Brush arrangement for electrical machine
First Claim
1. An electrical machine, wherein the electrical machine has a first number (k) of commutator laminates (10, 12, 14) and brushes (16, 18), wherein the commutator laminates (10, 12, 14) are distributed uniformly in a circumferential direction on a circumference of a laminate support (24), characterized in that the brushes (16, 18) are arranged such that commutation times are distributed as uniformly as possible in order to reduce the current ripple when using a wave winding and a quantity of the brushes (16, 18) is less than the number of poles (2p) in the electrical machine;
- wherein the brushes (16, 18) comprise a first brush pair (16, 18), wherein a first circumferential angle α
1 exists between a first radial axis (20) of a first (16) of the brushes (16, 18) in the first brush pair (16, 18) and a second radial axis (22) of a second (18) of the brushes (16, 18) in the first brush pair (16, 18), the absolute magnitude abs (α
1) of which first circumferential angle α
1 differs from a brush nominal separation angle
α
nom=(360°
/2k)(2·
floor(U2·
(k/2p))+1)by no more than a tolerance angle α
T, where U2 is an odd natural number, abs ( ) is an absolute value function, floor ( ) is an integer rounding function and α
T is a tolerance angle, which is less than 8°
.
2 Assignments
0 Petitions
Accused Products
Abstract
An electrical machine, in particular an electric motor, has a first number (k) of commutator laminates (10, 12, 14) and brushes (16, 18), wherein the commutator laminates (10, 12, 14) are arranged distributed uniformly in the circumferential direction of a circumference of a laminate support (24). The brushes (16, 18) are arranged such that commutation times are distributed as uniformly as possible in order to reduce current ripple when using a wave winding and a number of brushes (16, 18) which is less than a number of poles (2p) in the electrical machine.
25 Citations
17 Claims
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1. An electrical machine, wherein the electrical machine has a first number (k) of commutator laminates (10, 12, 14) and brushes (16, 18), wherein the commutator laminates (10, 12, 14) are distributed uniformly in a circumferential direction on a circumference of a laminate support (24), characterized in that the brushes (16, 18) are arranged such that commutation times are distributed as uniformly as possible in order to reduce the current ripple when using a wave winding and a quantity of the brushes (16, 18) is less than the number of poles (2p) in the electrical machine;
- wherein the brushes (16, 18) comprise a first brush pair (16, 18), wherein a first circumferential angle α
1 exists between a first radial axis (20) of a first (16) of the brushes (16, 18) in the first brush pair (16, 18) and a second radial axis (22) of a second (18) of the brushes (16, 18) in the first brush pair (16, 18), the absolute magnitude abs (α
1) of which first circumferential angle α
1 differs from a brush nominal separation angle
α
nom=(360°
/2k)(2·
floor(U2·
(k/2p))+1)by no more than a tolerance angle α
T, where U2 is an odd natural number, abs ( ) is an absolute value function, floor ( ) is an integer rounding function and α
T is a tolerance angle, which is less than 8°
. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
- wherein the brushes (16, 18) comprise a first brush pair (16, 18), wherein a first circumferential angle α
Specification
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- Resources
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Current AssigneeRobert Bosch GmbH
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Original AssigneeRobert Bosch GmbH
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InventorsRoos, Gerald, Bernard, Pierre
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Primary Examiner(s)Nguyen, Tran
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Assistant Examiner(s)DESAI, NAISHADH N
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Application NumberUS13/320,592Publication NumberTime in Patent Office1,474 DaysField of Search310/224, 310/229, 310/230, 310/233, 310/234, 310/241, 310/248US Class Current310/233CPC Class CodesH02K 13/10 Arrangements of brushes or ...H02K 23/32 having wave or undulating w...
