# US 5,704,338 A · Flywheel magneto generator

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,704,338 A
- Document ID: US5704338A
- Status: Granted
- Kind: A
- Application number: 08/779,279
- Filed: 1997-01-06
- Granted: 1998-01-06
- Earliest claimed: 1997-01-06
- Assignees: Walbro Corporation
- Inventors: Martin N. Andersson; Michael J. Dale
- Web page: https://patentgrep.com/patent/US5704338A

## CPC

- H02K 7/1815: {structurally associated with reciprocating piston engines (general aspects of generating sets, e.g. housing, F02B63/04)}
- F02B 63/04: for electric generators
- F02B 75/007: {having vertical crankshafts}
- F02B 75/16: Engines characterised by number of cylinders, e.g. single-cylinder engines (F02B75/26 takes precedence)
- H02K 21/44: with armature windings wound upon the magnets
- F02P 1/02: the generator rotor being characterised by forming part of the engine flywheel
- F02P 1/08: Layout of circuits
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})
- F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G)
- F02P: IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES ({anti-pollution means for internal-combustion engines F02B17/00}; specially adapted for rotary-piston or oscillating-piston engines F02B53/12; {ignition of gas turbine plants F02C7/26; ignition of jet propulsion plants F02K9/95; starting of combustion engines F02N9/00}; ignition of combustion apparatus in general, glowing plugs F23Q; measuring of physical variables in general G01; controlling in general G05; data processing in general G06; electrical components in general see Section H; {ignition coils H01F38/12}; sparking plugs H01T13/00)

## Abstract

A magneto generator for an engine having a flywheel, in which the flywheel comprises a rotor mounted for axial rotation and has a rim of magnetically permeable material. A magnetically permeable core has first and second ends located adjacent to the rim at circumferentially spaced points. At least two wire coils are wrapped on the core. The rim defines a permeability path between the ends of the core. A fixed magnet is placed on one end of the core. The rim is interrupted at circumferentially spaced points to provide walls and windows alternately making and breaking the permeability path when the rotor is rotated to produce voltage pulses in sinusoidal form in the coils. The positive half cycles in one of the coils is used to charge an ignition storage capacitor for energizing a spark plug. The negative half cycles in the other winding are used to charge a battery.

## Claims

### Claim 1

A flywheel magneto generator for an engine comprising:
a flywheel rotor mounted for axial rotation and having a rim of magnetically permeable material,
a core of magnetically permeable material having first and second ends disposed adjacent to said rim at circumferentially spaced points,
a first coil wrapped on said core,
a second coil wrapped on said core,
said rim being adapted to define at least a portion of a permeability path between the ends of the core,
a magnet in said permeability path and fixed relative to said core,
said rim being interrupted at circumferentially spaced points to provide walls and spaces alternately making and breaking said permeability path when said rotor is rotating to produce multiple voltage pulses in sinusoidal wave form in each coil and an alternating current output from each coil,
a first receiver electrically connected to said first coil,
a second receiver electrically connected to said second coil,
means for half-wave rectifying the alternating current output from said first coil so that said first receiver is charged with the positive half cycles only of the alternating current output from said first coil, and
means for half-wave rectifying the alternating current output from said second coil so that said second receiver is charged with the negative half cycles only of the alternating current from said second coil.

### Claim 2 (depends on 1)

A flywheel magneto generator as defined in claim 1, wherein one of said receivers is a capacitor and the other of said receivers is a battery.

### Claim 3 (depends on 2)

A flywheel magneto generator as defined in claim 2, and further including an exciter for a spark plug, and means for triggering said capacitor to energize said exciter.

### Claim 4 (depends on 3)

A flywheel magneto generator as defined in claim 3, wherein said magnet is mounted on said first end of the core, and said magnet and said second end of the core are mounted closely adjacent to said rim in circumferentially spaced-apart relation to provide air gaps between said magnet and said rim and between said second end of the core and said rim.

### Claim 5 (depends on 4)

A flywheel magneto generator as set forth in claim 4, wherein the arcuate distance between said magnet and said second end of the core is a multiple of the arcuate spacing between said walls.

### Claim 6 (depends on 4)

A flywheel magneto generator as set forth in claim 4, wherein the arcuate distance between said magnet and said second end of said core is equal to the arcuate spacing between said walls.

### Claim 7 (depends on 6)

A flywheel magneto generator as set forth in claim 6, wherein said rotor, including said main body portion and said rim, is of integral, one-piece construction and is made of magnetically permeable material.

### Claim 8 (depends on 7)

A flywheel magneto generator as set forth in claim 7, wherein said air gaps are on the order of about 0.3 millimeters.