Technical Field
Present disclosure relates to automotive starter motors. In particular, the present disclosure relates to a splash protector for a starter motor used in automobiles.
Background
For vehicles built with internal combustion engines, the starter motor which is known in the art, is used to start the engine. Generally, a starter motor is electrically powered system, and has a pinion gear that engages with a ring gear of the engine. The ring gear is fixed on a flywheel of the engine and imparts the required starting torque and speed enabling the engine to start.
The starter motor fitted on the engine may get exposed to mud including dust, water and oil or other foreign particles, while the vehicle is operating in a muddy or dusty environment. During such instances, such foreign matter may get accumulated on the pinion gear affecting its starting process. Also, the accumulated foreign matter may damage the pinion gear when the pinion gear is actuated as and when powered through ignition switch by a driver.
To protect the pinion gear from exposure to foreign matter, a nose-cone type starter motor is known in the art. In such nose-cone type starter motors, the pinion gear is partially covered by a nose shaped extended portion of the housing, also called as a Snout, at the front side of the starter motor. The nose-cone or snout sits inside the bell housing of the engine block when the starter motor is assembled on the engine. A front mounting bracket of the starter motor abuts against an engine block face and the bracket is firmly fastened using suitable fixing bolts. Though the abutting face of the starter motor rests on the engine block, the projected portion of starter motor's pinion gear is always exposed to environment inside the engine housing including, clutch dust, engine oils, engine's clutch seal leakages inside the engine

compartment, which all get mixed up to form a slurry and muddy solution inside the engine housing.
In general, a starter motor is operated for a few seconds during engine starting process. In such instances, the pinion gear moves forward and engages the fly wheel to rotate the flywheel and then retreats to a rest position. When the engine is fired and picks up speed, and the fly wheel is on rotational mode, the internal fumes along with slurry oil-mud mix deposits become turbulent inside engine compartment. These foreign particles may deposit on or around the pinion of the starter motor and negatively affect working of the starter motor or the overall starting process. For example, when the pinion gear moves forward to engage the fly wheel a space is created behind the pinion gear. Such space may be susceptible to deposition of foreign material. The deposition of foreign material behind the pinion gear may result in noise or may affect the normal movement of the pinion gear. Accordingly, there is a need for protecting the pinion side of the starter motor from deposit of or exposure to the foreign particles present in the engine housing.
While continuous running of engine taking place, such slurry oil-mud mixture seeps into the motor portions, passing through clearance spaces of helical gear slot portions, and remain inside motor compartment. During operations, such foreign matter spreads inside the motor and damages internal parts, thus effecting the life of the starter motor.
The present disclosure addresses one or more problems as discussed above or other associated problems with the art.
Summary
A splash protector for a starter motor is disclosed. The starter motor has a pinion gear on a pinion shaft and the pinion gear is adapted to move between a forward position to engage a component of an engine to impart a starting torque to an engine and a rest position wherein the pinion gear is disengaged from the component. The

splash protector has a plane wall defining a perforation and the perforation is configured for receiving the pinion shaft. A cylindrical wall extends perpendicularly from a periphery of the plane wall, the cylindrical wall has a diameter corresponding to a diameter of the pinion gear to peripherally cover an axial length of teeth of the pinion gear.
In an aspect, the splash protector has a circular rim extending from the periphery of the plane wall beyond the cylindrical wall, the rim is configured to be received in a circular rim recess provided on the starter motor for securing the splash protector on the starter motor.
In an aspect, the splash protector is made of a polymeric material.
In an aspect, the polymeric material is a nylon 66 with 50% glass fiber.
In an aspect, the splash protector is made of a metal.
In an aspect, the perforation has a diameter less than the diameter of the pinion gear.
In an aspect, the perforation has a diameter corresponding to the diameter of the pinion shaft.
A starter motor having a pinion shaft adapted to move between a rest position and a forward position. A pinion gear is positioned on the pinion shaft. The pinion gear is configured to engage a component of the engine in the forward position to impart a starting torque to the engine. The starter motor as a splash protector having a plane wall defining a perforation. The perforation is configured for receiving the pinion shaft. A cylindrical wall extends perpendicularly from a periphery of the plane wall. The cylindrical wall has a diameter corresponding to a diameter of the pinion gear to peripherally cover an axial length of teeth of the pinion gear.

