Drum brake and electric actuator therefor
AssigneeSKF Engineering and Research Centre B.V.
InventorsHendrikus Jan Kapaan, Jacobus Zwarts
Life of this patent
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Abstract
An actuator for a drum brake comprises a housing (1), a screw mechanism having at least one screw (3,6) and a nut (4, 7), which screw mechanism (2) is supported with respect to the housing (1), and drive means (3) which are drivingly connected to the screw mechanism for providing a linear movement of at least one of the screw and nut with respect to the housing upon driving the screw mechanism. The screw mechanism comprises two axially aligned screws which have opposite lead angles and two corresponding nuts, said screws each engaging a respective nut, the drive means being connected to both screws or to both nuts.
Claims20
An actuator for a drum brake, comprising:
- a housing (1),
- a screw mechanism (2) comprising at least one screw (3) and a first nut (4), wherein the screw mechanism is supported with respect to the housing (1), and
- drive means (5) that are drivingly connected to the screw mechanism (2) for providing a linear movement of the at least one screw (3) and the first nut (4) with respect to the housing (1) upon driving the screw mechanism (2), wherein
- the screw mechanism (2) further comprises two axially aligned screws (3, 6) which have opposite lead angles, and two corresponding nuts (4, 7),
- each of the two axially aligned screws (3, 6) engages a respective nut of the two corresponding nuts (4, 7) with the at least one screw (3) engaging the first nut (4),
- the drive means (5) are connected to both of the two axially aligned screws (3, 6) or to both of the two corresponding nuts (4, 7),
- the housing comprises a cylindrical tube (1), the two corresponding nuts (4, 7) having a corresponding cylindrical circumference and fitting slidably within the cylindrical tube (1), and
- the drive means comprise a disc (5) which is drivable through an opening (12) in the cylindrical tube (1).
An arrangement for a drum brake, comprising:
- a backing plate (19) to be connected to a vehicle wheel suspension,
- a pair of brake shoes (20, 21) supported on the backing plate (19),
- a screw actuator engaging the brake shoes, and
- a motor (13) for driving the screw actuator (1, 2) to obtain a linear movement thereof for displacing the brake shoes (20, 21) outwardly and away from each other,
- the screw actuator further comprising a housing (1) and a screw mechanism (2) which is supported with respect to the housing (1), and two axially aligned screws (3, 6) which have opposite lead angles and two corresponding nuts (4, 7), wherein
- each of the two axially aligned screws (3, 6) engages a respective nut of the two corresponding (4, 7),
- the drive means (5) are connected to both of the axially aligned screws (3, 6) or to both of the two corresponding nuts (4, 7),
- the housing comprises a cylindrical tube (1), the two corresponding nuts (4, 7) having a corresponding cylindrical circumference and fitting slidably within the cylindrical tube (1), and
- each of the two corresponding nuts (4, 7) have an actuating member (8, 9) at opposite ends of the two corresponding nuts (4, 7) facing away from each other.
Dependencies are inferred from the claim text.