Transmission module for a hybrid drive vehicle

Abstract

A transmission module for a hybrid drive vehicle, suitable for insertion between an internal combustion engine and a vehicle transmission and comprising a tray-like support structure and a module driver, the support structure defining a housing for a decoupling clutch and suitable for being fixed to the internal combustion engine, the module driver being carried by the support structure and comprising a first transmission member suitable for being connected to the decoupling clutch via a torsional vibration damper and a second transmission member suitable for being connected to an electric motor; the damper comprising an actuator centered relative to a crankshaft and a transmission torque converter and a seat for a support bearing of the support structure.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the priority of Italian Patent Application No. 102019000009612, filed on June 20, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to a transmission module for a hybrid drive vehicle, and more particularly to a transmission module suitable for insertion between an internal combustion engine and a transmission of a hybrid drive vehicle. Background Art

[0004] As is known, hybrid drive vehicles include an internal combustion engine and at least one electric machine that can function as a generator or a motor depending on vehicle operating conditions to deliver torque in conjunction with (or instead of) the internal combustion engine.

[0005] Configurations using an electric motor connection between an internal combustion engine and a vehicle transmission are generally referred to as "P2." Modular units are known that are suitable for insertion between a vehicle's internal combustion engine and transmission (hence currently referred to as "P2 modules"), which modular units include, in addition to the electric motor, one or more clutches to selectively connect the transmission to the internal combustion engine and / or the electric motor in addition to associated actuators and transmission elements.

[0006] A problem associated with known P2 modules is the complexity of installation and assembly due to the fact that said modules comprise relatively heavy parts which must be accurately centered and supported relative to the internal combustion engine on which they are installed and relative to the module. Summary of the Invention

[0007] The object of the present invention is to produce a P2 transmission module that solves the above-mentioned problems.

[0008] The above objects are achieved by a transmission module for a hybrid drive unit of a vehicle, the drive unit comprising an internal combustion engine provided with a crankshaft, a decoupling clutch arranged coaxially with the crankshaft and the vehicle transmission, the transmission module being configured to be inserted between the engine and the transmission and comprising: a support structure configured to be fixed to the engine; a module driver accommodated in the support structure and comprising: a first transmission member having an axis which coincides with the axis of the crankshaft and the axis of the decoupling clutch in use; a torsional vibration damper configured to connect the output member of the decoupling clutch and the first transmission member; at least a first transmission member having an axis which coincides with the axis of the crankshaft and the axis of the decoupling clutch in use; a torsional vibration damper configured to connect the output member of the decoupling clutch and the first transmission member; and at least a second transmission member having an axis which coincides with the axis of the crankshaft and the axis of the decoupling clutch in use. Two transmission components, the second transmission component is suitable for being connected to the motor; a transmission element, the transmission element connecting at least the first transmission component and the second transmission component; the shock absorber comprises: an actuator provided with a hub, an actuator plate coaxial with the hub and suitable for being coupled to the first transmission component by elastic means, and a shaft extending from the side of the hub facing the engine when in use, wherein the shaft comprises an end portion and a spline portion, the end portion being configured to define centering relative to the crankshaft, the spline portion being used to be connected to the plate of the decoupling clutch in a rotationally fixed and axially sliding manner, the hub defining a seat for supporting a bearing of a support structure and a centering for the transmission component on a side facing the vehicle transmission when in use. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] For a better understanding of the present invention, preferred embodiments are described below with reference to the accompanying drawings, in which:

[0010] Figure 1 is a perspective view of a transmission module according to the present invention;

[0011] Figure 2 is a schematic diagram of a hybrid drive unit of a vehicle including the module of the present invention;

[0012] Figure 3 yes Figure 1 An exploded perspective view of the module;

[0013] Figure 4 、 Figure 5 and Figure 6 They include Figure 1 A front view, a rear perspective view, and a rear view of the hybrid power unit of the transmission module;

[0014] Figure 7 and Figure 8 Along the Figure 6 The cross section of line VII-VII and line VIII-VIII;

[0015] Figure 9 It is an exploded perspective view of the hybrid power unit;

[0016] Figure 10 and Figure 11 yes Figure 9 A perspective view of individual details of the unit;

[0017] Figure 12 yes Figure 1 An exploded perspective view of a damper of a transmission module;

[0018] Figure 13 and Figure 14 It is from Figure 12 a perspective view of the opposite side of the shock absorber detail; and

[0019] Figure 15 yes Figure 1 An enlarged cross section of the transmission module. DETAILED DESCRIPTION

[0020] refer to Figure 1 、 Figure 2 and Figure 15 , reference numeral 1 denotes the entire P2 transmission module, which is suitable for connecting between the internal combustion engine E and the transmission T of a hybrid vehicle to form a hybrid drive unit H as a whole.

