FIELD OF INVENTION:
[001] The present subject matter described herein, relates to a rack and pinion structure for a vehicle and, in particular, to pinion housing structure in rack 5 housing for sealing and to restrict entry of water and dust particles.
BACKGROUND AND PRIOR ART:
[002] In general, a pinion is mounted in a rack and pinion housing structure. The rack portion of the housing is a cylindrical structure having a neck portion which is a cylindrical structure at an angle to receive the pinion input shaft along with 10 pinion cover or pinion adjusting screw.
[003] Generally, the pinion cover has a plurality of slots that receive a device to assemble the pinion cover in the neck portion or pinion housing structure. The plurality of slots is provided for holding the pinion cover during assembly and tightening in the pinion housing to adjust the pinion input shaft. Further, the 15 pinion cover is covered by a dust cover to restrict entry of water and dust particles in the assembly of the pinion input shaft with rack shaft. A rubber seal is provided in between the pinion cover and the pinion input shaft to restrict entry of the water and dust particles.
[004] During underbody washing, water jet is used which gets inside the dust 20 cover and pinion oil seal area. This water gets accumulated in the slots of pinion cover and slowly causes rusting near the oil seal and pinion junction. The rusted pinion slowly erodes the oil seal creating gap through which the accumulated water gets inside the rack and pinion housing.
[005] Despite having dust cover and rubber sealing, water enters the pinion 25 housing from lower direction of the pinion input shaft. The existing structures of the pinion housing and dust covers are not efficient enough to restrict entry of water and dust particles from all directions.
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[006] With the existing structure of pinion housing and the dust cover, water and dust particles enter the assembly of pinion shaft and rack shaft which decreases the smoothness of steering action and creates noise.
[007] Another technical problem associated with the existing structures is that it reduces lifetime of the rack and pinion assembly. 5
[008] Therefore, there is a need in the art to provide a pinion housing structure that can restrict entry of water and dust particles.
OBJECTS OF THE INVENTION:
[009] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed herein below. 10
[0010] The principal object of the present invention is to provide a pinion housing having a rib structure to restrict entry of water with dust particles.
[0011] Another object of the present subject matter is to provide a dust cover having a plurality of protrusions with optimized shape and height to restrict entry of water jet with dust particles. 15
[0012] Another object of the present subject matter is to provide a dust cover having a plurality of protrusions with optimized shape and height to allow exit of entrapped water.
[0013] Another object of the present subject matter is to provide rubber plugs with optimized shape and profile that can be inserted in the plurality of cavities or 20 slots provided in pinion cover to prohibit entry and accumulation of water and dust particles in the plurality of cavities.
[0014] Another object of the present subject matter is to provide a pinion cover with optimized sloped profile towards pinion housing to allow exit of entrapped water through sloped profile. 25
[0015] Another object of the present subject matter is to provide an optimized placement of oil seal in the pinion cover and pinion input shaft to allow exit of entrapped water.
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[0016] These and other objects and advantages will become more apparent when reference is made to the following description and accompanying drawings.
SUMMARY OF THE INVENTION:
[0017] This summary is provided to introduce concepts related to pinion housing of rack and pinion assembly in vehicle. The concepts are further described below 5 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.
[0018] In an embodiment, the present disclosure relates to a rack and pinion housing structure including a pinion housing, a pinion input shaft and a pinion 10 cover. The pinion input shaft is fitted in the pinion housing together with the pinion cover. Further, an oil seal is provided in between the pinion input shaft and the pinion cover. The pinion housing has a rib structure that is diametrically extending from the pinion housing in between a lower end and a top end of the pinion housing. The pinion cover defines a plurality of cavities that are covered by 15 a plurality of rubber plugs. Once the pinion cover, oil seal, and rubber plugs are placed, a dust cover is provided over the pinion housing to cover the pinion cover, oil seal and rubber plugs to restrict entry of water jet with dust particles in the pinion housing.
[0019] In another embodiment, the present subject matter relates to a dust cover 20 that can be provided over the pinion housing to restrict entry of water jet with dust particles. The dust cover includes a tapered disc portion and a vertical wall portion that bends from the tapered disc portion defining a U shaped cross section. Further, the tapered disc portion defines a central hole at central axis (X). Further, the disc portion has a first continuous circular protrusion and a second continuous 25 circular protrusion formed around the central hole and concentric with the central axis (X). Both the protrusions are extending from the tapered disc portion in extended direction of the vertical wall portion. The first continuous circular protrusion and the second continuous circular protrusion are defined at radial distance from each other and from the center of the disc portion. The first 30
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continuous circular protrusion is provided in between the central hole and the second continuous circular protrusion. The second continuous circular protrusion is provided in between the first continuous circular protrusion and the vertical wall portion.
