A rear sub-frame assembly for mounting a multi-link suspension and motor in a vehicle

Abstract

The disclosure herein relates to a rear sub-frame assembly (100) for mounting a multi-link suspension (10) and motor (30) in a vehicle, and an assembling method (300) thereof. The assembly (100) includes a sub-frame (200), a plurality of motor mounting members (102,104), and a plurality of mounting members (110,120,130,140,150) for mounting multi-link suspension on the sub-frame. Each of a longitudinal member (206) of the sub-frame houses a front motor mounting member (102) near a front-end (200F), and accommodates hardpoints for mounting front upper and lower links in proximity to the member (102). A reinforcement member is disposed within the longitudinal member to provide structural support near the front end (200F). The assembly and method allow flexibility in positioning hardpoints, allows larger overhang, better strength to weight ratio, ease in maintenance.

Description

A REAR SUB-FRAME ASSEMBLY FOR MOUNTING A MULTI-LINK SUSPENSION AND MOTOR IN A VEHICLETECHNICAL FIELD

[0001] The embodiments herein generally relate to rear sub-frame assemblies of vehicles and more particularly, to a rear sub-frame assembly for mounting a multi-link suspension and motor in a rear wheel drive electric vehicle and an assembling method thereof.BACKGROUND

[0002] Generally, a rear subframe assembly of a vehicle facilitates mounting for suspension links, and a powertrain system in a rear of the vehicle. In an electric vehicle with a rear wheel drive, the rear sub-frame assembly is designed to allow mounting of a motor along with the suspension links, and other components of the powertrain system. A sub-frame on which the motor and the suspension links are mounted needs to be designed to enable the mounting of the motor and multiple suspension links. Conventionally, in a vehicle with a pentalink suspension, three links are positioned on the front of the sub-frame and two links are positioned on the rear of the sub-frame. Further, to facilitate mounting of the motor on the subframe, two mounting points are provided on the rear of the sub-frame, and one mounting point is provided on the front of the sub-frame. In such type of arrangement, the mounting bushes which are provided at the rear of the sub-frame to facilitate mounting of the motor, consume considerable space on the sub-frame, thereby leaving limited space to mount only one link near the rear mounting point of the motor. Therefore, in such type of conventional rear sub-frame assembly, there is less flexibility in positioning of hardpoints for mounting of other suspension links which impacts the size of the sub-frame, requiring the sub-frame to be sizeable to accommodate the hardpoints of suspension links and the motor on the sub-frame.

[0003] Further, in some vehicles, the rear sub-frame assembly is designed to facilitate mounting of the motor at two mounting points provided on the front of the sub-frame, and one mounting point provided on the rear of the sub-frame. In such type of mounting arrangement, two suspension links are mounted on the front of the sub-frame near the front motor mounting point, and three suspension links are mounted towards the rear of the sub-frame. To accommodate hardpoints of two suspension links near the front mounting point of the motor, sleeves for mounting the mounting bushes are mounted on a longitudinal member of the subframe. Although, such mounting of sleeves on the longitudinal member allows compactassembly of the motor and the suspension links, however, it affects the structural integrity of the sub-frame. Also, such arrangement fails to provide the required flexibility of positioning the hardpoints for mounting the suspension links due to constraints such as strength and structural integrity of the sub-frame, and the space required for mounting the sleeves on the longitudinal member. In some sub-frame assemblies, the longitudinal member has a tubular structure to improve the structural integrity of the sub-frame. However, this increases the weight of the sub-frame, thereby impacting the performance of the vehicle. Furthermore, the tubular structure of the longitudinal member puts restraint on the positioning of the hardpoints due to the limitation on the space available along the X- axis of the sub-frame, thus further affecting the flexibility of mounting the suspension links on the sub-frame.

[0004] Therefore, there exists a need for a rear frame sub-assembly which obviates the aforementioned drawbacks.OBJECTS

[0005] The principal object of embodiments herein is to provide a rear sub-frame assembly which facilitates mounting of a multi-link suspension and a motor in a vehicle.

[0006] Another object of embodiments herein is to provide the rear sub-frame assembly which provides compact packaging of the multi-link suspension and the motor in a rear of the vehicle by accommodating hardpoints for mounting a front upper link and a front lower link, and the motor towards a front end of a sub-frame without compromising structural integrity of the sub-frame.

[0007] Another object of embodiments herein is to provide the rear sub-frame assembly which has a motor mounting member disposed within a longitudinal member of the sub-frame to facilitate mounting of the motor towards a front end of the sub-frame and accommodate hardpoints for mounting the front upper link and front lower link in proximity to the front motor mounting member on the sub-frame, thereby foregoing the need to extend a length of the longitudinal member for accommodating the hardpoints on the sub-frame.

[0008] Another object of embodiments herein is to provide the rear sub-frame assembly which facilitates integrating of the motor mounting member in the longitudinal member without affecting the structural integrity of the sub-frame by reinforcing the longitudinal member and motor mounting member with a reinforcement member.

[0009] Another object of embodiments herein is to provide the rear sub-frame assembly which is configured to allow a larger overhang between a hardpoint of bush sleeve which facilitates in mounting the sub-frame in the vehicle and the motor mounting member without affecting structural integrity of the sub-frame.

[0010] Another object of embodiments herein is to provide the rear sub-frame assembly which provides access to the motor mounting member disposed within the longitudinal member, thereby facilitating ease in maintenance.

[0011] Another object of embodiments herein is to provide the rear sub-frame assembly which has better structural strength, lower weight, and lesser material cost.

[0012] Another object of embodiments herein is to provide a method for assembling the multi-link suspension and motor in the rear of the vehicle.

[0013] These and other objects of embodiments herein will be better appreciated and understood when considered in conjunction with following description and accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.BRIEF DESCRIPTION OF DRAWINGS

[0014] The embodiments are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:

[0015] Fig. 1 depicts an isometric view of a rear sub-frame assembly with a multi-link suspension and motor mounted thereon, according to embodiments as disclosed herein;

[0016] Fig. 2 depicts a top view of the rear sub-frame assembly with the multi-link suspension and motor mounted thereon, according to embodiments as disclosed herein;

[0017] Fig. 3 depicts an isometric view of the rear sub-frame assembly, according to embodiments as disclosed herein;

[0018] Fig. 4 depicts a bottom view of the rear sub-frame assembly, according to embodiments as disclosed herein;

[0019] Fig. 5A depicts a top view of a front end of a sub-frame of the rear sub-frame assembly, according to embodiments as disclosed herein;

[0020] Fig. 5B depicts an isometric view of the front end of the sub-frame, according to embodiments as disclosed herein;

[0021] Fig. 5C depicts a side view of the front end of the sub-frame, according to embodiments as disclosed herein;

[0022] Fig. 6A depicts another isometric view of the front end of the sub-frame showing a front motor mounting member, according to embodiments as disclosed herein;

[0023] Fig. 6B depicts yet another isometric view of the front end of the sub-frame, according to embodiments as disclosed herein;

[0024] Fig. 7 depicts a sectional view of the front end of the sub-frame, according to embodiments as disclosed herein;

[0025] Fig. 8A depicts an isometric view of the rear sub-frame assembly, according to embodiments as disclosed herein;

[0026] Fig. 8B depicts a top view of the rear sub-frame assembly, according to embodiments as disclosed herein;

[0027] Fig. 9A depicts an isometric view of a reinforcement member, according to embodiments as disclosed herein;

[0028] Fig. 9B depicts a front view of the reinforcement member, according to embodiments as disclosed herein;

[0029] Fig. 9C depicts a top view of the reinforcement member, according to embodiments as disclosed herein;

[0030] Figs. 10A depicts isometric view of the front motor mounting member mounted in a longitudinal member of the sub-frame, according to embodiments as disclosed herein;

[0031] Fig. 10B depicts another isometric view of the front motor mounting member mounted in the longitudinal member, according to embodiments as disclosed herein;

[0032] Fig. 10C depicts a top view of the front motor mounting member mounted in the longitudinal member, according to embodiments as disclosed herein;

[0033] Fig.lOD depicts a front view of the front motor mounting member mounted in the longitudinal member, according to embodiments as disclosed herein;

[0034] Fig. 11A depicts an isometric view of a first mounting member, according to embodiments as disclosed herein;

[0035] Fig. 1 IB depicts another isometric view of the first mounting member, according to embodiments as disclosed herein;

[0036] Fig. 12A depicts an isometric view of a second mounting member, according to embodiments as disclosed herein;

[0037] Fig. 12B depicts another isometric view of the second mounting member, according to embodiments as disclosed herein; and

[0038] Fig. 13 is a flowchart depicting a method for assembling the multi-suspension and the motor, according to embodiments as disclosed herein.DETAILED DESCRIPTION

[0039] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0040] The embodiments herein achieve a rear sub-frame assembly to mount a multilink suspension and a motor in a vehicle which allows accommodating hardpoints for mounting the motor and a front upper link and a front lower link towards a front end of a sub-frame in close proximity. Further, embodiments herein achieve a method for assembling the multi -link suspension and the motor in the rear of the vehicle. Referring now to the drawings Figs. 1 through 13, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.

[0041] Figs. 1 and 2 depict an isometric view and a top view of a rear sub-frame assembly (100) with multi-link suspension (10) and a motor (30) mounted thereon respectively, according to embodiments as disclosed herein. The rear sub-frame assembly (100) includes a sub-frame (200), a plurality of motor mounting members (102, 104) adapted to facilitate mounting of the motor (30) on the sub-frame (200), and a plurality of mounting members (110, 120, 130, 140, 150) (shown in figs. 1, 2, and 4) adapted to facilitate mounting of the multi-link suspension (10) on the sub-frame (200). For the purpose of this description and ease of understanding, the rear sub-frame assembly (100) is explained herein with below reference to mounting a multi-link suspension (10) having five suspension links, viz. a front upper link (12), a front lower link (14), a rear upper link (16), a lower control arm (18), and a toe link (20); and the motor (30) in a rear of the vehicle. However, it is also within the scope of the invention to use / practice the components of the assembly (100) for mounting any other type of multi-link suspension, and mounting the motor (30) and the multi-link suspension (10) in any other position in the vehicle, such as towards a front of the vehicle, without otherwise deterring the intended function of the assembly (100) as can be deduced from the description and corresponding drawings. The rear sub-frame assembly (100) is configured to facilitate mounting of the motor (30), and a plurality of links (12, 14, 16, 18, 20) of the multi-link suspension (10) on the sub-frame (200). In an embodiment, the rear sub-frame assembly (100) is configured to facilitate mounting of the front upper link (12), the front lower link (14), the rear upper link (16), the lower control arm (18), and the toe link (20) on each of a left side and a right side of the sub-frame (200) at corresponding hardpoints (110H, 120H, 130H, 140H, 150H) (shown in figs. 3and 4) on the sub-frame (200). Further, the rear sub-frame assembly (100) is configured to facilitate mounting of the motor (30) on the sub-frame (200) at at least three mounting points through the plurality of motor mounting members (102, 104), wherein two mounting points are disposed towards a front of the sub-frame (200), and at least one mounting point is disposed towards a rear of the sub-frame (200).

[0042] Figs. 3 and 4 depict an isometric view and bottom view of the rear sub-frame assembly (100) respectively, according to embodiments as disclosed herein. The sub-frame (200) includes a front cross-member (202), a rear cross-member (204) disposed parallel to the front cross-member (202), and two longitudinal members (206) connected transversely with the front cross-member (202) and the rear cross-member (204) to define a space (200S) to receive the motor (30). The motor (30) is mounted within the space (200S) through the plurality of the motor mounting members (102, 104). In an embodiment, the plurality of motor mounting members (102, 104) include at least two front motor mounting members (102), and at least one rear motor mounting member (104), wherein the front motor mounting member (102) is adapted to be mounted within each of the longitudinal member (206) towards a front end (200F) of the sub-frame (200), and the at least one rear motor mounting member (104) is adapted to be disposed within the rear cross-member (204). The two front motor mounting members (102) and the rear motor mounting member (104) thereby facilitate mounting of the motor (30) at at least three mounting points on the sub-frame (200). In an embodiment, the rear motor mounting member (104) is a sleeve adapted to be disposed at a center portion of the rear cross-member (204). In an embodiment, the assembly (100) includes two rear motor mounting members (104) disposed in the rear cross-member (204) (as shown in Fig. 8A). Further, the assembly (100) includes a plurality of bush sleeves (160), wherein at least two bush sleeves (160F) are disposed at two front comers (200 A) of the sub-frame (200), and at least two bush sleeves (160R) are disposed at two rear corners (200B) of the sub-frame (200). Each of the bush sleeve (160) is adapted to receive an insulator bush (162). The assembly (100) is adapted to be assembled onto a body-in-white (BIW) of the vehicle via the insulator bushes (162) press fitted into the plurality of bush sleeves (160).

[0043] Figs. 5A, 5B, and 5C depict an isometric view, a top view and a front view of the front-end (200F) of the sub-frame (200), according to embodiments as disclosed herein. The rear sub-frame assembly (100) facilitates mounting of at least two links (12, 14) of the plurality of links (12, 14, 16, 18, 20) in proximity to the front motor mounting point on the subframe (200), to allow compact packaging of the multi-link suspension (10) and the motor (30) in the vehicle. In an embodiment, at least two mounting members (110, 120) are provided towards the front end (200F) of the sub-frame (200) on each of the longitudinal member (206) in proximity to the at least one front motor mounting member (102). Further, in an embodiment, a first mounting member (110) is adapted to be connected on an upper portion (206A) of the longitudinal member (206) towards the front end (200F) of the sub-frame (200), in proximityto the front motor mounting member (102), to facilitate mounting of the front upper link (12) on the sub-frame (200). Further, a second mounting member (120) is connected on a lower portion of the longitudinal member (206) towards the front end (200F) of the sub-frame (200) in proximity to the front motor mounting member (102) to facilitate mounting of the front lower link (14) on the sub-frame (200). In an embodiment, the first mounting member (110) and the second mounting member (120) is connected on the longitudinal member (206) near a junction of the longitudinal member (206) and the front cross-member (202). Furthermore, the rear subframe assembly (100) is configured to facilitate mounting of at least one link (16) near a center of the longitudinal member (206), and at least two other links (18, 20) near a rear end (200R) of the sub-frame (200). In an embodiment, a third mounting member (130) is connected on the upper portion of the longitudinal member (206) to facilitate mounting of the rear upper link (16) on the sub-frame (200). A fourth mounting member (140) is connected near the rear end (200R) of the sub-frame (200) on the longitudinal member (206) to facilitate mounting of the lower control arm (18) on the sub-frame (200). A fifth mounting member (150) is provided near the rear end (200R) of the sub-frame (200) to facilitate mounting of the toe-link (20) on the sub-frame (200).

[0044] Figs. 6A and 6B depict isometric views of the front end (200F) of the sub-frame (200), according to embodiments as disclosed herein. Fig. 7 is a sectional view of the front end (200F) of the sub-frame (200), according to embodiments as disclosed herein. The front motor mounting member (102) is adapted to be mounted within the longitudinal member (206) such that the front motor mounting member (102) is housed within the longitudinal member (206). In an embodiment, the front motor mounting member (102) is disposed in a front portion (206F) of the longitudinal member (206) near a junction of the longitudinal member (206) and the front cross-member (202). In an embodiment, the front motor mounting member (102) is a sleeve adapted to be housed within the longitudinal member (206), wherein the sleeve is adapted to receive a motor mounting bush (102B) to facilitate mounting of the motor (30) on the sub-frame (200). A length (102L) of the motor mounting member (102) is adapted to allow housing of the front motor mounting member (102) within the longitudinal member (206), and prevent the front motor mounting member (102) from protruding from the longitudinal member (206). Accommodating the front motor mounting member (102) within the longitudinal member (206), therefore allows accommodating the hardpoints for mounting the front upper link (12) and the front lower link (14) on the longitudinal member (206) in proximity to the front motor mounting member (102). Further, in an embodiment, the assembly (100) includesa reinforcement member (108) adapted to be mounted within the longitudinal member (206). The reinforcement member (108) is adapted to receive the front motor mounting member (102) and provide structural support to the front motor mounting member (102) and the longitudinal member (206). The reinforcement member (108) is configured to reinforce the front motor mounting member (102) and the longitudinal member (206) near the front portion (206F) to enable the front motor mounting member (102) and the longitudinal member (206) sustain load and stress exerted on the front motor mounting member (102) and the longitudinal member (206) on mounting of the motor (30). Providing the reinforcement member (108) in connection with the front motor mounting member (102) and the longitudinal member (206) ensures that the structural integrity of the sub-frame (200) and the front motor mounting member (102) is not impacted due to shortening of length of the front motor mounting member (102).

[0045] Figs. 8A and 8B depict an isometric view and a top view of the rear sub-frame assembly (100), according to embodiments as disclosed herein. The longitudinal member (206) extends between the front comer (200A) and the rear comer (200B) of the sub-frame (200). The front portion (206F) of the longitudinal member (206) is skewed / sloped to connect the longitudinal member (206) with the front cross-member (202). The longitudinal member (206) is adapted to have a wider front-end portion (206G) to provide a larger connecting area between the front cross-member (202) and the longitudinal member (206). Further, a width and height of the longitudinal member (206) is adapted to house / receive the front motor mounting member (102) and the reinforcement member (108). The increase in height of the longitudinal member (206) to accommodate the front motor mounting member (102) allows accommodating the hardpoints for mounting the front upper link (12) and the front lower link (14) without affecting the structural integrity of the sub-frame (200). This eliminates the need for extending the length of the longitudinal member (206) for accommodating the hardpoints for mounting the multi-link suspension (10). In an embodiment, the longitudinal member (206) includes a top panel (208), and a bottom panel (210) adapted to be connected to the top panel (208) to form a substantially hollow structure. Further, in an embodiment, the longitudinal member (206) includes a receiving slot (212) to receive the front motor mounting member (102), and an access slot (214) to allow a user to access the front motor mounting member (102). In an embodiment, the access slot (214) is positioned near the front end (200F) of the sub-frame (200) in vicinity of the at least two mounting members (110, 120).

[0046] Figs. 9A, 9B, and 9C depict an isometric view, a front view, and a top view of the reinforcement member (108), according to embodiments as disclosed herein. Figs. 10A and 10B depict isometric views of the front motor mounting member (102) mounted in the longitudinal member (206), according to embodiments as disclosed herein. Figs. 10C and 10D depict a top view and a front view of the front motor mounting member (102) mounted in the longitudinal member (206), according to embodiments as disclosed herein. The reinforcement member (108) includes a plate having a cut-out (108C) to receive the front motor mounting member (102), and a plurality of flanges (108F) adapted to be connected with the longitudinal member (206) at an inside of the longitudinal member (206). In an embodiment, the plurality of flanges (108F) of the reinforcement member (108) include a bottom flange (108FB) adapted to be connected with a base (206B) of the longitudinal member (206), two top flanges (108FT) adapted to be connected with a top wall (206T) of the longitudinal member (206), and a side flange (108FS) adapted to be connected with a side wall (206S) of the longitudinal member (206). The reinforcement member (108) is disposed within the longitudinal member (206) such that a side (108A) of the reinforcement member (108) is in contact with the front cross-member (202). The front motor mounting member (102) is mounted within the longitudinal member (206) such that a front section of the front motor mounting member (102) which is facing towards the space (200S) defined by the sub-frame (200), is received by a receiving slot (206R) defined in the longitudinal member (206), and a rear section of the front motor mounting member (102S) is received in the cut-out (108C) of the reinforcement member (108). In an embodiment, the reinforcement member (108) and the front motor mounting member (102) is mounted on the bottom panel (210), wherein the front section of the front motor mounting member (102) is received by a bottom part of the receiving slot (212) defined in the bottom panel (210). Thereafter, the top panel (208) is connected with the bottom panel (210), wherein a top part of the receiving slot (212) receives the front section of the front motor mounting member (102), thereby housing the front motor mounting member (102) within the longitudinal member (206). Further, in an embodiment the reinforcement member (108) is welded with the top panel (208) and the bottom panel (210), wherein the top panel (208) and the bottom panel (210) include a plurality of apertures to provide access to connect the reinforcement member (108) and the front motor mounting member (102) within the longitudinal member (206). The structure of the longitudinal member (206) with the wider front end portion (206G), and reinforcement of the longitudinal member (206) through the reinforcement member (206) near the front end (200) of the sub-frame (200) allows an overhang of up to 300mm between thefront motor mounting-member (102) and the bush sleeve (160) on the front cross-member (202) without impacting the structural integrity of the sub-frame (200).

[0047] Figs. 11 A and 1 IB depict isometric views of the first mounting member (110), according to embodiments as disclosed herein. Figs. 12A and 12B depict isometric views of the second mounting member (120), according to embodiments as disclosed herein. In an embodiment, the first mounting member (110) includes a first bracket (112) adapted to facilitate mounting of the front upper link (12), and a first bracket reinforcement member (114) adapted to be connected with the first bracket (112) and the longitudinal member (206) to provide structural support to the first bracket (112). Further, the second mounting member (120) includes a second bracket (122) adapted to facilitate mounting of the front lower link (14), and at least two second bracket reinforcement members (124, 126) adapted to be connected with the second bracket (122) and the longitudinal member (206) to provide structural support to the second bracket (122). The bracket reinforcement members (114, 124 and 126) provide additional strength to the respective brackets (112, 122) to enable the brackets (112, 122) to sustain load upon mounting of the respective links (12, 14).

