Electric hybridization of a hydromechanical adjustable transmission

Abstract

Transmission system, including: a hydraulic pump that is rotaryally coupled to an input shaft; a hydraulic motor which is rotaryally coupled to an output shaft via a first drive range coupling; a planetary gear set comprising a sun gear rotaryally coupled to the hydraulic motor, a carrier rotaryally coupled to the output shaft, and a ring gear rotaryly coupled to one or more couplings connected to the input shaft; a primary drive source that is rotaryly coupled to the input shaft; and an electric machine which is optionally rotary-coupled to the input shaft or the output shaft via the actuation of a jaw coupling, or mechanically separated from the input shaft and the output shaft.

Description

TECHNICAL AREA

[0001] The present disclosure relates to a hybrid hydromechanical adjustable transmission and a control strategy for selectively coupling an electric machine via a claw coupling of the hybrid hydromechanical adjustable transmission. BACKGROUND AND DETOUR

[0002] The electric hybridization of power-sharing transmissions involves integrating an electric machine into a transmission assembly. By integrating the electric machine into the transmission assembly, the energy consumption of heavy-duty vehicles can be reduced due to high peak power recuperation during braking. The recovered and stored energy can be used to power the vehicle in all-electric mode, for example, when the diesel engine is switched off. The stored energy can also be used additionally or alternatively to increase power output during heavy maneuvers. In other examples, the electric machine can be used to charge a battery, with a primary drive source (e.g., the diesel engine) being used for power generation.The electric motor provides additional braking capacity, and an engine brake can be used to provide additional braking force to stop the rotational movement of shafts driven by the electric motor and / or the primary drive source. While hybrid power-split transmissions may be a relatively efficient solution (e.g., with an efficiency of approximately 80%) for transferring power from the primary drive source to the vehicle's wheels, there are several points in the power-split transmission where efficiency could be further improved. Furthermore, the inclusion of a second drive source (e.g., the electric motor) can reduce the vehicle's fuel consumption.Conventional hybrid power-sharing transmissions may require the use of an additional engine braking system to adequately stop the vehicle's movement when both the main power source and the electric machine are used to propel the vehicle.

[0003] Hydromechanical transmissions allow for the combination of performance characteristics such as efficiency, shift quality, drive characteristics, and control response from mechanical and hydrostatic transmissions to achieve vehicle design goals. Some hydromechanical transmissions, technically referred to as hydromechanical variable transmissions (HVTs), offer continuously variable gear ratios. Hydromechanical transmissions can be particularly desirable due to their efficiency. Vehicles used in industries such as agriculture, construction, mining, material handling, and the oil and gas industry utilize HVTs. However, relatively high fixed power losses in hydromechanical variable transmissions (HVTs) can lead to a decrease in transmission efficiency at lower power flows.For example, the efficiency of the transmission can decrease due to a charge pump, clutch resistance losses, and leaks in hydrostatic machines.

[0004] To solve at least some of the problems mentioned above, the inventors developed a hybrid HVT system. In one example, a hybrid HVT transmission system comprises a hydraulic pump rotaryly coupled to an input shaft; a hydraulic motor rotaryly coupled to an output shaft via a first drive range coupling; a planetary gear set comprising a sun gear rotaryly coupled to the hydraulic motor, a carrier rotaryly coupled to the output shaft, and a ring gear rotaryly coupled to one or more couplings coupled to the input shaft; a main drive source rotaryly coupled to the input shaft; and an electric machine that is optionally rotaryly coupled to the input or output shaft, or mechanically disconnected from the input and output shafts by actuating a jaw coupling.In this way, the operating efficiency of the transmission system is increased while simultaneously enabling the controllability of the transmission system, including the torque of the hydraulic motor.

[0005] It should be noted that the foregoing summary serves to present, in simplified form, a selection of concepts that are further explained in the detailed description. It does not serve to identify essential features of the claimed subject matter, the scope of which is defined exclusively by the claims following the detailed description. Furthermore, the claimed subject matter is not limited to implementations that eliminate the disadvantages mentioned above or in any part of this disclosure. BRIEF DESCRIPTION OF THE FIGURES Fig. Figure 1 shows a schematic representation of a vehicle with a hydromechanical adjustable hybrid transmission (HVT). Fig. 2A shows a table that describes the configuration of the couplings in the Fig. 1 indicates the hybrid HVT shown in different drive ranges. Fig. 2B shows a table illustrating the engagement of a claw coupling in the hybrid HVT of Fig. 1 indicates different energy management strategies. Fig. Figure 3 shows a schematic representation of an example of the hybrid HVT from Fig. 1 with a claw coupling in a first position. Fig. Figure 4 shows a schematic representation of the hybrid HVT with the claw coupling in a second position. Fig. Figure 5 shows a method for operating a hybrid HVT. Fig. Figure 6 shows a graphical representation of the efficiency of the transmission compared to the mechanical transmission ratio in a hydromechanical transmission. DETAILED DESCRIPTION

[0006] A hybrid hydromechanical variable displacement transmission (HVT) and a method for operating the hybrid HVT are described here. The hybrid HVT comprises a hydraulic motor with variable displacement and a hydraulic variable displacement pump in a hydrostatic arrangement, a main drive source, and an electric machine. The electric machine is selectively rotary-coupled to the main drive source, the hydrostatic arrangement, and / or an output of the transmission system via the selective engagement of a jaw coupling. Fig. Figure 1 shows a schematic representation of a vehicle with a hybrid HVT. Fig. 2A shows a table that describes the configuration of the couplings in the Fig. Figure 1 illustrates the hybrid HVT in different drive ranges. Fig. 2B shows a table illustrating the engagement of a claw coupling of the hybrid HVT from Fig. 1 indicates different energy management strategies. Fig. Figure 3 shows a schematic representation of an example of the hybrid HVT from Fig. 1 with the claw coupling in a first position, and Fig. Figure 4 shows a schematic representation of the hybrid HVT with the claw coupling in a second position. Fig. Figure 5 shows a method for operating a hybrid HVT. Fig. Figure 6 shows a graphical representation of the efficiency of the transmission compared to the mechanical transmission ratio in a conventional hydromechanical transmission.

[0007] Fig. Figure 1 shows a schematic representation of a transmission system 100 in a vehicle 102 or another suitable machine platform. The transmission system 100 is an example of a hybrid HVT. It is understood that the transmission system 100 includes a transmission 103. In one example, the vehicle 102 may be an off-road vehicle, although in other examples the transmission may also be used in road vehicles. An off-road vehicle may be a vehicle that, due to its size and / or its maximum speed, cannot be operated on highways for extended periods. For example, the width of the vehicle may be greater than a highway lane and / or the maximum speed of the vehicle may be below the minimum speed permitted or recommended on the highway.The industries and corresponding operating environments in which the Vehicle 102 can be used include construction, forestry, mining, agriculture, and the like. In both cases, the Vehicle 102 can be equipped with auxiliary systems powered by hydraulic and / or mechanical power take-offs (PTOs).

[0008] The Gear System 100 can function as a continuously variable transmission (CVT), in which the gear ratio is continuously controlled from a negative maximum speed to a positive maximum speed with an infinite number of gear ratio points. In this way, the Gear System 100 can achieve comparatively high adaptability and efficiency compared to transmissions operating with discrete gear ratios.

[0009] The transmission system 100 can exhibit asymmetrical maximum output speeds for forward and reverse travel. This asymmetry between forward and reverse travel allows the transmission system 100 to achieve a desired speed range. However, other suitable output speed variants were also considered, such as symmetrical output speeds in forward and reverse directions, but these require the use of one or more additional clutches, which can increase the complexity of the system.

[0010] The transmission system 100 can include or draw power from a main drive source 104 and / or an electric machine 133. The main drive source 104 can be an internal combustion engine (ICE), a diesel engine, an electric machine (e.g., an electric motor-generator), combinations thereof, and the like. If the main drive source 104 is an electric machine, the electric machine 133 can be an electric machine of the same or a different size, power capacity, fuel type, and / or configuration. The electric machine 133 can be connected to an inverter 135 and a battery 137. The battery 137 can be configured to store energy from the electric machine 133 and / or from another drive source (e.g., the main drive source 104). The battery 137 can, for example, be a rechargeable battery.The energy stored in battery 137 can be used in combination with and / or independently of the power from electric machine 133 and / or the main drive source 104 to drive the output shaft 170 via the gearbox 103. For example, the inverter 135 can draw power from battery 137 and convert it into a form that can be used by electric machine 133 to drive it (e.g., direct current (DC) to alternating current (AC)). The inverter 135 can also transfer power from electric machine 133 to battery 137 for energy storage.

[0011] Gears, such as bevel gears, can be used to rotaryally couple the main drive source 104 to an input shaft 106. The input shaft 106, along with the gears, couplings, other shafts, and the like described in more detail here, can be contained in a multi-gear transmission 107. This gear can conceptually be contained in a mechanical branch of the transmission, which may be coupled in parallel to a hydrostatic arrangement 109. It is understood that the multi-gear transmission 107 serves as a mechanical drive during driving operation. However, in other system modes, mechanical power can flow in the opposite direction through this transmission interface.

[0012] As described herein, a parallel connection between components, arrangements, and the like means that the input and output of the two components or groups of components are coupled (e.g., by rotation), so that power (e.g., mechanical power in the case of a mechanical connection) flows between them. This parallel arrangement allows power to be fed back through the hydrostatic arrangement under certain conditions, or, under other conditions, to be additively combined from the mechanical and hydrostatic branches. This increases the adaptability of the transmission, resulting in improved operating efficiency compared to purely hydrostatic transmissions.

[0013] Furthermore, as described here, a gear can be a mechanical component that rotates and has teeth profiled to engage with teeth in one or more corresponding gears to form a mechanical connection that enables the transmission of rotational energy through it. The input and output shafts of the transmission are further described with respect to a drive system in which the main drive source 104 and / or the electric machine 133 transmits mechanical power to the transmission, and the transmission in turn transmits mechanical power to downstream components such as axles, drive wheels, and the like.

[0014] The transmission system 100 also includes a reverse gear clutch 108 and a clutch for the second drive range 110. The reverse clutch 108 and the clutch for the second drive range 110, as well as the other clutches described here, can be friction clutches (e.g., wet friction clutches) and therefore contain plates (e.g., friction and separating plates) that frictionally engage during clutch engagement. During partial engagement or disengagement, slippage of these plates is permitted, so that the torque transmission through the clutch can be selectively increased. Furthermore, the numerous clutches described here can be hydraulically and / or electromechanically actuated. For example, the numerous clutches can include pistons 194 that control the engagement and disengagement of the clutch depending on the setting of the hydraulic fluid pressure in a piston chamber. Valves (e.g.,Hydraulic control valves, which can be electronically controlled, e.g., via an electromagnet, can be used to adjust the pressure supplied to the hydraulic actuating device (e.g., the piston assembly) of the multiple couplings. The multiple couplings may also include drums, separators, carriers, and the like.

[0015] The reverse clutch 108 and the clutch for the second drive range 110 can be designed to selectively engage with a gear 112 located on the input shaft 106. Specifically, the engagement of the clutch for the second drive range 110 can couple gear 112 to rotate with gear 114. Gear 114 can engage with gear 122, which in turn engages with gear 124, rotating with shaft 120. By engaging the reverse clutch 108, gear 112 can be coupled to rotate with gear 116. Gear 116 can be coupled to gear 118, which rotates with shaft 120. Thus, gears 118 and 124 can be fixedly coupled to shaft 120 or otherwise secured to rotate with shaft 120. In this way, the reverse clutch 108 and the clutch of the second drive range 110 can transmit a torque in the opposite direction to the shaft 120.A coupling for the third drive area 126 is arranged coaxially to the shaft 120 and is designed to selectively engage the gear 118 and a gear 128 coupled to the gear 112.

[0016] A gear 130, which is fixedly connected to the shaft 120 and can rotate with it, can mesh with a gear 132. The gear 132 can be connected via a shaft or a suitable assembly to a ring gear 134 in a planetary gear set 136. The ring gear 134 can be rotaryally coupled to one or more clutches (e.g., the clutch for the third drive range 126, the reverse clutch 108, the clutch for the second drive range 110) which are connected to the input shaft 106.

[0017] The planetary gear set 136 can be a simple planetary gear set, although more complex planetary arrangements can be used in other examples. For instance, the planetary gear set 136 can include planet gears 138 rotating on a carrier 140 and a sun gear 142. The sun gear 142 can be fixedly connected to a shaft 144 for rotation. The gear 146 can also be fixedly connected to the shaft 144 for rotation. The gear 146 can be connected to a gear 148. The mechanical connection between these gears is indicated by a dashed line and can be made by suitable mechanical components such as shafts, joints, and the like. The gear 148 can mesh with a gear 150, which is connected to a coupling of the first drive section 152.

[0018] The coupling of the first drive section 152 is designed to enable selectable torque transmission from the gear 150 to a shaft 160. A gear 162 connected to the carrier 140 can mesh with another gear 164 on the shaft 160. A further gear 166 on the shaft 160 can mesh with a gear 168 on an output shaft 170, which serves as a connection for downstream components such as drive gears 172, 173. For example, the drive gears 172, 173 can be mounted on and / or coupled to drive axles that are rotaryally coupled to the output shaft 170. Thus, the carrier 140 is rotaryally coupled to the output shaft 170 and the downstream components. Specifically, mechanical interfaces 174, 175 (e.g. yokes, joints and the like) can connect the output shaft 170 to the drive wheels 172, 173.Arrows 176 and 177 indicate the mechanical power transmission between the drive 172 and 173 and the mechanical interfaces 174 and 175. A drive train with a shaft, joints, etc., can be used for the mechanical power transmission between the gearbox and the axles.

[0019] The transmission system 100 further comprises a jaw coupling 129, which is optionally coupled to and rotates with a shaft 127. The shaft 127 can be an output shaft of the electric machine 133 and is referred to here as the shaft of the electric machine. The jaw coupling 129 can comprise a plurality of gears, which are optionally coupled to a body 131 of the jaw coupling 129. For example, the body 131 of the jaw coupling 129 can be fixedly connected to the shaft 127 and rotate with it. A first gear 123 and a second gear 125 of the jaw coupling 129 can optionally be coupled to the body 131 of the jaw coupling 129. The first gear 123 and the second gear 125 can be arranged radially around the shaft 127 and each supported by at least one bearing arrangement, allowing each gear to rotate freely on the shaft 127. The jaw coupling 129 can be engaged selectively, e.g.via valves and hydraulically controlled pistons 194 to couple the first gear 123 or the second gear 125 to the shaft 127.

[0020] The selectable engagement of the jaw coupling 129 supports the energy management of the transmission system 100. The jaw coupling 129 is in a first position when the first gear 123 is engaged with the body 131 of the jaw coupling 129. The first gear 123 is thus coupled to the shaft 127 and rotates with it when the jaw coupling 129 is in the first position. A gear 121 is fixed to the input shaft 106 and rotates with it. The first gear 123 is engaged with the gear 121. When the jaw coupling 129 is engaged in the first position, the shaft 127 and the input shaft 106 are rotationally coupled. The electric machine 133 is directly connected to the main drive source 104. In some examples, the main drive source 104 can be used as a generator to charge the battery 137 when the claw clutch 129 is engaged in the first position.In the case of heavy vehicles, where the proportion of idle time plays a more important role in material transport than in the case of light vehicles, the main drive source 104 can, for example, be used to charge the battery 137 during the time when the main drive source 104 is not being used to drive the vehicle by moving the claw coupling 129 into the first position.

[0021] Power can flow from the main drive source 104 along the input shaft 106 to the jaw coupling 129 via the gear 121 and to the battery 137 via the inverter 135. Power flows from the main drive source 104 via the input shaft 106 to the electric machine 133 and vice versa. By engaging the jaw coupling 129 in the first position, a power flow path of the transmission system 100 allows the battery 137 of the transmission system 100 to be charged, while simultaneously positioning a power source (e.g., the electric machine 133, the main drive source 104) in close proximity to the input shaft 106 and / or the battery 137 (e.g., with few gears, shafts, couplings, etc. in between) to minimize power losses. The power used to charge the battery 137 does not flow through the hydrostatic arrangement 109, which is the most dissipative subsystem of the transmission system 100 in terms of efficiency.In this way, power losses can be further reduced. The engagement of the claw clutch 129 in the first position is carried out in the . Fig. 2B, Fig. 3 and Fig. 5 described in more detail.

[0022] The jaw coupling 129 is engaged in a second position when the second gear 125 is in mesh with the body 131 of the jaw coupling 129. The second gear 125 is thus coupled to the shaft 127 and rotates with it when the jaw coupling 129 is in the second position. The second gear 125 is in mesh with the gear 162, which is coupled to the carrier 140. When the jaw coupling 129 is engaged in the second position, the shaft 127 is rotaryally coupled to the carrier 140 of the planetary gear set 136 and, via gear 164, shaft 160, gear 166, and gear 168, to the output shaft 170. Power can flow from the main drive source 104 and the electric machine 133 to the output shaft 170 and vice versa. In other examples, the power flows from the electric machine 133 to the output shaft 170 and vice versa, and must not flow to / from the main drive source 104.For example, the electric machine 133 is coupled to drive wheels 172, 173, which are rotatably mounted on the output shaft 170. Engaging the dog clutch 129 in the second position serves to increase the tractive force of the transmission system 100 and thus of the vehicle 102 and / or to recover energy when braking the vehicle 102. The engagement of the dog clutch 129 in the second position is described in the... Fig. 2B and 4-5 are described in more detail.

[0023] When the jaw coupling 129 is in a neutral position, neither the first gear 123 nor the second gear 125 may be engaged with the body 131 of the jaw coupling 129. When the jaw coupling 129 is in the neutral position, the electric machine 133 can be mechanically isolated from other components of the transmission system 100 (e.g., from the input shaft 106 and the output shaft 170).

[0024] The hydrostatic arrangement 109 comprises a hydraulic motor 158 and a hydraulic pump 178 (e.g., a bidirectional variable displacement pump). The hydraulic motor 158 can be a variable displacement axial piston motor, e.g., a rotary motor with an axially tapered piston and a curved shaft. In general, the hydraulic motor 158 is a variable displacement motor. Furthermore, the hydraulic pump 178 can, in one instance, be an axial piston pump. More specifically, in a particular example, the axial piston pump can include a swashplate that interacts with the pistons and cylinders to change the pump's delivery rate by altering the swashplate angle. However, other suitable types of bidirectional variable displacement pumps were also considered.

[0025] The hydraulic motor 158 and the hydraulic pump 178 can be hydraulically connected in series. Specifically, the hydraulic lines 179 and 180 are attached to the hydraulic interfaces of the hydraulic motor 158 and the hydraulic pump 178 so that the hydrostatic arrangement 109 can provide an additive power feedback function with respect to a mechanical branch formed in the multi-speed transmission 107 and coupled to the hydrostatic arrangement 109 (e.g., arranged in parallel to it). A mechanical interface 156 of the hydraulic motor 158 can be coupled to a gear 154. The gear 154 can also be coupled to the gear 148. The mechanical connection between these gears is indicated by a dashed line and can be established by suitable mechanical components such as shafts, joints, and the like. Thus, the sun gear 142 is rotaryally coupled to the hydraulic motor 158.

[0026] In an additive power mode, the power from both the hydrostatic and mechanical arrangements at the planetary gear set 136 is combined and delivered to the shaft 160. Therefore, the hydraulic pump 178 and the hydraulic motor 158 can be operated to supply power to the planetary gear set 136. In a power feedback mode, the power is fed back through the hydrostatic arrangement 109 to the input of the multi-speed transmission 107. Thus, in power feedback mode, power flows from the hydrostatic arrangement 109 to the gear 112.

[0027] The coupling of the hydrostatic arrangement 109 with the multi-speed transmission 107 enables the transmission to achieve power splitting, where power can flow synchronously through both paths to combine power additively or be fed back through the system. This power-splitting arrangement makes the transmission's power flow highly adaptable to increase efficiency across a wide range of operating conditions. For example, the transmission can be configured as a full power-splitting transmission.

[0028] A gear 184, coupled to the gear 116, can be rotationally connected to a charging pump 185. The charging pump 185 can be designed to supply pressurized fluid to hydraulic components in the transmission, such as the hydraulic motor 158, the hydraulic pump 178, and the like. The fluid 185 pressurized by the charging pump can also be used for actuating the clutch and / or lubricating the transmission. The charging pump 185 can include a piston, a rotor, a housing, chamber(s), and the like to enable the pump to move fluid. The hydraulic pump 178 is rotaryally coupled to the input shaft 106 via the gear 112 and the gear 184.

[0029] A first mechanical power take-off 181 and / or a second mechanical power take-off 182 can be coupled to a gear 183. The gear 183 can, in turn, be mechanically connected to the gear 112. The mechanical power take-offs 181, 182 can drive auxiliary systems such as a pump (e.g., a hydraulic pump, a pneumatic pump, etc.), a winch, a boom, a bed lifting device, etc. To enable power transmission to auxiliary components, the mechanical power take-offs can include an interface, shaft(s), a housing, and the like. In other examples, however, the mechanical power take-offs 181, 182 can be omitted from the transmission system 100. A further power take-off 169 can be rotaryally coupled to the hydraulic pump 178.

[0030] By incorporating the jaw coupling 129, the planetary gear set 136, the reverse coupling 108, the coupling for the second drive range 110, the coupling for the third drive range 126, and for the first drive range 152 into the transmission system 100, the transmission system 100 can be designed to be compact (e.g., requiring relatively little space in the vehicle 102) and provide a desired number of available drive ranges. The jaw coupling 129 can be adjusted between different positions to selectively couple the electric machine 133 to either the input shaft 106 or the output shaft 170 via the carrier 140 of the planetary gear set 136. The jaw coupling 129 can also be actuated to isolate the electric machine 133 from the transmission system 100, so that the electric machine 133 is mechanically free and neither transmits nor receives torque.In this way the claw clutch 129 can be actuated to adjust the power flow paths of the transmission system 100.

[0031] A control system 186 with a control unit 187 (e.g., transmission control unit (TCU), electronic vehicle control unit (ECU), combinations thereof, and the like) can also be integrated into the transmission system 100. The control unit 187 includes a processor 188 and a memory 189. Instructions can be stored in the memory 189 which, when executed by the processor, cause the control unit 187 to perform the various procedures, control strategies, etc., described herein. The processor 188 can contain a microprocessor unit and / or other types of circuitry. The memory 189 can include known data storage media such as working memory, read-only memory, diagnostic memory, combinations thereof, and the like.

[0032] The controller 187 can receive vehicle data and / or various signals from sensors located at different points in the transmission system 100 and / or in the vehicle 102. These sensors can include the wheel speed sensors 191, 192, and 195, which detect the rotational speed of gear 130, gear 164, and gear 183, respectively. In this way, the gear speed at the input and output of the system can be detected, along with the gear speed at the input of the planetary gear set 136. The rotational speeds of the elements of the jaw coupling 129 (e.g., the first gear 123, the second gear 125, and the body 131) can be derived from the measurements of sensors 192 and 195. The electric machine 133 can also include a speed sensor that detects the rotational speed of shaft 127. In other examples, the rotational speeds of at least some of the gears and / or shafts can be modeled by the controller.

[0033] The control unit 187 can send control signals to an actuator in the hydraulic pump 178 or to an actuation system coupled to the pump 178 to adjust the output volume, speed, and / or direction of the hydraulic fluid flow. In particular, the control unit can send signals to the pump to adjust the swashplate angle. Furthermore, one or more of the reverse clutch 108, the second drive range clutch 110, the third drive range clutch 126, the first drive range clutch 152, and the jaw clutch 129 (collectively, "the plurality of clutches") can receive commands (e.g., open or close commands) from the control unit 187, and the actuators in the plurality of clutches or the actuation systems coupled to the plurality of clutches can adjust the state of the clutch in response to receiving the command.

[0034] In a specific example, the plurality of clutches can be actuated via valves and hydraulically controlled pistons 194 contained in a hydraulic control system 193, although other suitable clutch actuation systems are also conceivable, such as electromechanical actuation systems and / or pneumatic actuation systems. The hydraulic control system 193 can include valves 197 that regulate the flow or pressure of the hydraulic fluid supplied to the plurality of clutches (e.g., the control pistons) for actuation. In one example, the hydraulic control system 193 can also include hydraulic lines and a pump. Alternatively, the charging pump 185 can supply or be contained within the hydraulic control system with pressurized hydraulic fluid (e.g., oil).The hydraulic control system 193, which can be implemented as a hydraulic circuit separate from the clutch control circuit, can further be configured to control the hydraulic motor 158 and / or the hydraulic pump 178. For example, a solenoid 198 can be used to control the displacement of the hydraulic motor 158. In such an example, the adjustment of the motor is proportional to the current supplied to the solenoid.

[0035] Other controllable components of the transmission system include the hydraulic pump 178, the hydraulic motor 158, the main drive source 104, the electric machine 133, and the like. These controllable components can function similarly by receiving control commands and setting an output and / or state of a component in response to receiving the command via an actuator. Additionally or alternatively, an ECU may be present in the vehicle to control the drive source (e.g., the internal combustion engine and / or electric motor). Furthermore, the control system 186, and in particular the control unit 187 with the memory 189 and the processor 188, can be configured to perform the functions described here in relation to Fig. The 5 explained control strategies for energy management will be implemented.

[0036] The transmission system 100 can include an input device 190 (e.g., an accelerator pedal, a control stick, levers, buttons, combinations thereof, and the like). The input device 190 can, in response to driver input, generate a request to adjust the transmission speed or torque and a desired direction of travel (e.g., forward or reverse). Furthermore, the transmission system 100 can automatically switch between drive ranges as needed. Thus, the driver can request a change in speed or torque for the forward or reverse drive range, and the transmission can increase the speed or torque and automatically switch between the drive ranges associated with the different drive ranges when desired (e.g., when the transmission approaches a desired shift point).In one example, the operator can request reverse gear while the vehicle 102 is in the forward drive range. In such an example, the transmission can automatically initiate a transition between the forward and reverse drive ranges. This allows the operator to control the vehicle 102 more efficiently. Furthermore, the main drive source 104 and / or the electric machine 133 can be controlled together with the transmission 103. For example, if a request for speed or torque adjustment is received from the controller, the output speed and / or torque of the main drive source 104 and / or the electric machine 133 can be increased accordingly.

[0037] The 100-series transmission system may additionally include a lubrication system, which, as already mentioned, may contain a sump. The lubrication system may further include conventional components for lubricating the gears and / or the various couplings, such as pumps, lines, valves, and the like.

[0038] A coordinate system is used as a reference. Fig. 1. Provided. In one example, the z-axis can be a vertical axis (e.g., parallel to a gravitational axis), the x-axis can be a lateral axis (e.g., a horizontal axis), and / or the y-axis can be a longitudinal axis. In other examples, however, the axes can have other orientations.

[0039] Fig. Figure 2A shows a diagram 200, which shows the configurations (indented or outdented) of the in Fig. Figure 1 illustrates the couplings 108, 110, 126, 152 in the different drive ranges (a first forward drive range, a second forward drive range, a third forward drive range, a first reverse drive range, a second reverse drive range and a third reverse drive range).

[0040] In the first forward drive range, the clutch of the first drive range 152 is engaged, and the clutch of the second drive range 110, the clutch of the third drive range 126, and the reverse clutch 108 are disengaged. In the second forward drive range, the clutch of the second drive range 110 is engaged, and the clutch of the first drive range 152, the clutch of the third drive range 126, and the reverse clutch 108 are disengaged. In the third forward drive range, the clutch of the third drive range 126 is engaged, and the clutch of the first drive range 152, the clutch of the second drive range 110, and the reverse clutch 108 are disengaged.

[0041] In the first reverse drive range, the first drive range clutch 152 and the reverse clutch 108 are engaged, while the second drive range clutch 110 and the third drive range clutch 126 are disengaged. In the second reverse drive range, the reverse clutch 108 and the clutch of the second drive range 110 are engaged, while the clutch of the first drive range 152 and the clutch of the third drive range 126 are disengaged. In the third reverse drive range, the reverse clutch 108 and the clutch for the third drive range 126 are engaged, while the clutch for the first drive range 152 and the clutch for the second drive range 110 are disengaged.

[0042] Fig. Figure 2B shows a diagram 250, which illustrates the optional engagement of the claw coupling 129 (of the in Fig. Figure 1 illustrates the operation of the transmission system 100 under various energy management strategies. When the jaw clutch 129 is engaged in the first position (e.g., the first gear 123 is engaged with the housing 131), the electric machine 133 is coupled to the main drive source 104. With the jaw clutch 129 engaged in the first position, the transmission system 100 can be in a configuration that allows efficient charging of the battery 137, with energy being supplied to the battery 137 via the electric machine 133. The position of the jaw clutch 129 can be adjusted independently of the factors shown in Figure 1. Fig. The gear drive ranges described in section 2A can be set. Energy can be supplied to the battery 137 when the jaw clutch 129 is in the first position, regardless of the engagement state of the multiple clutches.

[0043] When the jaw clutch 129 is engaged in the second position (e.g., the second gear 125 is engaged with the housing 131), the electric machine 133 is coupled to the drive gears 172, 173 of the transmission system 100. When the jaw clutch 129 is engaged in the second position, the transmission system 100 can be in a configuration that allows for both energy recovery and power increase. For example, a negative tractive force (e.g., a restoring force) can be required, and engaging the jaw clutch 129 in the second position allows the braking force from the drive wheels 172, 173 to be absorbed. In another example, a positive tractive force (e.g., an increase in power) can be required, and engaging the jaw clutch 129 in the second position allows power to be supplied to the drive wheels 172, 173 from both the electric machine 133 and the main drive source 104.

[0044] Fig. Figure 3 shows a schematic representation 300 of the gear system 100 with a higher architecture than in Fig. 1 shown. In the Fig. As shown in Figure 300, at least some of the components of the transmission system 100 and the other transmission systems described herein may have a similar structure and / or functionality to the components of the system described in Figure 300. Fig. 1. Gear system 100 shown. A redundant description is therefore omitted for the sake of brevity. In Fig. 3 the claw coupling 129 (not shown) is engaged in the first position, so that the electric machine 133 is coupled to the main drive source 104 (e.g. rotary coupled to the input shaft 106).

[0045] The input shaft 106 and the electric motor 133 are connected to the shaft 120 via the engagement of one or more of the reverse clutches 108, the second drive range clutch 110, and the third drive range clutch 126. The input shaft 106 is also connected to the mechanical interface 156 via the hydrostatic arrangement 109. The combined power of the electric motor 133 and the main drive source 104 (in Fig. (3 not shown) is combined with the power of the hydrostatic arrangement 109 at the planetary gear set 136. The transmission system 100 can supply power to the wheels when the jaw clutch 129 is in the first position, the power supplied to the wheels being a combined power from the electric machine 133 and the main drive source 104. For example, the power from shaft 120 enters the planetary gear set 136 at the ring gear 134, the power from the mechanical interface 156 enters the planetary gear set 136 at the sun gear 142, and the combined power from the electric machine 133, the main drive source 104, and the hydrostatic arrangement 109 is delivered to the output shaft 170 via the carrier 140.In some examples, the clutch for the first drive range 152 is engaged, and the power from the hydrostatic arrangement 109 is routed past the planetary gear set 136 and delivered to the output shaft 170 via the clutch for the first drive range 152. Alternatively, during a braking phase, the transmission system 100 can absorb power from the wheels by combining electric regenerative braking (e.g., to charge the batteries) and dissipative braking by the main drive source, either together or separately. In this way, various combinations of power from the electric machine 133, the main drive source 104, and the hydrostatic arrangement 109 can be delivered to the output shaft 170 via different combinations of clutch engagements.

[0046] Fig. Figure 4 shows a schematic representation 400 of the gear system 100 with a higher architecture than in Fig. 1 shown. In the Fig. As shown in Figure 400, at least some of the components of the transmission system 100 and the other transmission systems described herein may have a similar structure and / or functionality to the components of the system described in Figure 400. Fig. 1. Gear system 100 shown. A redundant description is therefore omitted for the sake of brevity. In the view of Fig. 4 the claw coupling 129 (not shown) is engaged in the second position, so that the electric machine 133 is rotaryally coupled to the output shaft 170.

[0047] The input shaft 106 is connected to the shaft 120 via the engagement of one or more of the reverse clutches 108, the clutch of the second drive range 110, and the clutch of the third drive range 126. Similar to the schematic representation 300 of Fig. 3. The input shaft 106 is connected to the mechanical interface 156 via the hydrostatic assembly 109. The power from the hydrostatic assembly 109 is transmitted to the output shaft 170 via the planetary gear set 136 (e.g., via the sun gear 142) and / or via the engagement of the clutch for the first drive range 152. Power from the hydrostatic assembly 109 and the main drive source 104 (e.g., via the input shaft 106) can be combined in the planetary gear set 136. The combined power is delivered by the planetary gear set 136 to the carrier 140. When the jaw clutch 129 is in the second position, the electric machine 133 is rotaryally coupled to the carrier 140. In this way, the power of the electric machine 133 can be added to the combined power of the planetary gear set 136. In other examples, the main drive source 104 can be switched off and not supply any power to the output shaft 170.By engaging the jaw clutch 129 in the second position, the electric machine 133 is coupled to the transmission system 100, enabling the electric machine 133 to deliver power to the output shaft 170 independently of the main drive source 104. Furthermore, during braking, the transmission system 100 can absorb power from the drive wheels 172 and 173 through a combination of regenerative braking and dissipative braking of the main drive source 104. The absorbed power can be used to charge the battery 137 (not shown). In this way, various combinations of power from the electric machine 133, the main drive source 104, and the hydrostatic arrangement 109 can be delivered to the output shaft 170 via different clutch engagement combinations.

