Rotor assembly structure of hybrid vehicle drive module
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-01-29
- Publication Date
- 2026-08-13
Smart Images
Figure KR2026001781_13082026_PF_FP_ABST
Abstract
Description
Rotor assembly structure of a hybrid drive module
[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2025-0015409 dated February 6, 2025, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.
[0002] The present invention relates to a rotor assembly structure of a hybrid vehicle drive module, and more specifically, to a structure of a rotor retainer and a rotor cover for reducing the number of parts or the size of the rotor assembly.
[0003] To configure the drive module of a hybrid vehicle, a drive motor must be installed in the power transmission path between the engine and the transmission. Generally, the stator is connected to a non-rotating component such as a housing, while the rotor is connected to a rotating shaft or rotor hub (or rotor sleeve) to transmit rotational force generated by the motor to the transmission or to regenerative braking using rotational inertia energy input from the transmission.
[0004] The rotor assembly of such a hybrid drive module consists of a rotor core containing a magnet (permanent magnet), a rotor cover that prevents the permanent magnet from deviating in the axial direction, and an end plate or rotor retainer that prevents the rotor cover from deviating in the axial direction.
[0005] In this case, a hot press-fitting process is often applied to a single component, referred to as an end plate or rotor retainer, to secure the rotor of the drive module to the rotor hub or rotor sleeve. However, since the rotor retainer is applied along with the rotor cover, there is a disadvantage in that the axial length of the drive module becomes longer.
[0006] On the other hand, there are cases where a rotor cover or rotor retainer is not applied to secure the rotor to the rotor core.
[0007] However, in this case, a hot press-fit process involving heating and pressing the rotor core must be applied. Since this requires the time and cost to heat and expand the rotor, equipment to apply pressure for assembling the heated rotor, and a process to sufficiently cool the assembled rotor assembly before moving on to the next stage, there is a high possibility that manufacturing equipment and production time will be excessively incurred.
[0008] As described above, additional parts such as a rotor cover or rotor retainer are required to fix the rotor of the drive module to the shaft or rotor hub, or additional manufacturing equipment is required to hot press-fit the rotor core itself, and the manufacturing time may be long.
[0009] Therefore, in order to produce a hybrid drive module that is simple yet competitive in terms of the drive module assembly structure, it is necessary to minimize the number of parts and manufacturing processes.
[0010] Accordingly, the present invention attempts to improve the rotor assembly structure of a hybrid drive module to solve the problems described above.
[0011] In this regard, Korean Published Patent Application No. 10-2022-0162662 (published Dec. 08, 2022), filed and disclosed by the applicant, describes technology regarding a rotor hub and a hybrid drive module equipped therewith. However, the aforementioned prior art describes a structure for coupling a rotor to a rotor hub, but does not provide a solution to the disadvantage of the aforementioned drive module having an increased axial length due to this coupling structure.
[0012] In addition, Korean Registered Patent Publication No. 10-2291313 (published on August 12, 2021), filed and registered by the applicant, also describes a hybrid drive module and a rotor assembly method equipped therewith; however, the problem regarding the disadvantage of the axial length of the conventional drive module still persists in the said prior art, as the rotor hub to which the rotor is coupled, the first and second retainers, and the spacer are coupled in the axial direction.
[0013] The present invention has been devised to solve the aforementioned conventional problems, and the objective of the present invention is to provide a rotor assembly structure for a hybrid drive module that overcomes the disadvantage of an increased axial length by improving the structure of the rotor assembly of the hybrid drive module.
[0014] In addition, the objective of the present invention is to minimize the number of parts and manufacturing processes in the assembly structure of a hybrid drive module in order to produce a simple yet competitive hybrid drive module.
[0015] The technical problems of the present invention are not limited to the purposes mentioned above, and other unmentioned purposes and advantages of the present invention may be understood from the following description and will be more clearly understood by the embodiments of the present invention. Furthermore, it will be readily apparent that the purposes and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.
[0016] The present invention can be applied to a structure that regulates the axial position of a rotor hub and a magnet relative to a rotor hub in a rotor assembly of a hybrid drive module.
[0017] The rotor assembly includes a rotor hub connected to an input shaft that receives rotational force from the engine and to an output shaft that provides rotational force to the transmission.
[0018] The input shaft and the rotor hub may be connected via an engine clutch. The input shaft and the rotor hub may be coupled or decoupled by the engine clutch.
[0019] The rotor hub and the output shaft may be connected via a fluid clutch. The fluid clutch may be a torque converter.
[0020] Additionally, the rotor hub and the output shaft can be connected through a lock-up clutch.
