Limited Slip Differential Having Cam Integrated Into Rotatable Cross-Shaft Carrier
A limited slip differential having a differential gearset and a cam-type limited slip mechanism. The differential gearset has a plurality of differential pinions that are journally supported by a cross-shaft. The cross-shaft is supported by a rotatable cross-shaft carrier. The limited slip mechanism includes a clutch pack, a pressure ring, a plurality of first cams, which are coupled to the cross-shaft carrier for rotation therewith, and a plurality of second cams that are coupled to the pressure ring. The first cams cooperate with the second cams to convert rotation of the cross-shaft carrier to translation of the pressure ring to thereby control engagement of the clutch pack.
1 . A limited slip differential comprising:
a differential case having a differential cavity formed therein, the differential case being rotatable about an axis;
a cross-shaft carrier received in the differential cavity and being moveable about the axis relative to the differential case, the cross-shaft carrier having a wall member and a plurality of first cams;
a differential gearset having first and second side gears, a plurality of pinion gears and a cross-shaft, the first and second side gears being received in the differential cavity and disposed along the axis such that the cross-shaft carrier is disposed between the first and second side gears, each of the pinion gears being meshingly engaged to the first and second side gears and journally supported on the cross-shaft, the cross-shaft being coupled to the wall member in a manner that inhibits rotation of the cross-shaft about the axis relative to the cross-shaft carrier;
a first pressure ring that is non-rotatably coupled to the differential case, the first pressure ring being slidable relative to the differential case along the axis, the first pressure ring having a plurality of second cams; and
a first clutch pack disposed between the differential case and the first pressure ring, the first clutch pack having one or more first clutch plates, which are non-rotatably coupled to the differential case, and one or more second clutch plates that are non-rotatably coupled to the first side gear, each of the second clutch plates being disposed adjacent an associated one of the first clutch plates;
wherein the first and second cams cooperate to coordinate rotational motion of the cross-shaft carrier relative to the differential case with movement of the first pressure ring along the axis.
2 . The limited slip differential of claim 1 , wherein the cross-shaft carrier includes a plurality of third cams and wherein the limited slip differential further comprises:
a second pressure ring that is non-rotatably coupled to the differential case, the second pressure ring being slidable relative to the differential case along the axis and having a plurality of fourth cams; and
a second clutch pack disposed between the differential case and the second pressure ring, the second clutch pack having one or more third clutch plates, which are non-rotatably coupled to the differential case, and one or more fourth clutch plates that are non-rotatably coupled to the second side gear, each of the fourth clutch plates being disposed adjacent an associated one of the third clutch plates;
wherein the third and fourth cams cooperate to coordinate rotational motion of the cross-shaft carrier relative to the differential case with movement of the second pressure ring along the axis.
3 . The limited slip differential of claim 2 , wherein each of the third cams, each of the fourth cams, or each of the third and fourth cams is configured in a non-symmetrical manner such that rotation of the cross-shaft carrier relative to the differential case through a predetermined angle in a first rotational direction from a neutral position moves the second pressure ring away from the cross-shaft carrier in a first manner, and rotation of the cross-shaft carrier relative to the differential case through the predetermined angle in a second, opposite rotational direction from the neutral position moves the second pressure ring away from the cross-shaft carrier in a second manner.
4 . The limited slip differential of claim 3 , wherein the first and second manners differ in a rate at which the second pressure ring travels along the axis per unit of rotation of the cross-shaft carrier relative to the differential case.
5 . The limited slip differential of claim 2 , further comprising a preload spring disposed between the second clutch pack and the differential case.
6 . The limited slip differential of claim 2 , wherein a quantity of the fourth clutch plates is equal in number to a quantity of the second clutch plates.
7 . The limited slip differential of claim 1 , wherein the cross-shaft comprises a first pin, a second pin and a third pin, the second and third pins being shorter than the first pin.
