US4992687A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Generator with inherent overload limiting
Assignee: TECHMAREX Pty Ltd
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Filing: 1989-02-15
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Granted: 1991-02-12
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Expires: 2009-02-15
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.
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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 |