[0001] The present subject matter described herein relates to case structure of a transmission mounted on a vehicle. In particular, the present subject matter relates to structure of transmission casing to improve its strength and stiffness.
BACKGROUND
[0002] The transmission is used in an automotive vehicle that has an internal combustion engine to transmit power to a live axle. Transmission is either equipped for a manual transmission with traditional clutch and flywheel, or automatic torque converter or automatic wet clutch, CVT and hybrids, north/south (rear wheel drive or front wheel drive), east/west (transverse and also with final drive unit) and transaxle configurations.
[0003] A transmission housing contains a transmission mechanism including a main transmission recording body, with a drive shaft and/or an output shaft of the transmission being specified in the longitudinal direction of the main housing or the entire transmission housing via a rotation axis. The transmission and/or a clutch of the transmission can be positioned at one axial end of the main body to connect a bell housing to the main housing to receive a torque converter.
[0004] In the transmission case, in the axial direction of the transmission case, and between the support walls, the inlet shaft and the outlet shaft, and further along the ends of the torque transmission shaft, such as the counter shaft, a pair of support walls are supplied at reasonable intervals. A bending vibration in a direction perpendicular to the axis is produced when each of the torque transmission shafts is rotated. The bending vibration is fed through the support wall to the transmission case, and the transmission case is similarly driven by the shaft. The vibration of the transmission case at this time is especially produced between the support walls. These vibrations spread in the entire transmission casing.
[0005] The problem with the conventional state of art is that during the time when the reverse gear is applied, a maximum fatigue is observed during loading. The reverse/idler gear teeth are subjected to the most severe kind of fatigue loading at the time of fully reversing loads. This load gets transferred to the idler shaft bolt and eventually to the transmission case leading to surface cracking.
[0006] Further in some prior arts, a rib structures were introduced in the transmission casing. But the prior arts fail to disclose a balanced formation of the rib structure on the transmission casing. The absence of balanced rib structure formation causes a lot of deformation and vibration in the outer surface of the transmission casing. This eventually leads to cracking of the transmission case.
[0007] The solution for the present problem is to introduce a balanced rib structure by connecting the high stiffness zones.
[0008] In this several known techniques in the state of art have provided techniques related to improving the design of the transmission casing.
[0009] In some of the conventional designs in the relevant industry a set of outer protrusions is formed on an outer surface of a case body and a transition section to protrude outwards. The designs present a set of inner protrusions formed at respective positions on an inner surface of the transmission case to protrude inward, where the set of inner protrusions is positioned corresponding to the set of outer protrusions.
[0010] However, the above mentioned transmission case does not have symmetric and balanced rib structure on the outer circumference of the transmission case which leads to frequent breakage of the transmission gear as it is not rigid to the extent that it can endure the stress received at the time of loading the reverse gear.
[0011] It is thereby required to maintain a symmetric and balanced rib structure on the outer circumference of the transmission case.
OBJECTS OF THE DISCLOSURE
[0012] It is therefore the object of the present disclosure to overcome the aforementioned and other drawbacks in prior method/product/apparatus.
[0013] It is a primary object of the present disclosure is to maintain a balanced rib structure throughout the outer surface transmission casing.
[0014] It is another object of the present disclosure to provide a balanced rib structure to connect high stiffness zones.
[0015] It is another object of the present disclosure to provide an embossed structure on the outer circumference of the bolts disposed in the transmission housing.
[0016] It is another object of the present disclosure to provide transverse and longitudinal ribs in the high stiffness zone between the bolts disposed in the transmission housing.
[0017] These and other objects and advantages of the present subject matter will be apparent to a person skilled in the art after consideration of the following detailed description taken into consideration with accompanying drawings in which preferred embodiments of the present subject matter are illustrated.
SUMMARY
[0018] Solution to one or more drawbacks of existing technology and additional advantages are provided through the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be a part of the claimed disclosure.
[0019] The present disclosure offers a solution in the form of a transmission housing unit accommodating a transmission mechanism, having a reinforcement rib structure formed on an outer lateral surface between a two adjacent bolt recesses of the transmission housing unit.
[0020] In an aspect of the invention, the reinforcement rib structure includes, an emboss structure formed surrounding an outer surface of the two adjacent bolt recesses arranged consecutively and the emboss structure extending transversely in width direction of the transmission housing unit.
[0021] The reinforcement rib structure includes a plurality of a longitudinal ribs connecting the emboss structure and a plurality of transverse ribs formed overlapping the longitudinal ribs. The plurality of transverse ribs is disposed between the first transverse bolts extending in transverse direction.
