing the functions described herein, and serves as a general, non-restrictive designation for the processing architecture or processing system of the work vehicle 100 or other computing device or group of devices.The control system 120 can, for example, comprise or correspond to any number of processors, control computers, computer-readable memories, power supplies, storage devices, interface cards, and other standardized components, and can also contain or interact with any number of firmware and software programs or computer-readable instructions designed to perform the various process tasks, calculations, and control / display functions described herein, all represented by a processor 126. Such computer-readable instructions can be stored in a non-volatile sector of a local on-board memory 128, which the control system 120 can access.Although represented as a single block, the memory 128 can include any number and type of storage media suitable for storing computer-readable code or instructions, as well as other data used to support the operation of the work vehicle 100. The memory 128 can be integrated into the control unit architecture in various embodiments, e.g., as a system-in-package system, a single-chip system, or another type of microelectronic package or module.

[0029] The work vehicle 100 can include various onboard sensors and actuators, collectively designated here by reference numerals 130 and 132 respectively, and a network interface 134. For example, the work vehicle 100 can include a ground speed sensor that detects the travel speed of the work vehicle 100 across a field by measuring the rotational speed of the ground engagement elements 104, a drive shaft, the axle, or other components. The travel speed can also be measured using a positioning system, such as a global positioning system (GPS), a dead reckoning system, a LORAN system, or a wide variety of other systems or sensors that provide an indication of the travel speed or direction.The onboard sensors 130 can comprise various different types of sensor architectures to provide the control system 120 with input signals relating to the operating parameters of the work vehicle 100, data relating to the work vehicle 100's environment, and other information helpful for the operation of the work vehicle 100. The onboard sensors 130 can include a receiver, chipset, or the like for determining position using a satellite navigation system, including, but not limited to, GPS, Galileo, Global Navigation Satellite System (GNSS or GLONASS), Compass-IGS01, and combinations of the satellites they contain.The onboard sensors 130 can also include various linear and angular position sensors, inertial sensors (for example, devices with microelectromechanical inertial measurement units “MEMS IMU”), strain sensors, pressure sensors, motor speed sensors, temperature sensors, humidity sensors, wear sensors, vibration sensors, image sensors or cameras and / or sensors for measuring high frequency (RF) signals.

[0030] Several of the aforementioned (or further) sensors can individually or in combination detect the driving speed, direction of travel, and spatial orientation (e.g., pitch, roll, and yaw) of the work vehicle 100. Furthermore, several of the aforementioned (or further) sensors can individually or in combination measure the load characteristics (e.g., mass, center of gravity, height, etc.) of the work vehicle 100, including the loads of implements attached to or carried on board the work vehicle 100 (e.g., loaders, backhoes, etc.) and of implements pulled or pushed behind or in front of the work vehicle 100 (e.g., tillage equipment, balers, plows, etc.).

[0031] Similarly, the actuators 132 on board the work vehicle 100 can take various forms to perform functions that support its operation. For example, the actuators 132 can provide traction for the ground engagement elements 104, operate pneumatic and hydraulic systems, and set the work implements attached to the work vehicle 100 into linear or rotary motion. The actuators 132 can take various forms, such as different motors, pumps, linear actuators (e.g., cylinders), solenoid and other valves, clutches, brakes, and other mechanisms that can transmit force from one component to another. The actuators 132 can include mechanical, electrical, and / or hydraulic components and can therefore be coupled to and powered by the electrical power system 136.

[0032] It is understood that the aforementioned onboard sensors 130 and actuators 132 can comprise any number of sensors and actuators used to acquire parameters of various implements powered by the work vehicle 100. These implements can include towed implements mounted at the rear of the work vehicle 100 (for example, various tillage implements, balers, sprayers, rakes, backhoes, etc.) as well as implements mounted at the front of the work vehicle 100 (for example, various loaders, plows, brushes, etc.). These implements can receive different forms of energy (for example, electrical and hydraulic), so that they are part of the electrical energy system 136, or they can have separate, self-contained drive systems, or they can otherwise be unpowered.

[0033] Network interface 134 can be any device or module that provides access to a network, such as a wireless (e.g., Wi-Fi or cellular) transceiver or a data link including an antenna. Network interface 48 can also include a satellite receiver and can receive data via a satellite link and enable communication with nearby cell towers or terrestrial nodes, such as wireless RF nodes included in a Controller Area Network (“CAN”) established over an agricultural area (e.g., a field or group of fields) where the work vehicle 100 is operating. Suitable network interface 134 devices include, among others, the telematics receivers and transmitters offered by Deere & Company, located in Moline, Illinois, under the brand name “JDLink™”.Notwithstanding such examples, the specific form of network interface 48 may vary, provided that network interface 134 provides continuous or intermittent wireless conductivity to the network.

[0034] The electrical power system 136 can comprise one or more battery packs 138, which may contain battery cells and associated circuit arrangements for supplying energy to and from the battery cells of various technologies (for example, lead-acid, lithium, lithium-ion, lithium-sulfur, lithium-ion phosphate, lithium-cobalt, nickel-metal hydride, nickel-cadmium, ultracapacitors, etc.). The battery packs 138 may include temperature sensors and channels for conveying coolant through the battery packs 138. The electrical power system 136 may include a battery management system (“BMS”) 140, which can, for example, manage charging, detect low charge levels, and predict the remaining operating time. The BMS 140 can also provide information about the current, voltage, and temperature of the battery packs 138.The BMS 140 can also use chargers attached to or integrated into the battery packs 138 to charge the battery packs 138 to optimal charge levels and temperatures. The BMS 140 can have or use a universal input / output interface (GPIO interface) for communication with the battery pack 138. The electrical power system 28 can have one or more inverters 142 for converting direct current (DC) to alternating current (AC). The inverters 142 can take any suitable form, such as insulated-gate bipolar transistors (IGBTs) and silicon carbide (SiC) inverters. The inverters 142 can receive DC from the battery packs 138 via the GPIO interface and the DC bus. The inverters 142 can also receive power from other sources (e.g.,from an on-board generator or through regenerative braking), which can be converted into direct current by the inverter 142 and supplied to the battery packs 138 via the GPIO interface and the DC bus.

[0035] Fig. Figures 3-11 show an exemplary drive arrangement 150 with an electric machine 152 (e.g., actuator 132) which can be arranged inside the motor compartment housing 106, and a transmission system 154 for coupling the electric machine 152 with the ground engagement elements 104. As also shown in Fig. As shown in Figure 3, the drive assembly 150 comprises a motor and inverter housing 160, a front housing 162, a middle housing 164, and a differential housing 166, each enclosing different components of the drive assembly 150. The motor and inverter housing 160 is attached to the front housing 162, the front housing 162 is attached to the middle housing 164, and the middle housing 164 is attached to the differential housing 166. The number of housings for the components of the drive assembly 150 can vary. The motor and inverter housing 160 encloses the electric machine 152 and includes an inverter 180 (e.g., inverter 142) attached to the housing 160. An end plate 178 is attached to the end of the motor and inverter housing 160.

