Title of Invention	A DUST GUARD FOR THE ARMATURE OF THE STARTER MOTOR OF AN IC ENGINE
Abstract	A dust guard comprising a non-metallic disc with a central hole for insertion over the armature shaft said disc being locatable between the armature cave assembly and the commutator, the disc having spaced radial vanes, the space between the vanes allowing connected to the communtator segments, said sic preventing the entry of loose copper burrs, formed during mechining of the commutator, into the commutator end basket area.

Title of Invention

A DUST GUARD FOR THE ARMATURE OF THE STARTER MOTOR OF AN IC ENGINE

Abstract

A dust guard comprising a non-metallic disc with a central hole for insertion over the armature shaft said disc being locatable between the armature cave assembly and the commutator, the disc having spaced radial vanes, the space between the vanes allowing connected to the communtator segments, said sic preventing the entry of loose copper burrs, formed during mechining of the commutator, into the commutator end basket area.

Full Text	The starter motor is an electromechanical device used in internal combustion engine applications. This device converts electrical energy from battery source to mechanical energy for cranking the engine and making it fire and continue to run. In a starter motor, the armature gets energized on application of DC voltage on the terminals and rotates converting electrical energy to mechanical energy. The.rotation of the armature drives the pinion attached to the with the ring gear of the engine for cranking and starting. As the armature is an electrical component, the conductors carrying the current have to be insulated appropriately to avoid failures such as shorting and earthing. This invention relates to a dust guard for use with the armature to prevent electrical failures. The dust guard ensures that during armature manufacturing the loose copper burrs generated during the machining operation of the commutator are deflected to prevent entry of the burrs into the commutator end basket area. Thus this arrangement prevents shorting of armature conductors and also helps in aligning the top and bottom conductors. The dust guard for the armature of the starter motor of an IC engine, according to this invention, comprises a non-metallic disc with a central hole for insertion over the armature said disc being locatabte 2 between the armature/and the commutator, the disc having spaced radial vanes, the space between the vanes allowing conductors of the armature ; to pass through for being connected to the commutator segments, said disc preventing the entry of loose copper,burrs formed during machining of the commutator, into the commutator end basket area. The dust guard will now be described with reference to the accompanying drawings which illustrate by way of example, and not by way of limitation, one of possible embodiments of this invention Fig.1.illustrating a view of the armature assembly with the dust guard in Place and Fig.2 Illustrating an exploded view of the armature dust guard and commutator In the conventional method of assembly some of the copper burrs generated during machining operation fall into the commutator end basket portion and remain during further processing. This results in the following problems 1. The burrs touch the exposed bare portions of the top and bottom conductors and result in shorting. 2. The loose burrs fly out during operation of the starter motor and get caught between the rotor and the stator resulting in malfunctioning of the starter motor. 3 in the embodiment illustrated a non-metallic disc D has a central hole H for insertion over the armature sgatt P said disc being beatable between the armature core assembly A and the commutator C, the disc having spaced radial vanes V, the space S between the vanes allowing conductors T of the armature winding to pass therethrough for being connected to the commutator segments. The said disc thus prevents the entry of loose copper burrs, formed during machining of the commutator, into the commutator end basket are* 'he following is the sequence of steps in the manufacture of the armature with the proposed dust guard 1. Insertion of pre-formed conductors Into the various slots of armature core. 2. Pressing of the conductors so that the free ends of the conductors project on the commutator end side of the armature core. 3. Twisting the projected conductors as per requirement 4. Insertion of the dust guard into the projected portion of conductors. 5. Carrying out brazing operation so as to join the bottom conductors on to commutator segments and top conductors on to the bottom conductors . 6. After varnishing operation, carrying out machining operation on the commutator. Mere the copper burrs formed during machining operation impinge on the dust guard and fall down - that is, the loose burrs do not have a way of entering into the commutator end basket portion of the armature. 7. Testing the armature. 4 The dust guard ensures 1. reliability of the armature by eliminating the failure through shorting of adjacent conductors. 2. proper alignment of top and bottom conductors for proper brazing operation. 3. cost saving. The terms and expressions herein are of description and not of limitation, since various other embodiments of this invention are possible without departing from the scope and ambit of this invention. 5

