US 5,713,445 AGranted

Transmission inertia brake with self energizing

AssigneeEaton Corporation

InventorsAlan R. Davis, Thomas N. Riley

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Abstract

A ball ramp mechanism is used to load a clutch pack in a transmission inertia brake to slow a rotating shaft where an armature having an angled peripheral surface engages a mating surface formed in an inertia brake housing to form a cone clutch where the armature is magnetically pulled toward the brake housing by an electromagnetic field generated by an electrical coil thereby introducing a frictional braking force on the armature. The armature is nonrotatably connected to the control ring of the ball ramp mechanism through a plurality of tapered pins which engage a corresponding plurality of conical sections so that relative rotation between the armature and the control ring causes the armature to be forced toward the housing thereby increasing the braking force on the armature and control ring. Relative rotation between the control ring and an actuation ring causes a plurality of rolling elements to transverse tapered grooves formed on the control ring and the actuation ring thereby axially expanding the ball ramp mechanism to load the clutch pack.

Claims19

Dependent claims

An inertia brake for slowing the rotation of a freely rotating shaft in a transmission comprising:

a transmission case containing at least one transmission shaft and a plurality of transmission gears for changing a gear ratio in a vehicle driveline;
an inertia brake housing having a cavity therein, said housing attached to said transmission case;
a clutch pack having a plurality of drive plates nonrotatably attached to said transmission shaft and a plurality of stationary plates attached to said brake housing;
a ball ramp actuator for loading said clutch pack comprising:
an actuation ring disposed adjacent to said clutch pack where axial movement of said actuation ring results in a loading and an unloading of said clutch pack;
a control ring disposed opposite to said actuation ring, said control ring and said actuation ring having opposed faces provided with circumferentially extending grooves, said grooves comprised of at least three opposed pairs of grooves having portions of varying depth;
and rolling members disposed one in each of opposed pair of said grooves, said groove formed in said actuation ring and said control ring being arranged so that relative angular movement of said actuation ring and said control ring from a starting position thereof, causes axial movement of said actuation ring away from said control ring to axially load said clutch pack;
an armature coupled to said control ring using a plurality of tapered pins engaging a like number of corresponding conical cavities such that relative rotation between said armature and said control ring results in an increase and decrease in axial separation between said armature and said control ring;
and
an electrical coil disposed to generate an electromagnetic field acting on said armature causing said armature to contact said inertia brake housing.

7 more elements

A ball ramp coupling mechanism comprising:

a rotating input shaft driven by a prime mover and rotating about an axis of rotation;
an inertia brake housing partially surrounding said input shaft;
a clutch pack comprised of a plurality of stationary clutch plates coupled to said brake housing interdigitated with a plurality of driven clutch plates coupled to said input shaft;
a ball ramp actuator for generating an axial movement comprising;
an annular control ring having an axis of rotation along said axis of rotation of said input shaft and having at least two circumferential control grooves formed in a first face of said control ring, said control grooves varying in axial depth, an equivalent number of rolling elements one occupying each of said control grooves, an actuation ring having an axis of rotation along said axis of rotation of said input shaft, said actuation ring having at least two actuation grooves substantially identical in number, shape and radial position as said control grooves in said control ring where said actuation grooves at least partially oppose said control grooves and where each of said rolling elements is trapped between said actuation ring and a respective at least partially opposed control ring, said control ring axially and rotationally movably disposed relative to said actuation ring, said actuation ring loading said clutch plate;
an armature nonrotatably linked to said control ring with a plurality of tapered pins, said tapered pins engaging a plurality of corresponding conical cavities, said armature applying a rotational braking force on said control ring to activate said ball ramp actuator;
and
a coil for creating a magnetic field in said armature thereby magnetically forcing said armature into frictional contact with said inertia brake housing to apply a rotational braking force on said armature.

5 more elements

Dependencies are inferred from the claim text.