The present disclosure, in general, relates to a transmission case for uniform pressure distribution at mating faces between cases bolted with each other in manual or automatic transmission for front-wheel-drive vehicle and rear-wheel drive vehicle, a differential case for rear-wheel-drive vehicle, a transfer case for a four-wheel-drive vehicle, for transmission system with more than one cases joined by bolting.
Background
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Transmission housing structures comprise of two types of cases depending upon the type of vehicle. In front-wheel drive vehicles, the transmission case includes a left case and a right case and in rear-wheel drive vehicles, the transmission case includes a front case and a rear case. These cases are clamped together by means of multiple bolts.
[0004] Since it is required to fill oil inside the transmission housing, a layer of a sealant paste is applied between the faces of flanges of the cases to be clamped together so as to prevent the leakage of oil from the transmission housing. In the usual procedure, the sealant paste is applied as a continuous line before the clamping of the cases with each other. Once the sealant has been applied to one of the flanges the cases are bolted with each other. Due to a clamping force, the sealant paste gets pressed and is spread on the flange surface to act as a sealant.
[0005] With the advent of technology, automobile manufacturers are regularly planning to modify the componential features of the vehicles. The prior art

reference DE Patent No. DE102014101994A1 provides disclosure on a motor vehicle transmission comprising a housing and a shaft arrangement arranged in the housing, wherein the housing has a first housing part and a second housing part, which are connected via a parting line sealingly connected to each other, wherein the first and/or the second housing part defines an outer peripheral portion, wherein the first and the second housing part on the outer peripheral portion in each case at least a first and a second connecting portion which are circumferentially spaced. In this case, a clamping element is arranged on one axial side of the first and / or the second housing part, which has a first end portion aligned with the first connecting portion and a second connecting portion aligned second end portion and an intermediate web portion which bears against an abutment portion of the axial side, wherein the clamping element via the connecting portions with the first and / or the second housing part is connected so that on the abutment portion an axial clamping element (F) is exerted. It also disclosed separate clamping elements to exert pressure on the center of the two mounting bolts due to which pressure may not be uniform. Further, the separate clamping element has a radial section to exert pressure on the outside of the transmission case and the radial section is defined in both the external section. The prime objective here is to increase the bolt pitch and reduce the outer circumference.
[0006] Further, another prior art JP2012041996A provides a disclosure on a transmission for a vehicle, the plurality of unit cases including the joint flange part which is extended outward from the end part of a cylindrical circumferential sidewall and has a plurality of fastening holes separately disposed in a circumferential direction are disposed along the longitudinal direction of a horizontally extended gear shaft, a fastening member (fastening bolt) is inserted to the respective fastening holes and corresponding to the joint flange parts and facing each other of the adjacent unit cases and fastened, and lubricating oil is enclosed in the inside. In the case of the transmission for the vehicle, at least at one part between the fastening holes adjacent in the circumferential direction of

the joint flange part of the unit case, a reinforcing plate 6 having prescribed mechanical strength is trained about and joined by the fastening member. It is preferable that the reinforcing plate has a press contact part and a reinforcing rib in the intermediate part. The disclosure provides for a separate reinforcement plate to increase rigidity and sealing performance. There is a contact point at the center to exert pressure and a plate is provided on one side. The prime objective of this prior art is to improve the sealing and rigidity of the flange.
[0007] However, none of the prior art provides disclosure on the requirement of such a transmission case which has a uniform pressure distribution at the mating faces of the transmission case. Further, it is important to take note that transmission cases are bolted to each other over a flange. The bolts are spaced from each other such that when pressure is applied at the contact surfaces such no leakage of transmission oil should take place from this area. An increase in pitch causes a reduction in contact force between two mating surfaces at the location which is farthest from the bolts, thus this causes uneven distribution of the contact force over the surface. The contact force is seen to be in higher value and with higher gradient near the bolt area, whereas it is very small value farthest from the bolt area.
[0008] In the view of the above-cited problems, there is a need wherein it is ensured that the pressure distribution of the contact pressure is uniform at the mating face between two bolting locations.
[0009] Accordingly, there is a need for a system that can overcome one or more limitations stated above or any other limitation associated with the conventional prior arts.
Objects of the Disclosure
[0010] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed hereinbelow.

[0011] It is a general object of the present disclosure to provide for a transmission case with uniform pressure distribution at mating faces.
[0012] It is another object of the present disclosure to ensure uniform distribution of contact force at the mating faces in a transmission case.
[0013] It is another object of the present disclosure to ensure that there is no leakage of oil from a transmission case.
[0014] It is another object of the present disclosure to provide for improved performance of a sealant applied between the transmission cases in a transmission housing.
[0015] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.
Summary
[0016] This summary is provided to introduce concepts related to a transmission case for uniform pressure distribution at mating faces between cases bolted with each other. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0017] The present disclosure relates to a transmission case for uniform pressure distribution at mating faces between cases bolted with each other, the transmission case comprising of a first case having a first connecting flange, a second case having a second connecting flange and a crowning formed on a mating face of one of the first connecting flange and a second connecting flange, said crowning being formed to uniformly distribute the contact pressure between

two clamping bolts when the first connecting flange is clamped on the second connecting flange.
[0018] In an aspect, the crowning is a protruding portion from the mating face of one of the first connecting flange and a second connecting flange, such that no thickness added at the bolt location and maximum thickness farthest from the bolt.
[0019] In an aspect, the crowning center is having maximum thickness depending upon bolt pitch and flange stiffness.
[0020] In an aspect, the maximum value of crowning depends upon bolt pitch and flange stiffness.
[0021] In an aspect, one of the first connecting flange and a second connecting flange is applied with a sealant paste before the first case and the second case are bolted with each other.
[0022] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
[0023] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.
[0024] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

Brief Description of the Drawings
[0025] The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and, together with the description, serve to explain the disclosed principles. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and/or methods in accordance with embodiments of the present subject matter are now described, by way of example only, and with reference to the accompanying figures, in which:
[0026] FIG. 1 illustrates a schematic view of a transmission housing comprising of the transmission cases;
[0027] FIG. 1A illustrates a schematic view of mating flanges and a bolt pitch in a transmission case;
[0028] FIG. IB illustrates a schematic view of a plane mating face in a transmission case in the present state of the art;
[0029] FIG. 2A illustrates a perspective view of a computationally simulated first case contact force contours in accordance with the present state of the art;
[0030] FIG. 2B illustrates a perspective view of a computationally simulated second case contact force contours in accordance with the present state of the art;
[0031] FIG. 3 illustrates a schematic view of present scenario pressure distribution over a bolt pitch in accordance with the present state of the art;
[0032] FIG. 4A illustrates a schematic view of a crowning location in accordance with an embodiment of the present disclosure;
[0033] FIG. 4B illustrates a schematic view of the crowning details in accordance with an embodiment of the present disclosure;

[0034] FIG. 5A illustrates a schematic view of the computationally simulated first case contact force contours in accordance with an embodiment of the present disclosure;
[0035] FIG. 5B illustrates a schematic view of the computationally simulated second case contact force contours in accordance with an embodiment of the present disclosure; and
[0036] FIG. 6 illustrates a schematic view of the present scenario pressure distribution over a bolt pitch in accordance with an embodiment of the present disclosure.
[0037] It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in a computer-readable medium and executed by a computer or processor, whether or not such computer or processor is explicitly shown.
Detailed Description
[0038] The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0039] It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of

the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
[0040] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a"," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes" and/or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
[0041] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
[0042] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0043] Embodiments explained herein pertain to a transmission case with uniform distribution of pressure at the mating faces of a transmission case.
[0044] FIG. 1 illustrates a three-dimensional perspective view of the transmission housing (100). Disclosed herein is a transmission housing (100)