[0021] Module 1 is part of a hybrid power unit 4 ( Figures 3 to 11 ), in addition to the module itself, the hybrid unit 4 comprises an electric machine 2 and optionally one or more accessories (such as, for example, a compressor 3 for the vehicle air conditioning system). The electric machine 2 is conveniently of the reversible type, i.e. it can be operated as an electric motor to transmit torque to the transmission (in conjunction with or as an alternative to the internal combustion engine), or as a generator to generate electricity.

[0022] The module 1 mainly comprises a tray-like support structure 5 and a module drive 6 , housed in the support structure 5 , for example by a belt, and configured to operatively and selectively connect a crankshaft 7 of the internal combustion engine E, the electric machine 2 and the transmission T to one another.

[0023] The supporting structure 5 has a substantially flat bottom wall 8 and a peripheral flange 9 extending perpendicularly thereto and forming a plurality of enlargements 10 in which holes are obtained for fastening the module 1 to the engine E. Respective tubular appendages 15, 16, 17 extend axially from the bottom wall 8 ( Figure 3 ), each tubular appendage defining a through seat inside it. The tubular appendages 15, 16, 17 have axes A, B and C coinciding respectively with the axes of the crankshaft 7 of the engine E, the motor 2 and the compressor 3, as will be better described hereinafter.

[0024] As in Figure 2、 Figure 4 and Figure 9 As can be clearly seen in the example of FIG. 1 , the module drive 6 comprises a first pulley 20 having an axis A and a torsional vibration damper 22 ( Figure 7 and Figure 8 ), the first pulley 20 being selectively connectable to the crankshaft 7 via a decoupling clutch 21 and also forming part of the hybrid unit 4.

[0025] The modular drive 6 further comprises a second pulley 23 with an axis B suitable for connection to the motor 2, and a third pulley 24 with an axis C suitable for connection to the compressor 3. To this end, the second pulley 23 and the third pulley 24 are provided with respective shafts 25 and 26 housed in respective tubular appendages 16, 17 and supported therein by respective bearings 27, 28 ( Figure 10 and Figure 11 ).

[0026] The modular drive 6 comprises a belt 29 , preferably of the poly-V type, which is wound around the pulleys 20 , 23 and 24 and rotationally connects the pulleys to one another.

[0027] Finally, the module drive 6 comprises a double-armed tensioner 30 having a first tensioner pulley 31 and a second tensioner pulley 32 which, under the thrust of elastic means not shown, act respectively on the portions 29a and 29b of the belt 29 between the second pulley 23 and the third pulley 24 and between the first pulley 20 and the second pulley 23.

[0028] The tensioner 30 includes ( Figure 4 and Figure 10 ):

[0029] - an annular bottom 33, fixed to the structure 5 surrounding the tubular appendage 16,

[0030] a first annular arm 34 revolving about the base 33 , on which the first tensioner pulley 31 is supported idling in an eccentric position, and

[0031] a second arm 35 having a first tubular end 36 articulated to the first arm 20 and a second end 37 on which the second tensioner pulley 32 is idlingly mounted.

[0032] The mentioned elastic means may comprise a spring (not shown) housed at the first end 36 of the second arm 35 and configured to urge the second arm 35 towards the first tensioner pulley 31 .

[0033] As an alternative to the example described, the tensioner may be of any other type having two arms suitable for maintaining a sufficient level of tension in the two parts 29a and 29b of the belt 29, each of which may be a slack part of the belt 29 depending on the operating conditions.

[0034] According to the description, the belt 29 can be pre-mounted on the support structure 5 and tensioned prior to the assembly of the support structure 5 on the engine E.

[0035] As in Figure 8 As can be clearly seen in the figure, the bottom wall 8 is designed so as to define the housing 38 of the clutch 21 on the side opposite the module driver 6. The clutch 21 can be part of the module 1 or, as in the example described, a unit that is separate from the module 1 and complementary thereto. In any case, since the side of the housing of the clutch 21 in the support structure 5 of the module 1 facing the clutch 21 is shaped in a manner complementary to the clutch 21, no additional axial dimensions are generated.

[0036] Tubular accessories 15( Figure 8 ) has a generally C-shaped cross-section open toward the housing 38 so as to define an annular seat 39 communicating with the housing 38. The seat 39 accommodates a hydraulic actuator 41 for controlling the clutch 21.

[0037] Conveniently, support structure 5 defines an internal passage 44 for supplying / draining oil from chamber 39 of actuator 41. Passage 44 establishes communication between chamber 39 and a radial adapter 45, which is arranged on peripheral flange 9 of support structure 5 and is adapted for connection to a hydraulic control circuit. In this way, additional dimensions, particularly axial dimensions, of actuator 41 and the associated control circuit are avoided. The internal passage is conveniently defined by two or more holes, which can be produced externally by conventional boring operations and intersect with each other to define a continuous path between adapter 45 and chamber 39. If necessary, the entrances to the holes can be closed by plugs.