[0048] Fig. 13 is a flow chart depicting a method for assembling the multi -link suspension (10) and the motor (30) in the rear of the vehicle. The method (300) includes at step (302), mounting the plurality of motor mounting members on the sub-fame (200). The step (302) includes mounting the front motor mounting member (102) within each of the longitudinal member (206) near the front end (200F) of the sub-frame (200), and mounting the rear motor mounting member (104) in the rear cross-member (204) of the sub-frame (200). The method (300) at step (304) includes, connecting the plurality of mounting members (110, 120, 130, 140, 150) at corresponding hardpoints (11 OH, 120H, 130H, 140H, 150H) on the sub-frame (200). The step (304) includes connecting at least two mounting members (110, 120) on the longitudinal member (206) near the front end (200F) of the subframe (200) in proximity to the front motor mounting member (102). Further, the method (300), at step (306) includes mounting the motor (30) in the space (200 S) defined by the sub-frame (200), through the plurality of motor mounting members (102, 104). Furthermore, the method includes, at step (308), mounting plurality of links (12, 14, 16, 18, 20) of the multi-link suspension (10) on the sub-frame (200) through the plurality of mounting members (110, 120, 130, 140, 150). In an embodiment, the step (302) includes, at step (302 A) connecting the reinforcement member (108) in the bottom panel (210) of the longitudinal member (206) and the front cross-member(202) near the front end (200F) of the sub-frame (200). At step (302B), the method (300) includes, receiving by the cut-out (108C) defined in the reinforcement member (108), the rear section of the front motor mounting member (102). At step (302C), the method (300) includes, connecting the top panel (208) of the longitudinal member (206) with the bottom panel (210) of the longitudinal member (206) and with the front cross-member (202), wherein a top part of the receiving slot (212) defined in the top panel receives the front section of the front motor mounting member (102). Further, at step (302D), the method (300) includes, housing by the longitudinal member (206) the front motor mounting member (102) and the reinforcement member (108). Furthermore, the method (300), at step (302E) includes, connecting the reinforcement member (108) with the top panel (208) of the longitudinal member (206) through plurality of apertures (216) defined in the top panel (208). In an embodiment, the step (304) includes, at step (304A), connecting the first mounting member (110) on the upper portion (206A) of each of the longitudinal member (206) to allow mounting of the front upper link (12) on the sub-frame (200). The method (300), at step (304B) includes connecting the second mounting member (120) on the lower portion (206B) of each of the longitudinal member (206) to allow mounting of the front lower link (14) on the sub-frame (200). Further, in an embodiment, the step (304 A) includes, connecting the first bracket (112) on the upper portion (206A) of the longitudinal member (206), and connecting the first bracket reinforcement member (114) with the first bracket (112) and the longitudinal member (206). Further, in an embodiment, the step (304B) includes, connecting the second bracket (122) on the lower portion (206B) of the longitudinal member (206), and connecting at least two second bracket reinforcement members (124) with the second bracket (122) and the longitudinal member (206). In an embodiment, the method (300), at step (304) includes allowing access through the access slot (214) to the front motor mounting member (102), wherein the access slot (214) is defined in the longitudinal member (206) near the front-end (200F) of the sub-frame (200) between the first mounting member (110) and the second mounting member (120).

[0049] The technical advantages of the rear sub-frame assembly (100) and method for assembling the multi-link suspension and motor in the rear of the vehicle are as follows. Flexibility in accommodating hardpoints for mounting plurality of link of the multi-link suspension, and allow mounting of two links at front near the front motor mounting member, thereby eliminating need for extending length of sub-frame. Facilitates compact packaging of motor and multi-link suspension, tolerates larger overhang without impacting structural integrity, improved structural strength, better strength to weight ratio, and lesser material cost.

[0050] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modifications within the spirit and scope of the embodiments as described herein.