Full Text

The starter motor is an electromechanical device used in internal combustion engine applications. This device converts electrical energy from battery source to mechanical energy for cranking the engine and making it fire and continue to run.
In a starter motor, the armature gets energized on application of DC voltage on the terminals and rotates converting electrical energy to mechanical energy. The.rotation of the armature drives the pinion attached to the with the ring gear of the engine for
cranking and starting. As the armature is an electrical component, the conductors carrying the current have to be insulated appropriately to avoid failures such as shorting and earthing.
This invention relates to a dust guard for use with the armature to prevent electrical failures.
The dust guard ensures that during armature manufacturing the loose copper burrs generated during the machining operation of the commutator are deflected to prevent entry of the burrs into the commutator end basket area. Thus this arrangement prevents shorting of armature conductors and also helps in aligning the top and bottom conductors.
The dust guard for the armature of the starter motor of an IC engine, according to this invention, comprises a non-metallic disc with a central hole for insertion over the armature said disc being locatabte
2

between the armature/and the commutator, the disc having spaced radial vanes, the space between the vanes allowing conductors of the armature ; to pass through for being connected to the commutator segments, said disc preventing the entry of loose copper,burrs formed during machining of the commutator, into the commutator end basket area.
The dust guard will now be described with reference to the accompanying drawings which illustrate by way of example, and not by way of limitation, one of possible embodiments of this invention
Fig.1.illustrating a view of the armature assembly with the dust guard in
Place
and Fig.2 Illustrating an exploded view of the armature dust guard and
commutator
In the conventional method of assembly some of the copper burrs generated during machining operation fall into the commutator end basket portion and remain during further processing.
This results in the following problems
1. The burrs touch the exposed bare portions of the top and bottom conductors and result in shorting.
2. The loose burrs fly out during operation of the starter motor and get caught between the rotor and the stator resulting in malfunctioning of the starter motor.
3

in the embodiment illustrated a non-metallic disc D has a central hole H for insertion over the armature sgatt P said disc being beatable between the armature core assembly A and the commutator C, the disc having spaced radial vanes V, the space S between the vanes allowing conductors T of the armature winding to pass therethrough for being connected to the commutator segments. The said disc thus prevents the entry of loose copper burrs, formed during machining of the commutator, into the commutator end basket are*
'he following is the sequence of steps in the manufacture of the armature with the proposed dust guard
1. Insertion of pre-formed conductors Into the various slots of armature core.
2. Pressing of the conductors so that the free ends of the conductors project on the commutator end side of the armature core.
3. Twisting the projected conductors as per requirement
4. Insertion of the dust guard into the projected portion of conductors.
5. Carrying out brazing operation so as to join the bottom conductors on to commutator segments and top conductors on to the bottom conductors .
6. After varnishing operation, carrying out machining operation on the commutator. Mere the copper burrs formed during machining operation impinge on the dust guard and fall down - that is, the loose burrs do not have a way of entering into the commutator end basket portion of the armature.
7. Testing the armature.
4

The dust guard ensures
1. reliability of the armature by eliminating the failure through shorting of adjacent conductors.
2. proper alignment of top and bottom conductors for proper brazing operation.
3. cost saving.
The terms and expressions herein are of description and not of limitation, since various other embodiments of this invention are possible without departing from the scope and ambit of this invention.
5

Documents:

0981-che-2006 abstract-duplicate.pdf

0981-che-2006 claims-duplicate.pdf

0981-che-2006 descripition(completed)-duplicate.pdf

0981-che-2006 drawings-duplicate.pdf

981-che-2006-claims.pdf

981-che-2006-complete description.pdf

981-che-2006-correspondance -others.pdf

981-che-2006-drawings.pdf

981-che-2006-form 1.pdf

981-che-2006-form 18.pdf

981-che-2006-form 26.pdf

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Patent Number

230325

Indian Patent Application Number

981/CHE/2006

PG Journal Number

13/2009

Publication Date

27-Mar-2009

Grant Date

25-Feb-2009

Date of Filing

07-Jun-2006

Name of Patentee

LUCAS-TVS LIMITED

Applicant Address

Padi, Chennai 50,

Inventors:

#	Inventor's Name	Inventor's Address
1	Muralidharan Dhandapani	Lucas-TVS Limited, Padi, Chennai 600 050,
2	Murugan Shanmugavel	Lucas-TVS Limited, Padi, Chennai 600 050,
3	Sundaram Krishna Kumar	Lucas-TVS Limited, Padi, Chennai 600 050,
4	Krishnavilasam Raghavan	Lucas-TVS Limited, Padi, Chennai 600 050,
5	Ananadakumaran Nair	Lucas-TVS Limited, Padi, Chennai 600 050,

PCT International Classification Number

F02B77/04

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA