A hybrid electric drive device

Abstract

The present invention provides a hybrid electric drive device, which includes: an engine, a first motor, a second motor and a power splitting mechanism, the power splitting mechanism includes at least one planetary gear, has an input end, a first output end and a second output end, the input end is connected to the engine, the first output end is connected to the first motor, the second output end is connected to the wheel, and the second motor is connected to the wheel; it also includes a bypass mechanism for selectively connecting the first output end and the second output end of the power splitting mechanism, when the engine is working, the bypass mechanism is disconnected, and the power of the engine drives the first output end and the second output end respectively after passing through the power splitting mechanism, when the engine is stationary, the bypass mechanism is connected, and the power of the first motor is directly transmitted from the first output end to the second output end without passing through the power splitting mechanism. Through the set bypass mechanism, the dual motors can jointly drive the vehicle forward or reverse in the pure electric driving mode, thereby improving the performance of the hybrid electric drive device.

Description

Technical Field

[0001] The present invention relates to the field of vehicle drive technology, in particular to the field of vehicle hybrid drive technology, and specifically to a hybrid electric drive device. Background Art

[0002] The existing power split hybrid electric drive device based on a planetary gear uses a planetary gear to decompose the engine power into two paths. One power flow drives the first motor to generate electricity, and the other power flow merges with the power output of the second motor to drive the vehicle.

[0003] However, it has the following shortcomings: In order to achieve dual motors driving the vehicle in pure electric driving mode, a one-way clutch is installed at the engine output end. The first motor can only rotate in one direction when driving, and reverse rotation will drag the engine to rotate. Therefore, when driving in pure electric mode, the first motor cannot provide assistance for reverse driving, and the second motor is the only one to drive the vehicle in reverse. When the second motor is not set large due to comprehensive considerations, the reverse driving torque is small, making it difficult to climb steep slopes, and the reverse performance is limited, especially difficult to meet the performance requirements of commercial vehicles. When reversing in hybrid mode, the driving force diverted by the engine to the wheels can only be in the forward direction, which not only does not help but also reduces the reverse driving torque. Therefore, it is difficult to meet the higher reverse performance requirements, especially for commercial vehicles. Therefore, it is also desirable to provide a power-split hybrid electric drive device with higher overall performance that can solve at least one of the above problems. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a hybrid electric drive device with higher comprehensive performance.

[0005] The present invention provides a hybrid electric drive device, comprising:

[0006] An engine, a first motor, a second motor, and a power splitting mechanism, wherein the power splitting mechanism includes at least one planetary gear, having an input end, a first output end, and a second output end, wherein the input end is connected to the engine, the first output end is connected to the first motor, the second output end is connected to the wheels, and the second motor is connected to the wheels;

[0007] It also includes a bypass mechanism, which is used to selectively connect the first output end and the second output end of the power split mechanism. The bypass mechanism includes an engagement and separation element. When the engine is working, the bypass mechanism is disconnected, and the power of the engine drives the first output end and the second output end respectively after passing through the power split mechanism. When the engine is stationary, the bypass mechanism is connected, and the power of the first motor is directly transmitted from the first output end to the second output end without passing through the power split mechanism.

[0008] Preferably, the speed ratio of the bypass mechanism from the first output end to the second output end is -k, where k is the ratio of the torque of the second output end to the torque of the first output end when the power of the engine is split by the power split mechanism.

[0009] Preferably, the power splitting mechanism includes: a first planetary row and a second planetary row, the first planetary row includes a first sun gear, a first planetary carrier and a first ring gear, the second planetary row includes a second sun gear, a second planetary carrier and a second ring gear, the engine is fixedly connected to the first planetary carrier, the first motor is fixedly connected to the first sun gear, the first planetary carrier is fixedly connected to the second sun gear, the first ring gear is fixedly connected to the second ring gear, the second planetary carrier is connected to the wheel, and K=k1+k1 / k2, where k1 and k2 are the structural characteristic parameters of the first planetary row and the second planetary row respectively.

