Differential gear

Claim 2

A differential gear (10) comprising first and second cases (22) supported rotatably about a co-axis and spaced axially from each other; pinions (24) disposed rotatably in each of said cases (22); first and second side gears (26) meshing with the pinions (24) and disposed rotatably in each of said cases (22); a first shaft (36) supported rotatably about the co-axis of said cases (22) and extending from the second side gear (26) in the first case (22) to the first side gear (26) in the second case (22); a second shaft (40) supported rotatably about the co-axis and extending from the first side gear (26) in the first case (22); a third shaft (42) supported rotatably about the co-axis and extending from the second side gear (26) in the second case (22) in the opposite direction to said second shaft (40); a driven means (44) provided in one of said first, second and third shafts (36,40,42); a first means (46) for rotating said driven means (44) to transmit driving force to said first, second and third shafts (36,40,42); a first worm wheel (50) provided in the first case (22); a second worm wheel (60) provided in the second case (22); a second rotary means (52) having a first worm (54) meshing with the first worm wheel (50); a third rotary means (62) having a second worm (64) meshing with the second worm wheel (60); and a control device (100) for calculating on the basis of signals from a steering angle sensor (102) and a vehicle speed sensor (104) to control number of revolutions of at least one of said second and third rotary means (52,62).

Claim 3

A differential gear (10) as claimed in claim l wherein said control device (100) controls at least one of said second and third rotary means (52,62) to maintain the difference between numbers of revolutions of said second and third shafts (40,42) within a predetermined range.

Claim 4

A differential gear (10) as claimed in claim 1, wherein said differential gear (10) is installed in one of front and rear drive lines and said second and third shafts (40,42) are connected respectively to left and right drive wheels (70,90), and wherein said control device (100) controls one of the second and third rotary means (52,62) which is located more near to an inside wheel in turning of a vehicle so as to reduce the number of revolutions of the shaft connected to the inside wheel.

Claim 5

A differential gear (10) comprising: first and second cases (22) supported rotatably about a co-axis and spaced axially from each other; pinions (24) disposed rotatably in each of said cases (22); first and second side gears (26) meshing with the pinions (24) and disposed rotatably in each of said cases (22); a first shaft (36) supported rotatably about the co-axis of said cases (22) and extending from the second side gear (26) in the first case (22) to the first side gear (26) in the second case (22); a second shaft (40) supported rotatably about the co-axis and extending from the first side gear (26) in the first case (22); a third shaft (42) supported rotatably about the co-axis and extending from the second side gear (26) in the second case (22) in the opposite direction to said second shaft (40); a driven means (44) provided in one of said first, second and third shafts (36,40,42); a first means (46) for rotating said driven means (44) to transmit driving force to said first, second and third shafts (36,40,42); a first worm wheel (50) provided in the first case (22); a second worm wheel (60) provided in the second case (22); a second rotary means having a first worm (54) meshing with the first worm wheel (50) and a second worm (64) meshing with the second worm wheel (60), the second rotary means being actuated by a single acutator (56); and a control device (100) for calculating on the basis of signals from a steering angle sensor and a vehicle speed sensor to control number of revolutions of said second rotary means.

Claim 6

A differential gear (10) comprising: first and second cases (22) supported rotatably about a co-axis and spaced axially from each other; pinions (24) disposed rotatably in each of said cases (22); first and second side gears (26) meshing with the pinions (24) and disposed rotatably in each of said cases (22); a first shaft (36) supported rotatably about the co-axis of said cases (22) and extending from the second side gear (26) in the first case (22) to the first side gear (26) in the second case (22); a second shaft (40) supported rotatably about the co-axis and extending from the first side gear (26) in the first case (22); a third shaft (42) supported rotatably about the co-axis and extending from the second side gear (26) in the second case (22) in the opposite direction to said second shaft (40); a driven means (44) provided in one of said first, second and third shafts (36,40,42); a first means (46) for rotating said driven means (44) to transmit driving force to said first, second and third shafts (36,40,42); a first worm wheel (50) provided in the first case (22); a second worm wheel (60) provided in the second case (22); a second rotary means having a first worm (54) meshing with the first worm wheel (50) and a second worm (64) meshing with the second worm wheel (60), the second rotary means being actuated by a single acutator (56); and a control device (100) for calculating on the basis of signals from a steering angle sensor and a vehicle speed sensor to control number of revolutions of said second rotary means.

Claim 7

A differential gear (10) as claimed in claim 4, wherein said second rotary means includes two single-­direction type clutches (124) and each of said worms (54,64) is rotated only in one direction.

Claim 8

A differential gear comprising: first and second sun gears (110) supported rotatably about a co-axis and spaced axially from each other; a plurality of planetary gears (112) meshing with each of said sun gears (110); a first shaft (36) supported rotatably about the co-axis of said sun gears (110) and extending from the first sun gear (110) to the second sun gear (110); a second shaft (40) supported rotatably about the co-axis and extending from the plurality of planetary gears (112) engaged with said first sun gear (110); a third shaft (42) supported rotatably about the co-axis and extending from the plurality of planetary gears (112) engaged with said second sun gear (110) in the opposite direction to said second shaft (40); a driven means (44) provided in one of said first, second and third shafts (36,40,42); a first means (46) for rotating said driven means (44) to transmit driving force to said first, second and third shafts (36,40,42); a first worm wheel (50) having an inner gear meshing with the plurality of planetary gears (112) engaged with the first sun gear (110); a second worm wheel (60) having an inner gear meshing with the plurality of planetary gears (112) engaged with the second sun gear (110); a second rotary means (52) having a first worm (54) meshing with the first worm wheel (50); a third rotary means (62) having a second worm (64) meshing with the second worm wheel (60); and a control device (100) for calculating on the basis of signals from a steering angle sensor (102) and a vehicle speed sensor (104) to control number of revolutions of at least one of said second and third rotary means (52,62).

Claim 9

A differential gear comprising: first and second sun gears (110) supported rotatably about a co-axis and spaced axially from each other; a plurality of planetary gears (112) meshing with each of said sun gears (110); a first shaft (36) supported rotatably about the co-axis of said sun gears (110) and extending from the first sun gear (110) to the second sun gear (110); a second shaft (40) supported rotatably about the co-axis and extending from the plurality of planetary gears (112) engaged with said first sun gear (110); a third shaft (42) supported rotatably about the co-axis and extending from the plurality of planetary gears (112) engaged with said second sun gear (110) in the opposite direction to said second shaft (40); a driven means (44) provided in one of said first, second and third shafts (36,40,42); a first means (46) for rotating said driven means (44) to transmit driving force to said first, second and third shafts (36,40,42); a first worm wheel (50) having an inner gear meshing with the plurality of planetary gears (112) engaged with the first sun gear (110); a second worm wheel (60) having an inner gear meshing with the plurality of planetary gears (112) engaged with the second sun gear (110); a second rotary means (52) having a first worm (54) meshing with the first worm wheel (50); a third rotary means (62) having a second worm (64) meshing with the second worm wheel (60); and a control device (100) for calculating on the basis of signals from a steering angle sensor (102) and a vehicle speed sensor (104) to control number of revolutions of at least one of said second and third rotary means (52,62).

Claim 10

A four wheel drive vehicle including a propeller shaft (48) extending longitudinally of the vehicle, a first differential gear (10) coupled with one end of the propeller shaft (48) and a second differential gear (80) coupled with the other end of the propeller shaft (48), in which one of the first and second differential gears (10,80) comprising: first and second cases (22) supported rotatably about a co-axis and spaced axially from each other; pinions (24) disposed rotatably in each of said cases (22); first and second side gears (26) meshing with the pinions (24) and disposed rotatably in each of said cases (22); a first shaft (36) supported rotatably about the co-axis of said cases (22) and extending from the second side gear (26) in the first case (22) to the first side gear (26) in the second case (22); a second shaft (40) supported rotatably about the co-axis and extending from the first side gear (26) in the first case (22), the second shaft (40) being connected to one of right and left drive wheels (70); a third shaft (42) supported rotatably about the co-axis and extending from the second side gear (26) in the second case (22) in the opposite direction to said second shaft (40), the third shaft (42) being connected to the other of the drive wheels (70); a driven means (44) provided in one of said first, second and third shafts (36,40,42); a first means (46) for rotating said driven means (44) to transmit driving force to said first, second and third shafts (36,40,42), the first rotary means (46) being connected to the propeller shaft (48); a first worm wheel (50) provided in the first case (22) a second worm wheel (60) provided in the second case (22); a second rotary means (52) having a first worm (54) meshing with the first worm wheel (50); a third rotary means (62) having a second worm (64) meshing with the second worm wheel (60); and a control device (100) for calculating on the basis of signals from a steering angle sensor (102) and a vehicle speed sensor (104) to control number of revolutions of at least one of said second and third rotary means (52,62)

Claim 11

A four wheel drive vehicle including a propeller shaft (48) extending longitudinally of the vehicle, a first differential gear (10) coupled with one end of the propeller shaft (48) and a second differential gear (80) coupled with the other end of the propeller shaft (48), in which one of the first and second differential gears (10,80) comprising: first and second cases (22) supported rotatably about a co-axis and spaced axially from each other; pinions (24) disposed rotatably in each of said cases (22); first and second side gears (26) meshing with the pinions (24) and disposed rotatably in each of said cases (22); a first shaft (36) supported rotatably about the co-axis of said cases (22) and extending from the second side gear (26) in the first case (22) to the first side gear (26) in the second case (22); a second shaft (40) supported rotatably about the co-axis and extending from the first side gear (26) in the first case (22), the second shaft (40) being connected to one of right and left drive wheels (70); a third shaft (42) supported rotatably about the co-axis and extending from the second side gear (26) in the second case (22) in the opposite direction to said second shaft (40), the third shaft (42) being connected to the other of the drive wheels (70); a driven means (44) provided in one of said first, second and third shafts (36,40,42); a first means (46) for rotating said driven means (44) to transmit driving force to said first, second and third shafts (36,40,42), the first rotary means (46) being connected to the propeller shaft (48); a first worm wheel (50) provided in the first case (22) a second worm wheel (60) provided in the second case (22); a second rotary means (52) having a first worm (54) meshing with the first worm wheel (50); a third rotary means (62) having a second worm (64) meshing with the second worm wheel (60); and a control device (100) for calculating on the basis of signals from a steering angle sensor (102) and a vehicle speed sensor (104) to control number of revolutions of at least one of said second and third rotary means (52,62)

Claim 12

A four wheel drive vehicle as claimed in claim 7, wherein further comprises a transfer (150) provided in relation to the propeller shaft (48) and said vehicle is also used as a two wheel drive vehicle.

Claim 13

A four wheel drive vehicle as claimed in claim 8, wherein said control device (100) controls said second and third rotary means (52,62) such that the number of revolutions of the driven means (44) becomes zero when used as a two wheel drive vehicle in straight running.