[0021] The rotor assembly includes a rotor core mounted to be rotationally constrained to the rotor hub. The rotor core extends in a circumferential direction.
[0022] The rotor core may be disposed on the radially outer side of the rotor hub. The rotor core may surround the rotor hub on the radially outer side of the rotor hub.
[0023] The above rotor hub may have an axial extension portion disposed radially inward of the rotor core and a radial extension portion extending radially outward from the rear end of the axial extension portion.
[0024] The rotor core is positioned in front of the radial extension and can surround the axial extension on the radial outer side of the axial extension.
[0025] The rotor assembly includes a plurality of magnets embedded in the rotor core so as to extend axially. The plurality of magnets are embedded in the rotor core so as to be spaced apart along the circumferential direction.
[0026] The above rotor core may have a magnet receiving space formed through it in the axial direction. The magnet receiving space may regulate the position of the magnet received within the receiving space in the radial direction and the circumferential direction.
[0027] The rotor assembly includes a first rotor cover interposed axially between the rear end of the rotor hub and the rear end of the rotor core and magnet. The first rotor cover extends circumferentially.
[0028] The first rotor cover may be positioned radially outward from the rotor hub. The position of the first rotor cover may be axially rearward and radially restricted by the rotor hub. The first rotor cover may be axially attached to the rear end of the rotor core and magnet to prevent rearward displacement of the magnet relative to the rotor core.
[0029] The first rotor cover is positioned in front of the radial extension so that rearward movement is restricted by the radial extension, and its radial position may be restricted by the axial extension.
[0030] The rotor assembly includes a second rotor cover that is in close contact with the front end of the rotor core and magnet in the axial direction. The second rotor cover extends in the circumferential direction.
[0031] The second rotor cover may be positioned on the radially outer side of the rotor hub. The second rotor cover may be in close contact with the front end of the rotor core and magnet in the axial direction to prevent the magnet from moving forward relative to the rotor core.
[0032] The radial inner surface of the second rotor cover is fixed to the front end of the rotor hub through a wedge connection.
[0033] By means of the wedge connection above, the second rotor cover can be axially attached to the front end of the rotor core and magnet.
[0034] Due to the wedge connection above, the second rotor cover can be subjected to strong pressure radially outward.
[0035] By means of the wedge connection above, the second rotor cover can be rotationally constrained with respect to the rotor hub.
[0036] The radial inner surface of the second rotor cover may be wedge-coupled directly to the front end of the rotor hub or indirectly wedge-coupled to the front end of the rotor hub through a rotor retainer.
[0037] In some examples, the rotor assembly may further include a rotor retainer that is inserted radially between the front end of the rotor hub and the second rotor cover and joined in a wedge shape.
[0038] The thickness of the rotor retainer measured in the axial direction may be equal to or smaller than the thickness of the second rotor cover measured in the axial direction. Accordingly, it is possible to ensure that the rotor retainer, which is a separate component, does not occupy any space in the axial direction.
[0039] The radial inner surface of the second rotor cover may include a first section in which the inner diameter gradually decreases toward the rear. The radial outer surface of the rotor retainer may include a second section in which the outer diameter gradually decreases toward the rear. Additionally, at least a portion of the first section and at least a portion of the second section may interlock in a wedge shape.
[0040] Then, by the force with which the rotor retainer presses the second rotor cover backward, the second rotor cover, the rotor core, the first rotor cover, and the radial extension can be strongly fixed in close contact with each other in the axial direction.
[0041] The above first section may be an inclined portion of the second rotor cover.
[0042] Optionally, the material of the second rotor cover may be softer than the material of the rotor retainer. The first section may be a plastically deformed portion.
[0043] The above second section may be a wedge portion of the retainer.
[0044] Optionally, the material of the second rotor cover may be harder than the material of the rotor retainer. The second section may be a plastically deformed portion.
[0045] An uneven surface may be formed on at least one side of the first section and the second section. Accordingly, the section made of a soft material is plastically deformed, thereby facilitating wedge joining and strengthening rotational restraint.
[0046] Optionally, preferably, the radially outer surface portion of the front end of the rotor hub that engages radially with the radially inner surface of the rotor retainer may be extended axially such that its outer diameter is constant.
[0047] In correspondence with this, additionally, the radial inner surface of the rotor retainer may be extended axially such that its inner diameter is constant.
[0048] Optionally, the radially outer surface portion of the front end of the rotor hub, which engages radially with the radially inner surface of the rotor retainer, may be extended such that its outer diameter gradually increases toward the rear.
[0049] In correspondence with this, additionally, the radial inner surface of the rotor retainer may be extended such that the inner diameter gradually increases toward the rear.