[0010] Preferably, the bypass mechanism includes: a first gear installed on the first output end, a second gear installed on the second output end, and several intermediate gears meshing and transmitting therebetween, and the total number of meshing times from the first gear to the second gear is an odd number.

[0011] Preferably, the power splitting mechanism includes: a first planetary gear, the first planetary gear includes a first sun gear, a first planetary carrier and a first ring gear, the engine is fixedly connected to the first planetary carrier, the first motor is fixedly connected to the first sun gear, the first ring gear is connected to the wheel, and K=k1, where k1 is the structural characteristic parameter of the first planetary gear.

[0012] Preferably, the bypass mechanism includes: a third planetary gear, the third planetary gear includes a third sun gear, a third planetary carrier and a third ring gear, the third ring gear is fixedly connected to the first ring gear, the third sun gear is fixedly connected to the first sun gear, the third planetary carrier is connected to the housing through the engaging and separating element, and the structural characteristic parameter k3=k1 of the third planetary gear.

[0013] Preferably, the third planetary gear set is the same as the first planetary gear set.

[0014] Preferably, in the pure electric driving mode, the engaging and disengaging elements are engaged, the engine remains stationary, and the first motor and the second motor jointly drive the vehicle forward or reverse.

[0015] Preferably, when switching from the pure electric driving mode to the hybrid driving mode, the engaging and disengaging elements are disengaged, the first motor drags the engine to start, and the second motor drives the vehicle.

[0016] Preferably, in hybrid driving mode, the engaging and disengaging element remains in a disengaged state, the power of the engine drives the first motor and the wheels after passing through the power split mechanism, and the second motor also participates in driving the wheels.

[0017] The hybrid electric drive device of the present invention can ensure that the dual motors jointly drive the vehicle forward or reverse in the pure electric driving mode by providing a bypass mechanism, thereby improving the performance of the hybrid electric drive device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of a hybrid electric drive device according to a first specific embodiment of the present invention;

[0019] Figure 2 is a schematic structural diagram of a hybrid electric drive device according to a second specific embodiment of the present invention;

[0020] Figure 3 2 is a schematic structural diagram of a hybrid electric drive device according to a third specific embodiment of the present invention.

[0021] Description of main component symbols:

[0022] 1. Engine; 2. First motor; 3. Second motor; 4. 40. 41. 42. Power splitter, input, first output, and second output, respectively; 4. 43. 431. 432. 433. 1. First planetary row, first sun gear, first planetary carrier, and first ring gear, respectively; 4. 441. 442. 443. 2. Second planetary row, second sun gear, second planetary carrier, and second ring gear, respectively; 5. 51. 52. 53. 54. 3. Bypass mechanism, engagement and disengagement element, first gear, second gear, and intermediate gear, respectively; 5. 551. 552. 553. 3. Third planetary row, third sun gear, third planetary carrier, and third ring gear, respectively; 8. Housing; 9. Wheel. DETAILED DESCRIPTION

[0023] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0026] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0027] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0028] Figure 1 Schematic diagram of the structure of the hybrid electric drive device of the first embodiment of the present invention. Figure 1The hybrid electric drive device includes: an engine 1, a first motor 2, a second motor 3 and a power splitting mechanism 4. The power splitting mechanism 4 includes at least one planetary gear, having an input end 40, a first output end 41 and a second output end 42. The input end 40 is connected to the engine 1, the first output end 41 is connected to the first motor 2, the second output end 42 is connected to the wheel 9, and the second motor 3 is connected to the wheel 9; it also includes a bypass mechanism 5, the bypass mechanism 5 is used to selectively connect the first output end 41 and the second output end 42, and the bypass mechanism 5 includes an engagement and separation element 51. When the engine 1 is working, the bypass mechanism 5 is disconnected, and the power of the engine 1 drives the first output end 41 and the second output end 42 respectively after passing through the power splitting mechanism 4. When the engine 1 is stationary, the bypass mechanism 5 is connected, and the power of the first motor 2 is directly transmitted from the first output end 41 to the second output end 42 without passing through the power splitting mechanism 4.

[0029] The speed ratio from the first output terminal 41 to the second output terminal 42 of the bypass mechanism 5 is -K, where K is the ratio of the torque at the second output terminal 42 to the torque at the first output terminal 41 when the power of the engine 1 is being diverted by the power diversion mechanism 4. When the speed ratio from the first output terminal 41 to the second output terminal 42 of the bypass mechanism 5 is -K, the kinematic equation of the diversion mechanism 4 including the planetary gear set indicates that the natural speed of the input terminal 40 is zero, and the speed of the engine 1 connected to the input terminal 40 is also zero. This ensures that the speed of the engine 1 is zero without adding a one-way clutch, and does not restrict the rotation direction of the first motor 2. This significantly improves vehicle performance under pure electric driving conditions.

[0030] Figure 2 Schematic diagram of the structure of the hybrid electric drive device of the second specific embodiment of the present invention. Figure 2 The power splitting mechanism 4 includes: a first planetary row 43 and a second planetary row 44. The first planetary row 43 includes a first sun gear 431, a first planetary carrier 432 and a first ring gear 433. The second planetary row 44 includes a second sun gear 441, a second planetary carrier 442 and a second ring gear 443. The engine 1 is fixedly connected to the first planetary carrier 432, the first motor 2 is fixedly connected to the first sun gear 431, the first planetary carrier 432 is fixedly connected to the second sun gear 441, the first ring gear 433 is fixedly connected to the second ring gear 443, and the second planetary carrier 442 is connected to the wheel, and K=k1+k1 / k2, where k1 and k2 are structural characteristic parameters of the first planetary row 43 and the second planetary row 44, respectively.

[0031] According to the kinematic equations of the first planetary gear 43 and the second planetary gear 44, the following kinematic and dynamic characteristics formulas (1) and (2) can be obtained after analysis:

[0032]

[0033] Tm1 :T out :T e =k2:k1(1+k2):(k1+k2+k1k2) (2)

[0034] In the formula: n m1 、n out 、n e 、T m1 、T out 、T e , k1, k2 are respectively the speed of the first motor 2 (i.e., the first output terminal 41), the speed of the second output terminal 42, the speed of the engine 1, the torque of the first motor 2, the output torque of the second output terminal 42, the torque of the engine 1, the structural characteristic parameters of the first planetary gear 43, and the structural characteristic parameters of the second planetary gear 44. Among them, the first output terminal 41 is as follows Figure 2 The first sun gear 431 and the second output end 42 are shown as follows. Figure 2 A second planet carrier 442 is shown.

[0035] It can be seen from this that when the power of the engine 1 is split by the power splitting mechanism 4, the torque ratio of the second output end 42 to the first output end 41 is K = k1 + k1 / k2, so the speed ratio of the bypass mechanism 5 from the first output end 41 to the second output end 42 is -(k1 + k1 / k2).

[0036] Reference Figure 2 The bypass mechanism 5 includes: a first gear 52 mounted on the first output end 41, a second gear 53 mounted on the second output end 42, and several intermediate gears 54 meshing and transmitting therebetween. The total number of meshing times from the first gear 52 to the second gear 53 is an odd number.

[0037] The first gear 52, several intermediate gears 54 and the second gear 53 should achieve a speed ratio of -(k1+k1 / k2), and usually adopt external gear meshing transmission, so the total number of meshing times is an odd number, thereby ensuring that the first output end 41 and the second output end 42 rotate in opposite directions when connected.

[0038] Figure 3 Schematic diagram of the structure of the hybrid electric drive device of the third specific embodiment of the present invention. Figure 3 The power splitting mechanism 4 includes: a first planetary row 43, the first planetary row 43 includes a first sun gear 431, a first planetary carrier 432 and a first ring gear 433, the engine 1 is fixedly connected to the first planetary carrier 432, the first motor 2 is fixedly connected to the first sun gear 431, the first ring gear 433 is connected to the wheel 9, and K=k1, where k1 is a structural characteristic parameter of the first planetary row 43.

