# US 8,541,914 B2 · Liquid cooled electrical machine

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- Number: US 8,541,914 B2
- Document ID: US8541914B2
- Status: Granted
- Kind: B2
- Application number: 13/063,451
- Filed: 2009-09-03
- Published: 2011-07-14
- Granted: 2013-09-24
- Earliest claimed: 2008-09-12
- Assignees: Controlled Power Technologies, Ltd.
- Applicants: Stephen Knight; Mike Dowsett; Toby Heason
- Inventors: Stephen Knight; Mike Dowsett; Toby Heason
- Web page: https://patentgrep.com/patent/US8541914B2

## CPC

- H02K 11/33: Drive circuits, e.g. power electronics (H02K11/38 takes precedence)
- H02K 5/20: with channels or ducts for flow of cooling medium
- H02K 5/203: {specially adapted for liquids, e.g. cooling jackets}
- H02K 11/05: Rectifiers associated with casings, enclosures or brackets
- H02K 9/193: with provision for replenishing the cooling medium; with means for preventing leakage of the cooling medium
- H02K 9/197: in which the rotor or stator space is fluid-tight, e.g. to provide for different cooling media for rotor and stator
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})

## Abstract

Flow control apparatus for an electrical machine and comprising an arrangement of shaped chambers and passages for conveying a liquid coolant. The rate of heat transfer from certain portions of the machine to the coolant is determined by the varying velocity of the liquid through the chambers, resulting in a generally uniform cooling of those portions of the machine.

## Claims

### Claim 1

A flow control apparatus for an electrical machine and comprising:
a first wall and a second wall, the second wall being inclined with respect to the first wall so as to define a tapered first chamber between the first and second walls, the first chamber including an entrance aperture and an exit aperture wherein;
in use the taper causes the velocity of a liquid in the first chamber to be varied as the liquid is conveyed between the entrance aperture and the exit aperture, such that a transfer of thermal energy from a heat source to the liquid via the first wall is substantially uniform between the entrance aperture and the exit aperture.

### Claim 2 (depends on 1)

The flow control apparatus as claimed in claim 1
wherein:
the second wall comprises a guide member, the guide member having a first face and a second face, the first face being inclined with respect to the second face so as to form a tapered profile between the first and second faces,
and wherein;
the tapered first chamber is defined by the first wall and the first face of the guide member.

### Claim 3 (depends on 2)

The flow control apparatus as claimed in claim 2 and further comprising:
a third wall comprising a flow path, the flow path being arranged to receive a liquid; and
a second chamber, defined by the third wall and the second face of the guide member, the exit aperture of the first chamber being coupled to the second chamber wherein;
in use the liquid is conveyed from the first chamber to the second chamber via the exit aperture and at least a portion of the liquid in the second chamber is diverted onto the flow path.

### Claim 4 (depends on 1)

The flow control apparatus as claimed in claim 1 wherein the first wall comprises an undulated surface suitable for inducing turbulence in the liquid.

### Claim 5 (depends on 2)

The flow control apparatus as claimed in claim 2 wherein the first face of the guide member comprises an undulated surface suitable for inducing turbulence in the liquid.

### Claim 6 (depends on 3)

The flow control apparatus as claimed in claims 3 wherein the first face of the guide member comprises an undulated surface suitable for inducing turbulence in the liquid.