Powertrain for a hybrid propulsion or traction motor vehicle with a mechanism for blocking a combustion engine - Patents.com

Abstract

1. A powertrain for a hybrid propulsion or traction motor vehicle comprising: a first machine (40) having a rotor (41) fixed to a sun gear (32) of a power split planetary gear train (30) and configured to be coupled or decoupled to the wheels of the vehicle via a differential assembly (80); a second machine (50) having a rotor (51) fixed to a secondary shaft (60) and configured to be coupled or decoupled to the wheels of the vehicle via the differential assembly (80); and a combustion engine (20), characterized in that the powertrain comprises a mechanism (100) for blocking the combustion engine, the mechanism (100) including a controlled pivot blocking finger configured to engage with at least one notch (21 a) carried by a rotating element (21) of the combustion engine connected to the crankshaft (20).

Description

Summary of the Invention

[0001] The present invention relates to the field of transmissions for hybrid propulsion or traction motor vehicles.

[0002] More particularly, the present invention relates to a powertrain comprising two electric machines and a combustion engine, the combustion engine being coupled to a planet carrier, a generator being coupled to a sun gear, and a vehicle being coupled to a ring gear via a gear set.

[0003] The invention relates in particular to variable speed drives, or so-called continuously variable transmissions (CVT), in which the ratio between input speed and output speed is continuously variable.

[0004] More particularly, the present invention relates to a continuously variable transmission that includes a power-splitting planetary gear set that mechanically connects a combustion engine and two electric machines that exchange electrical power.

[0005] In such a transmission, mechanical power from the combustion engine is split at the input element of the gear set between a first power path, where power is extracted by a first electric machine, and a second power path, where power is combined with mechanical power from a second electric motor. The mechanical power is collected at the output element of the gear set, from where it is transferred to the wheels of the vehicle with a transmission ratio that varies depending on the power exchanged between the two electric machines.

[0006] So-called "hybrid" transmissions are generally used in so-called "full hybrid" or "rechargeable hybrid" modes. When a transmission is used in a rechargeable hybrid, it is preferred to use an electric machine, called a generator, as the motor. Coupling the two electric machines during electric running is advantageous since the size of the electric machines can be reduced. The transmission of power from the generator to the wheels of the vehicle is possible via a planetary gear set, which then acts as a reducer, as long as the planet carrier is blocked.

[0007] It is known practice to use a freewheel system to block a planet carrier connected to a combustion engine.

[0008] In this regard, reference may be made to US Pat. No. 5,788,006, which describes a hybrid drivetrain called "e-CVT" comprising a combustion engine and a transmission based on a planetary gear set, which uses two electric machines to vary its gear reduction ratio. The combustion engine is connected to the planet carrier of the gear set. The first electric machine is connected to the sun gear. The change in its speed changes the ratio between the combustion engine and the ring gear of the gear set and the wheels, which are connected to the second electric machine. The rotation of the planet carrier shaft is blocked by a freewheel, which allows the use of a forward-only generator.

[0009] However, such a system allows blocking of the planetary carrier connected to the combustion engine only in forward motion.

[0010] It is also important to be able to use two electric machines in reverse, as the lack of the possibility of using a generator in reverse can result in the traction machine being oversized.

[0011] Oversizing the electric machine involves excessive power consumption, which depends on the use of the vehicle, and an increased footprint of the electric machine.

[0012] There is a need for improvements to the prior art hybrid automotive vehicle transmissions. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] U.S. Patent No. 5,788,006

[0014] It is therefore an object of the present invention to provide an electric powertrain with improved energy performance.

[0015] The present invention relates to - a first machine having a rotor rigidly connected to a sun gear of a power split planetary gear set and configured to be coupled and decoupled to the wheels of the vehicle via a differential assembly; - a second machine including a rotor rigidly connected to the secondary shaft and configured to be coupled and decoupled to the wheels of the vehicle via a differential assembly; - Combustion engines and The present invention relates to a powertrain for a hybrid propulsion or traction motor vehicle comprising:

[0016] The powertrain includes a mechanism for blocking the combustion engine, the mechanism including a controlled pivoting blocking finger configured to interact with at least one notch carried by a rotating element of the combustion engine connected to the crankshaft.

