DE102015100282B4 - Modular hybrid electric vehicle rotor hub - Google Patents

Abstract

A rotor hub (40) comprising: a sheet metal cylinder (200) having splines comprising angularly spaced ridges (210) and valleys; a tube (202) surrounding the sheet metal cylinder (200) and secured to the ridges (210), and supporting a rotor (34); a hub fixed to the canister (200) and supported for rotation; a torque converter; a flexplate (42) fixed to the hub and to the torque converter (49), the tube (202 ) and the serrations define first channels (214), the sheet metal cylinder (200) is formed with holes (216, 218), each hole (216, 218) extends through one of the indentations and communicates with one of the first channels (214), the tube (202) is formed with bleed holes, each bleed hole communicating with one of the first ports (214), the rotor (34) including second ducts (220), each second port (220) communicating through one of the bleed holes with one of the first channels (214) communicates, wherein the first channels (214) and the second channels (220) are aligned along an axis of rotation, the rotor hub (40) including endplates, each endplate being disposed at an opposite end of the rotor (34) and formed with radial passages, each passage communicating with one of said second passages (220), said passages being radially aligned with respect to an axis of rotation, said tube (202) being a seamless tube (202) and a tube (202) with a continuous weld, and said rotor hub ( 40) a clutch piston (86) disposed within the canister (200); clutch plates (83, 84) engaged with the splines and capable of being actuated by the clutch piston (86).

Description

REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part filing of the U.S. Application No. 13/362,018 , which was filed on January 31, 2012.

BACKGROUND OF THE INVENTION

This invention relates to a powertrain of hybrid electric vehicles, and more particularly to a powertrain module that can be installed and secured between an engine output and a transmission input.

Hybrid electric vehicles (HEVs) include both an internal combustion engine and an electric machine that are used alternatively or in combination to propel the vehicle. Various powertrains are used in hybrid automotive vehicles, for example a parallel configuration in which the internal combustion engine is connected to the electric motor via a disconnect clutch, with the electric motor driving a torque converter input of an automatic power transmission. The transmission has an output connected to a differential coupled to the two drive wheels of the vehicle.

There is a need in the industry for a hybrid electric powertrain that includes a modular subassembly for use with various internal combustion engines and transmissions such that the module can be installed and secured between an output of one or more internal combustion engines and an input of one or more transmissions. The assembled powertrain can then be used in various vehicles. The module should include a hydraulically actuated disconnect clutch, the electric machine and appropriate power paths between the internal combustion engine and the electric machine to the transmission input. Preferably, the module provides hydraulic communication from the transmission's hydraulic system to the clutch, a balance lock, and the electric machine. The module must provide an oil pan that contains hydraulic fluid that is supplied to the module and a path for continuously returning the fluid to the transmission oil pan so that the transmission pump is reliably and continuously supplied with fluid.

Most disconnect clutches are dry, but wet clutches are generally easier to control and allow for oil cooling of the clutch and electric motor. Having the disconnect clutch embedded within the engine rotor facilitates containment, but generally requires an expensive rotor hub since it must support the rotor, clutch piston and clutch plates.

The module should have low manufacturing and assembly costs, require no modifications to the vehicle body, and must provide reliable performance.

From the DE 102 21 625 A1 discloses a rotor hub comprising a sheet metal cylinder having splines comprising angularly spaced ridges and valleys, a tube surrounding the cylinder secured to the ridges and supporting a rotor, a hub secured to the cylinder and for rotation is mounted, a torque converter and a flexplate that is fixed to the hub and to the torque converter.

From the DE 10 2013 201 243 A1 discloses a powertrain module having an input, a first partition supporting the input for rotation, a hub, an electric machine including a stator connected to the first partition and a rotor connected to the hub, a clutch for alternately opening and closing a drive connection between the input and the rotor, and a second bulkhead supporting the input for rotation.

SUMMARY OF THE INVENTION

A rotor hub comprises a sheet metal cylinder having splines comprising angularly spaced ridges and valleys, a tube surrounding the cylinder that is fixed to the ridges and that supports a rotor, a hub that is fixed to the cylinder and fixed for rotation, a A torque converter and a flexplate attached to the hub and the torque converter, the tube and splines defining first channels, the cylinder being formed with holes, each hole extending through one of the indentations and communicating with one of the first channels, the tube formed with bleed holes, each bleed hole communicating with one of the first channels, the rotor including second runners, each second runner communicating with one of the first runners through one of the bleed holes, the first runners and the second runners being aligned along an axis of rotation , the rotor hub comprising end plates, where j each end plate is located at an opposite end of the rotor and is formed with radial passages, each passage communicating with one of the second channels, the passages being radially aligned with respect to an axis of rotation, the tube comprising a seamless tube and a tube with a continuous weld, and wherein the rotor hub includes a clutch piston disposed within the cylinder; clutch plates engaged with the spline teeth and capable of being actuated by the clutch piston.

A method of forming such a rotor hub according to the invention comprises forming a sheet metal cylinder with splines defining angularly spaced ridges and valleys, attaching a tube surrounding the cylinder to the ridges, attaching a rotor to the tube, forming a hub attached to the cylinder and constraining the hub for rotation about an axis, wherein constraining the tube at the ridges includes welding and forming an interference fit.

The rotor hub consists of three simple, inexpensive components, a cylinder, a cylindrical tube and a hub. Torque is transmitted between the hub and the torque converter through the flexplate.

Centrifugal force causes automatic transmission fluid (ATF) to continuously flow radially outward through the cylinder, tube, and rotor, transporting heat from the clutch plates, cylinder, and tube away from the module. ATF exiting the assembly falls by gravity into a pan at the bottom of the module, passes through a cooler and returns to the transmission pan from where it is drawn into the transmission pump for recirculation through the hydraulic system.

The scope of applicability of the preferred embodiment will become apparent from the following detailed description, claims, and drawings. It should be understood that the description and specific examples, while indicating preferred embodiments of the invention, are presented for purposes of illustration only. Various changes and modifications to the described embodiments and examples will be apparent to those skilled in the art.

character list

• 1A und 1B eine seitliche Querschnittsdarstellung eines Antriebsstrangmoduls umfassen, die eine vordere Verbindung mit einem Verbrennungsmotorausgang und eine hintere Verbindung mit einem Getriebedrehmomentwandlereingang zeigen;
• 2 eine seitliche Querschnittsdarstellung eines Abschnitts des Antriebsstrangmoduls ist, die einen Bauteil, der als Kupplungsreaktionsplatte dient, und eine Vorwärtslagerung des Rotors der elektrischen Maschine zeigt; und
• 3 eine seitliche Querschnittsdarstellung einer Rotornabe ist, die aus gestanzten Bauteilen besteht;
• 4 ein Querschnitt entlang einer Ebene 4-4 in 3 ist;
• 5 ein Querschnitt entlang einer Ebene 5-5 in 3 ist; und
• 6 eine Seitenansicht des Rotors und von Endplatten ist.

The invention will be more readily understood by reference to the following description taken in conjunction with the accompanying drawings, in which:

• 1A and 1B Figure 12 comprises a cross-sectional side view of a powertrain module showing a front connection to an engine output and a rear connection to a transmission torque converter input;
• 2 Figure 12 is a cross-sectional side view of a portion of the powertrain module showing a component serving as a clutch reaction plate and a forward mounting of the rotor of the electric machine; and
• 3 Figure 12 is a cross-sectional side view of a rotor hub made from stamped components;
• 4 a cross-section along a plane 4-4 in 3 is;
• 5 a cross-section along a plane 5-5 in 3 is; and
• 6 Figure 3 is a side view of the rotor and end plates.

DETAILED DESCRIPTION

1A and 1B Figure 12 shows a powertrain module 10 for a hybrid electric vehicle having an internal combustion engine with a rotary output 12; a torsion damper 14 fixed to the engine output 12; an input shaft 16 fixed by splines 18 to an output 20 of the damper 14; a disconnect clutch 22 supported on a clutch hub 24 which is fixed to the input shaft 16 by splines 26; an electric machine 28 including a stator 30 bolted to a front bulkhead 32 and a rotor 34 supported by a first leg 36 and a second leg 38 for rotation about an axis; a rotor hub 40 preferably secured to leg 38 by a weld; and a flexplate 42 secured at one end by a splined connection 44 to a rotor hub 40 and at the opposite end by bolts 46 to a torque converter housing 48 enclosing a hydrokinetic torque converter 49 . The electric machine 28 may be an electric motor or an electric motor-generator.

Torque converters suitable for use in the powertrain are disclosed in US Pat U.S. Patent Application No. 13/325,101 , filed December 14, 2011, the entire disclosure of which is incorporated herein by reference and referenced 4a , 4b , 5 , 12 and 15 described.

Torque converter 49 includes a vaned impeller disposed within and fixed to housing 48; a bladed turbine hydrokinetically driven by the impeller and fixed by gearing 50 to the input shaft 52 of an automatic transmission 54; and a vaned stator wheel located between the turbine and stator and fixed to a stator shaft 56 which is held against rotation on a gearbox 58 .