[0050] Preferably, the material of the rotor retainer may be softer than the material of the second rotor cover and the rotor hub.
[0051] The rotor retainer may be located radially inward from the magnet. Accordingly, it is not necessary to make the rotor retainer of a non-magnetic material.
[0052] In another example, the front portion of the rotor hub and the second rotor cover can be joined in a wedge shape.
[0053] The radial inner surface of the second rotor cover may include a third section in which the inner diameter gradually increases toward the rear. The radial outer surface of the front end of the rotor hub may include a fourth section in which the outer diameter gradually increases toward the rear. Additionally, at least a portion of the third section and at least a portion of the fourth section may interlock in a wedge shape.
[0054] The above third section may be a wedge portion of the rotor cover.
[0055] Optionally, the material of the second rotor cover may be softer than the material of the rotor hub. The third section may be a plastically deformed section.
[0056] The above-mentioned fourth section may be a wedge portion of the rotor hub.
[0057] Optionally, the material of the second rotor cover may be harder than the material of the rotor hub. The fourth section may be a plastically deformed section.
[0058] An uneven surface may be formed on at least one side of the third and fourth sections mentioned above. Accordingly, the section made of a soft material undergoes plastic deformation, thereby facilitating wedge joining and strengthening rotational restraint.
[0059] Either the material of the rotor hub and the material of the second rotor cover may be softer than the other.
[0060] Preferably, the material of the rotor hub may be softer than the material of the second rotor cover.
[0061] The above rotor hub may include SCM series carbon steel material.
[0062] The above rotor core may include a structure in which a plurality of thin electrical steel sheets are laminated in the axial direction.
[0063] The above magnet may include an Nd (neodymium) series ferromagnet that emits magnetic field lines.
[0064] The rotor cover may be made of a non-magnetic material that blocks the magnetic flux of the magnet. Preferably, the rotor cover may be made of austenitic stainless steel.
[0065] In another aspect, a rotor assembly structure of a hybrid drive module according to one embodiment of the present invention comprises: a rotor hub coupled to an input shaft of the hybrid drive module; a rotor core mounted circumferentially on the rotor hub; a magnet mounted circumferentially on the inner side of the rotor core; a first rotor cover inserted circumferentially between the rear end of the rotor hub and the rear end of the rotor core and the magnet; and a rotor retainer coupled in a wedge shape to the upper surface of the front end of the rotor hub with a second rotor cover.
[0066] According to another embodiment of the present invention, the rotor hub is coupled to the input shaft of a hybrid drive module; a rotor core is mounted circumferentially on the rotor hub; a magnet is mounted circumferentially on the inner side of the rotor core; and a first rotor cover is inserted circumferentially between the rear end of the rotor hub and the rear end of the rotor core and the magnet; wherein the rotor hub is coupled to the upper surface of the front end with a wedge-shaped rotor cover at the other end.
[0067] According to a preferred embodiment of the present invention, an uneven surface may be formed on the wedge portion of the rotor retainer.
[0068] According to a preferred embodiment of the present invention, an uneven surface may be formed on the coupling surface of the rotor hub.
[0069] According to a preferred embodiment of the present invention, the rotor hub may be made of SCM series carbon steel.
[0070] According to a preferred embodiment of the present invention, the rotor core may be a thin electrical steel sheet with a thickness of 0.2 mm to 0.35 mm, laminated in tens to hundreds of sheets.
[0071] According to a preferred embodiment of the present invention, the magnet is a ferromagnetic material of the Nd (neodymium) series and can emit strong magnetic field lines.
[0072] According to a preferred embodiment of the present invention, the rotor cover is made of a non-magnetic material of austenitic stainless steel and can prevent physical detachment of the rotor core and magnet and block the magnetic flux of the magnet.
[0073] According to a preferred embodiment of the present invention, the rotor assembly may be structured such that a first rotor cover having the same inner diameter and a rotor core on which the magnet is mounted are pushed into the rear end of the rotor hub in sequence, and a second rotor cover is pushed into the front end, and then a rotor retainer having the wedge portion is fixed by hot-pressing.
[0074] According to a preferred embodiment of the present invention, the rotor assembly may be structured to fix a rotor retainer having the wedge portion by press-fitting it without a hot heating process.
[0075] According to a preferred embodiment of the present invention, the outer diameter (d1) of the rotor retainer may be larger than the outer inner diameter (D1) of the rotor cover, and the inner diameter (d2) of the rotor retainer may be larger than the inner inner diameter (D2) of the rotor cover.
[0076] According to a preferred embodiment of the present invention, the width (w1) of the rotor retainer may be smaller than or equal to the width (W2) of the rotor cover.
[0077] According to another preferred embodiment of the present invention, the rotor assembly may be structured such that a first rotor cover having the same inner diameter and a rotor core on which the magnet is mounted are pushed in sequence into the rear end of the rotor hub, and a second rotor cover is pushed into the front end, and then the rotor cover having the wedge portion is fixed to the rotor hub by plastic deformation.
[0078] According to another preferred embodiment of the present invention, the plastic deformation may be achieved by a material having weak mechanical properties among the rotor hub and the rotor cover.
[0079] According to the present invention, by improving the structure of the rotor assembly of a hybrid drive module, there is an advantageous effect of overcoming the disadvantage of an increased axial length.
[0080] According to the present invention, there is an advantageous effect of improving product productivity by minimizing the number of parts and manufacturing processes for the production of a hybrid drive module.
[0081] In addition to the effects described above, the specific effects of the present invention are described together with the specific details for implementing the invention below.
[0082] FIG. 1 is a schematic cross-sectional view of the hybrid drive module of the present invention.
[0083] FIG. 2 is a perspective view of the rotor assembly structure of a hybrid drive module, which is an embodiment of the present invention.
[0084] FIG. 3 is a cross-sectional view of the retainer of the rotor assembly of the present invention in a separated state before joining.
[0085] FIG. 4 is a cross-sectional view of the rotor assembly of the present invention in a state where the retainer is coupled.
[0086] FIG. 5 is a perspective view of an object without protrusions on the rotor retainer of FIG. 3 and FIG. 4.
[0087] FIG. 6 is a perspective view of an object in which an uneven surface is formed on the rotor retainer of FIG. 3 and FIG. 4.
[0088] FIG. 7 is an enlarged view of the joint portion of the rotor retainer of FIG. 4.
[0089] FIG. 8 is a perspective view of the rotor assembly structure of a hybrid drive module, which is another embodiment of the present invention.
[0090] FIG. 9 is a cross-sectional view of the rotor cover separated before assembly in FIG. 8.
[0091] FIG. 10 is a cross-sectional view of the rotor cover in the state of being assembled in FIG. 9.
[0092] FIG. 11 is a perspective view of the rotor hub to which the rotor cover is attached in FIG. 8 to 10, in a state without protrusions or indentations.
[0093] FIG. 12 is a perspective view of the state in which an uneven surface is formed on the coupling surface of the rotor hub in FIG. 11.
[0094] FIG. 13 is an enlarged view of the combined state of the rotor cover and rotor hub of FIG. 10.
[0095] FIG. 14 is an enlarged cross-sectional view of section "A" of FIG. 3.
[0096] [Explanation of the symbol]
[0097] 10: Hybrid drive module, 20: Input shaft, 25: Engine clutch, 26: Lock-up clutch, 30: Output shaft, 100: Rotor assembly, 110: Rotor hub, 111: Rear end of rotor hub (rear side), 112: Front end of rotor hub (top surface), 115: Rotor hub coupling surface, 117: Uneven surface (rotor hub), 120: Magnet (permanent magnet), 130: Rotor core, 140: First rotor cover, 141: Second rotor cover, 145: Rotor cover wedge section (third section), 148 (112): Plastic deformation section of rotor cover (rotor hub), 150: Rotor retainer (retainer), 155: Plastic deformation section of retainer, 160: Retainer wedge section (second section), 170: Retainer, 200: Torque converter, d1: Outer diameter of the retainer, d2: Inner diameter of the retainer, D1: Outer inner diameter of the rotor cover, D2: Inner inner diameter of the rotor cover, w1: Width of the retainer, W2: Width of the rotor cover
[0098] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0099] The present invention is not limited to the embodiments disclosed below, but can be modified and implemented in various different forms. The embodiments provided are merely intended to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. Accordingly, the present invention should be understood not to be limited to the embodiments disclosed below, but to include all modifications, equivalents, and substitutions that fall within the technical spirit and scope of the present invention, as well as substituting or adding the configuration of any one embodiment with the configuration of another embodiment.
[0100] The attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the attached drawings; rather, it should be understood that they include all modifications, equivalents, and substitutions that fall within the spirit and technical scope of the invention. In the drawings, components may be depicted as being exaggeratedly large or small in size or thickness for the sake of convenience of understanding, but the scope of protection of the invention should not be interpreted restrictively as a result thereof.
[0101] The terms used in this specification are used merely to describe specific embodiments or examples and are not intended to limit the invention. Furthermore, singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as "includes" or "consists of" in this specification are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in this specification. That is, terms such as "includes" or "consists of" in this specification should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.
[0102] Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. Therefore, unless otherwise stated, the first component may be the second component.
