A retaining element for fastening elements or installations onto a shaft

Abstract

The present disclosure envisages a retaining element (100) or an external circlip. The retaining element (100) comprises two concentric rings, viz. an inner split ring (110) and outer circumferential ring (120) connected to each other at a bridge (115). The outer circumferential ring (120) includes at least one seat (125) portion defined on the radially inner side. Each of the seat (125) is configured to restrict the radial expansion of the inner split ring (110). The advantage of using the retaining element (100) is that there is no need of a separate component to prevent the expansion of the free ends (112) of the inner ring (110) beyond a predefined limit. The risk of loosening of the bearing or any other component fastened onto a shaft is eliminated.

Description

[0001] Title: A retaining element for fastening elements or installations onto a shaft

[0002] FIELD OF INVENTION

[0003] The present disclosure relates to the field of vehicles. More particularly, the present disclosure relates to the field of a retaining element (circlip) used in a transmission unit or drive device of a vehicle.

[0004] BACKGROUND

[0005] Recently, the average speed of prime movers and vehicles has considerably increased. The rotational speed of the components in a transmission system has also increased. Securing a high-speed rotating shaft is an important parameter for the desired functional requirement of the vehicle.

[0006] A circlip or a locking clip is used to secure the shaft in its axial position. The circlip rotates with the shaft and at higher rotational speeds the free ends of the circlip tend to move radially outwards. As a result, the contact surface between the shaft and the circlip is reduced. With further expansion of the circlip the shaft may come loose or there may be some misalignment in the assembly of the transmission system. In high-speed systems, any minor misalignment results in a drastic reduction in efficiency and may even trigger to safety issues. The useful working life of the components is also reduced.

[0007] Presently, a specially designed retaining component is provided to prevent, to restrict, or to limit the expansion of the circlip. However, these components themselves occupy some space and sometimes need special mounting / securing provision in the assembly. There is a risk of the retaining component itself getting loose from the assembly. There is therefore a need of a retaining element for fastening elements or installations onto a shaft, that solves the above-mentioned drawbacks.

[0008] OBJECTS

[0009] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:

[0010] An objective of the present disclosure is to provide a retaining element for fastening elements or installations onto a shaft.

[0011] An objective of the present disclosure is to provide a retaining element for fastening elements or installations onto a shaft, wherein the retaining element is resistant to radial expansion.

[0012] Another objective of the present disclosure is to provide a retaining element for fastening elements or installations onto a shaft, wherein the retaining element is easy to install.

[0013] Yet another objective of the present disclosure is to provide a retaining element for fastening elements or installations onto a shaft, wherein the need of a separate limiting component is avoided.

[0014] SUMMARY OF THE INVENTION

[0015] The present disclosure envisages a retaining element for fastening elements or installations onto a shaft. The retaining element comprises two concentric rings. The inner ring is configured to fit in a notch of a shaft while the outer circumferential ring encircles the inner ring. The inner ring is a split ring similar to a conventional circlip. Both the rings are interconnected using a bridge portion.

[0016] The outer circumferential ring may be a continuous ring and encircles the whole inner spilt ring. A gap is defined between the free ends of the arms of the inner split ring.

[0017] Further, the inner split ring may be connected to the outer circumferential ring by at least one bridge. Also, at least one seat may be provided on the inner side of the outer circumferential ring by projected surfaces, wherein the projected surface may be extended radially inwards. The dimension of the seat is preferably such that the seat does not touch the inner split ring even when the retaining element is installed on the shaft.

[0018] Alternatively and / or additionally, the seat may be configured to restrict the radial outward movement of the arms and the free ends of the inner split ring when the retaining element is rotating at high speeds.

[0019] Alternatively and / or additionally, the seats can be located at 90 degrees, 180 degrees, and 270 degrees from the bridge. Further, the seats can be provided at multiple locations or evenly distributed along the circumference of the outer ring.

[0020] A method of installing a retaining element, according to another aspect of the present disclosure, advantageously uses a tool to apply an axial force on the inner split ring to push the retaining element over the shaft. An axially opposite force is applied on the outer circumferential ring such as to facilitate the radial expansion of the inner split ring during installation of the retaining element.

[0021] BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING

[0022] Same reference numerals refer to same elements or elements of similar function throughout the various figures. Furthermore, only reference numerals necessary for the description of the respective figure are shown in the figures. The shown embodiments represent only examples of how the invention can be carried out. This should not be construed as a limitation of the invention.

[0023] For a better understanding of the invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings.

[0024] Figure 1 shows a conventional circlip and a shaft. Figure 2 shows the circlip and a limiting element installed on the shaft.

