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US4992687A Expired / Lapsed US ⏱️ 0.0 years remaining

Generator with inherent overload limiting

Assignee: TECHMAREX Pty Ltd
•
Filing: 1989-02-15
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Granted: 1991-02-12
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Expires: 2009-02-15
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Abstract

Abstract A dynamo in the form of a 3 phase welding generator. One stator winding has an in-phase excitation winding feeding the rotor through slip rings. This configuration allows for inherent short-circuit protection as the stator core under short-circuit saturates and prevents rotor excitation, a shaft-mounted fan cools inner and outer surfaces of a tubular heat sink that surrounds the generator and holds a diode-resistor bank.

Inventors

  • 👤 Gert Nel

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 21:18
CPC Classifications
H; H02; H02P; H02P9/00; H02P9/10; H02P9/107; H02K; H02K11/00; H02K11/04; H02K11/049; H02K11/05; H02K19/00; H02K19/16; H02K19/26; H02K19/28; H02K19/36; H02P9/14; H02P9/38

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 191 words
A dynamo means, said dynamo means being a three-phase welding generator in a housing, said generator having a rectified current output, with at least one excitation winding on the stator connected to supply field excitation current to the rotor winding and wound to be operatively in phase with a stator phase winding, wherein the generator has a heat sin, in the form of two particular metal sinks, secured within the housing of the generator to form a generally tubular section spaced apart from the housing and the windings, and held in position by axially spaced bolts with the rectified output from the stator provided from heavy duty diodes mounted on the heat sinks, said generator further having a shaft and a fan mounted on the shaft end for ventilation, and ventilation flow passages on both the inner and outer sides of the tubular heat sink, there being ventilation passageways passing through the resistor bank to provide cooling, with the resistor bank mounted to extend axially along the outer periphery of the housing, and the base of the bank being in communication with the housing interior for creation of the ventilation passageways.
Claim 2
Dependent Claim 191 words
A dynamo means, said dynamo means being a three-phase welding generator in a housing, said generator having a rectified current output, with at least one excitation winding on the stator connected to supply field excitation current to the rotor winding and wound to be operatively in phase with a stator phase winding, wherein the generator has a heat sin, in the form of two particular metal sinks, secured within the housing of the generator to form a generally tubular section spaced apart from the housing and the windings, and held in position by axially spaced bolts with the rectified output from the stator provided from heavy duty diodes mounted on the heat sinks, said generator further having a shaft and a fan mounted on the shaft end for ventilation, and ventilation flow passages on both the inner and outer sides of the tubular heat sink, there being ventilation passageways passing through the resistor bank to provide cooling, with the resistor bank mounted to extend axially along the outer periphery of the housing, and the base of the bank being in communication with the housing interior for creation of the ventilation passageways.
Claim 3
Dependent Claim 86 words
A dynamo means as claimed in claim 1 in which there is a fan mounted on the shaft end for ventilation, and there is arranged for ventilation flow passages on both the inner and outer sides of the tubular heat sink, there being ventilation passageways passing through the resistor bank to provide cooling, with the resistor bank mounted to extend axially along the outer periphery of the housing, and the base of the bank in communication with the housing interior for creation of the ventilation passageway.
Claim 4
Independent Claim 124 words
A method of providing a dynamo means with inherent output short circuit protection comprising winding a wound stator and rotor with at least one excitation winding on the stator connected to supply field excitation current to the rotor winding and wound to be operatively in phase with a stator phase winding, and utilizing stator core saturation on occurrence of a short circuit to prevent voltage induction in said excitation winding, and cause consequent cessation of field current in the rotor, and ventilating the dynamo housing with a fan mounted on the shaft end and guiding ventilation air through flow passages on both inner and outer sides of a tubular heat sink within the housing, and through a voltage controlling resistor bank to cool it.
Claim 5
Independent Claim 124 words
A method of providing a dynamo means with inherent output short circuit protection comprising winding a wound stator and rotor with at least one excitation winding on the stator connected to supply field excitation current to the rotor winding and wound to be operatively in phase with a stator phase winding, and utilizing stator core saturation on occurrence of a short circuit to prevent voltage induction in said excitation winding, and cause consequent cessation of field current in the rotor, and ventilating the dynamo housing with a fan mounted on the shaft end and guiding ventilation air through flow passages on both inner and outer sides of a tubular heat sink within the housing, and through a voltage controlling resistor bank to cool it.
Claim 6
Dependent Claim 47 words
A method as claimed in claim 3 in which the dynamo means is a polyphase machine having an excitation winding for each stator winding and one phase of the excitation windings is used to feed current through slip rings, to the field winding for providing rotor excitation.
Claim 7
Dependent Claim 51 words
A method as claimed in claim 3 including ventilating the dynamo housing with a fan mounted on the shaft end and guiding ventilation air through flow passages on both inner and outer sides of a tubular heat sink within the housing, and through a voltage controlling resistor bank to cool it.

References Cited (Backward Citations)

US3034035A Cited
GB870851A Cited
US3250929A Cited
US3702965A Cited
US4233555A Cited
US4477767A Cited
US4831294A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-02-11 1994-08-13 1995-02-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-02-11 1998-08-13 1999-02-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-02-11 2002-08-13 2003-02-12 $7700.00 Window Closed / Lapsed

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