[0103] When it is stated that one component is "connected" or "in contact" with another component, it should be understood that while it may be directly connected or in contact with that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly in contact" with another component, it should be understood that there are no other components in between.
[0104] When it is stated that one component is "above" or "below" another component, it should be understood that it is not only placed directly above the other component, but that another component may also exist in between.
[0105] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.
[0106] Hereinafter, the rotor assembly structure of a hybrid drive module according to one embodiment and another embodiment of the present invention will be described with reference to FIGS. 1 to 14.
[0107] As shown in FIG. 1, a schematic cross-sectional view of the hybrid drive module (10) shows that the rotor assembly (100) is connected to the input shaft (20) via an engine clutch (25) and can rotate with the driving force of the engine or drive motor. In addition, the rotor assembly (100) is connected to the output shaft (30) via a torque converter (200) and also connected to the output shaft (30) in parallel via a lock-up clutch (26) to provide rotational driving force to the transmission.
[0108] The rotor assembly (100) comprises a rotor hub (110), a rotor core (130), and a magnet (120). The rotor hub (110) is axially extended in a tube shape, and the ring-shaped rotor core (130) is coupled to the outer surface of the rotor hub (110) at the radial outer side of the rotor hub (110). For example, the rotor core (130) is axially fitted onto the rotor hub (110). An axially extending key and a keyway are provided on the inner surface of the rotor core (130) and the outer surface of the rotor hub (110), respectively, so that the rotor core (130) is connected to the rotor hub (110) so as to be rotationally constrained as the key and the keyway are coupled to interlock with each other.
[0109] The magnet (120), which is a permanent magnet, is arranged in a form that is extended in the axial direction. Multiple magnets (120) are spaced apart along the circumferential direction of the rotor core (130) and are inserted and mounted axially inside the rotor core (130). The strong magnetic force of the multiple magnets (120) embedded in the rotor core (130) can generate rotational force in the rotor assembly (100) of the drive module (10) by electromagnetically interacting with a stator (STATOR) that is fixedly installed radially outward from the magnets in the radial direction.
[0110] FIG. 2 shows an overall schematic perspective view of a rotor assembly (100) of a hybrid drive module (10) corresponding to one embodiment of the present invention, and FIG. 3 specifically shows a cross-sectional view of the rotor retainer (150) of the rotor assembly (100) of the present invention in a separated state before being coupled.
[0111] According to one embodiment of the present invention, the rotor assembly structure (100) of a hybrid drive module (10) comprises: a rotor hub (110) connected to an input shaft (20) of the drive module (10); a rotor core (130) mounted on the rotor hub (110) and extending in a circumferential direction; a plurality of magnets (120) embedded in the rotor core (130) so as to extend in an axial direction and be spaced apart in a circumferential direction; a first rotor cover (140) interposed laterally between the rear end of the rotor hub (110) and the rear end of the rotor core (130) and the magnet (120) and extending in a circumferential direction; and a second rotor cover (141) disposed radially outside the front end of the rotor hub (110) and in close contact with the front end of the rotor core (130) and the magnet (120). and includes a rotor retainer (150) that is coupled in a wedge shape between the rotor hub (110) and the second rotor cover (141) in the radial direction.
[0112] In the above embodiment, the structure of the rotor assembly (100) can be fixed by first pushing in, from the front to the rear of the annular rotor hub (110), a first rotor cover (140) having an inner diameter corresponding to the outer diameter of the rotor hub (110), a rotor core (130) fitted with the magnet (120) inserted therein, and a second rotor cover (141), and then forcibly pressing in a rotor retainer (150) having a wedge portion (160).
[0113] The rotor hub (110) provides rotational force of the drive motor to the output shaft (30), and it is preferable that its material be made of SCM series carbon steel. That is, SCM series carbon steel refers to chromium-molybdenum steel. The SCM series belongs to high-strength alloy steels and contains chromium (Cr) and molybdenum (Mo) as major alloying elements, resulting in high strength and hardness, excellent wear resistance and corrosion resistance, and can be used in automotive parts such as gears, shafts, and hubs. However, the material of the rotor hub (110) is not limited to this.
[0114] The rotor core (130) is mounted axially on the rotor hub (110) and surrounds the rotor hub (110) in a circumferential direction. The rotor core (130) of this embodiment has a structure in which tens to hundreds of thin electrical steel sheets with a thickness of 0.2 mm to 0.35 mm, extending radially, are stacked axially.
[0115] Each individual sheet of electrical steel in the rotor core (130) has both sides facing the axial direction coated with a non-conductive material, thereby limiting the emission of axial magnetic field lines from the permanent magnet (120). In other words, when viewed from the rotor assembly (100) of FIG. 3, the radial magnetic field lines toward the stator are excellent, while the axial magnetic field lines are limited.
