Integrated drive system

Abstract

The present invention relates to an integrated drive system (100), the integrated drive system (100) comprising: a motor (120), the motor (120) having a stator (129) and a rotor; an inverter (110), the inverter (110) being used to control the motor (120); a gearbox (130), the gearbox (130) being used to transmit torque provided by the motor (120); and a cooling system, wherein the cooling system comprises a coolant, the coolant being used to cool the inverter, the rotor, the stator and the gearbox along a cooling path.

Description

Technical Field

[0001] The invention relates to an integrated drive system, which comprises a motor, an inverter and a gear box. Background Art

[0002] In recent years, technologies related to electric or hybrid vehicles driven by electricity have been developing rapidly. An electric or hybrid vehicle may include: a motor that generates rotational force; an inverter for controlling the motor; a battery for powering the inverter; and a gearbox for transmitting torque from the motor to the wheels in the vehicle. How to place these components in the vehicle to limit the size of these components in the vehicle is increasingly being studied. For this purpose, it is known to provide an integrated drive system that combines these components in a device installed in the vehicle. For example, the disclosure of patent US9,030,063 B2 proposes integrating a motor, an inverter, and a gearbox in a single cylinder block.

[0003] The main problem of hybrid or electric vehicles remains how to effectively cool the components of the integrated drive system. US 9,030,063 B2 proposes a cooling system in which the cooling flow is divided into a first cooling path for cooling the rotor and gearbox of the motor and a second cooling path for cooling the stator and inverter of the motor. However, this parallel cooling method requires a manifold at which the cooling path is divided into the first cooling path and the second cooling path, and the rate flow of the coolant in each cooling path is controlled. This makes such an integrated system in the prior art difficult to implement.

[0004] Therefore, there is a need for an integrated drive system that demonstrates effective cooling of its components while being more easily implemented. Summary of the invention

[0005] The present invention relates to an integrated drive system, which includes: a motor having a stator and a rotor; an inverter, which is used to control the motor; a gearbox, which is used to transmit the torque provided by the motor; and a cooling system, which includes a coolant, which is used to cool the inverter, the rotor, the stator and the gearbox along a cooling path.

[0006] Therefore, the integrated system of the present invention utilizes a single cooling path to achieve cooling of the inverter, the motor and the gearbox. Therefore, no complicated flow splitting is required in the system of the present invention, thus simplifying its design.

[0007] An integrated drive system means that the inverter, the electric motor and the gearbox are arranged together in a common housing, for example, the housing is made of multiple parts. The integrated system thus forms an object that allows the inverter, the electric motor and the gearbox to be manipulated simultaneously. Such an integrated drive system allows all these components to be integrated simultaneously in the vehicle's drivetrain.

[0008] According to one embodiment, the coolant is used to cool the inverter, rotor, stator and gearbox in sequence. Some components, for which temperature needs higher attention, are arranged from the most affected by temperature to the least affected by temperature as follows: inverter, rotor, stator and gearbox. According to the priority cooling of the components most affected by temperature, these components are cooled when the temperature of the coolant is lower relative to the temperature at the output end, thereby providing more heat dissipation for the components that need cooling the most.

[0009] Preferably, the cooling path includes a plurality of continuous sections, including a first section for cooling the inverter, a second section for passing through and cooling the rotor, a third section for cooling the stator, and a fourth section for cooling the gearbox. The coolant flows through these sections one by one. It is worth noting that the cooling path is formed in each component of the integrated system so as to cool the component at the closest position.

[0010] According to one embodiment, the gearbox comprises a lubricating oil circuit containing lubricating oil, which is independent of the cooling system and thermally coupled to the cooling system. Preferably, the cooling liquid passes through a heat exchanger which allows heat exchange between the cooling liquid and the lubricating oil. Thus, the intrusion of the cooling system is limited in the gearbox without providing long cooling channels in the gearbox. After the lubricating oil has cooled down, it is sprayed on the hot spots of the gearbox.

[0011] According to one aspect of the present invention, the motor comprises a cylinder body surrounding the rotor and the stator, the cylinder body having:

[0012] - a side portion in the shape of a cylinder, which extends along the axis of the electric machine to surround the stator,

[0013] a first end portion at a first axial end of the electric machine, forming a so-called B-cover, closing the first axial end of the side portion, and

[0014] - a second end at a second axial end of the electric machine, opposite to the first axial end of the electric machine (120), the second end forming a so-called A-cage closing the second axial end of the side portion.

[0015] According to a variant, the A-cover is also part of the cylinder of the gearbox. The A-cover is thus shared between the cylinder of the motor and the cylinder of the gearbox. In particular, the A-cover of the motor has a concave shape opposite to the side of the motor in order to house the components of the gearbox and form the cylinder of the gearbox. The gearbox is thus at least partially placed on the A-cover of the motor.

[0016] According to one embodiment, the electric machine comprises a hollow rotor shaft to which the rotor is fixedly attached. The inner space of the rotor shaft extends along the axis of the rotor shaft and is used to accommodate a coolant for cooling the rotor. The B cover comprises a first channel for transferring the coolant to the rotor shaft and a second channel communicating with a cooling channel of the stator to transfer the coolant from the rotor to the cooling channel of the stator. Due to the second channel, the coolant is delivered to the stator to cool it. By integrating the second channel in the B cover, the integration of the cooling system in the components of the integrated system is improved.

[0017] Preferably, the B cover comprises:

[0018] - a peripheral portion integral with the side portion of the cylinder, the peripheral portion axially facing the stator, and

[0019] - a central portion distinct from said peripheral portion and axially facing said rotor shaft and forming a sealing relationship with said peripheral portion,

[0020] And, the first channel and the second channel have a first portion formed in the central portion of the B cover and a second portion formed in the peripheral portion of the B cover, respectively. By integrating the first channel and the second channel in the peripheral portion and the central central portion, the size of the motor is reduced relative to the case where the cooling channel is formed integrally in the central portion. In this case, the channel will have to intersect the peripheral portion on the surface of the peripheral portion, thereby increasing the size of the motor along its axis. Moreover, the central portion may be removable. The central portion serves as a maintenance cover to replace elements in the rotor or the rotor shaft, such as seals.

[0021] According to one embodiment, the cylinder of the motor comprises a portion referred to as an extension, which extends from a side portion of the cylinder of the motor, in a transverse direction relative to the axis of the motor, in particular perpendicular to the axis of the motor, from a position close to the B cover to a position away from the B cover. In particular, the axis of the motor corresponds to the axis of the rotor shaft of the motor.

[0022] Preferably, the gearbox is used to transfer torque from the rotor shaft of the motor to an output position, which is at a distance from the motor relative to the axis of the rotor shaft. The extension extends from the side portion of the cylinder body of the motor to face the output position of the gearbox, and the extension includes a hole for accommodating a secondary shaft connected to the output position of the gearbox. Therefore, the system includes a secondary shaft different from the rotor shaft. It is worth noting that one end of the secondary shaft is supported by the gearbox at its output position so as to receive torque from the gearbox. The other end of the secondary shaft is supported by the extension. Therefore, the secondary shaft is the output of the gearbox. In particular, at the end supported by the extension, the secondary shaft can be connected to the drivetrain of the vehicle. Therefore, the integrated system provides the torque transmitted by the gearbox at both axial ends of the system, thereby facilitating its integration in the drivetrain of the vehicle. When connecting the vehicle's drivetrain to the integrated drive system, it is only necessary to connect to the end of the layshaft located on the extension on the one hand and to the output point of the gearbox on the other hand, in particular on the side of the gearbox not facing the extension. At the output point of the gearbox, the differential gear can be positioned so as to transmit the torque to the left and right wheels via the layshaft on the one hand and to the left and right wheels of the vehicle via the output point from the side of the gearbox not facing the extension on the other hand.

[0023] Preferably, the inverter comprises a cylinder body, the cylinder body containing the components of the inverter, and the cylinder body of the inverter is supported on the cylinder body of the motor so that the outer surface of the cylinder body of the inverter extends in a plane tangential to the outer surface of the side portion of the cylinder body of the motor. The outer surface of the cylinder body of the inverter, the side portion of the cylinder body of the motor, the extension of the cylinder body of the motor and the gearbox define a space for accommodating a connecting duct of a cooling system connecting the inverter, the motor and the gearbox. In particular, the connecting duct extends only in the space. Therefore, when installed in a transmission system, the connecting duct is unlikely to break. In fact, the cylinder body of the inverter, the extension, the side portion of the cylinder body of the motor and the gearbox at least partially protect the connecting duct. In particular, the connecting duct is not included in the cylinder body of the motor, the gearbox or the inverter.

[0024] Preferably, the input of the cooling path of the rotor is located in the extension part, and the first conduit connects the output of the cooling path of the inverter to the input of the cooling path of the rotor. In particular, these inputs and outputs are located in the outer surface of the cylinder of the inverter, the side part of the cylinder of the motor, the extension part of the cylinder of the motor and the space defined by the gearbox. Thus, the protection of the cooling system is improved.

[0025] Preferably, the second conduit connects the interface of the cooling path of the stator to the interface of the cooling path of the gearbox. The interface of the cooling path of the stator and the interface of the cooling path of the gearbox are contained in the space defined by the outer surface of the cylinder of the inverter, the side portion of the cylinder of the motor, the extended portion of the cylinder of the motor and the gearbox. Therefore, the protection of the cooling system is improved.

[0026] Preferably, the extension portion includes an interface port of the cooling system, and a third conduit connects the interface of the cooling path of the gearbox to the interface port of the cooling system. In particular, the third conduit is located in the space defined by the outer surface of the cylinder of the inverter, the side portion of the cylinder of the motor, the extension portion of the cylinder of the motor and the gearbox. Thus, the protection of the cooling system is improved.

[0027] According to one embodiment, the inverter is mounted on a side portion of the cylinder of the motor and extends from the gearbox to the B-hood. In particular, the dimension of the inverter along the motor axis extends from the B-hood to the gearbox. Therefore, the dimension of the integrated system along the motor axis is determined by the gearbox and the motor.

[0028] The present invention also relates to an electric motor, comprising a cylinder body surrounding a rotor and a stator, the cylinder body having:

[0029] - a side portion in the shape of a cylinder, which extends along the axis of the electric machine to surround the stator,

[0030] a first end portion at a first axial end of the electric machine, forming a so-called B-cover, closing the first axial end of the side portion, and

[0031] - A second end at a second axial end of the electric machine, opposite to the first axial end of the electric machine, said second end forming a so-called A-cage closing the second axial end of the side part and serving to house a gearbox.

[0032] The electric machine may include any of the features of the electric machines described above.

[0033] The invention also relates to an electric or hybrid vehicle comprising the above-described integrated drive system.

[0034] The details of one or more embodiments are set forth in the accompanying drawings and the description below. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In the attached picture:

[0036] - Figure 1 is a perspective view showing an integrated system according to an example of the present invention;

[0037] - Figure 2 Yes means Figure 1 A view of the integrated system along its axis;

[0038] - Figure 3 It shows Figure 1 A cross-sectional view of a motor of a system;

[0039] - Figure 4 yes Figure 1 a partial side view of the example shown;

[0040] - Figure 5 yes Figure 1 A partial perspective view of the example shown. DETAILED DESCRIPTION

[0041] The accompanying drawings show an exemplary integrated drive system 100 according to an embodiment of the present invention. The integrated drive system includes a motor 120, an inverter 110 and a gearbox 130. The inverter 110 is used to control the motor 120, especially through a battery. The gearbox 130 is used to transmit the torque provided by the motor 110.

[0042] In one variation, the integrated drive system 100 includes a cooling system in which a coolant flows along a cooling path to cool the inverter 110, the motor 120, and the gearbox 130. In particular, the cooling system cools the inverter 110, the motor 120, and the gearbox 130 in sequence. To this end, the cooling system may be arranged as follows. The cooling system may include an input port 210 that receives coolant from outside the integrated drive system 100. The input port 210 is connected to a first cooling path portion passing through the inverter 110. Then, a first connecting conduit 215 connects the output of the first cooling path portion to an input 217 of a second cooling path portion passing through the rotor of the motor 120. Specifically, the first connecting conduit 215 is connected to a first channel 124 inside a cylinder 120c of the motor 120. The first channel 124 guides the coolant to the rotor shaft 126 of the motor 120. The second channel 128 in the cylinder 120c of the motor 120 guides the coolant to the third cooling path portion 218 to cool the stator 129 of the motor 120. Then the second connecting conduit 219 connects the output 218 of the third cooling path portion to the input 220 of the fourth cooling path portion, which cools the gearbox 130.

[0043] Specifically, the gearbox 130 can be cooled due to heat transfer between part of the fourth cooling portion and a lubrication circuit of the gearbox 130. The lubrication circuit contains lubrication oil that is cooled and then sprayed at the hot spots of the gearbox and passes through the cylinder of the gearbox 130. Such heat transfer between the coolant and the lubrication oil can be achieved by a heat exchanger 132.

[0044] The output 222 of the fourth cooling path portion is then connected to an output port 224 of the cooling system via a third connecting conduit 223 .

[0045] In particular, the cylinder 120c of the motor 120 surrounds the rotor and the stator 129 of the motor 120. In particular, the cylinder 120c has a side portion 121c in the shape of a cylinder. The side portion 121c extends along the axis Δ of the motor 120 and surrounds the stator 129. A so-called B-cover 122c is formed at a first end of a first axial end of the motor 120, which closes the first axial end of the side portion 121c. A so-called A-cover 123c is formed at a second end of the cylinder 120c, which closes the second axial end of the side portion 121c. The gearbox 130 is located on the A-cover 123c of the motor 120. In particular, the A-cover 123c is also part of the cylinder of the gearbox 130. In particular, the A-cover 123c of the motor 120 has a concave shape opposite to the motor side. In its concave shape, the A-cover 123c may house components of the gearbox.

[0046] In one variation, the rotor shaft 126 includes a hollow space inside to accommodate the coolant. The internal space may extend along the entire axis Δ of the rotor shaft 126 to guide the coolant to the inside of the rotor shaft 126. The internal space is in communication with the first channel 124 to accommodate the coolant, and is in communication with the second channel 128 to output the coolant to the side portion 121 c of the cylinder 120 c of the motor 120.

[0047] In a specific variation, the B-cover 122c includes a peripheral portion P integral with the side portion 121c of the cylinder 120c and a central portion C different from the peripheral portion P. The peripheral portion P axially faces the stator 129, and the central portion C axially faces the rotor shaft 126. A seal may be provided at least at the interface between the central portion C and the peripheral portion P to seal the internal space of the motor 120. The seal may be an O-ring. The first passage 124 has a first portion 124C formed in the central portion C of the B-cover 122c and a second portion 124P formed in the peripheral portion P of the B-cover 122c. Similarly, the second passage 128 has a first portion 128C formed in the central portion C of the B-cover 122c and a second portion 128P formed in the peripheral portion P of the B-cover 122c. This configuration makes the motor 120 more compact. Furthermore, the central portion C is preferably removable, for example to allow access to the interior of the motor 120 for maintenance.

[0048] Specifically, the gearbox 130 may be used to transfer torque from the rotor shaft 126 to an output location 132 at a distance Δ from the motor 120 relative to an axis Δ of the rotor shaft 126 .

[0049] In one variant, the cylinder 120c of the motor 120 comprises a portion called an extension 125c, which extends from a side portion 121c of the cylinder 120c of the motor 120. The extension 125c extends from a position close to the B-shield to a position away from the B-shield in a transverse direction relative to the axis of the motor, in particular perpendicular to the axis Δ of the rotor shaft. In a particular variant, the extension 125c faces the output position 132 of the gearbox 130 relative to the axis Δ and comprises a hole 126c that receives a secondary shaft 134 connected to the output position 132 of the gearbox 130.

[0050] Specifically, the inverter 110 may include a cylinder 110c, which contains components of the inverter 110. In particular, the cylinder 110c of the inverter 110 is supported on the cylinder 120c of the motor 120, so that an outer surface 112c of the cylinder 110c of the inverter 110 extends on a tangential plane relative to an outer surface of a side portion 121c of the cylinder 120c of the motor 120.

[0051] In one variation, the outer surface 112c of the cylinder 110c of the inverter 110, the side portion 121c of the cylinder 120c of the motor 120, the extension portion 125c of the cylinder 120c of the motor 120, and the gearbox 130 define a space together, which includes the connecting ducts 215, 219, 223 of the cooling system. In particular, these connecting ducts 215, 219, 223 are completely included in the defined space. Therefore, the connecting ducts 215, 219, 223 are at least partially protected.

[0052] Preferably, the input 217 of the second cooling path portion passing through the rotor 129 is located in the extension portion 125c. In particular, the input 217 and the output of the first cooling path portion are located within the defined space. Similarly, the output 218 of the third cooling path portion and the input 220 of the fourth cooling path portion are preferably included in the defined space. In particular, the output port 224 of the cooling system is preferably located in the extension portion 125c.

[0053] It should be understood that the present invention is not limited to the specific examples described in the above paragraphs and that an integrated drive system or motor within the scope of the present invention may be obtained from one or a combination or variation of the embodiments described herein.

Claims

1. An integrated drive system (100), comprising: An electric motor (120), wherein the electric motor (120) has a stator (129) and a rotor; An inverter (110), the inverter (110) being used to control the motor (120); a gearbox (130) for transmitting torque provided by the motor (120); and a cooling system, wherein the cooling system comprises a coolant, the coolant being used to cool the inverter (110), the rotor, the stator (129) and the gearbox (130) along a cooling path; The coolant is used to sequentially cool the inverter (110), the rotor, the stator (129) and the gear box (130); The motor (120) comprises a cylinder (120c) surrounding the rotor and the stator (129), and the cylinder (120c) has: - a cylindrical side portion (121c), the side portion (121c) extending along the axis of the motor (120) to surround the stator (129), - a first end portion at a first axial end of the motor (120), forming a so-called B-cover (122c), closing a first axial end of the side portion (121c), and - a second end portion at a second axial end of the motor (120) opposite to the first axial end of the motor (120), the second end portion forming a so-called A-cover (123c) closing the second axial end of the side portion (121c); The motor (120) comprises a hollow rotor shaft (126), the rotor is fixedly attached to the rotor shaft (126), an inner space of the rotor shaft (126) extends along the axis of the rotor shaft and is used to contain a coolant for cooling the rotor, and The B-shield (122c) includes a first passage (124) for transferring the coolant to the rotor shaft (126) and a second passage (128) communicating with a cooling passage of the stator (129) so as to transfer the coolant from the rotor to the cooling passage of the stator (129).

2. The integrated drive system (100) of claim 1, wherein the cooling path comprises a plurality of consecutive portions, the plurality of consecutive portions comprising a first portion cooling the inverter (110), a second portion passing through and cooling the rotor, a third portion cooling the stator (129), and a fourth portion cooling the gearbox (130).

3. The integrated drive system (100) of claim 1, wherein the B-hood (122c) comprises: - a peripheral portion (P) integral with the side portion (121c) of the cylinder (120c), the peripheral portion (P) axially facing the stator (129), and - a central portion (C) distinct from the peripheral portion (P) and axially facing the rotor shaft (126) and forming a sealing relationship with the peripheral portion (P), The first channel (124) and the second channel (128) respectively have a first portion (124C, 128C) formed in the central portion (C) of the B-cover (122c) and a second portion (124P, 128P) formed in the peripheral portion (P) of the B-cover (122c).

4. An integrated drive system (100) according to claim 1, wherein the cylinder body (120c) of the motor (120) includes a portion called an extension portion (125c), which extends from a side portion (121c) of the cylinder body (120c) of the motor (120), along a transverse direction relative to the axis of the motor (120), in particular, a direction perpendicular to the axis of the motor, from a position close to the B-cover (122c) to a position away from the B-cover (122c).

5. The integrated drive system (100) of claim 4, wherein the gearbox (130) is used to transfer torque from a rotor shaft (126) of the motor (120) to an output location that is a distance from the motor (120) relative to an axis of the rotor shaft, The extension portion (125c) extends from the side portion (121c) of the cylinder body (120c) of the motor (120) to face the output position of the gear box (130), and the extension portion (125c) includes a hole for accommodating a secondary shaft (134) connected to the output position of the gear box (130).

6. The integrated drive system (100) of claim 5, wherein the inverter (110) comprises a cylinder (110c) containing components of the inverter (110), and the cylinder (110c) of the inverter (110) is supported on the cylinder (120c) of the motor (120) such that an outer surface (112c) of the cylinder of the inverter (110) extends in a tangential plane relative to an outer surface of a side portion (121c) of the cylinder of the motor (120), in, The outer surface (112c) of the cylinder of the inverter (110), the side portion (121c) of the cylinder of the motor (120), the extension portion (125c) of the cylinder of the motor (120) and the gearbox (130) define a space for accommodating a connecting duct (215, 219, 223) of the cooling system, wherein the connecting duct (215, 219, 223) connects the inverter (110), the motor (120) and the gearbox (130).

7. The integrated drive system (100) according to any one of claims 4 to 6, wherein an input of a cooling path of the rotor is located in the extension portion (125c), and a first conduit (215) connects an output of a cooling path of the inverter (110) to the input of the cooling path of the rotor.

8. The integrated drive system (100) according to claim 6, wherein a second conduit (219) connects an interface of the cooling path of the stator (129) to an interface of the cooling path of the gearbox (130), the interface of the cooling path of the stator (129) and the interface of the cooling path of the gearbox (130) being contained in the space.

9. The integrated drive system (100) according to any one of claims 4 to 6, wherein the extension portion (125c) includes an interface port of the cooling system, and a third conduit (223) connects an interface of a cooling path of the gearbox (130) to the interface port of the cooling system.

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