[0017] It is therefore possible to block the combustion engine in both directions of rotation, thereby allowing the use of the generator as a motor in forward and reverse motion.

[0018] Advantageously, the pivot block finger comprises at least one stud configured to interact with the notch.

[0019] For example, a blocking finger may be pivotally mounted about its own pin.

[0020] Advantageously, the blocking mechanism comprises a first housing and a second housing, the pivot pin of the blocking finger being supported by bearings carried by the first and second housings.

[0021] Advantageously, the blocking mechanism comprises a control system configured to rotate the blocking fingers.

[0022] For example, if a control system: a control electric motor supported within the first housing; and - a screw attached to the spindle of the electric motor; - a nut with a nut head that interacts with the screw and with a nut shank that is coaxial with the spindle of the electric motor and extends on an opposite side of said electric motor; - a peg for blocking the rotation of the nut, the peg being rigidly connected to the first housing and parallel to the spindle of the electric motor; Equipped with:

[0023] The nut is therefore only capable of axial movement.

[0024] For example, the control system further includes an olive washer slidably mounted on the shank of the nut and held pressed against the stop pin by an engagement spring mounted between the head of the nut and the washer, the washer configured to rotate the pivot block finger during axial movement.

[0025] For example, the nut is supported by two bearings mounted in the first and second housings, respectively.

[0026] Advantageously, the power train comprises a flywheel housing, the blocking mechanism being supported by the flywheel housing.

[0027] The powertrain may incorporate, for example, a power-splitting electric continuously variable transmission (e-CVT) that includes a power-splitting planetary gear set configured to mechanically connect a combustion engine and two electric machines that exchange electrical power.

[0028] According to a second aspect, the invention relates to a hybrid propulsion or traction motor vehicle comprising at least two drive wheels and a powertrain as described above arranged to rotate said drive wheels.

[0029] Further objects, features and advantages of the present invention will become apparent from a reading of the following description, given purely as a non-limiting example, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0030] [Figure 1] 1 is a schematic longitudinal view of an electric continuously variable transmission (e-CVT) of a motor vehicle according to an embodiment of the present invention, comprising a device for blocking a combustion engine; [Diagram 2] FIG. 2 is a partial cross-sectional view of the device for blocking a combustion engine of FIG. 1, with the flywheel in a blocked state; [Diagram 3] FIG. 2 is a partial cross-sectional view of the device for blocking a combustion engine of FIG. 1, with the flywheel in an unblocked state; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] As shown very diagrammatically in FIG. 1, a hybrid powertrain, generally designated by the reference numeral 1, is intended to be incorporated in a hybrid propulsion or traction motor vehicle (not shown).

[0032] The powertrain 1 comprises two electric machines 40, 50 intended to drive drive shafts (not shown) of the driving wheels of the vehicle via a differential assembly 80. Each electric machine 40, 50 is provided with its own driveline.

[0033] The powertrain 1 further comprises a combustion engine represented by a crankshaft 20 .

[0034] The powertrain 1 incorporates a power-split electric continuously variable transmission (e-CVT) having a power-split planetary gear set 30 that mechanically connects a combustion engine 20 and two electric machines 40, 50 that exchange power with each other.

[0035] As shown, the elements of the planetary gear set 30 include a planet carrier 31 connected to the combustion engine, in particular its crankshaft 20, a sun gear 32 connected to a first electric machine 40 used primarily as a generator, and a ring gear 33 connected to a differential 80 by means of two gear stages (not numbered) carried by an intermediate shaft 70.

[0036] The second electric machine 50 is used primarily as a motor and is connected to a differential 80 by means of two gear stages (not numbered) carried by a secondary shaft 60 and an intermediate shaft 70. The gear stages are already known and will not be described further.

[0037] As shown, the powertrain 1 comprises three separate housings 10, 11, 12: a housing 10 for the flywheel and differential, a housing 11 for the mechanical equipment, and a housing 12 for the electric machine.

[0038] The flywheel housing 10 incorporates a crankshaft 20, a combustion engine flywheel 21, a torque limiter 22 and a vibration damping device 23.

[0039] The flywheel housing 10 and the machinery housing 11 define between them a first compartment (not numbered) in which all the machinery is mounted, in particular the power transmission means, the coupling system, the parking brake engagement mechanism and the like.

[0040] The machinery housing 11 and the electric machine housing 12 define between them a second compartment (not numbered) in which two electric machines 40, 50 are mounted.

[0041] A first electric machine 40 , called a generator, comprises a rotor shaft 41 and a stator 42 .

[0042] Rotor shaft 41 supports at its end the sun gear 32 , which is the central gear of the power split gear set 30 .

[0043] The sun gear 32 interacts with gears 31a (only one is shown) carried by a planet carrier 31. The planet carrier, the central element of the gear set 30, is connected to the damper hub 23 of a flywheel 21 which is rigidly connected to the crankshaft 20 of the combustion engine.

[0044] The planet carrier is guided in the flywheel housing 10 by roller bearings (without reference number), the teeth of whose planet gears are guided on the inside in the teeth of the sun gear 32 and on the outside in the teeth of the ring gear 33 of the gear set 30 .

[0045] The external output element of gear set 30, being ring gear 33, is carried by a sleeve 34 supported by roller bearings (not numbered) in housings 10 and 11. This sleeve has teeth 34a on its outer periphery which mesh with a gear 71 carried by a shaft 70, thereby transmitting to it the power from the combustion engine not taken off by generator 40. The teeth 70a of shaft 70 in turn transmit power to a ring gear 81 mounted on a differential 80 which is connected by a shaft (not shown) to the wheels of the vehicle.

[0046] The second electric machine 50, or main machine, comprises a rotor 51 and a stator 52. The rotor 51 terminates in splines 51a capable of driving a primary shaft 60. The teeth 60a transfer power from the motor 50 to a gear 71 carried by a shaft 70. The teeth 70a of the shaft 70 in turn transfer power to a ring gear 81 attached to a differential 80 which is connected by a shaft (not shown) to the wheels of the vehicle.

[0047] As shown in detail in FIGS. 2 and 3, the powertrain 1 comprises a mechanism 100 for blocking the combustion engine, in particular the flywheel 21 .

[0048] The blocking mechanism 100 is attached to the flywheel housing 10 and includes a first housing 101 and a second housing 102.

[0049] The blocking mechanism 100 comprises a control system 120 having an electric control motor 103 supported in a first housing 101, a screw 104 attached to a spindle of the electric motor 103, and a nut 105 interacting with the screw 104 and supported by two bearings 101a, 102a mounted in the first housing 101 and the second housing 102, respectively.

[0050] The nut 105 has a nut shaft portion 105 a that is coaxial with the spindle of the electric motor 103 and extends on the opposite side of the electric motor 103 .

[0051] The control system 120 further comprises a peg 106 fixedly connected to the first housing 101 and parallel to the spindle of the electric motor 103 and interacting with a nut 105 to prevent rotation.

[0052] Thus, the nut 105 is only capable of axial movement.

[0053] The control system 120 further includes a washer 107. The washer 107 is slidably attached to the shaft portion 105a of the nut 105, and is pressed against a stop pin 109 by an engagement spring 108 attached between the head of the nut 105 and the washer 107.

[0054] The blocking mechanism 100 further comprises a pivoting block finger 110 including a stud 110 a that interacts with a notch 21 a located on the outer periphery of the flywheel 21 .

[0055] The blocking finger 110 pivots about a pin 111 , the bearings of which (not shown) are supported by the first housing 101 and the second housing 102 .

[0056] The washer 107 moves axially to contact the pivot block finger 110 .

[0057] When the vehicle is in electric driving mode, the combustion engine is turned off and the stud 110 a of the blocking finger 110 is engaged in one of the notches 21 a of the flywheel 21 .

[0058] The random angular position of the flywheel 21 at rest means that engagement of the notches 21a with the studs 110a of the blocking fingers 110 is not guaranteed.

[0059] In this case, the blocking finger 110 is unable to make a full engagement rotation and the washer 107 does not move along its full stroke, but the nut 105 continues without a nominal stroke, placing the washer under tension with the spring 108 being compressed. Starting the generator 40 will therefore rotate the flywheel 21 as long as the required bearing torque of the planet carrier exceeds the motor drag.

[0060] As soon as the stud 110 a of the blocking finger 110 coincides with one of the notches 21 a of the flywheel 21 , the spring 108 instantly pushes back the washer 107 , thus having the effect of completing the engagement of the blocking finger 110 .

[0061] The blocking mechanism 100 therefore enables the generator 40, by means of the planet carrier 31, to transmit all of the power it requires to the ring gear 33 of the planetary gear set 30 and then via the intermediate shaft 70 and differential 80 to the wheels of the vehicle.

[0062] The blocking mechanism 100 works in both rotational directions and can be used in reverse and forward motion.

[0063] When the driving mode of the vehicle is changed to the hybrid mode, the flywheel 21 must be released from the blocking mechanism 100 .

[0064] In this case, the electric motor 103 of the blocking mechanism 100 moves the nut 105 towards the motor 103 via the screw 104, which drives the washer 107 via the pin 109. The stud 110a of the blocking finger 110 is disengaged from the notch 21a of the flywheel 21 by a return member (not shown), for example a spring.

[0065] The invention therefore makes it possible to block the planetary carrier connected to the combustion engine in both directions of rotation in order to optimise the dimensions of the electric machine, thereby enabling the use of the generator as a motor in forward and reverse and therefore the use of both electric machines in forward and reverse in electric travel mode.

Claims

1. - A first machine (40) comprising a rotor (41) firmly connected to the sun gear (32) of a power split planetary gear set (30) and configured to be coupled or decoupled to the vehicle wheels via a differential assembly (80); - A second machine (50) comprising a rotor (51) firmly connected to a secondary shaft (60) and configured to be coupled or decoupled to the vehicle wheels via the differential assembly (80); - A combustion engine (20); In a powertrain for a hybrid propulsion or traction motor vehicle comprising: A mechanism (100) including a controlled pivot block finger (110) configured to interact with at least one notch (21a) supported by a rotating element (21) of the combustion engine connected to a crankshaft (20), the mechanism (100) comprising a mechanism for blocking the combustion engine, characterized in that it is a powertrain.

2. The powertrain according to claim 1, wherein the pivot block finger (110) comprises at least one stud (110a) configured to interact with the notch (21a).

3. The powertrain according to claim 1 or 2, wherein the block finger (110) is pivotally mounted around its own pin (111).

4. The powertrain according to claim 3, wherein the block mechanism (100) comprises first and second housings (101, 102), and the pivot pin (111) of the block finger (110) is supported by bearings supported by the first and second housings (101, 102).

5. The powertrain according to claim 1 or 2, wherein the notch (21a) is supported by a flywheel (21).

6. The powertrain according to claim 1 or 2, wherein the block mechanism (100) comprises a control system (120) configured to rotate the block finger (110).

7. The block mechanism (100) comprises a control system (120) configured to rotate the block finger (110), The control system (120) is - An electric motor (103) supported within the first housing (101); - A screw (104) attached to the spindle of the electric motor (103); - A nut (105) that interacts with the screw (104), has a nut shaft portion (105a) that is coaxial with the spindle of the electric motor (103) and extends to the opposite side of the electric motor (103); - A peg (106) for blocking the rotation of the nut (105), the peg (106) being firmly connected to the first housing (101) and parallel to the spindle of the electric motor (103); - A washer (107) slidably attached to the shaft portion (105a) of the nut (105), the washer (107) being pressed and held against a stop pin (109) by an engagement spring (108) attached between the head of the nut (105) and the washer (107), and configured to rotate the pivot block finger (110) during axial movement; the washer (107); The power train according to claim 4, comprising:

8. The power train according to claim 7, wherein the nut (105) is supported by two bearings (101a, 102a) respectively attached within the first and second housings (101, 102).

9. The power train according to claim 1 or 2, comprising a flywheel housing (10), wherein the blocking mechanism (100) is supported by the flywheel housing (10).

10. The power train according to claim 1 or 2, incorporating a power-split electric continuously variable transmission comprising a power-split planetary gear set (30) configured to mechanically connect the combustion engine (20) and two electromechanical devices (40, 50) that exchange power with each other.

11. A hybrid propulsion or traction motor vehicle comprising at least two drive wheels and the power train (1) according to claim 1 or 2 configured to rotate the drive wheels.

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