[0116] Additionally, each of the above magnets (120) is axially inserted into the inner part of the rotor core (130) as described above, and a plurality of magnets (120) are arranged along the circumferential direction. The rotor core (130) supports each magnet (120) both in the radial inner and outer directions, and supports both sides in the circumferential direction. Accordingly, the magnets (120) move together with the rotor core (130) while embedded in the rotor core (130), with their relative movement to the rotor core (130) restricted.
[0117] For reference, the magnet (120) is an Nd (neodymium) series ferromagnetic material characterized by emitting strong magnetic field lines. The Nd (neodymium) series magnet (120) provides high magnetic flux density and energy efficiency, and is suitable for miniaturization and lightweighting, which has the advantage of contributing to the improvement of performance and fuel efficiency of hybrid vehicles. However, the magnet (120) is not necessarily limited to the Nd series.
[0118] According to the present invention, the first rotor cover (140) is inserted axially between the rear end of the rotor hub (110) and the rear end of the rotor core (130) and magnet (120), and extends in a closed loop shape along the circumferential direction. The second rotor cover (141) is also inserted axially in front of the front end of the rotor core (130) and magnet (120), and extends in a closed loop shape along the circumferential direction. Accordingly, the rotor covers (140, 141) can be positioned at both ends of the rotor hub (110) in the axial direction, as shown in FIGS. 3 and 4.
[0119] Here, the first rotor cover (140) is externally fitted to be in axial contact with a flange-shaped radial extension provided at the rear end (111) of the rotor hub (110), and the second rotor cover (141) is externally installed at the front end (112) of the tube-shaped rotor hub (110).
[0120] As shown in FIGS. 3 and 4, the rotor cover (140, 141) can tightly support the rotor core (130) and the magnet (120) in the axial direction to prevent them from moving out of the axial direction. In addition, the rotor cover (140, 141) may be made of a non-magnetic material such as austenitic stainless steel, and accordingly, can perform the function of blocking the magnetic flux of the magnet (120).
[0121] A wedge portion (160) is formed in the rotor retainer (150) of the present invention, which has a wedge shape (wedge shape) having a taper as shown in FIGS. 3 and 4, and can be joined to a wedge-shaped second rotor cover (141) by a press-fit process or a press-fit process on the radially outer side of the front end of the rotor hub (110). The press-fit process is preferably a cold press-fit. However, the present invention does not exclude hot press-fit.
[0122] A wedge portion (160) inclined downward toward the rear of the rotor retainer (150) is formed on the outer surface of the retainer (150) and comes into surface contact with an inclined portion formed on the inner surface of the second rotor cover (141) that is combined with it, thereby forming a plastic deformation portion (155) as shown in FIG. 7 through the processes described above. Accordingly, the two materials can be strongly bonded.
[0123] Additionally, an uneven surface (170) may be formed on the wedge portion (160) of the rotor retainer (150). Specifically, one or more uneven surfaces (170) having an intaglio or embossed shape may be implemented on the wedge portion (160). Accordingly, it is possible to prevent slippage and strengthen the bonding force between the rotor and the rotor retainer (150).
[0124] To explain this in detail, as shown in FIGS. 6 and 7, the uneven portion (170) formed on the wedge portion (160) of the rotor retainer (150) is plastically deformed by a press fit without a hot press-fitting process or a hot heating process, as the wedge portion (160) is fitted together with the second rotor cover (141). During this plastic deformation process, the frictional force between the rotor and the rotor retainer (150) is maximized, and the overall bonding force (bonding force) of the rotor assembly (100) can be further strengthened. Meanwhile, although the drawings illustrate an uneven portion in a rectangular shape, this is merely an example, and it is obvious that uneven portions of various shapes can be formed.
[0125] In an embodiment of the present invention, as shown in FIG. 7, the characteristics such as mechanical strength of the retainer (150) are set to be weaker than those of the rotor cover (141), so that plastic deformation occurs in the retainer (150); however, plastic deformation may also occur in the rotor cover (141).
[0126] According to one embodiment of the present invention, as shown in FIGS. 3 and FIGS. 14, the outer diameter (d1) of the rotor retainer (150) is larger than the outer inner diameter (D1) of the rotor cover (141), and the inner diameter (d2) of the rotor retainer (150) is set larger than the inner inner diameter (D2) of the rotor cover (141).
[0127] In order to strengthen the fastening force of the rotor assembly (100) of the present invention during the press-fitting process, it is preferable that the outer diameter (d1) of the rotor retainer (150) is larger than the outer inner diameter (D1) of the rotor cover (141), and that the inner diameter (d2) of the rotor retainer (150) is larger than the inner inner diameter (D2) of the rotor cover (141).
[0128] According to one embodiment of the present invention, as shown in FIGS. 3 and FIGS. 14, the width (w1) of the rotor retainer (150) is implemented in a form that is smaller than or equal to the width (W2) of the rotor cover (141). By making the width (w1) of the rotor retainer (150) smaller than or equal to the width (W2) of the rotor cover (141), it is possible to ensure that there is no part of the rotor retainer (150) protruding further in the axial direction than the rotor cover (141) after the rotor retainer (150) is pressed in. However, the present invention is not necessarily limited to this dimensional relationship. For instance, it is also possible to make the width (w1) of the rotor retainer (150) larger than the width (W2) of the rotor cover (141) to achieve the effect of maximizing the bonding force using friction.
[0129] According to another embodiment of the present invention, as shown in FIG. 9, the rotor assembly structure (100) of the hybrid drive module (10) comprises: a rotor hub (110) coupled to the input shaft (20) of the drive module; a rotor core (130) mounted in the circumferential direction of the rotor hub (110); a magnet (120) mounted in the circumferential direction on the inner side of the rotor core (130); and a first rotor cover (140) inserted in the circumferential direction between the rear end of the rotor hub (110) and the rear end of the rotor core (130) and the magnet (120); wherein the rotor hub (110) is coupled to the upper surface of the front end with a wedge-shaped rotor cover (141) of the other end.
[0130] Another embodiment of the present invention has a structure of a rotor assembly (100) in which the rotor retainer (150) of the above-described embodiment is omitted, as shown in FIGS. 8 to 13, in order to reduce the number of parts of the rotor assembly (100). Instead, the function of the omitted rotor retainer is implemented in the second rotor cover (141).
[0131] That is, another embodiment of the present invention is implemented such that, instead of the rotor retainer (150), a wedge portion (145) having an inclined wedge shape (wedge shape) is formed on the inner circumference of the second rotor cover (141) so as to extend radially outward toward the rear, and the wedge portion (145) is wedge-coupled to the rotor hub (110). To this end, an inclined portion is provided on the outer circumference of the rotor hub (110) so as to extend radially outward toward the rear, and the rotor hub (110) and the second rotor cover (141) can be directly wedge-coupled by combining the wedge portion (145) and the inclined portion. Additionally, the material of the second rotor cover (141) may include aluminum.
[0132] Specifically, as shown in FIGS. 9 and 10, the second rotor cover (141) forms a wedge portion (145) in which the inner circumferential surface of its inner diameter is inclined inward, and the wedge shape (wedge shape) can be joined together by the above-described press-fit process or press-fit process by making surface contact with the upper surface (112) of the front portion of the rotor hub (110). The press-fit process is preferably a cold press-fit. However, the present invention does not exclude hot press-fit.
[0133] Additionally, as illustrated in FIG. 12, a plurality of protrusions (117) arranged along the circumferential direction may be formed on the coupling surface (115) of the rotor hub (110). Although the drawing illustrates protruding protrusions in a rectangular shape, this is merely an example, and it is obvious that protrusions of various shapes may be formed.
[0134] Additionally, in another embodiment of the present invention as shown in FIG. 9 and FIG. 10, the rotor assembly (100) may insert a first rotor cover (140) having the same inner diameter into the rear end (111) of the rotor hub (110), then insert a rotor core (130) on which the magnet (120) is mounted, then insert a second rotor cover (141) into the front end (112), and then forcibly press-fit the second rotor cover (141) having the wedge portion (145), thereby plastically deforming at least one of the rotor hub (110) and the second rotor cover (141) and fixing them to each other.
[0135] As shown in the combined enlarged view of FIG. 13, the plastic deformation can be achieved by a material having weak mechanical properties (e.g., strength, hardness, toughness, etc.) among the rotor hub (110) and rotor cover (141).
[0136] In other words, as shown in Fig. 13, if the mechanical properties of the rotor cover (141) are weak, a plastic deformation part (148) may be formed therein, and if the rotor hub (110) is weak, a plastic deformation part (112) may be formed in the rotor hub (110).
[0137] As described above, various technical embodiments have been described through one embodiment and other embodiments of the present invention, but the basic concept of the present invention is to apply a wedge-shaped part (retainer, 150) made of a material weaker (softer) than the rotor cover (141) and rotor hub (110) and to apply a press-fitting process without a heating process, wherein the wedge (retainer, 150) can be plastically deformed and tightly bonded between the rotor hub (110) and the rotor cover (141). Also, since the movement of the axial electromagnetic field of the rotor core (130) is restricted by the coating of a non-magnetic material, the wedge part does not need to be a non-magnetic material. However, for reference, the creepage distance (insulation distance) according to the electrical appliance safety standard KC 60664-1 must be satisfied.
[0138] Although the present invention has been described above with reference to the illustrated drawings, the present invention is not limited by the embodiments and drawings disclosed in this specification, and it is obvious that various modifications can be made by a person skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration according to the present invention were not explicitly described while describing the embodiments of the present invention above, it is natural to acknowledge that the effects predictable by said configuration should also be recognized.
Claims
1. A rotor hub connected to an input shaft that receives rotational force from the engine and to an output shaft that provides rotational force to the transmission; A rotor core extending in the circumferential direction and mounted to be rotationally constrained to the rotor hub; A plurality of magnets embedded in the rotor core so as to extend in the axial direction and spaced apart along the circumferential direction; A first rotor cover interposed in the axial direction between the rear end of the rotor hub and the rear end of the rotor core and magnet, and extending in the circumferential direction; A second rotor cover that is in close contact with the front end of the rotor core and magnet in the axial direction and extends in the circumferential direction; and A rotor assembly of a hybrid drive module comprising: a rotor retainer inserted radially between the front end of the rotor hub and the second rotor cover and coupled in a wedge shape.
2. A rotor assembly according to claim 1, wherein the thickness of the rotor retainer measured in the axial direction is equal to or smaller than the thickness of the second rotor cover measured in the axial direction.
3. In claim 1, the radial inner surface of the second rotor cover includes a first section in which the inner diameter gradually decreases toward the rear, and The radial outer surface of the above-mentioned rotor retainer includes a second section in which the outer diameter gradually decreases toward the rear, and A rotor assembly in which at least a portion of the first section and at least a portion of the second section interlock in a wedge shape.
4. A rotor assembly according to claim 3, wherein an uneven surface is formed on at least one side of the first section and the second section.
5. The rotor assembly according to claim 1, wherein the radially outer surface portion of the front end of the rotor hub, which engages with the radially inner surface of the rotor retainer in the radial direction, is extended in the axial direction such that its outer diameter is constant.
6. A rotor assembly according to claim 1, wherein the material of the rotor retainer is softer than the material of the second rotor cover and the rotor hub.
7. A rotor hub connected to an input shaft that receives rotational force from the engine and to an output shaft that provides rotational force to the transmission; A rotor core extending in the circumferential direction and mounted to be rotationally constrained to the rotor hub; A plurality of magnets embedded in the rotor core so as to extend in the axial direction and spaced apart along the circumferential direction; A first rotor cover interposed in the axial direction between the rear end of the rotor hub and the rear end of the rotor core and magnet, and extending in the circumferential direction; and It includes a second rotor cover that is in close contact with the front end of the rotor core and magnet in the axial direction and extends in the circumferential direction. A rotor assembly of a hybrid drive module, wherein the front portion of the rotor hub and the second rotor cover are joined in a wedge shape.
8. In claim 7, the radial inner surface of the second rotor cover includes a third section in which the inner diameter gradually increases toward the rear, and The radial outer surface of the front section of the rotor hub includes a fourth section in which the outer diameter gradually increases toward the rear, and A rotor assembly in which at least a portion of the third section and at least a portion of the fourth section interlock in a wedge shape.
9. A rotor assembly according to claim 8, wherein an uneven surface is formed on at least one side of the third section and the fourth section.
10. A rotor assembly according to claim 7, wherein either the material of the rotor hub and the material of the second rotor cover is softer than the other.
11. A rotor assembly according to any one of claims 1 to 10, wherein the rotor hub comprises an SCM series carbon steel material.
12. A rotor assembly according to any one of claims 1 to 10, wherein the rotor core comprises a structure in which a plurality of thin electrical steel sheets are laminated in the axial direction.
13. A rotor assembly according to any one of claims 1 to 10, wherein the magnet comprises an Nd (neodymium) series ferromagnetic material that emits magnetic field lines.
14. A rotor assembly according to any one of claims 1 to 10, wherein the rotor cover is made of a non-magnetic material that blocks the magnetic flux of the magnet.
15. A rotor assembly according to claim 14, wherein the rotor cover is made of austenitic stainless steel.
16. In any one of claims 1 to 10, the rotor hub comprises an axial extension portion disposed radially inward of the rotor core and a radial extension portion extending radially outward from the rear end of the axial extension portion, A rotor assembly wherein the first rotor cover is positioned in front of the radial extension so as to restrict rearward movement by the radial extension.