An aft bulkhead 60, which is secured by bolts 62 to the transmission case 58, is provided with a hydraulic seal 64 on the radially inner surface which contacts the radially outer surface of the rotor hub 40. As shown in FIG.

A flywheel 66, fixed by bolts 68 to the engine's rotary output 12, supports an engine starter pinion 70, which is fixed by a washer 72 welded to the starter pinion and flywheel.

A bearing 74 supports the first leg 36 for rotation on the front bulkhead 32. A bearing 76 supports the second leg 38 for rotation on the rotor hub 40. A tube 78 aligned with the axis 39 supports the rotor 34 for rotation about the Axle stores is fixed to the first leg 36 and the second leg 38. Skirts 80, 82 at the front and rear ends of the tube 78, respectively, may be rolled radially outward to secure the rotor 34 to the tube 78 and to prevent axial displacement of the rotor 34 with respect to the tube. The inner surface of the tube 78 is formed with an axial toothing 81, in which the legs 36, 38 and interchangeable plates 83 of the separating clutch 22 engage. The friction plates 84 of the clutch 22 are defined by axial splines formed on the radially outer surface of the clutch hub 24 .

A hydraulic servo control for actuating the clutch 22 includes a piston 86, a balance lock 88, a return spring 90, and hydraulic lines for transmitting apply pressure to the pressure control volume 92 on the right side of the piston 86 and the pressure balance volume 94 on the left side of the piston. Piston 86 moves to the left in a cylinder formed by right leg 38 when actuating pressure and hydraulic fluid is supplied to volume 92 through the use of seals 151 and 152, causing clutch 22 to engage the rotor 34 and the engine output 12 through the damper 14, the input shaft 16, the clutch hub 24 and the clutch 22 engages and connects them for driving.

Since the piston 86, balance lock 88 and return spring 90 are journalled on the rotor hub 40, the moment of inertia of the piston 86, balance lock 88 and return spring 90 is on the output side, i.e. the rotor side, of the clutch 22.

The rotor 34 is continuously drivably connected to the transmission input shaft 52 via the torque path which includes the rear leg 38, the rotor hub 40, the flexplate 42, the torque converter housing 48, the hydrodynamic drive connection between the torque converter impeller and the turbine, which is via the Gearing 50 is connected to the transmission input shaft 52.

A transducer 100, a highly accurate type of rotary electrical transducer used to measure rotary angles, is secured to the front separator plate 32 by bolts 102, supported on the front separator plate 32 and a first leg, and axially between the front separator plate 32 and the rear partition plate 60 arranged.

The teeth of the splined connection 44, which provides a rotational drive connection between the flexplate 42 and the rotor hub 40, are mated so that there is no backlash when torque is transmitted between the flexplate and the rotor hub. The flexplate 42 is formed with a thick wall portion 104 having a threaded hole 106 terminating at a ridge 108 . The outer teeth of the splines on the flexplate 42 are urged axially into engagement with the inner teeth of the splines on the rotor hub 40 by bolts 110 which engage threaded holes in the right end of the rotor hub 40 . The teeth engaged on spline connection 44 are disengaged upon removing bolts 110 and threading a larger bolt into hole 106 so that the bolts contact the web, pushing the flexplate axially to the right.

The rotor hub 40 is provided with a plurality of axially aligned hydraulic passages 120 and laterally aligned passages 122, 124, 126, 128, 120 that carry hydraulic fluid and pressure to the module 10 from the transmission 54 hydraulic system. The passages 120, 122, 124, 126, 128, 129 carry hydraulic fluid and pressure, resulting in the control volume 92 of the servo control of the clutch 22 located on the right side of the piston 86, via the pressure balance volume 94 between the balance lock 88 and the piston to a variable force solenoid (VFS) 130 and to the surfaces of the rotor 34 and stator 30, the surfaces of which are fluid-cooled. The rear divider panel 60 is provided with a passage 128 that communicates hydraulically with the VFS 130 .

The rear divider plate 60 supports a pan 132 which contains fluid supplied to the module 10 from the hydraulic system of the transmission 54 . The transmission 54 includes a sump 136 containing hydraulic fluid which is supplied by a transmission pump 134 to the transmission hydraulic system from where fluid and control pressure are supplied to the module 10, torque converter 49, transmission clutches and brakes, bearings, shafts, gears, etc .