[0051] List of reference numerals:

Claims

STATEMENT OF CLAIMSWe claim;1. A rear sub-frame assembly (100) for mounting a multi -link suspension (10) and a motor (30) in a vehicle, said rear sub-frame assembly (100) comprising: a sub-frame (200) comprising two longitudinal members (206) connected transversely with a front cross-member (202) and a rear cross-member (204) to define a space (208) to receive the motor (30); a plurality of motor mounting members (102, 104) provided on the sub-frame (200) to facilitate mounting of the motor (30), wherein at least one front motor mounting member (102) is adapted to be mounted within each of said longitudinal member (206) towards a front end (200F) of said sub-frame (200); and a plurality of mounting members (110, 120, 130, 140, 150) provided on the subframe (200) to facilitate mounting of multi-link suspension (10) at corresponding hardpoints (110H, 120H, 130H, 140H, 150H) on said sub-frame (200), wherein at least two mounting members (110, 120) are connected towards a front end (200F) of said sub-frame (200) on each of said longitudinal member (206) in proximity to said at least one front motor mounting member (102).

2. The assembly (100) as claimed in claim 1, wherein said rear sub-frame assembly (100) includes a reinforcement member (108) adapted to be disposed within each of said longitudinal member (206), wherein said reinforcement member (108) comprises: a cut-out (108C) to receive said front motor mounting member (102); and a plurality of flanges (108F) adapted to be connected with said longitudinal member (206) at an inside of said longitudinal member (206); and said reinforcement member (108) is adapted to provide structural support / reinforcement to said front motor mounting member (102) and said longitudinal member (206) near said front end (200F) of said sub-frame (200).

3. The assembly (100) as claimed in claim 2, wherein said plurality of flanges (108F) comprise: a bottom flange (108FB) adapted to be connected with a base (206B) of said longitudinal member (206);two top flanges (108FT) adapted to be connected with a top wall (206T) of said longitudinal member (206); and a side flange (108FS) adapted to be connected with a side wall (206S) of said longitudinal member (206), wherein said reinforcement member (108) is disposed within said longitudinal member (206) and a side (108A) of said reinforcement member (108) is in contact with said front cross-member (202).

4. The assembly (100) as claimed in claim 2, wherein said front motor mounting member (102) is a sleeve adapted to receive a motor mounting bush (102B), and wherein said reinforcement member (108) is connected with said longitudinal member (206) by welding said plurality of flanges (108F) with said longitudinal member (206).

5. The assembly (100) as claimed in claim 3, wherein said front motor mounting member (102) is mounted within said longitudinal member (206), wherein a front section of said front motor mounting member (102) which is facing said space (200S) of said sub-frame (200) is received by a receiving slot (206R) defined in said longitudinal member (206), and a rear section of said front motor mounting member (102S) is received in said cut-out (108C) of said reinforcement member (108).

6. The assembly (100) as claimed in claim 1, wherein said longitudinal member (206) is adapted to extend between a front corner (200A) and a rear corner (200B) of said sub-frame (200), wherein a front portion (206F) of said longitudinal member (206) is skewed to connect said longitudinal member (206) with said front cross-member (202); and a front-end portion (206G) of said longitudinal member (206) which is connected with said front cross-member (202) is adapted to be wider to provide a larger connecting / contact area between said longitudinal member (206) and said front cross-member (202).

7. The assembly (100) as claimed in claim 6, wherein said longitudinal member (206) comprises: a top panel (208), and a bottom panel (210) adapted to be connected with said top panel (208) to form a substantially hollow structure; a receiving slot (212) adapted to receive said front motor mounting member (102);an access slot (214) adapted to provide access to said front motor mounting member (102), wherein said access slot (214) is positioned near said front end (200F) of said sub-frame (200) in vicinity of said at least two mounting members (110, 120); and a plurality of apertures (216) defined on said top panel (208) and said bottom panel (210) to allow access to connect said reinforcement member (108) and said front motor mounting member (102) within said longitudinal member (206); wherein a height of said longitudinal member (206) is configured to accommodate said front motor mounting member (102), and facilitate mounting of said at least two motor mounting members (110, 120).