In an aspect, the starter motor has a front housing having a rim recess to support the splash protector.
In an aspect, the starter motor has a cylindrical sleeve extending from the front housing. The cylindrical sleeve is configured to support the splash protector.
Brief Description of Drawings
FIG. 1 illustrates a front perspective view of a starter motor with the pinion gear in
a rest position in accordance with an embodiment of the present disclosure.
FIG. 2 illustrates a front perspective view of a starter motor with the pinion gear in
a forward position, in accordance with an embodiment of the present disclosure.
FIG. 3 illustrates a partial sectional view of the starter motor of FIG. 1 along a
plane extending along an axis of the pinion gear with the pinion gear in the rest
position in accordance with an embodiment of the present disclosure.
FIG. 4 illustrates a partial sectional view of the starter motor of FIG. 1 along a
plane extending along an axis of the pinion gear with the pinion gear in the forward
position in accordance with an embodiment of the present disclosure.
FIG. 5 illustrates a back perspective view of a splash protector in accordance with
an embodiment.
FIG. 6 illustrates a front perspective view of the splash protector of FIG. 5 in
accordance with an embodiment.
FIG. 7 illustrates a splash protector positioned on the pinion gear in accordance
with this embodiment.
Description
A starter motor with a splash protector is disclosed. The splash protector is configured to protect a pinion gear of the starter motor from foreign matters like mud, dust with water and oil mixture, inside the engine compartment.

Referring to FIG. 1, a starter motor (10) in accordance with an embodiment is shown. The starter motor (10) has a front housing (12), a pinion gear (14), a solenoid assembly (16), a body (18) and a splash protector (20). The pinion gear (14) is configured for engaging a corresponding ring gear (not shown) associated with a fly wheel of the engine as known in the art.
The front housing (12) may have a flange (22) configured for clamping the starter motor (10) on an engine (not shown) of a vehicle. In the embodiment as illustrated, the flange (22) has a flat shape with a locating step (24) that has a dimension configured to match with a corresponding dimensions on the engine for mating of the locating step (24) with the engine housing. In the embodiment as illustrated, the locating step (24) is shown having a circular shape (spigot diameter) for mating with a corresponding circular step in the engine housing.
Further, the front housing (12) is provided with bolt holes (26) to facilitate clamping of the starter motor (10) using bolts (not shown). The front housing (12) may have other provisions for a snug mounting of the starter motor (10) on the engine block.
The front housing (12) is provided with a cylindrical sleeve (28) extending from the front housing (12) along an axis of the pinion gear (14) as shown in FIG. 1 and FIG. 2. The cylindrical sleeve (28) surrounds the pinion gear (14) and the splash protector (20) and supports the splash protector (20). The cylindrical sleeve (28) may be made integrally with the front housing (12).
The solenoid assembly (16) is mounted on the body (18) of the starter motor (10) using suitable fasteners. The body (18) of the starter motor (10) may support and house other components as required in the starter motor (10).
FIG. 2 illustrates a perspective view of the pinion gear (14) in a forward position. When the starter motor (10) is in powered and switched on condition, the pinion

gear (14) moves forward axially to engage the ring gear to impart rotating motion to the fly wheel. The forward position may also generally be referred to as an actuated condition or a functional condition.
In FIG. 3 and FIG. 4, a portion of the front housing (12) with splash protector (20) is shown in partial sectional view to reveal other components of a front portion of the starter motor (10). As shown, the starter motor (10) may have a pinion shaft (30), a pinion drive assembly (32), a bearing (34) and other components as requi red in the starter motor (10). The pinion shaft (30) supports the pinion gear (14) such that the pinion gear (14) rotates along with rotation of the pinion shaft (30) about the axis. In an embodiment, the pinion gear (14) and the pinion shaft (30) may be made integrally with each other. The bearing (34) is mounted in the front housing (12) and in turn the bearing (34) supports the pinion shaft (30) to facilitate rotary motion of the pinion shaft (30) relative to the front housing (12).
The pinion drive assembly (32) facilitates the rotational movement of the pinion shaft (30) relative to the front housing (12), as well as sliding movement of the pinion shaft (30) in the axial direction for movement of the pinion gear (14) between the forward position and the rest position. Any mechanism known in the art may be incorporated for enabling the sliding and rotational movement of the pinion shaft (30) as required.
The splash protector (20) is provided to protect the pinion gear (14) from deposition of foreign matter onto and around the teeth (46) of the pinion gear (14). As shown in FIG. 5 and FIG. 6, the splash protector (20) is of hollow cylindrical shape. The splash protector (20) is positioned over radial periphery of the pinion gear (14) when the pinion gear (14) is in rest position, such that the cylindrical shape substantially covers the outer axial length of the pinion gear (14), as shown in FIG. 1 and FIG. 3. When the pinion gear (14) is in the forward position, the splash protector (20) partially covers the radial periphery of the pinion gear (14) as shown in FIG. 2 and FIG. 4.

