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EP-4737166-A1 - A CONTROLLED ENGINE ASSIST SYSTEM

EP4737166A1EP 4737166 A1EP4737166 A1EP 4737166A1EP-4737166-A1

Abstract

The present invention provides a controlled engine assist system (10) for a hybrid vehicle having an internal combustion engine (12) and an electric power source (14) with a battery (15). The system (10) comprises a shaft (16) connecting the internal combustion engine (12) and a torque cushioning clutch (18). A power transmission arrangement (20) couples the torque cushioning clutch (18) to the electric power source (14). The torque cushioning clutch (18) partially transmits torque from the internal combustion engine (12) to the electric power source (14) during recuperation. This regulates transmission of sudden rotational irregularities to the electric power source (14), thereby, helping in minimizing damage to the electric power source (14).

Inventors

  • PS, Satyanarayana

Assignees

  • Deere & Company

Dates

Publication Date
20260506
Application Date
20250918

Claims (7)

  1. A controlled engine assist system (10) for a hybrid vehicle having an internal combustion engine (12) and an electric power source (14) with a battery (15), said system (10) comprising: a torque cushioning clutch (18) configured to be in an engaged configuration and a disengaged configuration; a shaft (16) connecting the internal combustion engine (12) and said torque cushioning clutch (18); and a power transmission arrangement (20) coupling said torque cushioning clutch (18) to the electric power source (14).
  2. The system (10) as claimed in claim 1, wherein said torque cushioning clutch (18) is configured to assist in transmitting controlled torque from the internal combustion engine (12) to the electric power source (14).
  3. The system (10) as claimed in claim 1, wherein said torque cushioning clutch (18) is a slip assist clutch selected from a group consisting of Mechanical slipper clutch, Hydraulic slipper clutch and Electromagnetic slipper clutch.
  4. The system (10) as claimed in claim 1, wherein the electric power source (14) is selectively operable to transmit torque to the internal combustion engine (12).
  5. The system (10) as claimed in claim 1, wherein said torque cushioning clutch (18) is configured to positively transmit torque from the electric power source (14) to the internal combustion engine (12), during a start-up mode and a power boost mode of the hybrid vehicle.
  6. The system (10) as claimed in claim 1, wherein the electric power source (14) is configured to selectively operate as a motor and a generator for supplying torque to the internal combustion engine (12) and charge the battery (15), respectively.
  7. The system (10) as claimed in claim 1, wherein said torque cushioning clutch (18) partially transmits torque from the internal combustion engine (12) to the electric power source (14) during recuperation.

Description

FIELD OF THE INVENTION The present invention relates to the field of transmission system for a vehicle. Particularly, the present invention relates to the field of hybrid vehicle having two sources of power. BACKGROUND OF THE INVENTION Hybrid vehicle includes two power source- one from engine and another from electric power source. The electric power source selectively supplies power to the engine, based on requirement. On the other hand, torque is transmitted from the engine to the electric power source for operating as a generator to change a battery associated with the electric power source. Hybrid vehicle can recover vehicle energy during braking and provides power boost to the internal combustion engine during peak load. This facilitates cranking of the engine, thereby reducing fuel consumption and carbon dioxide emissions. In existing hybrid vehicles, engine is coupled to the electric power source though a belt. The poses belt tensioning challenges. Hence, belt tensioners are required to be utilized to continuously monitor and manage the belt tension with an optimum value. The belt tensioner causes to increase belt tension during cranking mode, a boost mode, that is, transmission of torque from the engine to the electric power source and during recuperation, that is, torque transmission from electric power source to the engine. Alternatively, the belt tensioner is required to reduce tension during normal driving to cause minimum friction loss. As the belt is part of power transmission between the engine and the electric power source, speed and torque fluctuations creates high forces on the belt especially during boost mode and recuperation. During acceleration and deceleration of the engine, forces acting on the electric power source results in rotational irregularities. This causes adverse effect on the belt and the electric power source. The electric power source being expensive, such adverse effect requires extensive cost of maintenance and majority of the time it is required to be replaced. In view of the above, there is a requirement for a system which can minimize damage to the electric power source due to rotational irregularities transmitted by the engine. OBJECTS OF THE INVENTION The present invention envisages achieving at least one of the following objects, thereby overcoming the drawbacks of prior art: An object of the present invention is to minimize impact of sudden change in engine torque on an electric power source of a hybrid vehicle.Another object of the present invention is to minimize the maintenance cost and replacement cost for the electric power source. Other objects of the present invention will be apparent when the description of the invention is read in conjunction with the accompanying drawings. The accompanying drawings provided herein are merely illustrative and does not intend to limit the scope and ambit of the present invention. SUMMARY OF THE INVENTION In accordance with the present invention there is provided a controlled engine assist system for a hybrid vehicle having an internal combustion engine and an electric power source with a battery. The system comprises a shaft connecting the internal combustion engine and a torque cushioning clutch. The torque cushioning clutch is configured to be in an engaged configuration and a disengaged configuration. A power transmission arrangement couples the clutch to the electric power source. The torque cushioning clutch is configured to assist in transmitting controlled torque from the internal combustion engine to the electric power source. The torque cushioning clutch is a slip assist clutch selected from a group consisting of Mechanical slipper clutch, Hydraulic slipper clutch and Electromagnetic slipper clutch. The electric power source is selectively operable to transmit torque to the internal combustion engine. The torque cushioning clutch is configured to positively transmit torque from the electric power source to the internal combustion engine, during a start-up mode and a power boost mode of the hybrid vehicle. The electric power source is configured to selectively operate as a motor and a generator for supplying torque to the internal combustion engine and charge the battery, respectively. The torque cushioning clutch partially transmits torque from the internal combustion engine to the electric power source during recuperation. Various features, aspects and advantages of the present invention will be apparent from the following detailed description of the invention when read in conjunction with the accompanying drawings wherein like numerals represent like components. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS The present invention will now be described with respect to the accompanying drawings: Figure 1 illustrates an internal combustion engine connected to an electric power source via a torque cushioning clutch, a power transmission arrangement and a shaft. DETAILED DESCRIPTION The present invention of a contr