[0025] Figure 3 shows a front view of a retaining element for fastening elements or installations onto a shaft, in unstressed condition, when the retaining element is not installed on the shaft, in accordance with an embodiment of the present invention. Figure 3a shows an enlarged view of the retaining element of figure 3.

[0026] Figure 4 shows a front view of the retaining element, in a stressed condition, when the retaining element is installed on the shaft and when the shaft is rotating at high speed, in accordance with an embodiment of the present invention. Figure 4a shows an enlarged view of the retaining element of figure 4.

[0027] Figure 5 shows a perspective view of the retaining element of figure 3.

[0028] Figure 6 shows a method of installing the retaining element onto the shaft.

[0029] LIST OF REFERENCE NUMERALS

[0030] 10 - Conventional circlip

[0031] 12 - Free ends of conventional circlip

[0032] 15 - Shaft

[0033] 15a - Groove on shaft

[0034] 20 - Limiting element for circlip

[0035] 100 - Retaining element

[0036] 105 - Shaft

[0037] 105a - Groove on shaft

[0038] 110 - Inner split ring

[0039] 110a - Arms of inner split ring

[0040] 112 - Free end of split ring 115 - Bridge

[0041] 120 - Outer circumferential ring

[0042] 125 - Seat

[0043] 150 - Tool

[0044] DETAILED DESCRIPTION

[0045] In this application similar or corresponding features are denoted by similar or corresponding reference signs. The description of the various embodiments is not limited to the examples shown in the figures and the reference numbers used in the detailed description and the claims are not intended to limit the description of the embodiments, but are included to elucidate the embodiments by referring to the example shown in the figures.

[0046] Same reference numerals refer to same elements or elements of similar function throughout the various figures. Furthermore, only reference numerals necessary for the description of the respective figure are shown in the figures. The shown embodiments represent only examples of how the invention can be carried out. This should not be construed as a limitation of the invention.

[0047] In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail as the same are known to the person skilled in the art.

[0048] The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise.

[0049] For a better understanding of the invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings. Terms such as first, second, third etc., (used to distinguish one element, component, region, layer or section from another component, region, layer or section) when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.

[0050] The present disclosure is related to a retaining element 100 for retaining a component or bearing on a shaft, also known as a circlip, c-clip, or a snap ring. More particularly, the present disclosure is related to external circlips. The external circlips are fitted around a shaft or a circular component having a groove. The external circlip provides constant radial clamping force to a circular component (such as a shaft) by clamping inwards.

[0051] Circlips are fasteners used for axial fixation of components on shafts or inside bores. The circlips are installed in grooves and provide a shoulder to prevent any lateral movement of components, like bearings in relation to the groove. Once the circlip is fixed, the exposed piece functions as a shoulder which holds the particular element or installation.

[0052] A convention circlip 10 and a shaft 15 with a groove 15a defined thereon is shown in figure 1. The inner diameter d3 of the circlip 10 is slightly smaller than the outer diameter d2 of the groove 15a.

[0053] In some conventional circlips 10 available in the market, grip holes (not shown in figures) are provided on free ends (lugs 12) of the circlips 10 to allow these circlips 10 to be installed or removed by using a circlip plier.

[0054] In recent times there has been a significant increase in the rotational speed of machines, engines, transmissions, and drive units. As a result, the circlips 10 are subjected to higher centrifugal forces. When the centrifugal forces on the circlip 10 exceeds the clamping force the free ends 12 (ears) and arms of the circlip 10 move radially outward. As a result, the tightness and alignment of components and oil seals may be adversely affected. Further, there is a risk of loosening and disengagement of components that are fastened together by the circlip 10. For example, a bearing mounted on the shaft 15 may come loose due to radial expansion of the conventional circhps 10.

[0055] In some conventional solutions available in the market, a limiting element 20 as shown in figure 2 is used to prevent excessive radial expansion of the circlip 10 and to prevent the circlip 10 from coming out.

[0056] Figure 3 shows a retaining element (or circlip) 100, in accordance with an embodiment of the present disclosure. As seen figure 3, the retaining element 100 comprises two concentric rings. The inner ring locks in a notch of a shaft 105 while the outer ring encircles the inner ring. Both the rings are interconnected. Figure 3 shows the front view of the retaining element 100, in an unstressed condition, when the retaining element 100 is not installed on the shaft 105. Figure 3a shows an enlarged view of the retaining element of figure 3. In this condition, there is still a gap maintained between the inner and outer ring.

[0057] The retaining element 100, in according to one embodiment of the present disclosure, comprises an inner split ring 110 and an outer circumferential ring 120. The outer circumferential ring 120 is a continuous ring and encircles the whole inner spilt ring 110. The inner split ring 110 comprises arms 110a and a gap is defined between free ends 112 of the arms 110a. The inner split ring 110 is configured to function in a manner similar to a conventional circlip.

[0058] The inner split ring 110 is connected to the outer ring 120 by at least one bridge 115. At least one seat 125 is defined on the inner side of the outer circumferential ring 120 by a projected surface, wherein the projected surface is extended radially inwards. The dimension of the seat 125 is such that the seat 125 does not touch the inner split ring 110 even when the retaining element 100 is installed on the shaft 105.

[0059] The inner diameter of the inner split ring 110 is slightly smaller than the diameter of the notch 105a of the shaft 105 onto which the inner ring 110 is installed. The retaining element 100 is manufactured using an elastic and resilient material such a spring steel. In an embodiment, the material of the retaining element 100 is selected from the group consisting of stainless steel, spring steel, EN42J and stainless steel in 304 and 316 as per DIN : 471 & IS: 3075. The retaining element 100 is usually manufactured using highly elastic and surface hardened material.

[0060] Figure 4 shows a front view of the retaining element 100, in a stressed condition, when the retaining element 100 is installed on the shaft and when the shaft is rotating at high speed. Figure 4a shows an enlarged view of the retaining element 100 of figure 4.

[0061] Figure 5 shows a perspective view of the retaining element 100. It can be seen that the seat 125 is defined in the circumferential gap between the inner split ring 110 and the outer circumferential ring 120.

[0062] In one of the embodiment and variation of the retaining element 100, a seat 125 is located diagonally opposite to the bridge 115.

[0063] In another embodiment and variation of the retaining element 100, wherein there are multiple seats 125, the seats 125 are located at 90 degrees from one another. Say for example, at zero degree, 90 degrees, 180 degrees angular positions (as per Cartesian coordinate system) on the retaining element 100 as can be visualized in front view of the retaining element 100 of figure 3. The seats 125 can be defined at any desired location as per the need and design constraints.

[0064] The seat 125 is configured to restrict the radial outward movement of the arms 110a and the free ends 112 of the inner split ring 110 when the retaining element 100 is rotating at high speeds.

[0065] The seats 125 can be located at 90 degrees, 180 degrees, and 270 degrees from the bridge 115. Further, the seats 125 can be provided at multiple locations or evenly distributed along the circumference of the outer ring 120. A method of installing the retaining element 100 of the shaft 105 is illustrated in figure 6. The steps of installation are shown from left to right. The method comprises the following steps:

[0066] First the retaining element 100 is placed close to the shaft 105.

[0067] Then the bridge 115 and inner ring 110 is supported by a tool or thumb.

[0068] Then the portion of the outer ring 120 away from the bridge 115 is subjected to an axial force away from the shaft, such that the gap between the free ends 112 is increased due to stresses created at the bridge 115 portion. As a result, the inner diameter of the inner split ring 110 increases.

[0069] Then the retaining element 100 is slid onto the shaft 105 until the inner ring 110 fits into the groove 105a of the shaft 105.

[0070] The axial force on the outer ring 120 is released. The outer ring 120 returns to its original position.

[0071] The retaining element 100 is designed in such a manner that the gap between the free ends 112 is increases when axially opposite forces are applied at the bridge 115 and a portion of the outer circumferential ring 120. This facilitates installation and / or removal of the inner split ring 110 onto / from the shaft 105.

[0072] In the method of installing a retaining element 100 as described above, a tool 150 can be used to apply an axial force on the inner split ring 110 to push the retaining element 100 over the shaft 105 while an axially opposite force is applied on the outer circumferential ring 120. By doing this there occurs radial expansion of the inner split ring 110 to facilitate installation and / or removal of the retaining element 100.

[0073] The benefits of the retaining element 100 of the present disclosure are mentioned below.

[0074] The retaining element 100 is more reliable and resilient. The retaining element 100 prevents radial expansion of free ends 112 and arms preventing the loosening of conventional circlips is ehminated.

[0075] The total number of parts in an assembly is reduced. The risk of misalignment and loosening of assembled components is reduced.

[0076] The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that embodiment but are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.

[0077] The various embodiments which are described above may be used implemented independently from one another and may be combined with one another in various ways. The reference numbers used in the detailed description and the claims do not limit the description of the embodiments nor do they limit the claims. The reference numbers are solely used to clarify.

[0078] In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor, element or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0079] In the present disclosure, the expression “at least one of A, B and C” means “A, B, and / or C”, and that it suffices if, for example, only B is present. A single element or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0080] Any reference signs in the claims should not be construed as limiting the scope. TECHNICAL ADVANCEMENTS

[0081] The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a retaining element for fastening elements or installations onto a shaft, that: is reliable and resilient; is able to prevent radial expansion of free ends (ears) of a split ring installed in the groove of a shaft; eliminates the need of using a separate component for preventing the loosening of conventional circlips; reduces the total number of parts in an assembly; is more robust due to a reduced number of components; and reduces the risk of misalignment and loosening of assembled components.

[0082] The present disclosure envisages a retaining element or an external circlip. The retaining element comprises two concentric rings, viz. an inner split ring and outer circumferential ring connected to each other at a bridge. The outer circumferential ring includes at least one seat portion defined on the radially inner side. Each of the seat is configured to restrict the radial expansion of the inner split ring. The advantage of using the retaining element is that there is no need of a separate component to prevent the expansion of the free ends of the inner ring beyond a predefined limit. The risk of loosening of the bearing or any other component fastened onto a shaft is eliminated.

[0083] For the purpose of clarity and a concise description, features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described. It may be understood that the embodiments shown have the same or similar components, apart from where they are described as being different. The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments 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.

[0084] The foregoing description of the specific embodiments to 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 preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

[0085] While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation. Modifications and improvements to the above-described embodiments of the present invention may become apparent to those skilled in the art. The foregoing description is intended to be exemplary rather than limiting. The scope of the present invention is therefore intended to be limited solely by the scope of the appended claims.

Claims

Claims1. A retaining element (100) for fastening elements or installations onto a shaft (105), said retaining element (100) comprising: an inner split ring (110) configured for receiving a groove (105a) defined on a shaft (105); free ends (112) of said split ring (110) with a gap defined therebetween; an outer circumferential ring (120) encircling said inner spilt ring (110); and at least one bridge (115) connecting said inner split ring (110) with said outer circumferential ring (120).

2. The retaining element (100) for fastening elements or installations onto a shaft (105) as claimed in claim 1, wherein at least one seat (125) defined on inner side of said outer circumferential ring (120) by a projected surface, each of said seats (125) extending radially inwards.

3. The retaining element (100) for fastening elements or installations onto a shaft (105) as claimed in any of the previous claims, wherein said seat (125) is defined in the circumferential gap between said inner split ring (110) and said outer circumferential ring (120).

4. The retaining element (100) for fastening elements or installations onto a shaft (105) as claimed in any of the previous claims, wherein said seat (125) is located diagonally opposite to said bridge (115).

5. The retaining element (100) for fastening elements or installations onto a shaft (105) as claimed in any of the previous claims,wherein said seats (125) are located at 90 degrees, 180 degrees, and 270 degrees from the bridge (115).

6. The retaining element (100) for fastening elements or installations onto a shaft (105) as claimed in any of the previous claims, wherein said seats (125) are provided at multiple locations or evenly distributed along the circumference of said outer ring (120).

7. The retaining element (100) for fastening elements or installations onto a shaft (105) as claimed in any of the previous claims, wherein said seat (125) is configured to restrict the radial outward movement of arms (110a) and said free ends (112) of said inner split ring (110) under the action of centrifugal forces when the retaining element (100) is rotating at high speed.

8. The retaining element (100) for fastening elements or installations onto a shaft (105) as claimed in any of the previous claims, wherein the material of said retaining element (100) is selected from the group consisting of stainless steel, spring steel, EN42J and stainless steel in 304 and 316.

9. The retaining element (100) for fastening elements or installations onto a shaft (105) as claimed in any of the previous claims, wherein when an axial force is applied on said outer circumferential ring (120) the gap between said free ends (112) is increased to facilitate installation and removal of said inner split ring (110) onto the shaft (105).

10. The retaining element (100) for fastening elements or installations onto a shaft (105) as claimed in any of the previous claims, wherein the gap between said free ends (112) is configured to increase whenaxially opposite forces are applied at said bridge (115) and a portion of said outer circumferential ring (120), to facilitate installation and removal of said inner split ring (110) onto the shaft (105).

11. A method of installing a retaining element (100) as claimed in any of the previous claims, wherein a tool (150) is used to apply an axial force on the inner split ring (110) to push said retaining element (100) over said shaft (105) while an axially opposite force is applied on said outer circumferential ring (120) such as to facilitate the radial expansion of said inner split ring (110) during installation of said retaining element (100).

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