[0039] According to the kinematic equation of the first planetary gear 43, the following kinematic and dynamic characteristics formulas (3) and (4) can be obtained after analysis:

[0040] n m1 +k1 n out =(1+k1)n e (3)

[0041] T m1 :T out :T e =1:k1:(1+k1) (4)

[0042] In the formula: n m1 、n out 、n e 、T m1 、T out 、T e , k1, k2 are respectively the speed of the first motor 2 (i.e., the first output terminal 41), the speed of the second output terminal 42, the speed of the engine 1, the torque of the first motor 2, the output torque of the second output terminal 42, the torque of the engine 1, the structural characteristic parameters of the first planetary gear 43, and the structural characteristic parameters of the second planetary gear 44. Among them, the first output terminal 41 is as follows Figure 3 The first sun gear 431 and the second output end 42 are shown as follows. Figure 3 The first ring gear 433 is shown.

[0043] It can be seen from this that when the power splitting mechanism 4 is used to split the power of the engine 1, the torque ratio K of the second output end 42 to the first output end 41 is k1, so the speed ratio of the bypass mechanism 5 from the first output end 41 to the second output end 42 is -k1.

[0044] The bypass mechanism 5 includes: a third planetary row 55, the third planetary row 55 includes a third sun gear 551, a third planetary carrier 552 and a third ring gear 553, the third ring gear 553 is fixedly connected to the first ring gear 433, the third sun gear 551 is fixedly connected to the first sun gear 431, and the third planetary carrier 552 is connected to the housing 8 via an engaging and separating element 51. The structural characteristic parameter k3 of the third planetary row 55 is k1.

[0045] Bypass mechanism 5 is implemented using a planetary gear, which is more compact and easier to arrange than a fixed-axis gear structure. The speed ratio of the third planetary gear 55 when the third planet carrier 552 is locked is -k3. After the engagement and release element 51 are disengaged in power split mode, the third planetary gear 55 idles. The rotational speeds of the third ring gear 553 and the first ring gear 433 are equal, and the rotational speeds of the third sun gear 551 and the first sun gear 431 are equal. Therefore, the rotational speed of the third planet carrier 552 is equal to the rotational speed of the engine 1.

[0046] The third planetary gear set 55 is identical to the first planetary gear set 43. Since the third planetary gear set 55 and the first planetary gear set 43 share the same structural parameters, they can be manufactured as the same set for ease of manufacture and cost considerations. Furthermore, since the third ring gear 553 is fixedly connected to the first ring gear 433, only two bearings are required to support these two components, resulting in a very simple structure.

[0047] A plug-in hybrid electric vehicle (PHEV) has a pure electric driving mode and a hybrid driving mode, and its operating principles are described below.

[0048] In the pure electric driving mode, the engagement and disengagement element 51 is engaged, the engine 1 remains stationary, and the first motor 2 and the second motor 3 jointly drive the vehicle forward or reverse.

[0049] When the pure electric driving mode is switched to the hybrid driving mode, the engagement and separation element 51 is disengaged, the first motor 2 drags the engine 1 to start, and the second motor 3 drives the wheels.

[0050] In hybrid driving mode, the engagement and separation element 51 remains in a disengaged state, and the power of the engine 1 drives the first motor 2 and the wheels after passing through the power split mechanism 4, and the second motor 3 also participates in driving the wheels.

[0051] The hybrid electric drive device of the specific embodiment of the present invention can be used in a front-engine front-drive vehicle, a front-engine rear-drive vehicle, or a rear-engine rear-drive vehicle, without limitation thereto.

[0052] The hybrid electric drive device of the specific embodiment of the present invention can ensure that the dual motors jointly drive the vehicle forward or reverse in the pure electric driving mode by providing a bypass mechanism, thereby improving the performance of the hybrid electric drive device.

