Coaxial type starter

• US 5,154,089 A
• Filed: 04/12/1991
• Issued: 10/13/1992
• Est. Priority Date: 05/15/1990
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Konishi, Keiichi
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Krolikowski, Julie
• Application Number:
  US07/684,085
• Time in Patent Office: 550 Days
• Field of Search: 74/7 A, 74/7 C, 74/7 E
• US Class Current: 74/7.00E
• CPC Class Codes: F02N 15/066 the starter being of the coaxial type
• CPC Class Codes: Y10T 74/132 Separate power mesher
• CPC Class Codes: Y10T 74/134 Clutch connection
• CPC Class Codes: Y10T 74/137 Reduction gearing

Abstract

In a coaxial type starter, the rear end portion of the clutch inner of its overrunning clutch is supported through a bearing on the front end portion of the armature rotary shaft, and the front end portion is supported through a bearing on the front bracket. Both end portions of the clutch outer are supported through bearings on the clutch inner, and the clutch outer is fitted into the cylindrical portion of the planetary gear frame in such a manner that the clutch outer and the cylindrical portion slide relative to each other when torque larger than a predetermined value is applied thereto. The clutch inner and the clutch outer are maintained coaxial at all times, and the clutch inner and the bearings or rollers are prevented from being abnormally worn out.

Claims

1. A coaxial type starter including:

an electric motor having a hollow armature rotary shaft;

an output rotary shaft which includes a rear end portion inserted into side armature rotary shaft, and a front end portion on which a pinion is mounted in such a manner that said pinion is engaged with an engine ring gear when said pinion is moved in a forward direction;

an electromagnetic switch device coaxially coupled to a rear end portion of said electric motor, said electromagnetic switch device comprising an exciting coil fixed to said motor so as to cause a stationary core fixed to said coil to attract a movable core which is coupled to said output rotary shaft by a push rod so that said output rotary shaft is moved forwardly when said coil is energized, a movable contact being coupled to said movable core so as to be placed in contact with a pair of stationary contacts when said coil is energized to electrically energize said electric motor thereby to rotate said armature rotary shaft;

a planetary gear speed reducer coupled to said electric motor, so as to reduce the rotation of said armature rotary shaft which is transmitted through a planetary gear frame of said planetary gear speed reducer;

an overrunning clutch including a clutch outer member and a clutch inner member, said overrunning clutch being coupled to a front end portion of said planetary gear frame to transmit the rotation thus reduced to said output rotary shaft; and

a front bracket coupled to a front end portion of said electric motor in such a manner as to accommodate said planetary gear speed reducer and said overrunning clutch,

said clutch outer member being fitted into a cylindrical portion of said planetary gear frame in such a manner that said clutch outer member and said cylindrical portion slide relative to each other when a torque larger than a predetermined value is applied thereto,

said clutch inner member having a rear end portion which is supported through a first bearing on a front end portion of said armature rotary shaft and a front end portion which is supported through a second bearing on an inner wall of a front end portion of said front bracket, and

said clutch outer member having a front end portion and a rear end portion which are respectively supported through third and fourth bearings on said clutch inner member.

2. A coaxial type starter according to claim 1, in which said overrunning clutch further comprises:

a plurality of rollers arranged between said clutch inner member and said clutch outer member;

a retaining plate fixed to said clutch outer member and positioned so as to maintain a position of said rollers; and

a holding cap secured, to an outer cylindrical wall of said clutch outer member, said holding cap being supported through said fourth bearing on said clutch inner member.

3. A coaxial type starter according to claim 1, in which said first through fourth bearings are ball bearings.