[0020] In an aspect, rubber plugs are provided to cover the plurality of cavities or 5 slots of the pinion cover.
[0021] In an aspect, the second continuous circular protrusion is positioned opposite to top end of the pinion housing and the first continuous circular protrusion is positioned opposite to a plurality of cavities of the pinion cover.
[0022] To further understand the characteristics and technical contents of the 10 present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit scope of the present subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] It is to be noted, however, that the appended drawings illustrate only 15 typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same 20 numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods 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:
[0024] Fig. 1 illustrates general rack and pinion housing structures; 25
[0025] Fig. 2 illustrates structure of pinion housing with pinion input shaft, in accordance with an embodiment of the present subject matter;
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[0026] Fig. 3 illustrates top perspective view of pinion housing with pinion input shaft and pinion cover, in accordance with an embodiment of the present subject matter;
[0027] Fig. 4 illustrates perspective view of plugs to be inserted in the pinion cover, in accordance with an embodiment of the present subject matter; 5
[0028] Fig. 5 illustrates un-assembled view of rubber plug with the pinion cover, in accordance with an embodiment of the present subject matter;
[0029] Fig. 6 illustrates assembled view of rubber plug with pinion cover, in accordance with an embodiment of the present subject matter;
[0030] Fig. 7 illustrates bottom perspective view of the dust cover, in accordance 10 with an embodiment of the present subject matter.
[0031] Fig. 8a illustrate un-assembled view of dust cover and rubber plug with the pinion cover, in accordance with an embodiment of the present subject matter;
[0032] Fig. 8b illustrates cross section view of pinion housing structure with input shaft, pinion cover, rubber seal, rubber plug, and dust cover, in accordance with 15 an embodiment of the present subject matter; and
[0033] The figures depict embodiments of the present subject matter for the purposes of 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 20 of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0034] 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 25 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
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falling within the scope of the present disclosure as defined by the appended claims.
[0035] 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, 5 and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
[0036] 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 10 plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the tennis “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, 15 components and/or groups thereof.
[0037] 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 20 involved.
[0038] 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 25 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.
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[0039] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the 5 principles of the present subject matter and are included within its scope.
[0040] Referring to fig. 1 that illustrates rack and pinion housing structure. The rack housing and pinion housing are hollow cylindrical structures. The pinion housing is connected with the rack housing at an angle. The pinion housing defines like a neck portion to the rack housing. From the pinion housing, the 10 pinion input shaft passes and meshes with rack of the rack housing for steering operations. In order to avoid entry of water jet with dust particles, a dust cover is provided to cover the pinion housing.
[0041] Figures 2 and 3 illustrate rack and pinion housing structure in accordance with the present subject matter. The rack and pinion housing structure includes a 15 pinion housing 400, a pinion input shaft 200, a pinion cover 300, an oil seal (500) and a dust cover (not shown in figures 2 and 3). The pinion housing 400 is a cylindrical hollow structure configured to receive the pinion input shaft 200 and the pinion cover 300. The pinion input shaft 200 is fitted in the pinion housing 400 together with the pinion cover 300. Further, an oil seal 500 is provided in 20 between the pinion input shaft 200 and the pinion cover 300 in the pinion housing 400. As shown in the figures, the pinion housing 400 defines a rib structure 401 that is diametrically extending from outer surface of the pinion housing 400. The rib structure 401 is provided in form of circular flange that expand from the outer surface of the cylindrical pinion housing 400. The rib structure 401 is provided in 25 between a lower end 400b and a top end 400a of the pinion housing 400. As shown in the figure 6, diameter ‘D’ of the rib structure 401 is greater than diameter ‘d’ of the pinion housing 400. Further, as shown in figure 8b, width ‘W’ of the rib structure 401 can be optimized to restrict entry of water jet with dust particles from downward direction. 30
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[0042] As shown in the figure 3, the pinion cover 300 has a plurality of cavities or slots 301. The plurality of cavities 301 provides assistance for holding the pinion cover 300 with a torque device (not shown in figures) for tightening the pinion cover 300 with the pinion housing 400. Further, each cavity from the plurality of cavities 301 is separated by a solid portion 302. The solid portion 302 5 of the pinion cover 300 defines a sloped profile that is sloped down towards top end 400a of the pinion housing 400. Further, top surface of the pinion cover 300 defines a sloped profile that is sloped down towards top end 400a of the pinion housing 400. The pinion cover 300 is provided as an adjusting screw for adjusting the smoothness of the pinion input shaft 200 with the rack shaft (not shown in 10 figures). In the existing structures, water gets entrapped in these cavities which causes corrosion in pinion near oil seal area resulting in entry of water with dust particles in the assembly of rack and pinion shafts. The plurality of cavities 301 are covered by plugs 600, as shown in figure 4, preferably rubber plugs 600. Each cavity has a corresponding rubber plug. After adjusting the pinion cover 300 with 15 the pinion housing 400, the cavities 301 of the pinion cover 300 is covered by rubber plugs 600.
[0043] Referring to figure 4, each of the rubber plugs 600 comprises a base portion 602 and one or more protruded portions 601 that extend away from the base portion 602. Further, shape and configuration of the protruded portion 601 is 20 defined corresponding to the cavity 301 of the pinion cover 300. During assembly, the protruded portion 601 matches with the cavity 301 and the base portion 602 rests over the solid portion 302 of the pinion cover 300. In other words, the cavity 301 defines a female portion having shape and configuration that exactly matches with the shape and configuration of the protruded portion 601 of the rubber plug 25 600 that act as a male portion. The rubber plug 600 has interference fit with the pinion cover 300. The rubber plug 600 is provided in pair of two protruded portion 601. Each rubber plug 600 having two protruded portions 601 is in interference fit with two adjacent cavities 301 of the pinion cover 300. The base portion 602 of each rubber plug 600 rests over the solid portion 302 of the pinion 30 cover 300. For example, to cover the pinion cover 300 having four cavities 301,
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two rubber plugs 600 are required where each rubber plug 600 has two protruded portions 601. In the present assembly two solid portions 302 in between the cavities 301 remain uncovered from the base portion 602 of the rubber plugs 600. The un-covered solid portions 302 define a channel for exit of entrapped water in the housing (explained in subsequent paragraphs). 5
[0044] In an aspect, each rubber plug 600 defines a sloped profile in accordance with sloped profile of the pinion cover 300.
[0045] Fig. 5 illustrates un-assembled view of rubber plug 600 with the pinion cover 300. Fig. 6 illustrates assembled view of the rubber plug 600 with the pinion cover 300. The rubber plug 600 is provided only after adjustment of the pinion 10 input shaft 200 with the rack shaft in the rack and pinion assembly. Once the rubber plugs 600 are inserted in the plurality of cavities 301 of the pinion cover 300, a dust cover 700 is provided to cover the assembly of the rubber plug 600 and pinion cover 300, and assembly of input shaft 200 with the oil seal 500 and the pinion cover 300 as shown in the figure 8a and 8b. 15
[0046] As shown in the fig. 8a, the dust cover 700 defines a tapered disc portion 701 and a vertical wall portion 702. The vertical wall portion 702 bends from the tapered disc portion 701. The dust cover 700 with the tapered disc portion 701 and the vertical wall portion 702 define a U shaped cross section profile. Further, a central hole 704 is provided at center of the tapered disc portion 701. The central 20 hole 704 is defined at central axis ‘X’ of the tapered disc portion 701 to receive the pinion input shaft 200.
[0047] Referring to figs. 7 and 8b, the tapered disc portion 701 has a first continuous circular protrusion 701a and a second continuous circular protrusion 701b formed in circular formation. The first continuous circular protrusion 701a 25 and the second continuous circular protrusion 701b are extending from the tapered disc portion 701 in extending direction of the vertical wall portion 702. The first continuous circular protrusion 701a and the second continuous circular protrusion 701b are provided at radial distance from the central hole 704. The first continuous circular protrusion 701a is provided closer to the central hole 704 as 30
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compared to the second continuous circular protrusion 701b. Further, the first continuous circular protrusion 701a and the second protrusion 701b are provided at a radial distance from each other.
[0048] In an aspect, the first continuous circular protrusion 701a is provided in between the central hole 704 and the second continuous circular protrusion 701b. 5 Whereas, the second continuous circular protrusion 701b is provided in between the first continuous circular protrusion 701a and the vertical wall portion 702. Further, distance between the first continuous circular protrusion 701a and the second continuous circular protrusion 701b is an optimized distance that depends on the size of the pinion housing 400. As shown in the figure 6, the pinion input 10 shaft 200 has a circular groove 201 to receive the dust cover 700. In the circular groove 201, the central hole 704 of the dust cover 700 is fitted to cover the oil seal 500 and to avoid entry of water jet with dust particles inside the pinion housing 400.
[0049] Figure 8b illustrates cross section view of assembled dust cover 700, 15 pinion cover 300, pinion input shaft 200, oil seal 500, and rubber plugs 600. The circular groove 201 (shown in figure 6) defines a diameter 201a that is less than diameter 200b of the pinion input shaft 200. Further, diameter 704a of the central hole 704 of the dust cover 700 is lesser than the diameter 201a of the circular groove 201 to ensure interference fit between the circular groove 201 and the dust 20 cover 700.
[0050] Referring to figure 7 and 8b, a continuous circular protrusion 704b extended peripherally from the central hole 704 in extending direction of the vertical wall portion 702 is provided for mating with pinion input shaft 200 and the oil seal 500. The diameter 704c of the continuous circular protrusion 704b is 25 more than diameter 704a of the central hole 704 and diameter 201a of the pinion input shaft circular groove 201. The continuous circular protrusion 704b rests over the oil seal 500 to avoid entry of water and dust particles. Further, the oil seal 500 is moved in upward direction to match with profile of the pinion cover 300 and have a contact with the continuous circular protrusion 704b of the dust cover 700. 30
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[0051] In an aspect, internal diameter 700b of the dust cover 700 is more than diameter ‘d’ of the pinion housing 400 and less than diameter ‘D’ of the rib structure 401. Further, width 700a of the vertical wall portion 702 is less than extending portion width ‘W’ of the rib structure 401. Accordingly, the rib structure 401 covers the vertical wall portion 702 completely to restrict entry of 5 water jet with dust particles from downward direction.
[0052] In the assembly, the dust cover 700 is mounted in the circular groove 201 of the input shaft 200. Further, the dust cover 700 defines a gap ‘G’ in between the rib structure 401 and vertical wall portion 702 to allow exit of entrapped water which may get inside despite obstruction provided by the rib structure 401. The 10 gap ‘G’ act as a channel to allow passage of water that got entrapped via any means near the oil seal 500.
[0053] As shown in the assembly, the first continuous circular protrusion 701a has shorter extending length as compared to the second continuous circular protrusion 701b. Further, the first continuous circular protrusion 701a is 15 positioned opposite to the plurality of cavities 301 of the pinion cover 300 that are covered by the rubber plugs 600. The second continuous circular protrusion 701b is positioned opposite to top end 400a of the pinion housing 400. A gap is provided in between the top surface of the rubber plug 600 and the first continuous circular protrusion 701a to allow exit of entrapped water. Similarly, a 20 gap is defined in between the top end 400a and the second continuous circular protrusion 701b to allow exit of entrapped water.
[0054] As shown in the figure 8b, if some water gets entrapped in the pinion housing in between the rubber plug 600 and dust cover 700 or in between the oil seal 500 and the dust cover 700, the entrapped water passes through the optimized 25 channel provided by means of slopped profile, uncovered solid portion 302 of the pinion cover 300, gap provided between the first continuous circular protrusion 701a and the rubber plug 600, gap provided between the second continuous circular protrusion 701b and the top end 400a, and gap provided between the rib structure 401 and vertical wall portion 702 of the dust cover 700. By such means, 30
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the present subject matter provides a better and efficient sealing structure for the pinion housing to restrict entry and accumulation of water jet with dust particles.
[0055] 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 5 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 10 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 15 introduced claim recitation to inventions 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. In addition, 20 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 25 analogous to “at least one of A, B, and C, etc.” is used, in general such a 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.). 30 In those instances where a convention analogous to “at least one of A, B, or C,
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etc.” is used, in general such a 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 5 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.” 10
[0056] 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 15 to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

We claim:
1. A rack and pinion housing structure (800) comprising:
a pinion housing (400);
a pinion input shaft (200) fitted in the pinion housing (400) 5 together with a pinion cover (300) and an oil seal (500) provided in between the pinion input shaft (200) and the pinion cover (300);
characterized in that
a rib structure (401) diametrically extending from the pinion housing (400) in between a top end (400a) and a lower end (400b) of the 10 pinion housing (400);
a dust cover (700) provided over the pinion housing (400) to restrict entry of water jet with dust particles in the pinion housing,
the pinion input shaft (200) defines a circular groove (201) to receive the dust cover (700). 15
2. The rack and pinion housing structure (800) as claimed in claim 1, wherein the pinion cover (300) defines a plurality of cavities (301), the plurality of cavities (301) are covered by plugs (600), wherein the plugs (600) are rubber plugs.
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3. The rack and pinion housing structure (800) as claimed in claim 2, wherein each of the plugs (600) comprises a base portion (602) and one or more protruded portions (601) extending away from the base portion (602), the protruded portion (601) is defined corresponding to a cavity (301) of the pinion cover (300).
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4. The rack and pinion housing structure (800) as claimed in claim 1, wherein the pinion cover (300) is sloped down towards the top end (400a) of the pinion housing (400).
5. The rack and pinion housing structure (800) as claimed in claim 4, wherein 30 each of the plugs (600) defines a sloped profile in accordance with sloped profile of the pinion cover (300).
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6. The rack and pinion housing structure (800) as claimed in claim 1, wherein the dust cover (700) comprises:
a tapered disc portion (701) and a vertical wall portion (702) that bent from the tapered disc portion (701);
a central hole (704) defined at central axis (X) of the tapered disc 5 portion (701);
a first continuous circular protrusion (701a) extended from the tapered disc portion (701) in extending direction of the vertical wall portion (702); and
a second continuous circular protrusion (701b) extended from the 10 tapered disc portion (701) in extending direction of the vertical wall portion (702), wherein
the first continuous circular protrusion (701a) and the second protrusion (701b) defined at radial distance from each other,
the first continuous circular protrusion (701a) is defined in between 15 the central hole (704) and the second continuous circular protrusion (701b), and
the second continuous circular protrusion is defined in between the first continuous circular protrusion (701a) and the vertical wall portion (702). 20
7. The rack and pinion housing structure (800) as claimed in claim 6, wherein a continuous circular protrusion (704b) is extended peripherally from the central hole (704) in extending direction of the vertical wall portion (702), the diameter (704c) of the continuous circular protrusion (704b) is more than diameter (704a) 25 of the central hole (704) and diameter (201a) of the pinion input shaft circular groove (201).
8. The rack and pinion housing structure (800) as claimed in claim 1, wherein diameter (700b) of the dust cover (700) is more than diameter (d) of the pinion 30 housing (400) and less than diameter (D) of the rib structure (401).
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9. The rack and pinion housing structure (800) as claimed in claim 1, wherein a gap (G) is defined in between the rib structure (401) and vertical wall portion (702) of the dust cover (700).
10. The rack and pinion housing structure (800) as claimed in claim 6, wherein 5 the first continuous circular protrusion (701a) defines shorter extending length as compared to the second continuous circular protrusion (701b), and the first continuous circular protrusion (701a) and the second continuous circular protrusion (701b) are positioned opposite to a plurality of cavities (301) of the pinion cover (300) covered by rubber plugs (600) and top end (400a) of the pinion 10 housing (400) respectively.
11. A dust cover (700) comprises:
a tapered disc portion (701) and a vertical wall portion (702) that bent from the tapered disc portion (701); 15
a central hole (704) defined at central axis (X) of the horizontal disc portion (701);
a first continuous circular protrusion (701a) extended from the tapered disc portion (701) in extending direction of the vertical wall portion (702); and 20
a second continuous circular protrusion (701b) extended from the tapered disc portion (701) in extending direction of the vertical wall portion (702), wherein
the first continuous circular protrusion (701a) and the second protrusion (701b) is defined at radial distance from each other, 25
the first continuous circular protrusion (701) is defined in between the central hole (704) and the second continuous circular protrusion (701b), and
the second continuous circular protrusion is defined in between the first continuous circular protrusion (701a) and the vertical wall portion 30 (702).
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12. The dust cover (700) as claimed in claim 11, wherein a continuous circular protrusion (704b) extended peripherally from the central hole (704) in extending direction of the vertical wall portion (702), diameter (704c) of the continuous circular protrusion (704b) is more than diameter (704a) of the central hole (704).
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13. A rack and pinion housing structure (800) comprises:
a pinion input shaft (200) fitted in the pinion housing (400) together with a pinion cover (300);
an oil seal (500) provided in between the pinion input shaft (200) and the pinion cover (300); 10
a plurality of cavities (301) provided in the pinion cover (300);
a rubber plug (600) provided in each of the plurality of cavities (301) of the pinion cover (300); and
a dust cover (700) provided to cover the pinion housing (400).
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14. The rack and pinion housing structure (800) as claimed in claim 13, wherein the rubber plug (600) comprises a base portion (602) and one or more protruded portions (601) extending away from the base portion (602), the protruded portion (601) is defined corresponding to a cavity (301) of the pinion cover (300).