US-20260124900-A1 - A CONTROLLED ENGINE ASSIST SYSTEM

US20260124900A1US 20260124900 A1US20260124900 A1US 20260124900A1US-20260124900-A1

Abstract

A controlled engine assist system for a hybrid vehicles 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. A power transmission arrangement couples the torque cushioning clutch to the electric power source. The torque cushioning clutch partially transmits torque from the internal combustion engine to the electric power source during recuperation. This regulates transmission of sudden rotational irregularities to the electric power source, thereby, minimizing potential damage to the electric power source.

Inventors

Satyanarayana PS

Assignees

DEERE & COMPANY

Dates

Publication Date: 20260507
Application Date: 20250611
Priority Date: 20241104

Claims (7)

1 . A controlled engine assist system for a hybrid vehicle having an internal combustion engine and an electric power source with a battery, the system comprising: a torque cushioning clutch configured to be in an engaged configuration and a disengaged configuration; a shaft connecting the internal combustion engine and the torque cushioning clutch; and a power transmission arrangement coupling the torque cushioning clutch to the electric power source.
2 . The system as claimed in claim 1 , wherein the torque cushioning clutch is configured to assist in transmitting controlled torque from the internal combustion engine to the electric power source.
3 . The system as claimed in claim 1 , wherein the torque cushioning clutch comprises a slip assist clutch.
4 . The system as claimed in claim 1 , wherein the electric power source is selectively operable to transmit torque to the internal combustion engine.
5 . The system as claimed in claim 1 , wherein 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.
6 . The system as claimed in claim 1 , wherein 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.
7 . The system as claimed in claim 1 , wherein the torque cushioning clutch partially transmits torque from the internal combustion engine to the electric power source during recuperation.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 U.S. C. § 119 to patent application IN 202421084043, filed on 4 Nov. 2024, the disclosure of which is incorporated herein by reference. FIELD OF THE DISCLOSURE The present disclosure relates generally to vehicle transmission systems and more particularly to hybrid vehicles having two sources of power. BACKGROUND OF THE DISCLOSURE Hybrid vehicles typically include two power sources, an engine and an electric power source. Torque is transmitted from the engine to the electric power source for operating as a generator to charge a battery associated with the electric power source, which selectively supplies power to the engine. Hybrid vehicles can often recover vehicle energy during braking and this provides a 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, the 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 increases belt tension during a 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 minimize friction loss. As the belt is part of power transmission between the engine and the electric power source, speed and torque fluctuations create 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 result in rotational irregularities. This causes adverse effects on the belt and the electric power source. The electric power source being expensive, such adverse effects require 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. SUMMARY OF THE DISCLOSURE An object of the present disclosure is to minimize impact of a sudden change in engine torque on an electric power source of a hybrid vehicle. Another object of the present disclosure is to minimize the maintenance cost and replacement cost for the electric power source. Other objects of the present disclosure will be apparent when the description of the disclosure is read in conjunction with the accompanying drawings. In accordance with the present disclosure 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 may be a slip assist clutch such as a mechanical slipper clutch, a hydraulic slipper clutch, or an 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 charging the battery, respectively. The torque cushioning clutch partially transmits torque from the internal combustion engine to the electric power source during recuperation. Other features and aspects will become apparent by consideration of the detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 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 FIG. 1 shows a controlled engine assist system (10). A hybrid vehicle (not shown in FIGURE) has an internal combustion engine (12) and an electric power source (14) with a battery (15). A shaft (16) connects the internal combustion engine (12) with a torque cushioning clutch (18). The torque cushioning clutch (18) is shifted between an engaged configuration and a disengaged configuration, based on predefined modes of operation of the inte