[0038] Insofar as this is necessary for the understanding of the invention but does not form part of it, the clutch 21 described here in general terms comprises essentially a first plate 46 adapted to be fixed to the crankshaft 7 and a second plate 47, the second plate 47 being connected in an integral angular but axially free manner to a shaft 48 (of axis A) of the shock absorber 22 via a spline coupling 59. Figure 8 ).

[0039] More precisely, as in Figure 7 As can be clearly seen in the figure, the first plate 46 of the clutch 21 is provided with a series of holes 43 for fastening to the end flange 61 ( Figure 9 ).

[0040] One or more friction plates 49 are interposed between plates 46 and 47 of clutch 21. In the non-operating state of actuator 41, clutch 21 is held normally closed by elastic means (not shown) and rotationally connects shaft 48 of shock absorber 22 to crankshaft 7. When actuator 41 is hydraulically operated, it resists the elastic closing force, separating second plate 47 from first plate 46. A bearing 42 is interposed between actuator 41 (rotationally fixed) and second plate 47 (rotating), allowing for the transmission of axial loads and relative rotation.

[0041] Shock absorber 22 Figures 12 to 15 , and comprises an actuator 51 provided with a hub 54 rigidly (and preferably integrally) connected to a shaft 48 projecting from the hub 54 towards the internal combustion engine E. A disc 52 extends radially from the hub 54 and is provided with two radial spokes 53. The actuator 51 is supported on the tubular appendage 15 by a bearing 50, as will be better described below.

[0042] The shock absorber 22 further comprises an annular housing 55 formed by a half-shell 56 housed inside the first pulley 20 and the first pulley 20 .

[0043] The housing 55 delimits an annular chamber 57 divided into diametrically opposed inner lugs 58 of the half-shell 56 and the inner lug 58 of the first pulley 20, with two substantially semicircular shells respectively arranged inside a bow spring 60. The spokes 53 of the disc 52 of the actuator 51 run inside the annular chamber 57 and are contained between the respective ends of the spring 60, which stops the lugs 58 so as to elastically couple the first pulley 20 in rotation to the actuator 51, so that the second disc 47 coupled to the clutch 21 is rotationally integral with the shaft 48 of the actuator 51.

[0044] The half shell 56 and the pulley 20 are formed into one piece with each other by press-fitting and / or welding, and the ... Figure 12 ) is supported in a rotatable manner relative to the disk 52 of the actuator 51.

[0045] Conveniently, the second plate 47 of the clutch 21 and the plate 52 of the actuator 51 of the shock absorber 22 are provided with a corresponding series of holes 64, 65 having a position corresponding to the hole 43 and a diameter sufficient to allow the head 63 of the screw 62 to pass to fasten the first plate 46 to the flange 61 of the crankshaft 7.

[0046] The flexible plate 66 is fixed to the disk 52 of the actuator 51 , constituting the interface member between the module 1 and the transmission T.

[0047] In particular, the flexible plate 66 is connected to the disk 52 by a plurality of rivets 67 near its inner edge and is adapted to be connected to the torque converter (not shown) of the transmission T at its outer edge. The flexible plate 66 is able to compensate for slight relative axial displacements between the module 1 and the transmission T.

[0048] The actuator 51 , in addition to providing the kinematic functions described, also has a crucial role for the relative centering of the elements of the hybrid drive unit H and therefore in facilitating the assembly operations.

[0049] In particular, refer to Figure 13 、 Figure 14 and Figure 15 , the shaft 48 has at one end a cylindrical centering nose 67 suitable for sliding coupling with a centering hole to the crankshaft 7; at the opposite end, the actuator 51 has an axial blind hole 68 suitable for coupling a corresponding centering nose (not shown) of the torque converter.

[0050] The hub 54 of the actuator 51 defines a seat 69 for the bearing 50 (and is therefore centred relative to the support structure 5 ).

[0051] The disk 52 extends radially from the hub 54 near the end of the hub which, in use, faces towards the vehicle transmission T; the hub 54 forms at said end an annular lug 70 for centering the flexible plate 66 .

[0052] refer to Figure 9 and Figure 10 The motor 2 is provided with a housing 71 and a rotor (not shown) connected to a splined shaft 72. The splined shaft 72 is slidingly engaged with a splined inner portion 73 of the shaft 25 so as to achieve an angular but axially free coupling.

[0053] refer to Figure 9 and Figure 11 The compressor 3 is provided with a housing 73 and a rotor (not shown) connected to a splined shaft 74. The splined shaft 74 is slidingly engaged with an internal splined sleeve 75 rigidly connected to the shaft 26 so as to achieve an angular but axially free coupling of said sleeve.