8. The assembly (100) as claimed in claim 1, wherein at least two mounting members (110, 120) comprise: a first mounting member (110) adapted to be mounted on an upper portion (206 A) of said longitudinal member (206) near said junction of said longitudinal member (206) and said front cross-member (202), wherein said first mounting member (102) is adapted to facilitate mounting of a front upper link (12) of said multi-link suspension (10) on said subframe (200); and a second mounting member (120) adapted to be mounted on a lower portion (206B) of said longitudinal member (206) near said junction of said longitudinal member (206) and said front cross-member (102), wherein said second mounting member (120) is adapted to facilitate mounting of a front lower link (14) of said multi-link suspension (10) on said subframe (200).

9. The assembly (100) as claimed in claim 8, wherein said first mounting member (110) comprises: a first bracket (112) adapted to facilitate mounting of said front upper link (12), and a first bracket reinforcement member (114) adapted to be connected with said first bracket (112) and said longitudinal member (206) to provide structural support to said first bracket (112), and wherein said second mounting member (120) comprises: a second bracket (122) adapted to facilitate mounting of said front lower link (14); and at least two second bracket reinforcement members (124, 126) adapted to be connected with said second bracket (122) and said longitudinal member (206) to provide structural support to said second bracket (122).

10. A method (300) for assembling a multi-link suspension (10) and a motor (30) in a rear of a vehicle, said method (300) comprising: mounting a plurality of motor mounting members (102, 104) on a sub-fame (200), wherein said mounting of said plurality of motor mounting members (102, 104) comprises: mounting a front motor mounting member (102) within each of a longitudinal member (206) of said sub-frame (200) near a front end (200F) of said sub-frame (200); and mounting a rear motor mounting member (104) in a rear cross-member (204) of said sub-frame (200); connecting a plurality of mounting members (110, 120, 130, 140, 150) at corresponding hardpoints (110H, 120H, 130H, 140H, 150H) on said sub-frame (200); wherein said connecting said plurality of mounting members (110, 120, 130, 140, 150) comprises: connecting at least two mounting members (110, 120) on said longitudinal member (206) near said front end (200F) of said subframe (200) in proximity to said front motor mounting member (102); mounting said motor (30) in a space (200S) defined by said sub-frame (200), through said plurality of motor mounting members (102, 104); and mounting plurality of links (12, 14, 16, 18, 20) of said multi-link suspension (10) on said sub-frame (200) through said plurality of mounting members (110, 120, 130, 140).

11. The method (300) as claimed in claim 10, wherein said mounting said front motor mounting member (102) comprises: connecting a reinforcement member (108) in a bottom panel (210) of said longitudinal member (206) and said front cross-member (202) near said front end (200F) of said sub-frame (200); receiving by a cut-out (108C) defined in said reinforcement member(108), a rear section of said front motor mounting member (102); receiving by a bottom part of a receiving slot (214) defined in said bottom panel (210) of said longitudinal member (206), a front section of said front motor mounting member (102); connecting a top panel (208) of said longitudinal member (206) with said bottom panel (210) of said longitudinal member (206) and with said front cross-member (202), whereina top part of said receiving slot (212) defined in said top panel (208) receives said front section of said front motor mounting member (102); housing by said longitudinal member (206) said front motor mounting member (102) and said reinforcement member (108); and connecting said reinforcement member (108) with said top panel (208) of said longitudinal member (206) through plurality of apertures (216) defined in said top panel (208).

12. The method (300) as claimed in claim 10, wherein said connecting said at least two mounting members (110, 120) comprises: connecting a first mounting member (110) on an upper portion (206A) of each of said longitudinal member (206) to allow mounting of a front upper link (12) on said sub-frame (200); connecting a second mounting member (120) on a lower portion (206B) of each of said longitudinal member (206) to allow mounting of a front lower link (14) on said sub-frame (200), wherein said connecting said first mounting member (110) comprises: connecting a first bracket (112) on said upper portion (206A) of said longitudinal member (206); and connecting a first bracket reinforcement member (114) with said first bracket (112) and said longitudinal member (206); said connecting said second mounting member (120) comprises: connecting a second bracket (122) on said lower portion (206B) of said longitudinal member (206); and connecting at least two second bracket reinforcement members (124) with said second bracket (122) and said longitudinal member (206); and said mounting of said plurality of links (12, 14, 16, 18, 20) of said multi -link suspension (10) comprises: allowing access through an access slot (214) to said front motor mounting member (102), wherein said access slot (214) is defined in said longitudinal member (206) near said front-end (200F) of said sub-frame (200) between said first mounting member (110) and said second mounting member (120).

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