[0053] The present invention is not limited to the above-described embodiments, but covers all changes and modifications made without departing from the spirit and scope of the present invention. These changes and modifications should not be considered to depart from the spirit and scope of the present invention, and all modifications such as are obvious to those skilled in the art should be included within the scope of the appended claims.

Claims

1. A hybrid electric drive device, characterized in that: include: An engine, a first motor, a second motor, and a power splitting mechanism, wherein the power splitting mechanism includes at least one planetary gear, having an input end, a first output end, and a second output end, wherein the input end is connected to the engine, the first output end is connected to the first motor, the second output end is connected to the wheels, and the second motor is connected to the wheels; The engine further includes a bypass mechanism, the bypass mechanism being configured to selectively connect the first output end and the second output end of the power split mechanism, the bypass mechanism including an engaging and disengaging element. When the engine is operating, the bypass mechanism is disengaged, and the power of the engine passes through the power split mechanism to drive the first output end and the second output end respectively. When the engine is stationary, the bypass mechanism is engaged, and the power of the first motor is directly transferred from the first output end to the second output end without passing through the power split mechanism. The speed ratio of the bypass mechanism from the first output end to the second output end is -K, where K is the ratio of the torque of the second output end to the torque of the first output end when the power of the engine is split by the power split mechanism.

2. The hybrid electric drive device according to claim 1, characterized in that: The power splitting mechanism includes: a first planetary row and a second planetary row, the first planetary row includes a first sun gear, a first planetary carrier and a first ring gear, the second planetary row includes a second sun gear, a second planetary carrier and a second ring gear, the engine is fixedly connected to the first planetary carrier, the first motor is fixedly connected to the first sun gear, the first planetary carrier is fixedly connected to the second sun gear, the first ring gear is fixedly connected to the second ring gear, the second planetary carrier is connected to the wheel, and K=k1+k1 / k2, where k1 and k2 are structural characteristic parameters of the first planetary row and the second planetary row respectively.

3. The hybrid electric drive device according to claim 2, characterized in that: The bypass mechanism includes: a first gear installed on the first output end, a second gear installed on the second output end, and several intermediate gears meshing and transmitting therebetween, and the total number of meshing times from the first gear to the second gear is an odd number.

4. The hybrid electric drive device according to claim 1, characterized in that: The power splitting mechanism includes: a first planetary gear, the first planetary gear includes a first sun gear, a first planetary carrier and a first ring gear, the engine is fixedly connected to the first planetary carrier, the first motor is fixedly connected to the first sun gear, the first ring gear is connected to the wheel, and K=k1, where k1 is a structural characteristic parameter of the first planetary gear.

5. The hybrid electric drive device according to claim 4, characterized in that: The bypass mechanism includes: a third planetary gear, the third planetary gear includes a third sun gear, a third planetary carrier and a third ring gear, the third ring gear is fixedly connected to the first ring gear, the third sun gear is fixedly connected to the first sun gear, the third planetary carrier is connected to the housing through the engaging and disengaging element, and the structural characteristic parameter k3 of the third planetary gear is k1.

6. The hybrid electric drive device according to claim 5, characterized in that: The third planetary gear is the same as the first planetary gear.

7. The hybrid electric drive device according to claim 1, characterized in that: In the pure electric driving mode, the engaging and disengaging element is engaged, the engine remains stationary, and the first motor and the second motor jointly drive the vehicle forward or reverse.

8. The hybrid electric drive device according to claim 7, characterized in that: When switching from the pure electric driving mode to the hybrid driving mode, the engaging and disengaging elements are disengaged, the first motor drives the engine to start, and the second motor drives the wheels.

9. The hybrid electric drive device according to claim 8, characterized in that: In the hybrid driving mode, the engaging and disengaging element remains in a disengaged state, the power of the engine drives the first motor and the wheels after passing through the power split mechanism, and the second motor also participates in driving the wheels.

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