[0022] In an aspect of the invention, a flange is formed adjacent to the emboss structure and extending transversely in width direction of the transmission housing unit from one end of the transmission housing unit to the other end.
[0023] In an another aspect of the invention, the transmission housing comprises of a cover, a first casing and a second casing being integrated to the cover coupled with plurality of a first transverse bolts inserted into the two adjacent bolt recesses in a transverse axis direction, wherein the first casing mounted on the transmission mechanism, coupled with a first bolt towards an outer lateral surface and the first casing.
[0024] In yet another aspect of the invention, the first bolt couples the first casing on an idler shaft of the transmission mechanism.
[0025] 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
[0026] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the present disclosure may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, 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 or methods or structure in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0027] Fig. 1 is an illustrative view of the transmission housing unit;
[0028] Fig. 2 is a perspective inner view of the transmission mechanism inside the transmission housing unit;
[0029] Fig. 3 is a perspective view for depicting the reinforcement rib structure of the present invention.
[0030] The figures depict embodiments of the present subject matter for illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
[0031] While the embodiments of the disclosure are subject to various modifications and alternative forms, a specific embodiment thereof has been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
[0032] The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device, system, assembly that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, or assembly, or device. In other words, one or more elements in a system or device proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or device.
[0033] Referring to Fig.1 and 2 of the present invention, the transmission housing unit (100) is depicted. The transmission housing unit (100) houses arrangement of a transmission including a main housing accommodating a plurality of meshing gears for driving the powertrain of the vehicle. The meshing gears constitutes the transmission mechanism (101). The transmission mechanism (101) function is transferring engine power to the driveshaft and rear wheels (or axle half shafts and front wheels in a front-wheel-drive vehicle). Gears inside the transmission mechanism (101) change the vehicle's drive-wheel speed and torque in relation to engine speed and torque. The constant working of the transmission mechanism imparts severe shocks and vibrations on the transmission housing unit. Thus, causing surface cracks occurs on the surface of the transmission housing unit.
[0034] As for the purpose of an example in the invention, without limiting the scope, the transmission housing unit (100) has structurally three different parts. A cover (12) forming the canopy for the transmission mechanism. A first casing (11a) and a second casing (11b) further arranged in series housing the transmission mechanism (101). However, as appreciated by ordinary skill in art, the transmission housing unit (100) shall not be limited by first casing or second casing. The transmission housing unit ay include multiple casings within the scope of this invention. Thus, the entire transmission housing unit (100) acts as a casing enclosing the transmission mechanism (101).
[0035] The cover (12) is integrated with the first casing (11a) by coupling the outer periphery of the cover and first casing (11a) with a plurality of a first transverse bolts. The first transverse bolts are fastened in the transverse axis direction in the two adjacent bolt recesses (13). The outer periphery of cover (12) coupling with the first casing is preferably elliptical in formation. Thus, plurality of first transverse bolts is fastened with the cover (12) and first casing (11a).
[0036] The first casing (11a) coupled in series with the cover is mounted on the transmission mechanism (101) coupled with a first bolt (14). The first bolt (14) is preferably an idler shaft bolt fastening the first casing (11a) with an idler gear (17) shaft of the transmission mechanism (101). The first bolt (14) is present on a lateral side of the first casing (11a) connecting with the idler gear shaft (17).
[0037] As previously mentioned, the first casing (11a) receives maximum vibrations and shocks during the functioning of the transmission mechanism, a reinforcement rib structure is introduced in the first casing to reduce the vibrations and shocks in the high stiffness zones. Referring to Fig. 4, in the first casing (11a) following protrusions and bulge out structures are created in form of ribs structure to so that the overall deformation is minimum under the impact of shock loads leading to more strength in the first casing of the transmission housing.
[0038] The reinforcement rib structure formed on an outer lateral surface between a two adjacent bolt recesses (13) of the transmission housing unit (100) as illustrated in Fig. 3 includes, an emboss structure (18) formed surrounding an outer lateral surface of adjacent bolt recesses (13). The emboss structure (18) is a bulge out molding on the adjacent two bolt recesses (13) extending transversely in width direction of the first casing (11a). As mentioned previously, there are plurality of first transverse bolts fastened inserted into the adjacent bolt recesses (13) coupling the cover (12) with the first casing (11a). For the purpose of this invention, at least two first transverse bolts which are arranged consecutively inserted into the adjacent two bolt recesses (13) or in series adjacent to each other includes the emboss structure (18).
[0039] In the invention, plurality of a longitudinal ribs (19) in form of the protrusions are formed on outer surface of the first casing (11a). The longitudinal ribs (19) are extended connecting the emboss structure of the two adjacent bolt recesses (13) which are arranged consecutively or in series adjacent to each other.