A bearing 140 fitted in the front bulkhead 32 and a bearing 142 fitted in the rotor hub 40 support an input shaft 16 for rotation about an axis 39. The front bulkhead 32 also supports the stator 30 in its own axial and radial positions relative to rotor 34. Bearing 76 fitted between rear bulkhead 60 and a rotor hub 40 and bearing 142 support rotor hub 40 for rotation about axis 39. Front and rear bulkhead 32, 60 together support the rotor 34 in rotation about the axis 39 by means of a bearing 74 fitted in the bulkhead 32 and a bearing 76 fitted in the bulkhead 60.

Seal 64 fitted in rear bulkhead 60 and seal 141 fitted in front bulkhead 32 prevent fluid from module 10 located between end walls 32,60 from passing through. Another dynamic seal 144 prevents contaminants from passing between the engine compartment 146 and the module 10.

The components of module 10 are built into and assembled within the module. The assembled module can then be installed between and connected to the engine output 12 and the torque converter housing 48 .

In operation, the engine output 12 is driven by an internal combustion engine, torque is transferred from the engine through the rotor hub 40 and flexplate to the torque converter housing 48 provided the clutch 22 is engaged. The electric machine 28 of the rotor 34 is continuously drivably connected to the torque converter shell 48 by the tube 78 , leg 38 , rotor hub 40 and flexplate 42 . Therefore, the torque converter housing 48 can be driven by the engine alone provided the electric machine 28 is off and the clutch 22 is engaged; from the electric machine alone, provided the internal combustion engine is switched off or the internal combustion engine is running and the clutch is disengaged; and from the internal combustion engine and the electric machine at the same time.

As in 2 As can be seen, the rotor 34 of the electric machine 28 is supported on a tube 78 which is supported by a shroud 160 which is connected to the tube 78 by a weld 162 and is welded to the rotor hub 40 and via a leg 164 which extends through an axial internal spline 166 is fixed to the shroud 160 is fixed. A single snap ring 168 secured to the shroud 160 and in contact with the leg 164 limits axial displacement of the friction plates 84 which are secured to the shroud 160 by splines 166 . Spacer plates 83 are fixed to the clutch hub 24 by external axial teeth 170 .

A thrust bearing 172 contacts the clutch hub 24 and a flange 174 on a shaft 176 which is parallel to an axis 19 . A bearing supports the clutch hub on the shaft 176. The engine output 12 is connected to the clutch hub 24 by a flywheel 66, a damper 20, an input shaft 16 and a spline 26. As shown in FIG.

A bearing 182 fitted between front bulkhead 32 and leg 164 supports rotor 23 for rotation about axis 19 and provides a reaction to axial force transmitted between leg 164 and bulkhead 32 .

In operation, when pressurized hydraulic fluid is provided through passage 184 to cylinder 186 containing piston 86, piston 86 moves to the left against the force of return spring 90 . The disconnect clutch 22 is engaged when the friction plates 83 and spacer plates 84 are urged into mutual frictional contact by the piston 86 , thereby creating a driving connection between the rotor hub 40 and the engine output 12 . The rotor 34 is continuously drivably connected to the rotor hub 40 by the shroud 160 .

The leftward axial force exerted by piston 86 is transmitted through plates 83, 84 through 164, snap ring 168 and shroud 160.

3-6 show a rotor hub made from stamped components including a clutch cylinder 200, a tube 202 and a hub 204. FIG. The cylinder 200 includes a bore 204 which includes a clutch piston 86, preferably formed by a stamping process, and Thrust splines 166 which engage clutch separator plates 84, the cylinder 200 and splines 166 being formed by any of a variety of methods including open die forging.

The rotor 34 of the electric machine 28 is supported by the tube 202, which has rolled ends 208 to hold the rotor on the tube. The tube 202 may be a seamless tube or a tube with a continuous weld. Cylinder 200 is preferably secured to tube 202 by an interference fit.

The hub 40 is preferably fixed to the cylinder 200 by welding. The hub 40 transmits torque from the electric machine 28 and engine through the clutch 22 to the torque converter 49 through the flexplate 42.

4 12 shows that the spline 166 of the cylinder 200 includes a series of angularly spaced depressions in the bore 206 and ridges 210. FIG. Each ridge 210 is fixed to the inner radial surface 212 of the tube 202 .

Angularly spaced, axially aligned first channels 214 are defined by a surface 212 and the serrations 166 of the cylinder 200 . The surfaces of cylinder 200 which form the indentations are formed with a radial hole 216 which communicates with channel 214 located radially outward of the respective indentation. The cylinder 202 is formed with a series of axially spaced bleed holes 218 each communicating with one of the passages 214 .

5 12 shows that the rotor 34 is formed with a series of axially aligned second ports 220 that each communicate with one of the ports 214 of the cylinder 200 through a bleed hole 218 . Some of the channels 214 receive an axially directed projection 222 which extends radially into the channel, thereby connecting the tube 202, the cylinder 200 and the rotor 34 so that they rotate as a unit about the axis 39, which prevents the Rotor 34 on the outer surface 404 of the tube 202 rotates.

6 1 shows that each axial second channel 220 terminates at an end plate 224, 226 located at axially opposite ends of the rotor 23. FIG. Each end plate 224, 226 is formed with a series of radially aligned passages 228, 230, each passage being aligned with one of the second axial passages 220. As shown in FIG.

In operation, centrifugal force causes automatic transmission fluid (ATF) in module 10 to flow radially outward through holes 216, passages 214, holes 218, passages 220 and passages 228, 230, thereby removing heat from clutch plates 83, 84, from cylinder 200, from Tube 202 and the rotor 34 is transported away from the module 10. As the fluid exits passages 228 and 230, centrifugal force causes the oil to be sprayed radially outward, contacting the end turns of stator 30, thereby cooling the stator. ATF exiting the assembly falls by gravity into a pan at the bottom of the module 10, passes through a cooler and returns to the transmission pan from where it is drawn into the transmission pump for recirculation through the hydraulic system.

As required by the patent statutes, the preferred embodiments have been described. However, it should be noted that alternative embodiments may be practiced otherwise than as specifically illustrated and described.

Claims (5)

A rotor hub (40) comprising: a sheet metal cylinder (200) having splines comprising angularly spaced crests (210) and valleys; a tube (202) surrounding the can (200) and fixed to the ridges (210) and supporting a rotor (34); a hub fixed to the sheet metal cylinder (200) and supported for rotation; a torque converter; a flexplate (42) fixed to the hub and to the torque converter (49), the tube (202) and splines defining first channels (214), the sheet metal cylinder (200) being formed with holes (216, 218), each hole (216, 218) extends through one of the indentations and communicates with one of the first passages (214), the tube (202) is formed with bleed holes, each bleed hole communicating with one of the first passages (214), the rotor (34) second channels (220), each second channel (220) communicating with one of the first channels (214) through one of the vent holes, the first channels (214) and the second channels (220) being aligned along an axis of rotation , wherein the rotor hub (40) includes end plates, each end plate being disposed at an opposite end of the rotor (34) and being formed with radial passages, each passage communicating with one of the second channels (220), the passages radially in Are aligned with respect to an axis of rotation, wherein the tube (202). seamless tube (202) and a tube (202) with a continuous weld, and wherein the rotor hub (40) includes a clutch piston (86) disposed within the canister (200); clutch plates (83, 84) engaged with the splines and capable of being actuated by the clutch piston (86). Rotor hub (40) according to claim 1 comprising: a sheet metal cylinder (200) having splines comprising angularly spaced crests (210) and valleys; a tube (202) surrounding the can (200) and fixed to the ridges (210) and supporting a rotor (34); a hub fixed to the sheet metal cylinder (200) and supported for rotation, the tube (202) and splines defining first channels (214), the sheet metal cylinder (200) being formed with holes (216, 218), each hole ( 216, 218) extending through one of the recesses and communicating with one of the first passages (214), the tube (202) being formed with vent holes, each vent hole communicating with one of the first passages (214), the rotor (34) second channels (220), each second channel (220) communicating with one of the first channels (214) through one of the vent holes, the first channels (214) and the second channels (220) being aligned along an axis of rotation, the A rotor hub (40) includes end plates, each end plate being located at an opposite end of the rotor (34) and being formed with radial passages, each passage communicating with one of the second channels (220), the passages being radial in ref ug are aligned with an axis of rotation, wherein the tube (202) is a seamless tube (202) and a tube (202) with a continuous weld seam, and wherein the clutch piston (86) disposed in the sheet metal cylinder (200); clutch plates (83, 84) engaged with the splines and capable of being actuated by the clutch piston (86). A method of forming a rotor hub (40). claim 1 or 2 comprising: forming a sheet metal cylinder (200) with splines defining angularly spaced peaks (210) and valleys; attaching a tube (202) surrounding the sheet metal cylinder (200) to the ridges (210); attaching a rotor (34) to the tube (202); and forming a hub fixed to the sheet metal cylinder (200). procedure after claim 3 , further comprising forming the sheet metal cylinder (200) by open die forging. procedure after claim 3 , further comprising using a flexplate (42) to drivably connect the hub to a torque converter (49).

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