comprising of transmission cases (101, 102) for a uniform contact pressure at mating faces of the transmission case.
[0045] As shown in FIG. 1, FIGS. 1A and IB, the bolts (101a) are used for bolting of the transmission cases (101, 102), the transmission case comprises a first case (101) having a first connecting flange (106), a second case (102) having a second connecting flange (107) and the distance between or the space between these bolts (101a) is termed as a 'pitch'(104a) as shown in FIG. 1A. In the existing state of the art, as illustrated in FIG. IB, the mating surface (105) is a plane surface.
[0046] FIG. 2A and FIG. 2B illustrates the transmission case computationally simulated contact force contours (201, 202) for the first case (101) and second case (102), respectively wherein the contact pressure is low at the plane mating surface (105) (region highlighted by a circle). Further, FIG. 3 provides a schematic view of the pressure distribution over the pitch (104a) in the existing state of the art, wherein the pressure is lower at the mating face and the pressure distribution is uneven (302) between the bolts along the bolting centreline (301).
[0047] The present invention as illustrated in FIG. 4A and FIG. 4B, a transmission case (101, 102) for uniform pressure distribution at mating faces between cases (101, 102) bolted with each other, the transmission case comprising a first case (101) having a first connecting flange (106), a second case (102) having a second connecting flange (107). The transmission case (101, 102) is similar in construction and possesses the same components as those shown in FIG. 1. However, a crowning (401) is formed on a mating face of one of the first connecting flange (106) and a second connecting flange (107) shown in FIGS, 4A and 4B, said crowning (401) being formed to uniformly distribute the contact pressure between two clamping bolts (101) when the first connecting flange (106) is clamped on the second connecting flange (107). The crowning (401) is a protruding portion from the mating face of one of the first connecting flange (106) and a second connecting flange (107) such that no thickness added at the bolt

location and maximum thickness farthest from the bolt (101) having the maximum thickness depending upon bolt pitch and flange stiffness. In an aspect, the crowning center is having maximum thickness depending upon bolt pitch and flange stiffness.
[0048] Subsequently, one of the first connecting flange (106) and a second connecting flange (107) is applied with a sealant paste before the first case (101) and the second case (102) is bolted with each other.
[0049] FIG. 5A and FIG. 5B illustrates a schematic view of the computationally simulated contact force contours (501, 502) of the first case (101) and second case (102), respectively in accordance with an embodiment of the present invention depicting higher and more uniform contact pressure (region highlighted by circle) and thus there is no leakage of the sealant from the transmission housing (100). The even distribution of the pressure in accordance with the claimed invention has been illustrated in FIG. 6 wherein the contact pressure is uniform and of a higher value (602) at the mating faces between the bolts (101a) and along the bolting centrelines (601).
[0050] The subject matter disclosed herein has the following advantages such as uniform distribution of contact force, improved sealant performance thereby preventing leakage of transmission oil through the bolted connecting flanges (106, 107), Increased pitch thus lesser number of bolts (101a) to bolt the connecting flanges (106, 107), even spreading of the sealant applied on one of the connecting flanges (106, 107) between the mating faces of the transmission case (101, 102) resulting into a uniform thickness of the sealant on account of uniform pressure distribution. Thus, a lesser quantity of sealant will be required in the claimed invention. The present invention also has an added advantage of being cost-effective as no external part or attachment is required for a uniform distribution of pressure between the mating faces of a transmission case (101, 102).
[0051] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing

from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.
Equivalents:
[0052] A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary, a variety of optional components are described to illustrate the wide variety of possible embodiments of the invention. When a single device or article is described herein, it will be apparent that more than one device/article (whether or not they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether or not they cooperate), it will be apparent that a single device/article may be used in place of the more than one device or article or a different number of devices/articles may be used instead of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features. Thus, other embodiments of the invention need not include the device itself.
[0053] The specification has described a transmission housing (100) comprising of transmission cases (101, 102) for a uniform contact pressure at mating faces of the transmission case (101, 102).
[0054] Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly,

the embodiments of the present invention are intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

We Claim:

1.A transmission case (101, 102) for uniform pressure distribution at
mating faces between cases (101, 102) bolted with each other, the
transmission case (101, 102) comprising:
a first case (101) having a first connecting flange (106);
a second case (102) having a second connecting flange (107); and
a crowning (401) formed on a mating face of one of the first connecting flange (106) between two adjacent bolts and a second connecting flange (107), said crowning (401) being formed to uniformly distribute the contact pressure between two clamping bolts (101a) when the first connecting flange (106) is clamped on the second connecting flange (107).
2. The transmission case (101, 102) as claimed in claim 1, wherein the crowning (401) is a protruding portion from the mating face of one of the first connecting flange (106) and the second connecting flange (107).
3. The transmission case (101, 102) as claimed in claim 1, wherein the center of crowning (401) is having maximum thickness depending upon bolt pitch and flange stiffness.
4. The transmission (101, 102) as claimed in claim 1, wherein the crowning (401) is having an orientation along with the bolt pitch.
5. The transmission (101, 102) as claimed in claim 1, wherein one of the first connecting flange (106) and the second connecting flange (107) is

applied with a sealant paste before the first case (101) and the second case (102) are bolted with each other.