[0040] Further in the present invention, at least a two transverse ribs (20) in form of the protrusions are formed on outer surface of the first casing (11a). The two transverse ribs (20) are arranged such that they overlap the longitudinal ribs (19) in corresponding plane extending in transverse direction.
[0041] In the invention, the longitudinal ribs (19) and the two transverse ribs (20) are disposed on the outer surface of the first casing (11a) between a periphery of the first casing (11a) and the first bolt (14) forming a balanced structure.
[0042] Further, the first casing (11a) is coupled to the second casing (11b) in series as part of the transmission housing unit (100). The first casing (11a) is fastened with the second casing (11b) using plurality of a second transverse bolts. The second transverse bolts couple the outer periphery of the first casing with the second casing.
[0043] In the invention, a flange (21) structure projects outwards adjacently from the emboss structure (18) and extending transversely in width direction of the first casing (11a). The flange (21) extends such that it originates adjacently from the first transverse bolt and is extended till lower periphery of the first casing (11a) coupled to second casing (11b) with the second transverse bolt.
[0044] Thus, in the present invention the transmission housing unit with a first casing 11a is provided. This first casing 11a is closed from the top using a cover 12. A reinforcement rib structure is disposed on the upper casing on the top part of its circumference. The ribs structure ends at the idler shaft nut or the first bolt to give hardness to the first casing. Inside the transmission housing unit an input shaft (15) and a counter shaft (16) are installed forming part of the transmission mechanism. The shafts are then connected to the idler gear (17). The connection between the shaft and the idler gear (17) is made using an idler shaft nut (14).
[0045] It is an advantage of the invention thus, to introduce the balanced ribs structure in transmission housing unit, preferably in the first casing. The reinforcement ribs structure shall be disposed and arranged in a manner as disclosed in the present invention thus reducing the overall deformation by connecting the high stiffness zones under the impact of shock loads leading to more strength. The present invention provides minimum deformation of mode shapes (natural frequencies) eventually leading to better noise-vibration performance.
[0046] Referring to the Figures of the present invention, the following reference numeral table depict the elements of the invention:
11a First Casing
11b Second Casing
12 Cover
13 Bolt Recesses
14 First Bolt
15 Input Shaft
16 Counter Shaft
17 Idler gear
18 Emboss Structure
19 Longitudinal Ribs
20 Transverse Ribs
21 Flanges
100 Transmission Housing Unit
101 Transmission Mechanism

[0047] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation, no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to disclosures containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. Also, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general, such construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to “at least one of A, B, or C, etc.” is used, in general, such construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
[0048] It will be further appreciated that functions or structures of a plurality of components or steps may be combined into a single component or step, or the functions or structures of one-step or component may be split among plural steps or components. The present disclosure contemplates all of these combinations. Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the disclosure, and other dimensions or geometries are possible. Also, while a feature of the present disclosure may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present disclosure. The present disclosure also encompasses intermediate and end products resulting from the practice of the methods herein. The use of “comprising” or “including” also contemplates embodiments that “consist essentially of” or “consist of” the recited feature.

Claims:1. A transmission housing unit (100) accommodating a transmission mechanism (101), having a reinforcement rib structure formed on an outer lateral surface between a two adjacent bolt recesses (13) of the transmission housing unit (100) characterized in that, the reinforcement rib structure comprising of:
an emboss structure (18) formed surrounding an outer surface of the two adjacent bolt recesses (13) and the emboss structure (18) extending transversely in width direction of the transmission housing unit;
a plurality of a longitudinal ribs (19) connecting the emboss structure (18); and
a plurality of transverse ribs (20) formed overlapping the longitudinal ribs (19) and disposed between the two adjacent bolt recesses (13) extending in transverse direction.
2. The transmission housing as claimed in claim 1 wherein, a flange (21) formed adjacent to the emboss structure (18) and extending transversely in width direction of the transmission housing unit from one end of the transmission housing unit to the other end.
3. The transmission housing as claimed in claim 1, wherein, the transmission housing comprises of (101), a cover (12), a first casing (11a) and a second casing (11b) being integrated to the cover (12) coupled with plurality of a first transverse bolts inserted into the two adjacent bolt recesses (13) in a transverse axis direction, wherein the first casing (11a) mounted on the transmission mechanism (101), coupled with a first bolt (14) towards an outer lateral surface and the first casing (11a).
4. The transmission housing as claimed in claim 3 wherein, the first bolt (14) couples the first casing (11a) on an idler shaft of the transmission mechanism.