FIG. 3 and FIG. 4 illustrate a starter motor (10) without the cylindrical sleeve (28) in accordance with an embodiment. As shown in FIG. 5 and FIG. 6, the splash protector (20) has a plane wall (36) and a cylindrical wall (38). The cylindrical wall (38) extends perpendicularly from the plane wall (36). The plane wall (36) is shown of a circular ring shape and is provided with a perforation (40) for receiving the pinion shaft (30) through the plane wall (36). The perforation (40) may have dimensions lesser than the diameter of the pinion gear (14) and greater than the diameter of the pinion shaft (30). The dimension of the perforation (40) may further be configured as required. For example, in the embodiment as shown in FIG. 7, the pinion shaft (30) is provided with helical gears (42) for engagement with pinion drive assembly (32) and effecting rotary motion of the pinion shaft (30). The perforation (40) in the plane wall (36) may have dimension slightly greater than the outer diameter of the helical gear (42) for securing the splash protector (20) between the pinion gear (14) and the helical gear (42). Preferably, the dimension of the perforation (40) may be kept corresponding to the diameter of the pinion shaft (30), as required.
The splash protector (20) has dimensions such that it is situated in close proximity of the pinion gear (14). The cylindrical wall (38) may be positioned around the teeth (46) of the pinion gear (14) and the plane wall (36) may be positioned in a plane perpendicular to the axis of the pinion gear (14). The splash protector (20) may be configured such that the splash protector (20) allows for free rotation of the pinion gear (14) inside the cylindrical wall (38) and also covers the radial periphery of the teeth (46) for restricting entry of any foreign particles behind the teeth (46). For example, in an embodiment, a gap of 1 to 1.5 mm may be provided between the inner surface of the cylindrical wall (38) of the splash protector (20) and the outer diameter of the pinion gear (14). The splash protector (20) gear may also cover an axial periphery of the pinion gear (14) from the back side, i.e. the side of the pinion gear (14) that is oriented towards the pinion shaft (30).

It may be understood that the dimensions of the splash protector (20) are to be designed and configured according to the axial width of the teeth (46) of the pinion gear (14) and the length of travel of the pinion shaft (30) between the rest position and the forward position as shown in FIG. 1 and FIG.2, respectively. The splash protector (20) should be sized such that when the pinion gear (14) moves between the forward position and the rest position, the teeth (46) of the pinion gear (14) revolve around the axis and move axially, without any difficulty. Accordingly, necessary clearances may be provided between the splash protector (20) and the pinion gear (14) to facilitate obstruction free relative movement between the two.
As better shown in FIG. 5 and FIG. 6, the splash protector (20) has the cylindrical wall (38) that is configured as a protection sleeve positioned around the pinion gear (14). As shown in FIG. 3 and FIG. 4, in an assembled state of the starter motor (10) mounted with the splash protector (20), the cylindrical wall (38) extends axially outwards from the flange (22) of the front housing (12). The plane wall (36) of the splash protector (20) is positioned between the pinion gear (14) and a portion of the front housing (12) positioned axially behind the pinion gear (14). In the embodiment as illustrated, the splash protector (20) is further provided with a circular rim (44) on a periphery of the plane wall (36). The circular rim (44) projects radially outward further than the cylindrical wall (38). The circular rim (44) is configured to be located into a corresponding circular rim recess (48) defined in the front housing (12) for securing the splash protector (20) in the front housing (12). Any other suitable provision may be configured for securing the splash protector (20) on the starter motor (10).
The plane wall (36) may act as a separator to separate the space in which the pinion gear (14) is placed from the inner space of the motor where components of the pinion drive assembly (32) are located. This way the plane wall (36) also protects the inner components of the pinion drive assembly (32) from direct exposure to foreign particles present in the engine housing, which otherwise may deposit on the components of the pinion drive assembly (32) during splashing of muddy suspension inside the engine housing during operation of the starter motor (10).