[0048] Fig. Figure 5 shows a method 500 for operating a transmission system. Method 500 describes the actuation of a dog clutch of the transmission system to execute various energy management strategies for a vehicle in which the transmission system is implemented. Method 500 and / or the other methods and control techniques described herein can be implemented in an example by any of the methods described above. Fig. The transmissions and components or combinations thereof described in 1-3 can be used. In other examples, however, Procedure 500 and / or the other procedures can also be performed with other suitable transmissions and corresponding components. Furthermore, Procedure 500 and the other procedures can be executed in the form of instructions, which are stored in non-volatile memory and executed by a processor in a controller. Thus, the execution of the procedure steps can involve sending and / or receiving commands that trigger the adjustment of the associated components, as already mentioned. The configuration of the transmission system and the procedures described here enables regenerative braking and the use of an electric machine within the transmission system to store kinematic energy in a battery and to selectively utilize the stored energy.Compared to conventional transmission systems, where the kinematic energy is drawn away / lost from the main drive source, this reduces the power losses of the transmission system.

[0049] In procedure 502, procedure 500 includes the determination of operating conditions. Operating conditions may include: hydraulic motor speed, hydraulic motor speed setpoint, hydraulic pump torque, hydraulic pump torque setpoint, hydrostatic unit differential pressure, transmission speed, transmission load, transmission torque, vehicle speed, driver torque request, driver speed request, main drive source speed, main drive source load, clutch positions, ambient temperature, transmission temperature, battery charge level, traction requirement, and similar parameters. These operating conditions may be determined using sensor data and / or modeling algorithms.

[0050] In procedure 504, procedure 500 includes determining whether a battery charge is requested (e.g., determining whether a battery charge request is received). A battery charge may be requested when the power delivered by the electric machine and / or the main propulsion source is greater than the power requirement of the transmission system. For example, an input device may generate a transmission speed request (e.g., a power request) in response to driver input, where the transmission speed request is less than the current transmission speed determined in procedure 502. The excess power may be used to charge the battery. Battery charging may also be requested when the battery's state of charge (SOC) falls below a non-zero threshold. The battery's SOC threshold may, for example, be 30% of the battery's maximum capacity.In response to the determination that a battery charge is requested (YES at 504), the procedure 500 includes synchronizing the electric machine shaft and the input shaft at 506 to enable a rotary connection of the electric machine shaft with the input shaft and the hydraulic pump. For example, a differential rotational speed between the input shaft and the electric machine shaft can be reduced to zero.

[0051] In 508, method 500 includes the instruction to activate the electric machine to rotate the shaft of the electric machine at a first speed. In 510, method 500 further includes the instruction to activate the main drive source to rotate the input shaft at the first speed. In 512, method 500 includes actuating the jaw clutch into the first position to rotaryally couple the shaft of the electric machine to the input shaft and the hydraulic pump. An example of a schematic diagram of the transmission system with a jaw clutch engaged in the first position is shown in Fig. 3 shown.

[0052] If it is determined in 504 that no battery charging is required (NO in 504), procedure 500 continues with 514 and does not include synchronizing the electric machine shaft and the input shaft, nor actuating the dog clutch to the first position. Battery charging must not be requested if the battery state of charge is greater than the battery state of charge threshold and / or if the power delivered by the electric machine and / or the main drive source is less than or equal to the power requirement of the transmission system.

[0053] At 514, procedure 500 includes determining whether a traction recovery (e.g., negative) or a power boost (e.g., positive) is requested (e.g., determining whether a request for power boost or a request for traction recovery is received). Traction recovery may be required when the vehicle decelerates and / or brakes. Traction boost may be requested when the power delivered by the main propulsion source is less than the power demand (e.g., generated by the input device). In response to a request for traction recovery (e.g., negative) or power boost (e.g., positive) (JA at 514), procedure 500 includes actuating the jaw clutch to the second position to rotaryly couple the shaft of the electric machine to the output shaft (e.g., to the drive wheels) and to the hydraulic motor at 516.If, on the other hand, it is determined that no traction force recovery (e.g. negative traction force) or traction force amplification (e.g. positive traction force) is required (NO at 514), procedure 500 continues with 518 and does not include actuation of the jaw coupling to the second position.

[0054] In procedure 518, process 500 involves actuating the jaw clutch into the neutral position to mechanically disconnect the electric machine from the input and output shafts. Process 500 ends after process 514 or process 518.

[0055] Furthermore, the jaw clutch can be actuated from the neutral position to the first or second position, from the second position to the first or third position, and from the first position to the second or third position without this deviating from the scope of the present disclosure. For example, when the jaw clutch is in the third position, so that the electric machine is mechanically isolated as described herein, an operating mode can be requested in which the vehicle is stationary (i.e., neither the main drive source nor the electric machine is driving the vehicle's movement), and battery charging is requested.The electric machine can be operated to synchronize the shaft of the electric machine with the input shaft, the jaw coupling can be moved into the first position, and the electric machine can be used to brake the main drive source so that power is directed into the battery to store energy.

[0056] Integrating a dog clutch into an electric hybrid transmission system, where the clutch selectively couples an electric motor to the transmission system, increases efficiency and reduces power losses. The transmission system described here does not require an additional engine braking system (e.g., an engine brake) to decelerate the main drive source, as the electric motor provides additional braking capacity to the transmission system. During low-power, low-torque maneuvers, the main drive source can be switched off, and the transmission system can use an electrical power source (e.g., stored energy in the battery and / or the electric motor) to supply power to the output shaft. This increases the efficiency of the transmission system compared to conventional transmission systems.Furthermore, during demanding driving maneuvers, the transmission system receives a boost in power and torque by engaging the dog clutch in the second position and utilizing the electric motor to increase vehicle performance by driving the transmission output. When the battery's energy storage is low, and therefore little energy is available to power the electric motor, the main power source can be used to drive the transmission system. During idle periods when the vehicle is stationary (e.g., during material transport), the dog clutch can be engaged in the first position to direct power flow to the battery and charge it.In cases where the energy stored in the battery is low, the dog clutch can be engaged in the first position to recharge the battery when some power is available from the main drive source (e.g., during periods of low engine demand, such as driving at low and / or constant speeds). This allows the electric machine to draw power from the main drive source without affecting the transmission output's ability to propel the vehicle. To further reduce the transmission system's energy consumption, the electric machine can be decoupled from the transmission system when not in operation by moving the dog clutch to the neutral position. The dog clutch can also be moved to the neutral position in other situations where it is desirable to decouple the electric machine from other elements of the transmission system, for example...if the electrical machine and / or its components are damaged.

[0057] Fig. Figure 6 shows a diagram 600, which shows the efficiencies of the in Fig. Figures 1-5 depict the HVT transmission under different load conditions. The efficiency of the transmission system is plotted on a vertical axis, and the HVT ratio on a horizontal axis. The HVT ratio is a continuously variable transmission ratio of a power-split system. The HVT ratio is controlled by two independent hydrostatic units, and the power flow is measured by a hydrostatic branch of the HVT.

[0058] As briefly described above, a conventional high-voltage transmission (HVT) can exhibit relatively high fixed power losses, leading to a reduction in transmission efficiency at lower power flows. The maximum operating power of an HVT is referred to here as the HVT's rated power. A first diagram, 602, shows the efficiency of the HVT's transmission (e.g., transmission system 100 of Fig. 1) at various HVT ratios, when the HVT operates at its rated power, where the rated power is 200 kilowatts (kW). A second diagram 604 of diagram 600 shows the HVT efficiency at half the rated power (e.g., 100 kW). A third diagram 606 shows the HVT efficiency at three-quarters of the rated power (e.g., 150 kW). A fourth diagram 608 shows the HVT efficiency at one-quarter of the rated power (e.g., 50 kW). Relative to the HVT efficiency at 200 kW (e.g., at rated power), the HVT efficiency at 50 kW decreases by approximately 10%. If the conventional HVT is a half-power-division gearbox, a first fully hydrostatic gear provides a drive range with a relatively low efficiency of less than 70%. Kinematic energy available during a braking phase cannot be recovered, and all the energy is dissipated.

[0059] The gearbox described herein (see Fig. 1-5) The efficiency of the transmission is increased compared to conventional HVT systems, while retaining the advantages of hydrostatic power splitting in terms of cost and power density compared to an electric power-splitting transmission with the same power rating. A hybrid HVT, as described here, can, for example, include two 200 kW hydraulic machines and one 100 kW electric machine, and an electric power-splitting transmission can include two 200 kW electric machines. The hydraulic machines of the hybrid HVT supply the transmission with additional power that is lost in electric power-splitting transmissions and conventional HVTs (e.g., without an electric machine).

[0060] The technical effect of the transmission system and operating procedures described here is to increase the efficiency of the transmission and reduce power losses by incorporating an electric machine into the transmission system, which is optionally rotary-coupled or mechanically isolated to the input or output of the transmission system via the actuation of a jaw clutch.

[0061] The revelation also provides support for a transmission system comprising: a hydraulic pump rotaryly coupled to an input shaft; a hydraulic motor rotaryly coupled to an output shaft via a first drive-range coupling; a planetary gear set with a sun gear rotaryly coupled to the hydraulic motor, a carrier rotaryly coupled to the output shaft, and a ring gear rotaryly coupled to one or more couplings connected to the input shaft; a main drive source rotaryly coupled to the input shaft; and an electric machine that is optionally rotaryly coupled to the input shaft or the output shaft, or mechanically disconnected from both the input and output shafts by actuating a jaw coupling. In a first example of the system, the electric machine is rotaryly coupled to the input shaft when the jaw coupling is engaged in a first position.In a second example of the system, which optionally includes the first example, energy flows from the main drive source via the input shaft to the electric machine and vice versa. In a third example of the system, which optionally includes one or both of the first and second examples, energy flows from the main drive source and the electric machine to the output shaft and vice versa. In a fourth example of the system, which optionally includes one or more or each of the first three examples, the electric machine is rotary-coupled to the carrier when the jaw coupling is engaged in a second position. In a fifth example of the system, which optionally includes one or more or each of the first four examples, energy flows from the electric machine to the output shaft and vice versa.In a sixth example of the system, which optionally includes one or more or each of the first five examples, the electric machine is mechanically isolated from the input shaft when the dog clutch is in a neutral position. In a seventh example of the system, which optionally includes one or more or each of the first six examples, the primary drive source is an internal combustion engine. In an eighth example of the system, which optionally includes one or more or each of the first seven examples, the system also includes a rechargeable battery connected to the electric machine.In a ninth example of the system, which optionally includes one or more or each of the first through eighth examples, the system further comprises: a second-range drive clutch and a reverse clutch, both arranged on the input shaft and configured to selectively engage the input shaft with a shaft rotaryally coupled to the planetary gear set, wherein the engagement of the second-range drive clutch directs the shaft rotation in a forward direction and wherein the engagement of the reverse clutch directs the shaft rotation in a reverse direction.

[0062] The disclosure also provides support for a hybrid hydromechanical variable transmission (HVT) system comprising: a hydrostatic arrangement with a variable displacement hydraulic motor and a variable displacement hydraulic pump; a multi-speed transmission mechanically coupled to the hydrostatic arrangement and comprising a plurality of clutches configured to switch the system between a plurality of drive ranges; a planetary gear set mechanically coupled to the multi-speed transmission; the hydrostatic arrangement and an output shaft; an electric machine selectively coupled via a dog clutch to an input shaft of the multi-speed transmission and to a sun gear of the planetary gear set; a battery coupled to the electric machine; and a control unit with instructions stored in non-volatile memory.These actions, when executed in response to a battery charging request, cause the control unit to move the jaw clutch into a first position to rotaryally couple the electric machine to an input shaft of the hybrid HVT system, and, in response to an energy recovery or power-boost request, cause the control unit to move the jaw clutch into a second position to rotaryally couple the electric machine to the output shaft. In a first example of the system, the variable displacement hydraulic motor is coupled in series with the variable displacement hydraulic pump. In a second example of the system, which optionally includes the first example, the electric machine is coupled to the variable displacement hydraulic pump when the jaw clutch is engaged in the first position. In a third example of the system, which optionally includes one or both of the first and second examples,The electric machine is coupled to the variable-displacement hydraulic motor via the planetary gear set when the jaw clutch is engaged in the second position. In a fourth example of the system, which optionally includes one or more or any of the first three examples, the variable-displacement hydraulic motor is optionally rotaryally coupled to the output shaft via a coupling for the first drive range.

[0063] The disclosure also provides support for a method for a transmission system comprising: in response to a battery charging request, commanding the activation of an electric machine to rotate an electric machine shaft so that it rotates at a first speed; commanding the activation of a main drive source to rotate an input shaft at the first speed; and actuating a jaw clutch into a first position to rotary-couple the electric machine shaft to the input shaft and to a hydraulic pump; and in response to a request for energy recovery or power amplification, actuating the jaw clutch into a second position to rotary-couple the electric machine to an output shaft and to a hydraulic motor of the transmission system.In a first example of the method, the procedure further comprises: in response to receiving none of the requests for battery charging, energy recovery, or power amplification, commanding the activation of the jaw clutch to a neutral position in order to mechanically isolate the electric machine from the input and output shafts. In a second example of the method, which optionally includes the first example, the procedure further comprises: actuating a second drive-range clutch arranged on the input shaft to direct the power flow from the main drive source to a planetary gear set, causing a shaft rigidly coupled to a sun gear of the planetary gear set to rotate in the forward direction.In a third example of the method, which optionally includes one or both of the first and second examples, the method further comprises: actuating a reverse clutch arranged on the input shaft to direct the power flow from the main drive source to a planetary gear set, such that a shaft rigidly coupled to a sun gear of the planetary gear set rotates in a reverse direction. In a fourth example of the method, which optionally includes one or more or each of the first through third examples, the method further comprises: actuating a first drive range clutch to selectively couple the hydraulic motor to the output shaft.

[0064] The Fig.Figures 1 and 3-4 show example configurations with the relative arrangement of the various components. If these elements are in direct contact with each other or directly coupled, they can be described as being in direct contact or directly coupled, at least in one example. Similarly, elements shown side by side or adjacent to each other can be described as being adjacent to each other or adjacent to each other, at least in one example. For instance, components that are in planar contact with each other can be described as being in planar contact. As another example, elements that are separated from each other, with only a gap between them and that have no other components, can be described as such in at least one case.In yet another example, elements that are displayed above / below each other, on opposite sides, or to the left / right of each other can be described as such, relative to one another. Furthermore, in at least one example, as shown in the figures, a topmost element or the highest point of an element can be referred to as the "top" of the component, and a bottommost element or the lowest point of the element can be referred to as the "bottom" of the component. The terms top / bottom, upper / lower, and above / below used here can refer to a vertical axis of the figures and be used to describe the positioning of elements within the figures relative to each other. Thus, in one example, elements displayed above other elements are arranged vertically above the other elements.As a further example, the shapes of the elements depicted in the figures can be described as such (e.g., circular, straight, planar, curved, rounded, beveled, angled, and the like). Furthermore, in one example, elements that are coaxial with each other can be described as such. Additionally, the depicted elements that intersect each other can be described as intersecting elements or mutually intersecting elements in at least one example. Moreover, an element that is depicted inside or outside another element can be described as such. In other examples, elements that are offset from each other can also be described as such.

[0065] Although various embodiments have been described above, it should be clear that these serve only as examples and do not represent limitations. Those skilled in the art will recognize that the disclosed subject matter can be implemented in other specific forms without departing from the spirit of the subject matter. The embodiments described above are therefore to be regarded in every respect as illustrative and not as limiting.

[0066] It should be noted that the exemplary control and estimation sequences contained herein can be used with different powertrain and / or vehicle system configurations. The control methods and routines disclosed herein can be stored as executable instructions in non-transient memory and executed by the control system, including the controller, in combination with the various sensors, actuators, and other transmission and / or vehicle hardware. Furthermore, sections of the method can be physical actions taken to change the state of a device. The specific routines described herein can represent one or more from a variety of processing strategies. Thus, the various actions, operations, and / or functions shown can be performed in the sequence shown, in parallel, or, in some cases, independently.Likewise, the processing sequence is not strictly necessary to achieve the features and benefits of the examples described herein, but serves to simplify illustration and description. One or more of the actions, processes, and / or functions shown can be performed repeatedly, depending on the specific method used. Furthermore, the described actions, processes, and / or functions can graphically represent code to be programmed into non-volatile memory of the computer-readable storage medium in the vehicle and / or transmission control system, whereby the described actions are executed by carrying out the commands in a system that includes the various engine hardware components, together with the electronic control device. Steps in the procedure described herein may be omitted if necessary.

[0067] It is understood that the configurations and routines disclosed herein are exemplary and that these specific examples are not to be considered limiting, as numerous variations are possible. The technology described above can, for example, be applied to powertrains incorporating various types of power sources, including different types of electric machines and / or internal combustion engines. The scope of this disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, as well as other features, functions, and / or properties disclosed herein.

[0068] Unless otherwise stated, the term "approximately" is to be understood as meaning plus or minus three percent of the range.

[0069] The following claims highlight in particular certain combinations and subcombinations that are to be considered novel and not obvious. These claims may refer to "one" element or "a first" element, or the equivalent thereof. Such claims are to be understood as including one or more such elements, with two or more such elements neither required nor excluded. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amending the present claims or by filing new claims in this or a related application. Such claims, whether they have a broader, narrower, the same, or different scope than the original claims, are also to be considered as included in the subject matter of the present disclosure.

Claims

[1] Transmission system, comprising: a hydraulic pump that is rotaryally coupled to an input shaft; a hydraulic motor which is rotaryally coupled to an output shaft via a first drive range coupling; a planetary gear set comprising a sun gear rotaryally coupled to the hydraulic motor, a carrier rotaryally coupled to the output shaft, and a ring gear rotaryly coupled to one or more couplings connected to the input shaft; a primary drive source that is rotaryly coupled to the input shaft; and an electric machine which is optionally rotary-coupled to the input shaft or the output shaft via the actuation of a jaw coupling, or mechanically separated from the input shaft and the output shaft. [2] Gear system according to claim 1, wherein the electric machine is rotary-coupled to the input shaft when the jaw coupling is engaged in a first position. [3] Gear system according to claim 2, wherein power flows from the main drive source via the input shaft to the electric machine and vice versa. [4] Gear system according to claim 2, wherein power flows from the main drive source and the electric machine to the output shaft and vice versa. [5] Gear system according to one of the preceding claims, wherein the electric machine is rotary-coupled to the carrier when the jaw coupling is engaged in a second position. [6] Gear system according to claim 5, wherein power flows from the electric machine to the output shaft and vice versa. [7] Gear system according to one of the preceding claims, wherein the electric machine is mechanically separated from the input shaft when the jaw coupling is in a neutral position. [8] Transmission system according to one of the preceding claims, wherein the main drive source is an internal combustion engine. [9] Transmission system according to one of the preceding claims, further comprising a rechargeable battery coupled to the electric machine. [10] Transmission system according to one of the preceding claims, further comprising a second drive range clutch and a reverse clutch, both of which are arranged on the input shaft and are configured to selectively engage the input shaft with a shaft which is rotary-coupled with the planetary gear set, wherein the engagement of the second drive range clutch causes the shaft to rotate in the forward direction and the engagement of the reverse clutch causes the shaft to rotate in the reverse direction.

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