[0036] The electric machine 152 drives the transmission system 154 to power the ground engagement elements 104 of the work vehicle 100. The rear ground engagement elements 104 can be attached to the wheel end units 168, for example, by guiding fastening bolts through matching bolt hole patterns on the rotatable hubs 170 of the wheel end units 168 and the corresponding hubs of the ground engagement element 104. The wheel end units 168 are substantially identical in the illustrated example (i.e., as symmetrical left and right versions) and are designed to attach one rear left and one rear right ground engagement element 104. The wheel end units 168 are mounted on the differential housing 166.

[0037] As in Fig. 4 and Fig. As shown in Figure 5, the electric machine 152 drives a planetary gear set 184, which in turn drives a drive shaft 186. The planetary gear set 184 comprises a sun gear S1, planet gears P1, a ring gear R1, and a carrier C1. The ring gear R1 is stationary and mounted on the front housing 162, which holds the ring gear R1 in a stationary position. The electric machine 152 includes an output shaft 188 extending from the electric machine 152. The output shaft 188 is coupled to drive the sun gear S1 such that the rotation of the output shaft 188 drives the sun gear S1 about the reference axis 192. The output shaft 188 may, for example, have teeth that mesh with the teeth of the sun gear S1. The sun gear S1 is coupled to the planet gears P1, with the teeth of the sun gear meshing with the teeth of the planet gears P1. The rotation of the sun gear S1 therefore causes the planet gears P1 to rotate around the sun gear S1 and the reference axis 192.The teeth of the planet gears P1 mesh with the teeth of the ring gear R1 in such a way that the planet gears P1 act against the stationary ring gear R1 and rotate around the sun gear S1. The planet gears P1 are attached to a carrier C1 via pins 190, and the planet gears P1 can rotate relative to the carrier C1. The movement of the planet gears P1 about the reference axis 192 causes the carrier C1 to rotate about the reference axis 192. The carrier C1 is engaged with the drive shaft 186, so that the rotation of the carrier C1 rotates the drive shaft 186. In at least one aspect, the planet gear set 184 is used to control the rotational speed (min. -1 ) to reduce and increase the torque of the electric machine 152. Therefore, the rotational speed is lower and the torque higher at the drive shaft 186 than at the output shaft 188.

[0038] The drive shaft 186 extends from the support C1 through two bearings 194 to opposite ends of the drive shaft 186. The bearing 194 allows the drive shaft 186 to rotate freely while supporting and holding it in position. The bearings 194 can be held in position by the central housing 164. The rotation of the drive shaft 186 rotates the drive shaft 182 via the engagement of a low-speed gear assembly 202 or the engagement of a high-speed gear assembly 200. The rotation of the drive shaft 182 drives the differential assembly 204 to drive the wheel hubs 170 and the ground engagement elements 104.

[0039] As in Fig. As shown in Figure 6A, the low-speed gear assembly 202 comprises a first gear 206, a second gear 208, and an electrical coupling assembly 196. The high-speed gear assembly 200 comprises a first gear 198, a second gear 210, and an electrical coupling assembly 212. In at least one aspect, the electrical coupling assembly 196 is identical to the electrical coupling assembly 212. The drive shaft 186 extends through the electrical coupling assembly 196, the first gear 206, and the first gear 198. The first gear 198 is mechanically coupled to the drive shaft 186, such that the rotation of the drive shaft 186 rotates the first gear 198. For example, splined connections on the drive shaft 186 can mesh with splined connections of the first gear 198 to mechanically couple the first gear 198 to the drive shaft 186.The drive shaft 186 is mechanically coupled to the first gear 206 via the electrical coupling assembly 196. Therefore, the first gear 206 rotates with the drive shaft 186 when the electrical coupling assembly 196 is engaged, and the first gear 206 does not rotate with the drive shaft 186 when the electrical coupling assembly 196 is disengaged.

[0040] The drive shaft 182 extends through the electrical coupling assembly 212, the second gear 210, and the second gear 208. The second gear 208 is mechanically coupled to the drive shaft 182, so that the rotation of the drive shaft 182 rotates the second gear 208. For example, splines on the drive shaft 182 can mesh with splines on the second gear 208 to mechanically couple the second gear 208 to the drive shaft 182. The drive shaft 182 is mechanically coupled to the second gear 210 via the electrical coupling assembly 212. Therefore, the second gear 210 rotates with the drive shaft 182 when the electrical coupling assembly 212 is engaged, and the second gear 210 does not rotate with the drive shaft 182 when the electrical coupling assembly 212 is disengaged.

[0041] The first gear 198 is mechanically coupled to the second gear 210; for example, the teeth of the first gear 198 mesh with the teeth of the second gear 210. Therefore, the rotation of the first gear 198 causes the second gear 210 to rotate, and vice versa. The first gear 206 is mechanically coupled to the second gear 208; for example, the teeth of the first gear 206 mesh with the teeth of the second gear 208. Therefore, the rotation of the first gear 206 causes the second gear 208 to rotate, and vice versa. In the low-speed gear arrangement 202, the first gear 198 is smaller than the second gear 210. Therefore, when the electric clutch arrangement 212 is engaged and the electric clutch arrangement 196 is disengaged, the drive shaft 182 rotates more slowly than the drive shaft 186. In the high-speed gear arrangement 200, the first gear 206 is larger than the second gear 208.When the electric clutch assembly 212 is disengaged and the electric clutch assembly 196 is engaged, the drive shaft 182 therefore rotates faster than the drive shaft 186. Engaging the high-speed gear assembly 200 causes the drive shaft 182 to rotate faster than engaging the low-speed gear assembly 202.

[0042] In at least one aspect, the first gear 198 and the second gear 208 are identical; and the first gear 206 and the second gear 210 are identical. In this aspect, engaging the electric clutch assembly 196 can cause the speed of the drive shaft 182 to be increased by a specific gear ratio; and engaging the electric clutch assembly 212 can cause the speed of the drive shaft 182 to be decreased by the same specific gear ratio. The desired increase or decrease in the gear ratio can be determined by the size of the first gears 206, 198 and the second gears 208, 210, respectively. In an alternative aspect, the first gear 198 and the second gear 208 are different; and the first gear 206 and the second gear 210 are different.Therefore, the gear ratios between the high-speed gear arrangement 200 and the low-speed gear arrangement 202 do not necessarily have to be the same. When the electric clutch arrangement 212 is engaged and the electric clutch arrangement 196 is disengaged, the first gear 206 rotates in accordance with the rotation of the second gear 208 caused by the rotation of the drive shaft 182. This rotation of the second gear 208 has no effect on the rotation of the drive shaft 182 or drive shaft 186. When the electric clutch arrangement 212 is disengaged and the electric clutch arrangement 196 is engaged, the second gear 210 rotates in accordance with the rotation of the first gear 198 caused by the rotation of the drive shaft 186. This rotation of the second gear 210 has no effect on the rotation of the drive shaft 182 or drive shaft 186.

[0043] During a load shift from fast to slow, the electric clutch assembly 196 disengages while the electric clutch assembly 212 engages. To achieve a smooth transition, both electric clutch assemblies 196 and 212 are briefly slightly engaged, slipping to maintain a constant rotational speed of the drive shaft 182. While both electric clutch assemblies 196 and 212 are slightly engaged, the rotation and torque of the drive shaft 182 are applied by both the high-speed and low-speed gear assemblies, with each gear assemblies slipping to some degree. This slippage is necessary to allow for a smooth transition between the gear systems without requiring a stop or 100% synchronous shifting.The uniform rotation of the drive shaft during the power shift process refers to a uniform speed and movement of the vehicle. The slippage of the two electric clutch assemblies 196, 212 during the power shift from slow to fast is similar.

[0044] The coupling arrangement 196 is now described in detail, and the description also applies to the coupling arrangement 212. As also in Fig. As shown in Figures 7-10, the clutch assembly 196 comprises a clutch pack 214, an input mechanism 216, and an actuating assembly 218. The clutch pack 214 is located on the first gear 206. The actuating assembly 218 is mechanically coupled to the first gear 206. The input mechanism 216 is used to cause the actuating assembly 218 to engage or disengage the clutch pack 214. When the clutch assembly 196 is engaged, the first gear 206 rotates with the clutch assembly 196, and when the clutch assembly is disengaged, the first gear 206 is no longer connected to the clutch assembly 196 for rotation. Alternatively, the first gear 206 can be any component that can be engaged and disengaged with respect to a drive component (e.g. gear, pulley, shaft, etc.).

[0045] The coupling assembly 214 comprises a plurality of first elements 260 and a plurality of second elements 262. To form the coupling assembly 214, the first elements 260 and second elements 262 are arranged alternately such that the first elements 260 are adjacent to second elements 262 and the second elements 262 are adjacent to first elements 260. In at least one aspect, the surfaces of the second elements 262 facing the first elements 260 and the surfaces of the first elements 260 facing the second elements 262 are rough surfaces. When a compressive force is applied to the coupling assembly 214, a frictional force is generated between the first elements 260 and the second elements 262. The compressive force pre-tensions the first elements 260 and the second elements 262 against each other.The pressure force and the friction force between the first elements 260 and second elements 262 are in a direct relationship, with the friction force increasing with increasing pressure force and the friction force decreasing with decreasing pressure force.

[0046] An increase in the pressure force engages the clutch pack 214. As the pressure force increases, the frictional force rises until it exceeds a first threshold, and the clutch pack 214 begins to engage, transmitting torque through it. As the clutch pack 214 begins to engage, the first elements 260 and the second elements 262 can slip relative to each other. This slippage allows only a portion of the total torque to be transmitted through the clutch pack 214. With a further increase in the pressure force, the frictional force eventually exceeds a second threshold, at which point the clutch pack 214 is fully engaged. With the clutch pack 214 fully engaged, the first elements 260 and the second elements 262 no longer slip relative to each other and rotate together.Furthermore, in the fully engaged position, the clutch pack 214 transmits the entire torque via the clutch pack 214. The threshold value can change in at least one aspect depending on the terrain (e.g., driving uphill, driving downhill, driving over rough terrain, driving through muddy terrain, etc.) and depending on the operation of the work vehicle (e.g., total weight of the work vehicle, driving speed of the work vehicle, etc.), as well as depending on the forces acting on the ground engagement elements. As the pressure force decreases, the frictional force falls below the second threshold value at which the clutch pack 214 can slip, and then below the first threshold value at which the clutch pack 214 is disengaged. When the clutch pack 214 is disengaged, the first elements 260 and second elements 262 can rotate differently about the reference axis 192, and no torque is transmitted via the clutch pack 214.

[0047] The first elements 260 and the second elements 262 are disks. The first elements 260 comprise internal teeth 264 on their inner circumference. The second elements 262 comprise external teeth 266 on their outer circumference. The clutch assembly 214 can be located outside a first component and inside a second component. The internal teeth 264 can engage with the first component, and the external teeth 266 can engage with the second component. When the clutch assembly 214 is engaged, the first and second components are connected to each other via the clutch assembly 214, so that torque is transmitted from the first or second component to the other. When the clutch assembly 214 is fully engaged, the first and second components rotate together.When the clutch pack 214 is disengaged, the first component and the second component are no longer connected to each other and can rotate independently of each other without transmitting any torque through the clutch pack 214.

[0048] The actuating assembly 218 comprises a clutch hub 228, a cam disc 230, an actuating piston 232, an adjusting spring 234, a thrust washer 236, a thrust bearing 238, a return spring 240, and a first snap ring 242. The actuating assembly 218 is arranged on the drive shaft 186, with the drive shaft 186 passing through each component. Each component 218, 228, 230, 232, 234, 236, 238, 240, 242 of the actuating assembly 218 is axially aligned with the reference axis 192. In the clutch assembly 212, the actuating assembly 218 is arranged on the drive shaft 182. The drive shaft 186 extends through an inner surface 223 of the clutch hub 228, and the clutch hub 228 is mechanically coupled to the drive shaft 186. The inner surface 223 may, for example, include splines that mesh with splines on the drive shaft 186. The clutch hub 228 rotates with the drive shaft 186.

[0049] The clutch hub 228 includes a projection 246 that defines a channel 248. The actuating piston 232 is located on the clutch hub 228 facing the opening of the channel 248. The first gear 206 is located on the clutch hub 228 opposite the actuating piston 232. The two bearings 268 are located between the first gear 206 and the clutch hub 228. The first gear 206 extends between the two bearings 268. The clutch hub 228 defines a channel 270 at the end with the first gear 206. A second snap ring 272 is located in the channel 270. The snap ring holds the bearings 268 in position, which in turn holds the first gear 206 in position on the clutch hub 228. The bearings 268 enable the first gear 206 to rotate relative to the clutch hub 228.

[0050] The first gear 206 includes a projection 274 extending along the reference axis 192. The projection 274 extends away from the bearings 268. The projection 274 defines a hole 276. The first gear 206 is positioned such that the projection 246 is located in the hole 276. The coupling assembly 214 is positioned between the inner surface 278 of the hole 276 and the outer surface of the projection 246. The inner surface 278 includes splines 280 that engage with the outer teeth 266 of the second elements 262. The outer surface of the projection 246 has splines 257 that engage with the inner teeth 264 of the first elements 260 of the coupling assembly 214. When the clutch pack 214 is engaged, it is compressed and the first gear 206 rotates with the clutch hub 228. When the clutch pack 214 is disengaged, the first gear 206 can rotate freely and independently of the clutch hub 228.

[0051] The actuating piston 232 can move along the clutch hub 228 at the reference axis 192. The actuating piston 232 defines a channel 250 that aligns with the channel 248 of the clutch hub 228 to form a single channel extending into the actuating piston 232 and the clutch hub 228. The return spring 240 is located within the single channel and applies a force to push the actuating piston 232 away from the projection 246 and clutch assembly 214. The actuating piston 232 can slide along the clutch hub 228. The actuating piston 232 includes a projection 252 located at the end defining the channel 250. The projection 252 extends radially away from the reference axis 192. The projection 252 defines a recess 254 which is arranged towards the projection 246.The projection 252 extends beyond the projection 246, and the recess 254 allows the projection 252 to slide over at least part of the projection 246. In at least one aspect, the projection 252 can move towards the clutch pack 214 to compress and engage the clutch pack 214.

[0052] The projection 252 further defines an annular channel 256, which is arranged on the side of the projection opposite the recess 254. The thrust bearing 238 is arranged within the annular channel 256, and the thrust bearing 238 extends outside the annular channel 256. The coupling hub 228 further defines a channel 258, which is arranged at the end of the actuating piston 232 opposite the projection 252. The first snap ring 242 is arranged in the channel 258.

[0053] The cam disk 230 is arranged along the reference axis 192 and concentrically around the actuating piston 232. The cam disk 230 has an annular circumferential flange 286 that defines a hole. The annular circumferential flange 286 extends along the reference axis 192 and in the direction of the projection 252. In at least one aspect, the hole 286 allows at least a portion of the cam disk 230 to slide over the projection 252. The cam disk 230 is positioned on the actuating piston between the first snap ring 242 and the projection 252. The cam disk 230 defines a hole 284 at the end opposite the hole 282. The first snap ring 242, when positioned in the channel 258, projects radially out of the channel 258. The first snap ring 242 prevents the cam disc 230 from moving away from the actuating piston 232 in a direction away from the projection 252 along the reference axis 192.Therefore, the first snap ring 242 acts as a stop to prevent the cam disc 230 from moving away from the actuating piston 232. When the cam disc 230 has reached its maximum distance to the projection 252, the first snap ring 242 rests in the channel 258. The first snap ring 242 emerges from the hole 284 when the cam disc 230 moves towards the projection 252.

[0054] The adjusting spring 234 is located in the hole 282 and around the actuating piston 232. The adjusting spring 234 is arranged concentrically around the actuating piston 232, and the cam disk 230 is also arranged concentrically around the adjusting spring 234. The adjusting spring 234 is located between the bottom of the hole 282 and the projection 252. The adjusting spring 234 applies a preload force to the bottom of the hole 282 and the projection 252 to move the projection 252 away from the cam disk 230. In at least one aspect, the adjusting spring 234 is one or more conical springs. The thrust washer 236 is located between the adjusting spring 234 and the thrust bearing 238. Thus, the thrust bearing 238 enables the actuating piston 232 to rotate about the reference axis 192 without the cam disk 230, the adjusting spring 234 and the thrust disk 236 having to rotate with the actuating piston 232.

[0055] The cam disk 230 does not rotate about the reference axis 192. The end of the annular circumferential flange 286 of the cam disk 230 comprises a toothed circumference 288 that extends radially away from the reference axis 192. The toothed circumference 288 holds the cam disk firmly in its rotational position. For example, the toothed circumference 288 can engage a splined section in the central housing 164, the splined section locking the cam disk 230 in a rotationally fixed position and allowing translation of the cam disk 230 along the splined section and thus along the reference axis 192. In at least one aspect, the actuating spring 234 and the pressure plate 236 do not rotate about the reference axis 192. The input mechanism 216 controls the translation of the cam disc 230 along the reference axis 192 to move the cam disc 230 towards or away from the projection 252.The movement of the cam disk 230 towards the projection 252 compresses the actuating spring 234, which in turn biases the actuating piston towards the clutch pack 214. The cam disk 230 is held in its translational position by the input mechanism 216. Thus, when the actuating spring 234 is compressed, it applies a bias force to the projection 252 via the thrust disk 236 and the release bearing 238 in the direction of the reference axis 192, away from the cam disk 230. The bias force generated by the actuating spring 234 increases as the cam disk 230 is moved towards the projection 252. This preload force moves the projection 252 towards the clutch pack 214. The cam disc 230 does not directly contact the actuating piston 232 to displace the actuating piston 232, but rather, through the preload force of the adjusting spring 234, causes a translation of the actuating piston 232. Fig. Figure 6A shows the actuating spring 234 of the high-speed assembly 200 in its compressed state, which causes the actuating spring 234 to move the actuating piston 232 to engage the clutch pack 214. The actuating spring 234 of the low-speed gear assembly 202 is shown uncompressed or less compressed with the clutch pack 214 disengaged.

[0056] To move the projection 252 towards the clutch pack 214, the preload force of the actuating spring 234 must be greater than the preload force of the return spring 240. Once the preload force of the actuating spring 234 has risen to a value above the threshold, the actuating piston 232 has moved sufficiently far to compress the clutch pack 214 between the projection 252 and the bottom of the hole 276 of the first gear 206, causing the clutch pack 214 to engage. As the preload force of the actuating spring 234 increases, the projection 252 begins to compress the clutch pack 214, causing the clutch pack 214 to slip and then fully engage when the first elements 260 and the second elements 262 are in contact with each other with sufficient force to rotate together. When the clutch pack 214 is fully engaged, the clutch hub 228 and the first gear 206 rotate together.As soon as the preload force of the adjusting spring 234 decreases to the point where it is less than the preload force of the return spring 240, the return spring 240 will push the projection 252 away from the clutch assembly 214 and disengage the clutch assembly 214. With decreasing preload force of the adjusting spring 234, the first elements 260 and the second elements 262 contact each other with less force until the clutch assembly 214 begins to slip and then disengages completely. There is a direct relationship between the preload force of the adjusting spring 234 and the translational position of the cam disc 230. When the cam disc 230 moves towards the projection 252, the preload force increases, and when the cam disc 230 moves away from the projection 252, the preload force decreases.The actuating spring 234 is therefore dimensioned and designed such that it positions the actuating piston 232 so that it engages the clutch elements 260, 262 in a first translational position of the cam disc 230. The actuating spring 234 is dimensioned and designed such that it positions the actuating piston 232 so that it does not engage the clutch elements 260, 262 in a second translational position of the cam disc 230. In the second translational position, the clutch assembly 214 could, for example, be disengaged.

[0057] The input mechanism 216 interacts with the cam disk 230 to effect a translation of the cam disk, for example, a translation towards and away from the first translation position and the second translation position. The input mechanism 216 comprises an electric motor 172, a pinion 220, a cam gear 290, a first pressure disk 292, a second pressure disk 294, and a cam gear holder 296. The electric motor 172 comprises an output shaft 222, which is mechanically coupled to a shaft 224 of the pinion 220. The shaft 224 extends towards the cam gear 290, and the teeth 226 of the pinion 220 are arranged on the shaft 224 such that they mesh with the teeth 298 of the cam gear 290. The cam gear 290 is arranged concentrically around the cam disk 230, and the cam gear 290 rotates around the reference axis 192.

[0058] In at least one aspect, the pinion 220 is a worm gear and the cam gear 290 is a ring gear formed by an annular body extending around the reference axis 192 and having an inner circumference and an outer circumference. The outer circumference has a plurality of teeth that mesh with the pinion 220, and the inner circumference has at least one cam tappet 300. In at least one case, the outer circumferential surface is configured to mesh with the pinion 220. The outer circumferential surface can, for example, have an annular, concave section 312 ( Fig. 9) which engages with the pinion 220. The annular concave section 312 can, for example, at least partially surround the pinion 220. The cam disk 230 comprises at least one cam ramp 302 ( Fig. 9), which is formed from a radially raised surface that tapers along the annular circumferential flange 286. The cam tappet 300 engages the cam ramp 302. The rotation of the cam gear 290 about the reference axis 192 moves the cam tappet 300 along the cam ramp 302, causing a translation of the cam disk 230 along the reference axis 192. The pinion 220 receives the rotation input from the electric motor 172. The electric motor 172 is controlled (e.g., by the control system 120) to rotate the pinion 220, thus causing a translation of the cam disk 230 along the reference axis 192 to engage or disengage the clutch pack 214.

[0059] The first pressure plate 292 lies along the reference axis 192 on one side of the cam gear 290, and the second pressure plate 294 lies along the reference axis 192 on the opposite side of the cam gear 290. The cam gear 290 defines a rounded annular channel 304 located on each side of the cam gear 290. The first pressure plate 292 and the second pressure plate 294 each have a rounded annular projection 306 extending along the reference axis 192. The rounded annular projection 306 is located within a rounded annular channel 304 to align the first pressure plate 292 and the second pressure plate 294 with the cam gear 290. The first pressure plate 292 and the second pressure plate 294 hold the cam gear 290 in a fixed translation position and only allow rotation of the cam gear 290 along the reference axis 192.

[0060] A cam gear holder 296 holds the first pressure disk 292 in position. The cam gear holder 296 includes an annular projection 308 that defines an annular channel 310. The first pressure disk 292 is arranged in the annular channel 310. The cam gear holder 296 can be held in a fixed position by the central housing 164. For example, the cam gear holder 296 can be positioned in an opening in the central housing 164, which holds the cam gear holder 296 in a fixed position. The cam gear holder 296 defines a recess 297 that provides space for the entry mechanism 216. The second pressure disk 294 is held in a fixed position by the central housing 164. For example, the middle housing 164 can enclose the second pressure disk 294 on the longitudinal side facing away from the cam gear 290 and radially enclose the second pressure disk 294 to hold the second pressure disk 294 in a fixed position.Therefore, the cam gear 290 is held translationally in a fixed position, while only its rotation about the reference axis 192 is permitted.

[0061] The cam gear 290 can be referenced to a clock position of the reference axis 192. The cam gear 290 can be rotated via the pinion 220 to change its clock position. Therefore, the pinion 220 can drive the cam gear 290 within a range of clock angles around the reference axis 192, which corresponds to a range of translation positions of the cam disk 230 along the reference axis 192. For example, rotating the cam gear 290 causes the cam tappet 300 to move along the cam ramp 302, which translates the cam disk 230 along the reference axis 192. The cam gear 290 can only rotate along the length of the cam ramp 302. The cam disk 230 has timing limiters 314 at opposite ends of the cam ramp 302, which engage in the cam tappet 300 to inhibit the rotation of the cam gear 290 about the reference axis 192.The timing limiters 314 can, for example, be in the form of radial projections on the cam ramp 302. If an attempt is made to rotate the cam gear 290 into a timing position outside the cam ramp 302, the cam tappet 300 collides with the timing limiter 314 at the end of the cam ramp 302 and stops the rotation of the cam gear 290 at the timing position at the end of the cam ramp 302.

[0062] According to the presentation in Fig. 9 and Fig. The cam gear 290 comprises three cam tappets 300, which are distributed at equal intervals around the inner circumference of the cam gear 290. The cam tappets 300 are thus 120 degrees apart. The three cam tappets 300 engage in three cam ramps 302 of the cam disk 230. The cam ramps 302 are arranged evenly around the annular circumferential flange 286, with a timing limiter located between each individual cam ramp 302. Thus, the cam gear 290 can rotate by approximately 120 degrees to move a cam tappet 300 along the entire length of the corresponding engaged cam ramp 302. The degree of rotation that the cam gear 290 can perform corresponds to the length of the cam ramp 302. In some aspects, the length of the cam ramp 302 can correspond to the number of cam ramps 302 arranged around the cam disk 230.For example, if the cam ramps 302 are evenly spaced around the cam disk 230 and occupy the greatest possible length around the cam disk 230, then the cam ramps 302 would be shorter the more cam ramps 302 are present to fill the space around the cam disk 230. Accordingly, the degree of rotation that the cam gear 290 can execute before it is inhibited by a cycle limiter 314 would decrease with an increasing number of cam ramps 302.

[0063] In an alternative aspect, the cam gear 290 can have any number of cam tappets greater than zero. In one aspect, each cam tappet 300 would have a corresponding cam ramp 302. In another aspect, more than one cam tappet 300 could engage a single cam ramp 302. In this case, the total amount of rotation that the cam gear 290 could execute would be limited by the placement of the cam tappets 300, since the rotation is inhibited as soon as a cam tappet 300 reaches a timing limiter 314.

[0064] As with reference to Fig. 5, Fig. 6A and Fig. As shown in Figure 8, the electric machine 172 (e.g., by the control system 120) is controlled to rotate the pinion 220, thereby causing the cam gear 290 to rotate and change its timing positions. The electric machine 172 can rotate the cam gear 290 from a first timing position, corresponding to a disengaged position of the clutch pack 214, to a second timing position, corresponding to an engaged position of the clutch pack 214. The cam gear 290 rotates and thus moves the cam tappets 300 along the cam ramps 302, which displaces the cam disk 230 toward the projection 252 of the actuating piston 232, thereby compressing the actuating spring 234. The actuating spring 234 generates a preload force that pushes the cam disk 230 away from the projection 252. Therefore, the preload force presses the cam ramps 302 against the cam tappets 300 and keeps the cam tappets 300 engaged with the cam ramps 302.The cam disc 230 cannot move away from the projection 252 because the central housing 164 holds the cam gear holder 296, the first thrust disc 292, and the cam gear 290 in a translational position against the preload force. Therefore, as the cam tappets 300 move along the cam ramps 302 toward the second stroke position, the cam disc 230 moves toward the projection 252, increasing the compressive preload force of the actuating spring 234. The return spring 240 generates a preload force that pushes the actuating piston 232 away from the first gear 206 and toward the cam disc 230. The adjusting spring 234 and the return spring 240 are dimensioned and designed such that they provide an adjusting spring preload force that overcomes the return spring preload force as soon as the cam disk 230 has moved beyond a translation threshold value in the direction of the projection 252.Once the spring preload force is overcome by the adjusting spring preload force of the actuating spring, the adjusting spring 234 moves the actuating piston 232 and the projection 252 towards the clutch pack 214. During this movement, the spring preload force increases as the actuating piston 232 moves towards the clutch pack 214. The adjusting spring 234 and the return spring 240 are dimensioned and designed such that the adjusting spring force overcomes the spring preload force in order to move the projection 252 and compress the clutch pack 214, engaging it against the first gear 206.

[0065] The speed required for the clutch assembly 214 to engage and disengage can depend on the type of vehicle 100 and the desired tasks 100 to be performed by the vehicle. The compression rate of the clutch assembly 214 depends on the translational movement of the actuating piston 232. The translational movement of the actuating piston 232 is determined by the magnitude of the preload force generated by the actuating spring 234. The engagement rate of the clutch assembly 214 can be changed by altering the rotational speed at which the electric motor 172 rotates the pinion 220, by changing the pitch of the cam ramp 302, and / or by changing the actuating spring 234 to a different spring constant, thereby affecting the generated preload force.The speed at which the pinion 20 rotates changes the speed at which the cam gear 290 rotates, which in turn affects the speed of the translational movement of the cam disk 230. The slope of the cam ramp 302 changes the translational speed at which the cam disk 230 moves when the cam gear 290 rotates. Changing the actuating spring 234 to a higher spring constant can cause a greater translation of the actuating piston 232 with a smaller translational movement of the cam disk 230.

[0066] In at least one aspect, the drive shaft 186 rotates due to a rotational input from the electric motor 152. The rotation of the drive shaft 186 causes the clutch hub 228 to rotate with the drive shaft 186. The actuating piston 232, the return spring 240, and the first elements 260 rotate with the clutch hub 228. In at least one aspect, the thrust bearing 238 prevents the cam disc 230 from rotating with the clutch hub 228 and keeps it rotationally fixed. When the clutch assembly 214 is disengaged, the first elements 260 and the second elements 262 can rotate at different speeds. For example, the clutch pack 214 of the clutch assembly 212 could be in the engaged position, causing the first gear 206 and the second elements 262 to rotate based on the rotation of the drive shaft 182 with the low-speed gear assembly engaged.In an alternative example, the clutch assembly 212 could also be in the disengaged position, while the drive shaft 182 is not rotating because the work vehicle is stationary. If the drive shaft 182 is not moving, the first gear 206 and the second elements 262 would also be stationary.

[0067] The actuating spring force causes the projection 252 to compress the clutch assembly 214 between the projection 252 and the bottom of the hole 276 of the first gear 206. As the compression pressure of the clutch assembly 214 increases, the first elements 260 and the second elements 262 begin to generate friction between them. As previously discussed, the friction increases until the first elements 260 and the second elements 262 touch and slip against each other, until they are fully engaged and rotate together. In both cases, the torque from the drive shaft 186 and the clutch hub 228 is transmitted via the clutch assembly 214 to the first gear 206. If the clutch pack 214 slips, not all of the torque supplied by the drive shaft 186 will be transmitted via the clutch pack 214 to the first gear 206.When the clutch pack 214 is fully engaged, all the torque supplied by the drive shaft 186 is transmitted via the clutch pack 214 to the first gear 206. The clutch pack 214 can be fully engaged in the second stroke position. By rotating the cam gear 290 from the second stroke position to the first stroke position, the clutch pack 214 moves from the fully engaged to the disengaged position. As the cam gear 290 rotates, the cam disc 230 moves away from the projection 252, thereby reducing the preload force of the actuating spring. With the reduction of the preload force of the actuating spring, the preload force of the return spring 240 moves the actuating piston 232 and the projection 252 away from the clutch pack 214. This reduces the pressure force on the clutch pack 214, allowing the clutch pack 214 to transition from the fully engaged state to slipping and then to the disengaged state.

[0068] The slippage of the clutch pack 214 is important to ensure a smooth transfer of torque from one gear assembly to the other during the powershift operation. During powershift, the vehicle switches between the high-speed gear assembly 200 and the low-speed gear assembly 202 while driving. During the shift, the clutch packs 214 slip as one clutch pack 214 begins to engage and the other clutch pack 214 begins to disengage. During this slippage, both the high-speed gear assembly 200 and the low-speed gear assembly 202 transmit torque from the input shaft 186 to the input shaft 182. The magnitude of the torque supplied by each gear assembly 200 and 202 changes as the gear assemblies 200 and 202 are engaged or disengaged.As a gear assembly 200, 202 is engaged, the torque supplied by that gear assembly 200, 202 increases until it reaches the fully engaged position. As a gear assembly 200, 202 is disengaged, the torque supplied by that gear assembly 200, 202 decreases until it reaches the fully disengaged position. To switch from one gear assembly 200, 202 to the other, the coupling assemblies 196, 212 move to the fully disengaged position and then to the fully engaged position.

[0069] The drive shaft 182 drives the differential assembly 204 to drive the wheel hubs 170 and the ground engagement elements 104. The hubs 170 are elongated elements that extend through the outer housings 316 of the wheel end units 168 and are rotatably mounted via one or more bearings 318 at each laterally inner and outer end, so that they rotate about a wheel axis 320, around which the ground engagement elements 104 rotate during the movement of the work vehicle 100. Alternatively, a longer or shorter wheel hub 170 is possible by shortening or lengthening the length of the wheel hub 170 and the outer housing 316. The laterally inner ends of the elongated hubs 170 connect to the wheel reduction gears 322. Each wheel reduction gear 322 can be a planetary gear set. However, other types of reduction gears can also be used.In the illustrated embodiment, the laterally inner end of each elongated hub 170 is grooved or toothed for engagement with the slots or teeth of a planet carrier C2. The carrier C2 has pinions that rotatably mount (for example, two, three, or more) planet gears P2, which are arranged in the annular space between a ring gear R2, formed in or attached relative to the housing of the wheel end unit 168, and a sun gear S2, in order to mesh with both the ring gear R2 and the sun gear S2. The sun gear S2 is rigidly connected to a shaft 324 so that it rotates as a whole about the wheel axis 320. Recesses in the outer lateral ends of the shafts 324 accommodate the heads of screws 326, which are screwed into the inner ends of the elongated hubs 170 to fasten retaining plates 328 in a stop with the supports C2 and thereby hold the elongated hubs 170 on the supports C2 so that they rotate with them.The illustrated wheel reduction gears 322 provide planetary gear arrangements with a power flow of the type drive sun gear - output planet carrier, which effect a low reduction ratio between the power input to the wheel end units 168 and the power output of the wheel end units 168 to the ground engagement elements 104.

[0070] As with reference to Fig. As can be seen further in Figure 5, the lateral inner end of the shaft 324 of each wheel reduction 322 projects into a differential assembly 204, which rotates about the wheel axis 320 relative to the wheel end housings 316 and the differential housing 166. In the illustrated example, the differential assembly 204 comprises a differential housing 330, which rotates on bearings 332 relative to mounting rings 336 coupled to the wheel end housings 316. The differential housing 330 defines an inner cavity in which differential drives 334 and differential gears 338 are arranged. In the illustrated example, there are four differential drives 334, which support four differential gears 338. The differential drives 334 intersect each other at right angles and are arranged orthogonally to the wheel axle 320, with their ends sitting in recesses in the interior of the differential housing 330.The differential gears 338 mesh with two side gears 340, 342, which are positioned on opposite sides of the differential assembly 204 and rigidly attached (for example, pressed in or keyed) to the inner lateral ends of the shafts 324. The differential gears 338 and the side gears 340, 342 are designed as bevel gears such that their axes of rotation are perpendicular. As can be seen, the differential assembly 204 allows the side gears 340, 342 to rotate at different speeds, thereby enabling the elongated hubs 170 of the wheel end units 168 to drive the ground engagement elements 104 at different speeds.

[0071] In the illustrated embodiment, the differential assembly 204 can be locked by means of a brake 344. The brake 344 can be electro-hydraulically activated via the control system 120 through an operator interface 124 by moving a piston 346 and engaging it with the brake 344. The brake 344 comprises a stack 348 of alternately interlocking plates and friction discs that are alternately meshed with the differential housing 330 and an annular hub 350 of the side gear 340. Actuating the brake 344 causes the side gear 340 to rotate with the differential housing 330, thereby causing the differential drives 334 and differential gears 338 to rotate the side gear 342 with the side gear 340 and the differential housing 330. This effectively “locks” the differential arrangement 204, so that both shafts 324 and the elongated hubs 170 rotate together.This in turn locks the left and right ground engagement elements 104, causing them to rotate together at the same speed, like a rigid axis. As in . Fig. 5 and Fig. As shown in Figure 11, the force is transmitted from the drive shaft 182 via a drive gear 352 to the differential assembly 204 and thereby to the wheel end units 168. The drive gear 352 is rigidly connected to the differential housing 330, so that it rotates with it about the wheel axis 320. The drive gear 352 is designed with an annular inclined surface 354, the teeth of which are defined by any suitable configuration, and which in the illustrated example are spherical bevel teeth. The drive shaft 182 extends through a bearing 357 into the differential assembly 204. The drive shaft 182 includes a gear output 356, which meshes with the teeth of the annular inclined surface 354 of the drive gear 352. The rotation of the drive shaft 182 causes the drive gear 352 to rotate, which in turn rotates the wheel end units 168 and the rear ground engagement elements 104 attached to the wheel end units 168.

[0072] The electric transaxle further comprises one or more power take-off (PTO) assemblies driven by the drive shaft 182. Each PTO assembly is attached to or at least partially contained within one or more housings (e.g., the motor and inverter housing 160, the front housing 162, and the center housing 164). The PTO assemblies are each designed to receive power from the drive shaft 182. The PTO assemblies can be mechanically coupled to drive the front ground engagement elements 104. For example, one of the PTO assemblies can be used to drive the front ground engagement elements 104 via a front differential assembly, which functions similarly to the differential assembly 204. In the illustrated embodiment, there are two PTO assemblies.The first power take-off arrangement is a continuous all-wheel drive arrangement 156 and the second power take-off arrangement is a mechanical instantaneous four-wheel drive arrangement 158.

[0073] The 100 series work vehicle can be equipped with rear-wheel drive only, selective four-wheel drive, or permanent four-wheel drive. The type of four-wheel drive can be selected depending on the specific model of the 100 series work vehicle or can be determined during manufacturing. For example, the desired type of four-wheel drive can be achieved by using or omitting the power take-off (PTO) system.

[0074] As in Fig. 5 and Fig. As shown in Figure 6B, in permanent all-wheel drive mode, the rear ground engagement elements 104 and the front ground engagement elements 104 are driven by the drive shaft 182. This process utilizes the continuous four-wheel drive arrangement 156. In this arrangement 156, the drive shaft 182 is connected to a front drive shaft 358 via a coupling device 360. The drive shaft 182 can, for example, have splines that mesh with splines on the coupling device 360, and the front drive shaft 358 can have splines that mesh with splines on the coupling device 360. The drive shaft 182 extends through a spacer 361 and a bearing 363 to the coupling device 360. The rotation of the drive shaft 182 rotates the front drive shaft 358.The front drive shaft 358 extends through the motor and inverter housing 160 and through the end plate 178 along the axis of rotation 174. The front drive shaft 358 extends through two bearings 362 housed in the end plate 178 and out through the end plate 178. The bearings 362 allow the front drive shaft 358 to rotate relative to the end plate 178. The end of the front drive shaft 358 is connected to an output coupling 364. The output coupling 364 can couple the front drive shaft 358 to another drive shaft to drive the front ground engagement elements 104. For example, the front drive shaft 358 can drive the front ground engagement elements via a front differential assembly, which functions similarly to the differential assembly 204.

[0075] As in Fig. 5, Fig. 6A and Fig.As shown in Figure 6B, in the selective four-wheel drive, the rear ground engagement elements 104 and the front ground engagement elements 104 are driven by the drive shaft 182 when the four-wheel drive is engaged, and only the rear-wheel drive is driven when the four-wheel drive is disengaged. This process utilizes the mechanical instantaneous four-wheel drive assembly 158. This assembly 158 includes a clutch assembly 366 for engaging and disengaging the four-wheel drive. The clutch assembly 366 functions in the same way as the clutch assembly 196 and the clutch assembly 212. For the sake of brevity, not all similarities will be discussed in detail. A gear 368 meshes with the second gear 208. The second gear 208 engages with the drive shaft 182 and rotates with the drive shaft 182. The rotation of the second gear 208 rotates the gear 368.In at least one aspect, the gear 368 is dimensioned such that the shaft 372 rotates at the same speed as the drive shaft 182.

[0076] The gear 368 defines a pivot axis 370. The gear 368 includes a shaft 372 that extends from the gear 368 along the pivot axis 370 in both directions. The shaft 372 extends through the bearing 374 and the bearing 376. The shaft 372 defines a recess 382 that provides space for the input mechanism 216 of the coupling assembly 212. The bearings 374 and 376 allow the gear 368 to rotate relative to the housings 160, 162, and 164. The bearing 374 is located in the central housing 164, and the bearing 376 is located in the cam gear holder 378 of the coupling assembly 366. The cam gear holder 378 is mounted on the front housing 162. The cam gear holder 378 functions in the same way as the cam gear holder 296. The cam gear holder 378 holds the first pressure plate 292 in position, and the second pressure plate 294 is held in position by the front housing 162.The first pressure plate 292 and the second pressure plate 294 hold the cam gear 290 in position and allow only one rotation of the cam gear 290 around the axis of rotation 370.

[0077] The gear 368 is connected to a front drive shaft 380 via the clutch assembly 366. Thus, when the clutch assembly 366 is engaged, the gear 368 and the front drive shaft 380 rotate together, and when the clutch assembly 366 is disengaged, the gear 368 and the front drive shaft 380 are disengaged and do not rotate together. The front drive shaft 380 extends radially away from the axis of rotation 370 in the direction of the gear 368. The front drive shaft 380 defines a hole 384 in the direction of the gear 368, and at least part of the shaft 372 is located in the hole 384. The shaft 372 is coupled to the clutch hub 228, so that the clutch hub 228 rotates with the shaft 372. For example, the splined shaft 372 can engage with the splined shaft 228 of the coupling hub. The projection 246 is located in the hole 384.The clutch assembly 214 is arranged between the clutch hub 228 and the front drive shaft 380. The first elements 260 engage with the clutch hub 228, and the second elements 262 engage with the inner surface of the hole 384 of the front drive shaft 380. As mentioned earlier, when the clutch assembly 214 engages, the first elements 260 are pressed against the second elements 262 until the first elements 260 and the second elements 262 rotate together, causing the clutch hub 228 and the front drive shaft 380 to rotate together.