8 . The limited slip differential of claim 7 , wherein the second and third pins are supported on the first pin.
9 . The limited slip differential of claim 1 , wherein each of the first cams, each of the second cams, or each of the second and third cams is configured in a non-symmetrical manner such that rotation of the cross-shaft carrier relative to the differential case through a predetermined angle in a first rotational direction from a neutral position moves the first pressure ring away from the cross-shaft carrier in a first manner, and rotation of the cross-shaft carrier relative to the differential case through the predetermined angle in a second, opposite rotational direction from the neutral position moves the first pressure ring away from the cross-shaft carrier in a second manner.
10 . The limited slip differential of claim 9 , wherein the first and second manners differ in a rate at which the first pressure ring travels along the axis per unit of rotation of the cross-shaft carrier relative to the differential case.
11 . The limited slip differential of claim 1 , further comprising a preload spring disposed between the first clutch pack and the differential case.
12 . The limited slip differential of claim 1 , further comprising:
a housing into which the differential case is rotatably supported;
an input pinion rotatably disposed in the housing;
a ring gear meshed with the input pinion, the ring gear being fixedly coupled to the differential case; and
first and second axle shafts, the first axle shaft being driven by the first side gear, the second axle shaft being driven by the second side gear.
13 . The limited slip differential of claim 1 , further comprising:
a housing into which the limited slip differential is rotatably received;
an annular gear coupled to the differential case for rotation therewith; and
an input gear meshingly engaged with the annular gear.
14 . The limited slip differential of claim 13 , wherein the annular gear is a bevel ring gear.
15 . A limited slip differential comprising:
a differential case having a differential cavity formed therein, the differential case being rotatable about an axis;
a differential gearset having first and second side gears, a plurality of pinion gears and a cross-shaft, the first and second side gears being received in the differential cavity, each of the pinion gears being meshingly engaged to the first and second side gears and journally supported on the cross-shaft;
means for supporting the cross-shaft for rotation relative to the differential case about the axis; and
means for frictionally engaging at least one of the first and second side gears to the differential case, the friction engaging means being responsive to relative rotation between the cross-shaft supporting means and the differential case.
16 . The limited slip differential of claim 15 , wherein the friction engaging means comprises a first cam, which is non-rotatably coupled to the cross-shaft supporting means, a pressure ring, which is non-rotatably coupled to the differential case, and a second cam that is non-rotatably coupled to the pressure ring and engaged to the first cam.
17 . The limited slip differential of claim 16 , wherein the friction engaging means further comprises a clutch pack disposed along the axis between the pressure ring and the differential case, the clutch pack having one or more first clutch plates, which are non-rotatably but axially slidably coupled to the differential case, and one or more second clutch plates that non-rotatably but axially slidably coupled to one of the first and second side gears, wherein each of the second clutch plates is disposed adjacent to an associated one of the first clutch plates.
18 . The limited slip differential of claim 17 , further comprising a spring received in the differential case and preloading the clutch pack.
19 . The limited slip differential of claim 15 , wherein the friction engaging means is configured such that rotation of the cross-shaft relative to the differential case about the axis in a first rotational direction by a predetermined angle from a neutral position produces frictional engagement between the at least one of the first and second side gears and the differential case of a first magnitude, and rotation of the cross-shaft relative to the differential case about the axis in a second, opposite rotational direction by the predetermined angle from the neutral position produces frictional engagement between the at least one of the first and second side gears and the differential case of a second magnitude that is different from the first magnitude.
20 . The limited slip differential of claim 15 , wherein the cross-shaft comprises a first pin, a second pin and a third pin, the second and third pins being shorter than the first pin.
21 . The limited slip differential of claim 20 , wherein the second and third pins are supported on the first pin.
22 . The limited slip differential of claim 15 , further comprising:
a housing into which the limited slip differential is rotatably received;
an annular gear coupled to the differential case for rotation therewith; and
an input gear meshingly engaged with the annular gear.