The splash protector (20) may be made of any suitable material such as metal, elastomer or a polymeric material or combination of different materials. In an embodiment, the splash protector (20) may be made using nylon 66 with 50% glass filling.
When the starter motor (10) is mounted on the engine, the pinion gear (14) is exposed to the interior environment of a bell housing compartment of the engine where fly wheel with ring gear is located. When the engine is operated with muddy environment inside engine block, the mud or other foreign matter may enter the area surrounding the flywheel and get splashed towards the components exposed to the interior of the engine housing such as the flywheel of the engine and the pinion gear (14) of the starter motor (10). The splash protector (20) of the present disclosure covers the periphery of the pinion gear (14) and prevents dirt from entering behind the teeth (46) of the pinion gear, i.e. in a gap between the pinion gear (14) and the plane wall (36). Thus, the splash protector (20) protects the pinion gear (14) from such slurry mix. Moreover, if any foreign matter reaches behind the teeth (46), during movement from forwarded position to rest position, the slurry is pushed out from the location behind the pinion gear (14).
Accordingly, the splash protector (20) in accordance with an embodiment of the present disclosure, improves the overall life and reliability of the starter motor (10). Further, the present disclosure provides for compact arrangement for protecting the starter motor (10) from the foreign matter and engine leakages entering inside. The splash protector (20) may also be retrofitted to an existing starter motor (10) 10. The front housing (12) of any starter motor (10) may be suitably adapted for retrofitting of the splash protector (20) as disclosed herein. Moreover, the embodiment has simple construction of the splash protector (20) for the starter motor (10), which makes it easy to manufacture and install on the starter motor (10).

List of Reference Numerals
Stater motor (10) Front housing (12) Pinion gear (14) Solenoid assembly (16) Body (18)
Splash protector (20) Flange (22) Locating step (24) Bolt holes (26) Cylindrical sleeve (28) Pinion shaft (30) Pinion drive assembly (32) Bearing (34) Plane wall (36) Cylindrical wall (38) Perforation (40) Helical gear (42) Circular rim (44) Teeth (46) Rim recess (48)

WE CLAIM:
1. A splash protector (20) for a starter motor (10), the starter motor (10)
having a pinion gear (14) on a pinion shaft (30), the pinion gear (14)
adapted to move between a forward position to engage a component of an
engine to impart a starting torque to an engine and a rest position wherein
the pinion gear (14) is disengaged from the component, the splash protector
(20) comprising:
a plane wall (36) defining a perforation (40), the perforation (40) configured for receiving the pinion shaft (30);
a cylindrical wall (38) extending perpendicularly from a periphery of the plane wall (36), the cylindrical wall (38) having a diameter corresponding to a diameter of the pinion gear (14) to peripherally cover an axial length of a teeth (46) of the pinion gear (14).
2. The splash protector (20) as claimed in claim 1, comprising:
a circular rim (44) extending from the periphery of the plane wall (36) beyond the cylindrical wall (38), the circular rim (44) configured to be received in a circular rim recess (48) provided on the starter motor (10) for securing the splash protector (20) on the starter motor (10).
3. The splash protector (20) as claimed in claim 1, wherein the splash protector (20) is made of a polymeric material.
4. The splash protector (20) as claimed in claim 3, wherein the polymeric material is a nylon 66 with 50% glass fiber.
5. The splash protector (20) as claimed in claim 1, wherein the splash protector (20) is made of a metal.

6. The splash protector (20) as claimed in claim 1, wherein the perforation (40) has a diameter less than the diameter of the pinion gear (14).
7. The splash protector (20) as claimed in claim 1, wherein the perforation (40) has a diameter corresponding to the diameter of the pinion shaft (30).
8. A starter motor (10) comprising:
a pinion shaft (30) adapted to move between a rest position and a forward position;
a pinion gear (14) positioned on the pinion shaft (30), the pinion gear (14) configured to engage a component of the engine in the forward position to impart a starting torque to the engine.
a splash protector (20) comprising:
a plane wall (36) defining a perforation (40), the perforation
(40) configured for receiving the pinion shaft (30);
a cylindrical wall (38) extending perpendicularly from a
periphery of the plane wall (36), the cylindrical wall (38) having a
diameter corresponding to a diameter of the pinion gear (14) to
peripherally cover an axial length of teeth (46) of the pinion gear
(14).
9. The starter motor (10) as claimed in claim 8, comprising a front housing (12) having a circular rim recess (48) to support the splash protector (20).
10. The starter motor (10) as claimed in claim 8, comprising a cylindrical sleeve (28) extending from the front housing (12), the cylindrical sleeve (28) configured to support the splash protector (20).
11. The starter motor (10) as claimed in claim 9, wherein the plane wall (36) is made integral with the front housing (12).