[0054] As previously described, the connection of the module 1 to the clutch 21, to the motor 2 and to the compressor 3 is achieved by simple axial coupling of the corresponding components (shaft 48, shaft 25, sleeve 75) of the module 1 of suitable configuration. Said components thus constitute the real "power ports" of the module 1, to which units complementary to the module can be connected with great ease and with which they can exchange mechanical power.

[0055] This greatly facilitates the assembly operations since the electric motor 2 and the compressor 3 can be connected to the module 1 before or after it is fixed to the engine E; alternatively, the electric motor 2 and the compressor 3 can be fixed to the engine E directly.

[0056] From the previous description, it is already partially apparent that the operation of the transmission module 1 is as follows:

[0057] When the clutch 21 is closed, the actuator 51 is connected to the internal combustion engine (E) and the electric machine 2 via the damper 22 and a module drive 6 known per se, in addition to being connected to the vehicle transmission T via the flexible plate 66 .

[0058] In this case, the electric machine 2 can be used both as a generator (for charging the battery when the internal combustion engine is on, or as a regenerative brake) and as an electric motor for starting the internal combustion engine or for delivering additional torque when the internal combustion engine is on (boost).

[0059] When the clutch 21 is open, the electric motor can be used for electric driving, electric braking, and coasting when the internal combustion engine is switched off.

[0060] From an inspection of the features of a module 1 made according to the invention, the advantages it offers are apparent.

[0061] In particular, the module of the invention, thanks to the centering function of the actuator 51 concentrated on the shock absorber 22 , facilitates the assembly of the module and allows easy and precise centering during assembly.

[0062] Finally, it is obvious that modifications and variations may be made to the module 1 described without departing from the scope of protection defined by the claims.

[0063] Especially, module drive 6 can be replaced by chain or gear with belt.In this case, the pinion that is used for chain or gear is used to replace pulley, and the lubrication device of module must be provided.

Claims

1. A transmission module (1) for a hybrid drive unit of a vehicle, the drive unit comprising: An internal combustion engine (E) provided with a crankshaft (7), a decoupling clutch (21) being arranged coaxially with the crankshaft (7) and a vehicle transmission (T), The transmission module is configured to be inserted between the engine (E) and the transmission (T), and includes: a support structure (5) configured to be fixed to the engine (E); A modular driver (6) housed within the support structure (5) and comprising: a first transmission member (20) having an axis (A) which, in use, coincides with the axis of the crankshaft (7) and the axis of the decoupling clutch (21); a torsional vibration damper (22) configured to connect an output member (47) of the decoupling clutch and the first transmission member (20); at least a second transmission member (23) adapted to be connected to the electric machine (2); a transmission element (29) connecting at least the first and second transmission members (20, 23); The shock absorber (22) comprises an actuator (51) provided with a hub (54), an actuator disc (52) coaxial with the hub and adapted to be coupled to the first transmission member (20) by elastic means, and a shaft (48) extending from a side of the hub (54) facing the engine (E) in use, The shaft (48) comprises an end portion (67) configured to define a centering relative to the crankshaft (7), and a spline portion (59) for rotationally fixedly and axially slidingly coupling with a plate of the decoupling clutch, the hub defining a seat (69) for supporting a bearing (50) of the support structure and a centering (70) for a transmission member (56) on the side facing the vehicle transmission in use.

2. The module according to claim 1, wherein The end portion (67) of the shaft (48) is a cylindrical nose adapted to engage with a centering hole (76) formed on an end flange of the crankshaft (7).

3. The module according to claim 1, wherein The hub (54) has a plurality of axial holes (65) distributed and arranged around the axis so as to allow the fastening screws of the decoupling clutch (21) to face the crankshaft (7), and the holes (65) have a sufficient diameter to allow the screws to pass through.

4. The module according to claim 1, wherein The module comprises a flexible plate (66) fixed to the side of the actuator (51) facing the vehicle transmission and adapted to be connected to a transmission torque converter.

5. The module according to claim 4, wherein The actuator disc (52) extends radially from the hub (54) near one end of the hub which, in use, faces the vehicle transmission (T), the hub (54) forming a centering (70) for the flexible plate (66) at said end.

6. The module according to claim 5, wherein The actuator disc (52) is provided with a hole for connecting the flexible plate (66).

7. The module according to claim 4, wherein The centering for the transmission component includes an axial bore of the hub (54) configured to be engaged by a shaft of the torque converter.

8. The module according to claim 4, wherein The actuator disc (52) is provided with two radial spokes (53), the shock absorber (22) comprises an annular housing (55) integral with the first transmission member (20) and defining an annular chamber (57) in which the spokes (53) extend, the elastic means comprising at least one pair of bow springs (60) housed in the annular chamber (57) and configured to be inserted between the spokes (53) and corresponding internal stops (58) of the annular housing (55).

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