Title of Invention	A DEVICE FOR REDUCING THE VIBRATIONAL FORCES SET UP BY THE CRANKSHAFT OF AN ENGINE
Abstract	A device for reducing vibrational forces set up by the crankshaft of an engine, comprising a hub for mounting the said crankashaft and a pulley provided with a belt drive characterised in that an inertia member is tightly mounted on the hub, by means of a first elastic member circumferentially sandwiched between the mertia member and the hub; the pulley is tightly mounted on the hub by means of a second elastic member circumferentially san dwiched between the pulley and the hub.

Title of Invention

A DEVICE FOR REDUCING THE VIBRATIONAL FORCES SET UP BY THE CRANKSHAFT OF AN ENGINE

Abstract

A device for reducing vibrational forces set up by the crankshaft of an engine, comprising a hub for mounting the said crankashaft and a pulley provided with a belt drive characterised in that an inertia member is tightly mounted on the hub, by means of a first elastic member circumferentially sandwiched between the mertia member and the hub; the pulley is tightly mounted on the hub by means of a second elastic member circumferentially san dwiched between the pulley and the hub.

Full Text	This invention relates to a device for reducing vibrational forces set up by the crankshaft of an engine, either an automobile engine or a static engine. Conventionally, devices for reducing vibrational forces in both antomobile and static engines are known to the art. However in the device proposed herein two aspects of vibrational forces are addressed. The first kind of force causes torsional or linear vibration in crankshafts, the symptoms of which are power steering pressure pulses, alternator current fluctuations and Water pump output fluctuations to name but a few. Such vibrational forces result in the degradation of the life of the components. Conventionally, torsional or linear vibration is controlled by means of using a damper. A crankshaft will twist back and forth at a high frequency while rotating. This twisting can be reduced by using a crankshaft damper. The second kind of force causes rigid body mode vibration on front engine accessories. Devices for isolating FEAD (front engine accessories devices) from excessive speed variation and for reducing the dynamic load on the FEAD are also known to the art. Such devices are called isolators. Known devices such an the damper cannot perform the function of an isolator; nor can the known devices such as the isolator perform the function of a damper for the reason that their respective constructions do not allow of performance of these functions. It is an object of this invention, therefore, to propose a device for reducing vibrational forces set up by the crankshaft of an engine which can perform the function of a damper as well as that of an isolator. The device, according to this invention, for reducing vibrational forces set up by the crankshaft of an engine, comprises a hub for mounting the said crankshaft and a pulley provided with a belt drive characterised in that an inertia member is tightly mounted on the hub, by means of a first elastic member circumferentially sandwiched between the inertia member and the hub; the pulley is tightly mounted on the hub by means of a second elastic member circumferentially sandwiched between die pulley and the hub. The device proposed herein will now be described with reference to the accompanying drawings which illustrate, by way of example, and not by way of limitation, one of various possible embodiments of this invention. Fig. illustrating a sectional assembled view of the embodiment And Fig.2 illustrating an exploded view of the said embodiment. The embodiment illustrated will be seen to consist of a hub H provided for mounting the crankshaft (not illustrated for the sake of clarity) of the engine. A pulley P is provided with a Vee belt drive, the grooves for seating the belts being indicated by 0. The belt drive is intended for taking off power from the crankshaft. The characteristic features of this invention, are : An mertia member J is tightly mounted on the hub H, by means of a first elastic member El circumferentially. sandwiched between the inertia member J and the hub H, whereby any torsional or linear vibrational forces set up by the rotating crankshaft are reduced or damped by the flexible joint between the inertia member J and the hub H. The damping action, in effect, reduces vibration by modifying the mass elastic system of the crankshaft. It nay be noted that the inertia member J is not directly coupled to the pulley P, there being a gap F between the said member J and the pulley. The pulley P is tightly mounted on the hub J by means of a second elastic member E2 circumferentially sandwiched between the said pulley and the hub H whereby the pulley is isolated from the negative effects of rigid body mode vibration, that is to say, reduces the transmission of vibration forces set up by the crankshaft to another part of the vehicle where the vibration will be felt or heard by the driver or passenger. It may be noted that the inertia wheel J is directly coupled to the pulley P through the second elastic member E2. A bearing B is located between the pulley P and the hub H. The torsional or linear vibration of the engine as well as the negative effects of rigid body mode vibration on front engine accessories are thus reduced by the damping and isolating action of the device proposed herein The terms and expressions herein are of description and not of limitation, masmnch as various other embodiments of the said device are possible without departing from the scope and ambit of this invention. We Claim: 1. A device for reducing vibrational forces set up by the crankshaft of an engine, comprising a hub for mounting the said crankshaft and a pulley provided with a belt drive characterised m that an inertia member is tightly mounted on the hub. by means of a first elastic member circumferentially sandwiched between the inertia member and the hub; the pulley is tightly mounted on the hub by means of a second elastic member circumferentially sandwiched between the pulley and the hub. 2. A device as claimed in Claim 1 wherein the engine is an automobile engine. 3. A device as claimed in Claim 1 wherein the engine is a static engine. 4. A device for reducing vibrational forces set up by the crankshaft of an engine substantially as herein described with reference to, and as illustrated in, the accompanying drawings.

