Abstract:
A hydraulic hybrid powertrain for a vehicle is disclosed. The powertrain has an internal combustion engine selectively drivingly engaged with an input of a stepped-ratio transmission through a torque converter and through a speed direction changing device. An output of the stepped-ratio transmission is selectively drivingly engaged with a vehicle output. An intermediate gear set is drivingly engaged with the speed direction changing device and drivingly engaged with the input of the stepped-ratio transmission. A hydraulic machine in fluid communication with a hydraulic accumulator assembly, a transmission shaft of the hydraulic machine being drivingly engaged or selectively drivingly engaged with the intermediate gear set for providing energy to the intermediate gear set and for absorbing energy from the intermediate gear set. Also disclosed are methods of operating the hydraulic hybrid powertrain.
Abstract:
The invention relates to a dual motor hydraulic hybrid transmission. The transmission comprises a power source, a hydraulic circuit including a pump drivingly engaged with the power source and two displacement units, a hydraulic accumulator assembly including high and low pressure accumulators, one or more control valves, and an output shaft drivingly engaged with the first hydraulic displacement unit. The displacement units are in fluid communication with the hydraulic pump. The accumulators are in fluid communication with the hydraulic circuit. The second hydraulic displacement unit is drivingly engaged with the output shaft. The control valves are configured to selectively fluidly connect the hydraulic pump to the first hydraulic displacement unit while fluidly disconnecting the hydraulic pump from the second hydraulic displacement unit; and, simultaneously, fluidly connect the hydraulic accumulator assembly to the second hydraulic displacement unit while fluidly disconnecting the hydraulic accumulator assembly from first hydraulic displacement unit.
Abstract:
A series hydraulic hybrid system for a vehicle is described. The hydraulic hybrid system has a hydraulic circuit and a high pressure accumulator. The hydraulic circuit has a first hydraulic displacement unit in fluid communication with a second hydraulic displacement unit. The high pressure hydraulic accumulator is in fluid communication with the hydraulic circuit and a low pressure hydraulic accumulator in fluid communication with the hydraulic circuit. The high pressure hydraulic accumulator is in fluid communication with the hydraulic circuit through a proportional flow control valve. The proportional flow control valve is adapted to continuously vary a flow of hydraulic fluid between the high pressure hydraulic accumulator and the hydraulic circuit.
Abstract:
A series hydraulic hybrid system for a vehicle is described. The system has a hydraulic circuit, a hydraulic working assembly, and a hydraulic accumulator assembly. The hydraulic circuit has a first hydraulic displacement unit in fluid communication with a second hydraulic displacement unit. The first hydraulic displacement unit is drivingly engaged with a power source. The hydraulic working assembly has a hydraulic implement and a hydraulic working pump in fluid communication with the hydraulic implement, the hydraulic working pump drivingly engaged with the power source. The hydraulic accumulator assembly has a high pressure hydraulic accumulator and a low pressure hydraulic accumulator. The hydraulic accumulator assembly selectively fluidly connects to the hydraulic circuit and the hydraulic accumulator assembly selectively fluidly connects to the hydraulic working assembly.
Abstract:
A series hydraulic hybrid system for a vehicle and a method of operating the same is described. The series hydraulic hybrid system has a hydraulic circuit, high and low pressure hydraulic accumulators, and a control unit. The hydraulic circuit has first and second hydraulic displacement units in fluid communication. The first hydraulic displacement unit is drivingly engaged with an internal combustion engine. The high pressure hydraulic accumulator and the low pressure hydraulic accumulator are fluidly connected to the hydraulic circuit through at least one accumulator valve. The control unit is adapted to receive an input from an operator, compute a requested torque and a target system pressure based on the input, compare an accumulator pressure to the target system pressure, and control at least one of a speed of the internal combustion engine and a valve state of the accumulator valve based on the outcome of the comparison.
Abstract:
A series hydraulic hybrid driveline for a vehicle is described. The driveline has a power source, a hydraulic circuit having a first hydraulic displacement unit and a second hydraulic displacement unit, a hydraulic accumulator assembly with high pressure and low pressure hydraulic accumulators, at least one accumulator valve, at least one input device, and a control unit. The first hydraulic displacement unit is drivingly engaged with the power source. The accumulator assembly is selectively fluidly connected to the hydraulic circuit through the accumulator valve. The control unit is configured to compute a total power requested from the power source based on an input command from the input device, compare the computed total power to a threshold power, and control a valve state of the accumulator valve based upon the result of the comparison. A method of controlling the driveline is also described.
Abstract:
A method of charging a hydro-pneumatic energy storage system is described. The system has a first hydro-pneumatic accumulator with a first hollow vessel. Disposed within the first hollow vessel is a first compressible volume containing a first amount of gas. The system has a second hydro-pneumatic accumulator with a second hollow vessel. Disposed within the second hollow vessel is a second compressible volume containing a second amount of gas. The gas contained in the first volume is pre-pressurized to a first hydrostatic pre-charge pressure and the gas contained in the second volume is pre-pressurized to a second hydrostatic pre-charge pressure. The second pre-charge pressure is higher than the first pre-charge pressure. In addition, the gas in the first volume is pressurized by discharging a non-compressible hydraulic fluid into the first vessel while keeping a quantity of non-compressible hydraulic fluid contained in the second vessel constant to keep the pressure of the gas contained in the second volume at the second pre-charge pressure.
Abstract:
A hybrid driveline which may be operated in a hydrostatic drive mode and a direct drive mode and a method of operating a hybrid driveline in a hydrostatic drive mode and a direct drive mode is provided. The hybrid driveline comprises a power source, a first hydrostatic unit drivingly engaged with the power source, a second hydrostatic unit selectively drivingly engaged with a vehicle output and in fluid communication with the first hydrostatic unit, an accumulator assembly in fluid communication with the first hydrostatic unit and the second hydrostatic unit, and a clutching device selectively drivingly engaged with the vehicle output and one of the first hydrostatic unit and the second hydrostatic unit. The hybrid driveline provides the benefits of a series hybrid arrangement and a parallel hybrid arrangement, reduces torque interruptions during operation and shifting procedures, and increases an efficiency of a vehicle the driveline is incorporated in.
Abstract:
A hydrostatic driveline is provided. The hydrostatic driveline comprises a power source, a hydrostatic pump, a hydrostatic motor, a direct drive link, and a transmission portion. The power source is drivingly engaged with an input member. The hydrostatic pump is in driving engagement with the input member. The hydrostatic motor is in fluid communication with the hydrostatic pump. The direct drive link is in driving engagement with the input member. The transmission portion is in driving engagement with a vehicle output and at least one of the hydrostatic motor and the direct drive link The transmission portion includes at least one engagement device and a drive ratio. The hydrostatic pump, the hydrostatic motor, and the transmission portion form a first power path for the hydrostatic driveline and the direct drive link forms a second power path for the hydrostatic driveline.
Abstract:
a invenção se refere a um método de engatar, de modo acionável, um primeiro motor (4) de uma unidade de acionamento de duplo motor (1; 100) a um eixo de saída (14) acionado por um segundo motor (7) da unidade de acionamento de duplo motor (1; 100), o método compreendendo as etapas de: atuar um dispositivo de embreagem (9) para engatar, de modo acionável, o primeiro motor (4) ao eixo de saída (14); sincronizar uma velocidade rotacional (32) do primeiro motor (4) com uma velocidade rotacional do eixo de saída (14); quando a velocidade rotacional (32) do primeiro motor (4) e a velocidade rotacional do eixo de saída (14) são sincronizadas, reduzir um torque de saída do primeiro motor (4); e quando o dispositivo de embreagem (9) engata de modo acionável o primeiro motor (4) ao eixo de saída (14), aumentar o torque de saída do primeiro motor (4). a invenção ainda se refere a uma unidade de acionamento de duplo motor (1; 100) para realizar o método.