Prime-mover dynamo plants – Electric control – Electric-starting motor
Utility Patent
1997-10-06
2001-01-02
Enad, Elvin (Department: 2834)
Prime-mover dynamo plants
Electric control
Electric-starting motor
C290S00100C, C290S03800C, C290S03800C, C290S03800C, C074S00700R
Utility Patent
active
06169333
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to starter motor assemblies, and more particularly to drive stops for starter motors.
2. Description of the Related Art
In typical designs for starter motor assemblies for motor vehicle engines, an output shaft is coupled to be driven by the armature of the starter motor. This output shaft typically has external splines which interact with internal splines on a starter motor “drive” assembly. A pinion gear is affixed to the drive assembly for rotation therewith. The splines on the output shaft and on the drive assembly cooperate to transmit rotational power from the starter motor to the pinion gear. The splines also act to facilitate translation of the pinion gear into mesh with a ring gear of the engine being cranked by the starter motor.
Overtranslation of the drive assembly, and therefore of the pinion gear, must be avoided. In some designs, an outboard pinion stop surface is provided, against which the pinion gear abuts to prevent overtranslation. In other designs, a stop is provided on the output shaft, slightly outboard of the splines. The stop is located so that the splines of the spline tube abut against the stop once the maximum intended translation of the drive assembly (and therefore the pinion gear) has been reached. U.S. Pat. No. 5,370,009, issued to Isozumi, discloses such a drive stop, designated therein as reference numeral
10
.
Locating the stop on the output shaft has the distinct advantage of reducing the axial length of the starter motor assembly when compared to designs with an outboard stop against which the pinion gear abuts. However, as presently practiced in the art, designs with a stop on the output shaft have some disadvantages of their own. First, such a stop adds length to the output shaft beyond that necessary for the splines. This added length translates into added overall length for the starter motor assembly. Reduced package size is an ever-present requirement in the design of motor vehicle components; added length for a starter motor assembly is therefore disadvantageous. Second, as presently practiced in the art, a drive stop on the output shaft outboard of the splines requires one or more added manufacturing steps beyond the process of rolling the splines. The added manufacturing steps add cost to the manufacture of the output shaft.
Therefore, a drive stop design for a starter motor assembly which can reduce the added length and added cost required for prior-art drive stops will provided advantages over the prior art.
SUMMARY OF THE INVENTION
The present invention provides a method for forming a starter motor drive stop. The method includes forming a splined portion on a starter motor output shaft, the splined portion comprising alternating grooves and ridges. The method also comprises forming at least one stop surface as an integral part of the spline forming step.
The present invention also provides a second method for forming a starter motor drive stop. The method comprises forming a splined portion in a starter motor output shaft, the splined portion comprising alternating grooves and ridges and having a first axial end and a second axial end. Additionally, the method includes forming at least one stop surface between the first axial end and the second axial end of the splined portion.
Further, the present invention provides a starter motor output shaft. The output shaft includes a splined portion comprising a plurality of alternating ridges and grooves disposed about a circumference of the output shaft, the splined portion having a first axial end and a second axial end. In addition, the output shaft comprises a plurality of stop surfaces, each stop surface disposed between the first axial end and the second axial end of the splined portion.
Designs and manufacturing processes according to the present invention can result in reduced cost and reduced length of starter motor assemblies. In doing so, the present invention provides considerable advantage over the prior art.
REFERENCES:
patent: 3982415 (1976-09-01), Killop
patent: 4395923 (1983-08-01), Giometti
patent: 4900945 (1990-02-01), Isozumi et al.
patent: 4902905 (1990-02-01), Morishita
patent: 5044212 (1991-09-01), Isozumi et al.
patent: 5050441 (1991-09-01), Giometti
patent: 5105670 (1992-04-01), Isozumi et al.
patent: 5129271 (1992-07-01), Isozumi et al.
patent: 5370009 (1994-12-01), Isozumi
patent: 5848551 (1998-12-01), Ohmi et al.
patent: 0494681A1 (1992-07-01), None
patent: 0 562 475 A1 (1993-09-01), None
patent: 0 732 498 A1 (1996-03-01), None
patent: 2 270 954 (1993-11-01), None
patent: 55-96362 (1980-07-01), None
Pentland Alex Moses
Wilson Daryl Alan
Enad Elvin
McCoy-Pfau Rhonda L.
Visteon Global Technologies Inc.
LandOfFree
Starter motor drive stop does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Starter motor drive stop, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Starter motor drive stop will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2440278