[0078] Similar to the coupling arrangements 196, 212, the coupling arrangement 366 is engaged and disengaged by the input mechanism 216 of the coupling arrangement 366. The electric machine 176 comprises an output shaft which is mechanically coupled to a shaft 386 of a pinion 388. The pinion 388 functions in the same way as the pinion 220. The electric motor 176 is attached to the front housing 162, and the shaft 386 extends through the front housing 162 to the cam gear 290 of the clutch assembly 366. The pinion 388 receives the rotation input from the electric motor 176. The electric motor 176 is controlled (e.g., by the control system 120) to rotate the pinion 388, thereby causing the rotation of the cam gear 290, which in turn causes the translation of the cam disk 230 along the axis of rotation 370 to engage or disengage the clutch assembly 214.The toothed circumference 288 of the cam disc 230 engages with the front housing 162 to prevent the cam disc 230 from rotating and to allow only its translation along the axis of rotation 370. The cam disc 230 moves along the axis of rotation 370, which, due to the preload force of the actuating spring 234, causes the actuating piston 232 to translate along the same axis. The translation of the actuating piston 232 towards the front drive shaft 380 can compress the clutch pack 214 and ultimately fully engage it, while the translation of the actuating piston 232 away from the front drive shaft 380 can disengage the clutch pack 214.

[0079] The front drive shaft 380 extends through the motor and inverter housing 160 along the axis of rotation 370 and out of the motor and inverter housing 160. The front drive shaft 380 extends through two bearings 390 located within the motor and inverter housing 160. The bearings 390 allow the front drive shaft 380 to rotate relative to the motor and inverter housing 160. The end of the front drive shaft 380 is connected to an output coupling 392. The output coupling 392 can couple the front drive shaft 380 to another drive shaft to drive the front ground engagement elements 104 when the four-wheel drive is engaged via the electric clutch assembly 366.When the four-wheel drive is engaged via the electric clutch assembly 366, the front drive shaft 380 can, for example, drive the front ground engagement elements 104 via a front differential assembly that functions similarly to the differential assembly 204. An operator can activate the four-wheel drive via the operator interface 124 and cause the control system 120 to control the electric machine 176 in order to engage the electric clutch assembly 366. Likewise, the operator can deactivate the four-wheel drive via the operator interface to operate the work vehicle with rear-wheel drive.

[0080] Another type of four-wheel drive consists of the work vehicle being driven only at the rear wheels when the continuous four-wheel drive arrangement 156 or the mechanical instantaneous four-wheel drive arrangement 158 ​​is not used. For example, neither the output clutch 364 nor the output clutch 392 would be engaged to drive the front ground engagement elements 104. In this case, the front drive shaft 358 and the front drive shaft 380 can be removed, with the openings in the housing 160 and in the end plate 178 for the drive shafts 358 and 380 being closed. In the case of continuous four-wheel drive, the front drive shaft 380 can be removed, with the opening in the housing 160 for the drive shaft 380 being closed. In the case of selective four-wheel drive, the front drive shaft 358 can be removed, with the opening in the end plate 178 for the drive shaft 358 being closed.Alternatively, the front drive shaft 358 and the front drive shaft 380 can be retained for any type of four-wheel drive (i.e., rear-wheel drive only, permanent four-wheel drive, and selective four-wheel drive), with the output clutch 364, 392 being used for the type chosen for the work vehicle. With rear-wheel drive only, neither output clutch 364, 392 would be used.

Claims

[1] Electric coupling (196) comprising: a clutch package (214) with clutch elements (260, 262) which transmit a torque when engaged; having an input mechanism (216): a pinion gear (220) designed to receive a rotary input from an electric machine (172); and a cam gear (290) that meshes with the pinion (220) to rotate about a reference axis (192); and comprising an actuation arrangement (218): a spring (234); a cam disk (230) arranged around the reference axis (192) and engaging with the cam gear (290) on a cam ramp (302), such that a change in the timing position of the cam gear (290) around the reference axis (192) causes a translation of the cam disk (230) along the reference axis (192) to move the actuating spring (234); and an actuating piston (232) which is moved by the actuating spring (234) in response to the translation of the cam disc (230) to engage the clutch elements (260, 262) of the clutch pack (214). [2] Electric coupling (196) according to claim 1, wherein the pinion gear (220) drives the cam gear (290) between a range of indexing angles around the reference axis (192), which corresponds to a range of translation positions of the cam disk (230) along the reference axis (192). [3] Electric clutch (196) according to claim 2, wherein in a first translation position of the cam disc (230) the actuating spring (234) is dimensioned and designed such that it positions the actuating piston (232) in engagement with the clutch elements (260, 262), and in a second translation position of the cam disc (230) the actuating spring (234) is dimensioned and designed such that it does not position the actuating piston (232) in engagement with the clutch elements (260, 262). [4] Electric clutch (196) according to any one of claims 1 to 3, wherein the actuating spring (234) is designed to bias the actuating piston (232) in the direction of the clutch pack (214). [5] Electric coupling (196) according to any one of claims 1 to 4, wherein the cam disk (230) defines the cam ramp (302) and the cam gear (290) has a cam tappet (300) that engages in the cam ramp (302) to cause a translation of the cam disk (230) along the reference axis (192). [6] Electric coupling (196) according to any one of claims 1 to 5, wherein the cam disk (230) has an annular circumferential flange (286) extending around the reference axis (192) and having a toothed circumference that fixes a timing position of the cam disk (230); and wherein the cam ramp (302) is a radially raised surface that tapers along the annular circumferential flange (286) of the cam disk (230). [7] Electric coupling (196) according to one of claims 1 to 6, wherein the cam gear (290) is a ring gear formed by an annular body which extends around the reference axis (192) and has an inner circumference and an outer circumference, and the outer circumference has a plurality of teeth meshing with the pinion (220) and the inner circumference has the cam tappet (300). [8] Electric clutch (196) according to any one of claims 1 to 7, wherein the cam disk (230) defines pulse limiters (314) at opposite ends of the cam ramp (302) which engage in the cam tappet (300) to inhibit rotation about the reference axis (192). [9] Electric coupling (196) according to any one of claims 1 to 8, wherein the pinion (220) is a worm gear and the cam gear (290) is a ring gear with a toothed outer circumference which meshes with the worm gear to change the indexing position of the ring gear about the reference axis (192). [10] Electric clutch (196) according to any one of claims 1 to 9, wherein the actuating spring (234) is arranged concentrically around the actuating piston (232), the cam disk (230) is arranged concentrically around the actuating spring (234), and the cam gear (290) is arranged concentrically around the cam disk (230). [11] Electric clutch (196) according to any one of claims 1 to 10, wherein the actuating arrangement (218) further comprises a return spring which is dimensioned and designed to provide a return spring force which biases the actuating piston (232) away from the clutch pack (214); and wherein the actuating spring (234) is dimensioned and designed to provide an actuating spring force which overcomes the return spring force in at least one translational position of the cam disk (230) in order to move the actuating piston (232) towards the clutch pack (214). [12] Electric coupling (196) according to any one of claims 1 to 11, wherein the input mechanism (216) comprises the electric machine (172) driving the pinion (220).

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