Two-speed electric axle drive system

Abstract

The present invention provides a two-speed electric bridge drive system, which comprises an electric motor (E), a synchronizer (10), two engaging ring gears, a planetary gear set (30) and a first shaft (S10). The rotor of the electric motor (E) and the first shaft (S10) transmit torque to each other. The synchronizer (10) comprises a sliding sleeve (11) and a gear hub (12). The sliding sleeve (11) can enable the gear hub (12) to be selectively connected to the first engaging ring gear (21) or the second engaging ring gear (22) in a torsion-proof manner. The gear hub (12) is used to transmit torque to a differential (D). The first engaging ring gear (21) is connected to the first shaft (S10) in a torsion-proof manner. The second engaging ring gear (22) is connected to the planet carrier (33) of the planetary gear set (30) in a torsion-proof manner. The first shaft (S10) is also connected to the sun gear (31) of the planetary gear set (30) in a torsion-proof manner. The gear hub (34) of the planetary gear set (30) is fixed. The electric bridge drive system according to the present invention has a compact structure, occupies a small space and can realize two-speed shifting.

Description

Technical Field

[0001] The present invention relates to the field of motor vehicles, in particular to the field of vehicle transmissions, especially to an electric bridge drive system in a pure electric vehicle or a hybrid electric vehicle, and more specifically to a two-speed electric bridge drive system. Background Art

[0002] For electric vehicles, including pure electric vehicles and hybrid (oil-electric hybrid) vehicles, their electric drive modes include central motor drive and wheel hub motor drive. A common layout of the central motor drive system is also called an eAxle drive system.

[0003] Figure 1 A two-speed electric bridge drive system is shown, which includes a motor E, a differential D, a dual clutch C, a motor shaft Se, a first shaft S1, a second shaft S2 and three gear sets.

[0004] The active part of the dual clutch C is connected to the motor shaft Se in a torsion-proof manner (i.e., it cannot rotate relative to each other). The two driven plates of the dual clutch C are respectively connected to the first gear set G1 and the second gear set G2 in a torsion-proof manner to provide two different transmission ratios. The first gear set G1 and the second gear set G2 transmit power between the first shaft S1 and the second shaft S2. The third gear set G3 transmits power from the second shaft S2 to the differential D.

[0005] The dual clutch C used in the above-mentioned electric bridge drive system has a complex structure, and requires two actuators to respectively control the movement of the two driven plates, which not only occupies a large space but also is costly.

[0006] In addition, the electric bridge drive system needs to be provided with three sets of parallel shafts, namely: a first set of shafts consisting of the coaxial motor shaft Se and the first shaft S1, a second set of shafts consisting of the second shaft S2, and a third set of shafts consisting of the first output half shaft S01 and the second output half shaft S02 of the differential D. The radial space occupied by the three sets of parallel shafts is large. Summary of the invention

[0007] The purpose of the present invention is to overcome or at least alleviate the deficiencies of the above-mentioned prior art and to provide a two-speed electric bridge drive system.

[0008] The present invention provides a two-speed electric bridge drive system, which includes a motor, a synchronizer, a first engaging ring gear, a second engaging ring gear, a planetary gear set and a first shaft.

[0009] The rotor of the motor and the first shaft transmit torque to each other,

[0010] The synchronizer comprises a sliding sleeve and a gear hub, wherein the sliding sleeve enables the gear hub to be selectively connected to the first engagement ring gear or the second engagement ring gear in a non-rotatable manner, and the gear hub is used to transmit torque to the differential.

[0011] The first engagement ring gear is connected to the first shaft in a non-rotatable manner.

[0012] The second engagement ring gear is connected to the planet carrier of the planetary gear set in a non-rotatable manner.

[0013] The first shaft is also connected to the sun gear of the planetary gear set in a non-rotatable manner.

[0014] The ring gear of the planetary gear set is fixed.

[0015] In at least one embodiment, the gear hub is sleeved on the outer circumference of the first shaft so as to be rotatable relative to the first shaft.

[0016] In at least one embodiment, the electric bridge drive system further includes a first gear of a first gear set and a second gear of a first gear set meshing with each other, wherein the first gear of the first gear set is non-rotatably connected to the rotor, and the second gear of the first gear set is non-rotatably connected to the first shaft.

[0017] In at least one embodiment, a radius of the second gear of the first gear set is greater than a radius of the first gear of the first gear set.

[0018] In at least one embodiment, the electric bridge drive system further includes a motor shaft, which connects the first gear of the first gear set and the rotor together in a non-rotatable manner, and the motor shaft is a hollow shaft.

[0019] In at least one embodiment, the electric bridge drive system further includes a first gear of a second gear set and a second gear of a second gear set meshing with each other, the first gear of the second gear set being non-rotatably connected to the gear hub, and the second gear of the second gear set being used to transmit torque to the differential.

[0020] In at least one embodiment, the second gear of the second gear set is connected to the housing of the differential in a rotationally fixed manner.

[0021] In at least one embodiment, a radius of the second gear of the second gear set is greater than a radius of the first gear of the second gear set.

[0022] In at least one embodiment, the electric bridge drive system further includes the differential, wherein an output half shaft of the differential is coaxially arranged with the motor, and one of the output half shafts of the differential passes through the rotor.

[0023] In at least one embodiment, the output half shaft of the differential is arranged parallel to the first shaft.

[0024] The electric bridge drive system according to the present invention has a compact structure, occupies a small space and can realize two-speed shifting. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of a possible two-speed electric bridge drive system.

[0026] Figure 2 Schematic diagram of a two-speed electric bridge drive system according to an embodiment of the present invention.

[0027] Description of reference numerals:

[0028] E motor; D differential; C dual clutch

[0029] Se motor shaft; S1, S10 first shaft; S2 second shaft; S01 first output half shaft; S02 second output half shaft;

[0030] G1 is the first gear set; G2 is the second gear set; G3 is the third gear set;

[0031] G11, first gear of first gear set; G12, second gear of first gear set; G21, first gear of second gear set; G22, second gear of second gear set;

[0032] 10 synchronizer; 11 sliding sleeve; 12 gear hub;

[0033] 21 first engagement ring gear; 22 second engagement ring gear;

[0034] 30 planetary gear set; 31 sun gear; 32 planetary gear; 33 planet carrier; 34 ring gear;

[0035] R is radial; A is axial. DETAILED DESCRIPTION

[0036] The exemplary embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present invention, and are not intended to exhaust all possible modes of the present invention, nor to limit the scope of the present invention.

[0037] Unless otherwise specified, refer to Figure 1 , A represents the axial direction of the electric bridge drive system, and the axial direction A is consistent with the axial direction of the motor E in the electric bridge drive system; R represents the radial direction of the electric bridge drive system, and the radial direction R is consistent with the radial direction of the motor E in the electric bridge drive system.

[0038] In this embodiment, the electric bridge drive system includes a motor E, a differential D, a synchronizer 10, a first engaging ring gear 21, a second engaging ring gear 22, a planetary gear set 30, a first gear G11 of the first gear set and a second gear G12 of the first gear set meshing with each other, a first gear G21 of the second gear set and a second gear G22 of the second gear set meshing with each other, a motor shaft Se and a first shaft S10.

[0039] The first gear set can transmit torque from the motor E to the first shaft S10, and the second gear set can transmit torque from the synchronizer 10 to the differential D. The synchronizer 10 is used to change the transmission ratio between the first gear set and the second gear set.

[0040] The motor axis Se is disposed parallel to the first axis S10.

[0041] The motor shaft Se connects the rotor of the motor E and the first gear G11 of the first gear set in a rotationally fixed manner, and the second gear G12 of the first gear set is connected to the first shaft S10 in a rotationally fixed manner.

[0042] The synchronizer 10 , the first engaging ring gear 21 , the second engaging ring gear 22 , and the planetary gear set 30 are all disposed coaxially with the first shaft S10 .

[0043] The synchronizer 10 includes a sleeve 11, a gear hub 12 and two synchronizer rings. The sleeve 11 is meshed with the gear hub 12, and the sleeve 11 can slide back and forth along the axial direction A, so that the first engagement ring gear 21 and the second engagement ring gear 22 are selectively meshed with the gear hub 12. The movement of the sleeve 11 is achieved, for example, by an actuator that can move along the axial direction A.

[0044] The gear hub 12 is sleeved on the first shaft S10 so as to be rotatable relative to the first shaft S10 .

[0045] The first clutch ring gear 21 is connected to the first shaft S10 in a rotationally fixed manner.

[0046] The second clutch ring gear 22 is connected to the planet carrier 33 of the planetary gear set 30 in a rotationally fixed manner, or the second clutch ring gear 22 is a part of the planet carrier 33 .

[0047] The sun gear 31 of the planetary gear set 30 is connected to the first shaft S10 in a rotationally fixed manner. The ring gear 34 of the planetary gear set 30 is fixed, for example, the ring gear is fixed to a housing of the electric axle drive system.

[0048] The gear hub 12 transmits the torque to the differential D through the second gear set.

[0049] The first gear G21 of the second gear set is sleeved on the first shaft S10 , and the first gear G21 of the second gear set is connected to the gear hub 12 in a rotationally fixed manner.

[0050] The second gear G22 of the second gear set is connected to the housing of the differential D in a rotationally fixed manner.

[0051] The two output half shafts (the first output half shaft S01 and the second output half shaft S02) of the differential D are both coaxially arranged with the motor E. The first output half shaft S01 passes through the rotor of the motor E, the housing of the differential D is located on one axial side of the motor E, and the first output half shaft S01 passes through the rotor along the axial direction A and extends to the other axial side of the motor E.

[0052] The motor shaft Se and the first gear G11 of the first gear set are both hollow structures for the first output half shaft S01 to pass through.

[0053] When the first engagement ring gear 21 is meshed with the gear hub 12, the electric bridge drive system has a first gear position. At this time, the power transmission path is: the motor E, the first gear G11 of the first gear set, the second gear G12 of the first gear set, the first shaft S10, the first engagement ring gear 21, the gear hub 12, the first gear G21 of the second gear set, the second gear G22 of the second gear set to the differential D.

[0054] When the second engagement ring gear 22 is meshed with the gear hub 12, the electric bridge drive system has a second gear position. At this time, the power transmission path is: the motor E, the first gear G11 of the first gear set, the second gear G12 of the first gear set, the first shaft S10, the sun gear 31, the planetary gear 32, the planetary carrier 33, the second engagement ring gear 22, the gear hub 12, the first gear G21 of the second gear set, the second gear G22 of the second gear set to the differential D.

[0055] Preferably, the radius of the second gear G12 of the first gear group is greater than the radius of the first gear G11 of the first gear group, and the radius of the second gear G22 of the second gear group is greater than the radius of the first gear G21 of the second gear group.

[0056] The present invention has at least one of the following advantages:

[0057] (i) The present invention utilizes the synchronizer 10 to realize the switching between two gears, and can drive the sleeve 11 to slide axially by only one actuator.

[0058] (ii) The motor shaft Se is coaxially arranged with the output half shaft of the differential D, so that the input and output shafts of the system can be collinear, facilitating the arrangement of the internal components of the vehicle.

[0059] (iii) The electric bridge drive system according to the present invention has only one axis (ie, the first axis S10 ) offset in the radial direction R from the motor axis Se, and the system occupies a small space in the radial direction R.

[0060] (iv) The electric axle drive system according to the present invention uses the planetary gear set 30, which can not only cooperate with the synchronizer 10 to provide two gear ratios, but also provide a large gear ratio.

[0061] Of course, the present invention is not limited to the above-mentioned embodiments, and those skilled in the art may make various modifications to the above-mentioned embodiments of the present invention under the guidance of the present invention without departing from the scope of the present invention.

Claims

1. A two-speed electric bridge drive system, comprising an electric motor (E), a synchronizer (10), a first engagement ring gear (21), a second engagement ring gear (22), a planetary gear set (30) and a first shaft (S10), The rotor of the motor (E) and the first shaft (S10) transmit torque to each other, The synchronizer (10) comprises a sliding sleeve (11) and a gear hub (12), wherein the sliding sleeve (11) enables the gear hub (12) to be selectively connected to the first engagement gear ring (21) or the second engagement gear ring (22) in a non-rotatable manner, and the gear hub (12) is used to transmit torque to a differential (D). The first engagement gear ring (21) is connected to the first shaft (S10) in a non-rotatable manner. The second engagement ring gear (22) is connected to the planet carrier (33) of the planetary gear set (30) in a non-rotatable manner. The first shaft (S10) is also connected to the sun gear (31) of the planetary gear set (30) in a non-rotatable manner. The ring gear (34) of the planetary gear set (30) is fixed.

2. The two-speed electric bridge drive system according to claim 1, characterized in that: The gear hub (12) and the first shaft (S10) are sleeved on the outer circumference of the first shaft (S10) so as to be rotatable relative to each other.

3. The two-speed electric bridge drive system according to claim 1, characterized in that: The electric bridge drive system also includes a first gear (G11) of a first gear set and a second gear (G12) of a first gear set that are meshed with each other, wherein the first gear (G11) of the first gear set is non-rotatably connected to the rotor, and the second gear (G12) of the first gear set is non-rotatably connected to the first shaft (S10).

4. The two-speed electric bridge drive system according to claim 3, characterized in that: The radius of the second gear (G12) of the first gear set is greater than the radius of the first gear (G11) of the first gear set.

5. The two-speed electric bridge drive system according to claim 3, characterized in that: The electric bridge drive system further comprises a motor shaft (Se), wherein the motor shaft (Se) connects the first gear (G11) of the first gear set and the rotor together in a non-rotatable manner, and the motor shaft (Se) is a hollow shaft.

6. The two-speed electric bridge drive system according to claim 1, characterized in that: The electric bridge drive system also includes a first gear (G21) of a second gear set and a second gear (G22) of a second gear set that mesh with each other, wherein the first gear (G21) of the second gear set is non-rotatably connected to the gear hub (12), and the second gear (G22) of the second gear set is used to transmit torque to the differential (D).

7. The two-speed electric bridge drive system according to claim 6, characterized in that: The second gear (G22) of the second gear set is connected to the housing of the differential (D) in a relatively non-rotatable manner.

8. The two-speed electric bridge drive system according to claim 6, characterized in that: The radius of the second gear (G22) of the second gear set is greater than the radius of the first gear (G21) of the second gear set.

9. The two-speed electric bridge drive system according to claim 6, characterized in that: The electric bridge drive system further comprises the differential (D), wherein an output half shaft of the differential (D) is coaxially arranged with the motor (E), and one of the output half shafts of the differential (D) passes through the rotor.

10. The two-speed electric bridge drive system according to claim 9, characterized in that: The output half shaft of the differential (D) is arranged in parallel with the first shaft (S10).

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