Electromagnetically operated clutch, transmission and hybrid vehicle

Abstract

An electromagnetically actuated clutch (50), comprising: first and second races (52, 54, 46), each mounted for rotation about an axis; a non-rotating coil (64) configured to generate a magnetic field in the first race (52, 54) in response to an electric current; and a pawl (58) mounted to rotate with the first race (52, 54) and pivot with respect to the first race (52, 54) in response to the magnetic field to engage a cam surface of the second race (46), wherein the pawl (58) is mounted to rotate about an axis of rotation parallel to the axis, further comprising a return spring (78) configured to rotate the pawl (58) out of engagement with the second race (46).

Claims

[1] Electromagnetically operated clutch (50), comprising: first and second races (52, 54, 46), each mounted for rotation about an axis; a non-rotating coil (64) configured to generate a magnetic field in the first race (52, 54) in response to an electric current; and a pawl (58) mounted to rotate with the first race (52, 54) and pivot with respect to the first race (52, 54) in response to the magnetic field to engage a cam surface of the second race (46), wherein the pawl (58) is mounted to rotate about an axis of rotation parallel to the axis, further comprising a return spring (78) configured to rotate the pawl (58) out of engagement with the second race (46). [2] The clutch (50) of claim 1, wherein the pawl (58) and the cam surface are configured such that the engagement precludes relative rotation between the first race (52, 54) and the second race (46) in one direction while allowing relative rotation in an opposite direction. [3] The clutch (50) of claim 2, wherein the pawl (58) and the cam surface have a taper to maintain the pawl (58) in engagement with the cam surface in the absence of the magnetic field. [4] A clutch (50) according to any one of claims 1 to 3, wherein the first race (52, 54) is radially inward of the second race (46) and the cam surface faces the axis. [5] Transmission, comprising: a first shaft (11) mounted for rotation about a first axis; a first gear (46) mounted for rotation about the first shaft; a non-rotating coil (64) configured to generate a magnetic field in the first shaft (11) in response to an electric current; and a pawl (58) mounted to rotate with the first shaft (11) and, in response to the magnetic field, to selectively couple the first gear to the first shaft (11), wherein the first gear (46) defines a cam surface such that engagement of the pawl (58) with the cam surface precludes rotation of the first gear (46) relative to the first shaft (11) in one direction while allowing relative rotation in an opposite direction, wherein the pawl (58) is mounted to rotate with respect to the first shaft (11) about an axis of rotation parallel to the first axis. [6] A transmission according to claim 5, wherein the pawl (58) and the cam surface have a taper to maintain the pawl (58) in engagement with the cam surface in the absence of the magnetic field. [7] A transmission according to claim 5 or 6, wherein the cam surface faces the first axis. [8] Transmission according to one of claims 5 to 7, further comprising: a second shaft (30) mounted for rotation about a second axis parallel to and offset from the first axis; and a second gear (48) fixedly coupled to the second shaft (30) and in continuous meshing engagement with the first gear (46). [9] Transmission according to claim 8, further comprising: a sun gear (16) which is fixedly connected to a first electric machine (20) in a drivable manner; a ring gear (18) which is fixedly connected to the second shaft (30) and to a second electric machine (34); a carrier (12) which is fixedly connected to the first shaft (11) in a drivable manner; and a plurality of planetary gears (14) mounted for rotation with respect to a support and meshing with the sun gear (16) and the ring gear (18). [10] Electric hybrid vehicle comprising: a planetary gear set comprising a sun gear (16) which is fixedly drivably connected to a first reversible electric machine (20), a ring gear (18) which is fixedly drivably connected to an output shaft (30), and a carrier (12) which is fixedly drivably connected to a motor (10); a second reversible electric machine (34) which is fixedly connected to the output shaft (30); and an electromagnetically actuated ratchet clutch (50) configured to selectively create a drivable connection between the sun gear (16) and the output shaft (30). [11] An electric hybrid vehicle according to claim 10, wherein the electromagnetically actuated ratchet clutch (50): an inner race (52, 54) which is fixedly connected to the sun gear (16) in a drivable manner; an outer race (46) which is fixedly connected to the output shaft (30) in a drivable manner; a non-rotating coil (64) configured to generate a magnetic field in the inner race (52, 54) in response to an electric current; and a pawl (58) mounted to rotate with the inner race (52, 54) and pivoting relative to the inner race (52, 54) in response to the magnetic field to engage a cam surface of the outer race (46); comprises. [12] The hybrid electric vehicle of claim 11, wherein the pawl (58) and the cam surface are configured such that engagement precludes relative rotation between the inner race (52, 54) and the outer race (46) in one direction while allowing relative rotation in a direction opposite to the one direction.

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