Full Text

This invention relates to a device for reducing vibrational forces set up by the crankshaft of an engine, either an automobile engine or a static engine.
Conventionally, devices for reducing vibrational forces in both antomobile and static engines are known to the art.
However in the device proposed herein two aspects of vibrational forces are addressed.
The first kind of force causes torsional or linear vibration in crankshafts, the symptoms of which are power steering pressure pulses, alternator current fluctuations and Water pump output fluctuations to name but a few. Such vibrational forces result in the degradation of the life of the components.
Conventionally, torsional or linear vibration is controlled by means of using a damper. A crankshaft will twist back and forth at a high frequency while rotating. This twisting can be reduced by using a crankshaft damper.
The second kind of force causes rigid body mode vibration on front engine accessories. Devices for isolating FEAD (front engine accessories devices) from excessive speed variation and for reducing the dynamic load on the FEAD are also known to the art. Such devices are called isolators.

Known devices such an the damper cannot perform the function of an isolator; nor can the known devices such as the isolator perform the function of a damper for the reason that their respective constructions do not allow of performance of these functions.
It is an object of this invention, therefore, to propose a device for reducing vibrational forces set up by the crankshaft of an engine which can perform the function of a damper as well as that of an isolator.
The device, according to this invention, for reducing vibrational forces set up by the crankshaft of an engine, comprises a hub for mounting the said crankshaft and a pulley provided with a belt drive characterised in that an inertia member is tightly mounted on the hub, by means of a first elastic member

circumferentially sandwiched between the inertia member and the hub; the pulley is tightly mounted on the hub by means of a second elastic member circumferentially sandwiched between die pulley and the hub.
The device proposed herein will now be described with reference to the accompanying drawings which illustrate, by way of example, and not by way of limitation, one of various possible embodiments of this invention.

Fig. illustrating a sectional assembled view of the embodiment
And
Fig.2 illustrating an exploded view of the said embodiment.
The embodiment illustrated will be seen to consist of a hub H provided for mounting the crankshaft (not illustrated for the sake of clarity) of the engine. A pulley P is provided with a Vee belt drive, the grooves for seating the belts being indicated by 0. The belt drive is intended for taking off power from the crankshaft.
The characteristic features of this invention, are :
An mertia member J is tightly mounted on the hub H, by means of a first elastic member El circumferentially. sandwiched between the inertia member J and the hub H, whereby any torsional or linear vibrational forces set up by the rotating crankshaft are reduced or damped by the flexible joint between the inertia member J and the hub H. The damping action, in effect, reduces vibration by modifying the mass elastic system of the crankshaft. It nay be noted that the inertia member J is not directly coupled to the pulley P, there being a gap F between the said member J and the pulley.

The pulley P is tightly mounted on the hub J by means of a second elastic member E2 circumferentially sandwiched between the said pulley and the hub H whereby the pulley is isolated from the negative effects of rigid body mode vibration, that is to say, reduces the transmission of vibration forces set up by the crankshaft to another part of the vehicle where the vibration will be felt or heard by the driver or passenger. It may be noted that the inertia wheel J is directly coupled to the pulley P through the second elastic member E2. A bearing B is located between the pulley P and the hub H.

The torsional or linear vibration of the engine as well as the negative effects of rigid body mode vibration on front engine

accessories are thus reduced by the damping and isolating action of the device proposed herein
The terms and expressions herein are of description and not of limitation, masmnch as various other embodiments of the said device are possible without departing from the scope and ambit of this invention.

We Claim:
1. A device for reducing vibrational forces set up by the
crankshaft of an engine, comprising a hub for mounting the
said crankshaft and a pulley provided with a belt drive
characterised m that an inertia member is tightly mounted on
the hub. by means of a first elastic member
circumferentially sandwiched between the inertia member
and the hub; the pulley is tightly mounted on the hub by
means of a second elastic member circumferentially
sandwiched between the pulley and the hub.
2. A device as claimed in Claim 1 wherein the engine is an
automobile engine.
3. A device as claimed in Claim 1 wherein the engine is a
static engine.
4. A device for reducing vibrational forces set up by the
crankshaft of an engine substantially as herein described
with reference to, and as illustrated in, the accompanying
drawings.

Documents:

055-che-2004-abstract.pdf

055-che-2004-claims filed.pdf

055-che-2004-claims granted.pdf

055-che-2004-correspondnece-others.pdf

055-che-2004-correspondnece-po.pdf

055-che-2004-description(complete) filed.pdf

055-che-2004-description(complete) granted.pdf

055-che-2004-drawings.pdf

055-che-2004-form 1.pdf

055-che-2004-form 19.pdf

055-che-2004-form 26.pdf

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Patent Number

200737

Indian Patent Application Number

55/CHE/2004

PG Journal Number

8/2007

Publication Date

23-Feb-2007

Grant Date

05-Jun-2006

Date of Filing

23-Jan-2004

Name of Patentee

SHRI. RAMACHANDRAN RAMAMURTHY

Applicant Address

T-57 32 CROSS STREET, BESANT NAGAR, CHENNAI 600 090.

Inventors:

#	Inventor's Name	Inventor's Address
1	SHRI. RAMACHANDRAN RAMAMURTHY	T-57 32 CROSS STREET, BESANT NAGAR, CHENNAI 600 090.
2	MAHESH RAMAMURTY	T-57 32 CROSS STREET, BESANT NAGAR, CHENNAI 600 090.

PCT International Classification Number

F16C3/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA