Description:“RESTRAINER ARRANGEMENT WITH HINDRANCE AND DIVERSION COURSE ON INTERFACE OF TRACTION MOTOR AND ITS DRIVE END GEAR ENCLOSURE”

FIELD OF INVENTION:

[001] The present invention relates to the development of restrainer arrangement with hindrance and diversion course on the interface of traction motor and its drive end gear enclosure, to prevent ingression of lube oil from gear enclosure to motor.

BACKGROUND OF INVENTION:

[002] 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.

[003] In the drive system powered by traction motors, the power is transmitted from motor to wheel through gear train arrangement. The pinion that is mounted over or plugged into the extended length of rotor shafts, overhang from the traction motor and is enclosed into the gear train enclosure. Pinion meshes with gear to transmit motion from motor to wheel axle. Generally, heat is produced due to friction between the meshing parts. This heat further aggravates the temperature of gear train affecting its life and performance.

[004] For smooth working and higher efficiency of gear train, the heat so produced by the friction between contacting gear and pinion must be removed. Generally, splash lubrication with lube oil is used for the purpose. Amount and type of lube oil used depends upon the rate of heat generated by the system and safe working temperature of gear and pinion. The lower teeth of the gear are immersed into the lube oil. When the gear starts rotating, this oil automatically passes over the moving parts and thus provides an effective lubricating effect. In process of splashing, the lube oil also hits the interface between the traction motor and drive end gear enclosure.

[005] In existing prior art for such application, a static cap with axially outwards multiple concentric labyrinths and a rotatable collar circumscribing the shaft with axially inwards multiple concentric labyrinths facing each other, provides a sealing arrangement. Also, in some arrangements radial labyrinths are supplemented.

[006] In the said arrangement, design and manufacturing of multiple concentric labyrinths are of prime importance in providing efficient sealing arrangement. Impermissible concentric labyrinths dimensions lead to inappropriate clearances between the static and rotating parts that may have any of the following two implications:

1. When labyrinth clearances less than the acceptable limits:
To achieve minimum clearances between the static retaining cap and rotatable collar, consistently maintaining multiple concentric labyrinths, in close tolerances, while manufacturing, is complex.
Consequently, in service, rubbing of labyrinths of static cap and rotatable collar might take place. Rubbing of metallic components causes rise of metal content in grease present in bearing assembly that subsequently leads to bearing seizure.

2. When clearances are more than the acceptable limits:
Ingression of lube oil from high pressure zone of gear enclosure into the low pressure zone of traction motor takes place. Ingression leads to mixing of lube oil with traction motor bearing grease. Mixing causes deterioration in elasto-hydrodynamic properties of the grease, due to formation of sludge and consequent loss of lubrication film. Insufficient lubrication of the bearing results into seizure and damage of bearing.

[007] The proposed development allows a balance between the above two cases, by providing a suitable arrangement with hindrance and diversion course on the interface of traction motors and its drive end gear enclosure, to prevent ingression of lube oil from enclosure to motor.

[008] Considering the space constraint, arrangement has been designed in existing envelope. This arrangement shall constraint and diverge the flow of lube oil from gear enclosure to motor.

OBJECTIVE OF INVENTION:

[009] Primary objective of the invention is to develop a restrainer arrangement with hindrance and diversion course on the interface between traction motor and its drive end gear enclosure, to prevent ingression of lube oil from gear enclosure to motor.

[0010] Another objective of the invention is to eliminate sole dependency on labyrinths by reducing quantity of lube oil encountered by it.

[0011] Still another objective of the invention is to design the arrangement in a manner that it can be incorporated in the existing space envelope with minimal changes.

[0012] Yet another objective of the invention is to refrain from using contact seal to increase the maintenance life of the arrangement and reduce frequent replacements of seal.

[0013] 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 OF THE INVENTION:

[0014] One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus/composition and a method as claimed in 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 part of the claimed disclosure.

[0015] The restrainer arrangement has been provided with hindrance and diversion course on the way of flow of lube oil from gear enclosure to traction motor. The arrangement eliminates the sole dependency on labyrinths for effective sealing and hence eliminates any failure due to same.

[0016] In this invention, a splash guard (004) has been provided on the interface to reduce the quantity of lube oil encountered by the labyrinths, to minimum in the arrangement. The inwards circumferential steps on guard and compressible rubber sheet on the joint face hinders the lube oil flow. The static retaining cap (005) has been devised for provision of guiding pathways, an inverted collecting chamber and seeping orifice for diversion of leaked lube oil back into the enclosure. Stationary diverter (008) has been introduced at the bottom of the seeping orifice providing shield to assembly from splashing oil.

[0017] The Restrainer arrangement is placed on the interface of traction motor and gear enclosure maintaining axial distance from pinion.

[0018] The Restrainer arrangement with the splash guard (004) faces the splashing oil and encloses rotating collar to reduce the quantity of lube oil encountered by the labyrinths.

[0019] The splash guard (004) allows minimal passage area for the lube oil between the rotor shaft (003) and splash guard (004)

[0020] The splash guard (004) is shrink fitted or bolted over the static bearing retaining guard.

[0021] The static bearing retaining guard (005) is having provision of tapered path, circumferential guiding pathways, inverted collecting chamber (024) & inclined outlet hose.

[0022] The stationary diverter (008) allows outward flow of leaked lube oil but restricts inward flow splashing oil.

[0023] The stationary diverter (008) is either inherent part of static bearing retaining guard or welded over or bolted with static bearing retaining guard.

[0024] The exposed passage opening between the arrangement and rotor shaft (015) is offset from the gap between rotating collar and static retaining cap, providing U-shaped hindrance path for leaked oil.

[0025] The inventive features of invention have been indicated in the Principal claim and subsidiary features have been mentioned in the dependent claims.
[0026] 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.

[0027] 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.

[0028] 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 ACCOMPANYING DRAWINGS

[0029] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:

Figure 1 shows: Setup of Restrainer Arrangement according to the present invention.

Figure 2 shows: Enlarged view of the Restrainer Arrangement in accordance with the present invention.

[0030] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily 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 OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS:

[0031] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have 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 alternative falling within the scope of the disclosure.

[0032] The instant invention pertains to technology directed to Restrainer arrangement with hindrance and diversion course on interface of traction motor and its drive end gear enclosure.

[0033] Reference may be made to Figure 1, which displays setup of restrainer arrangement and Figure 2 showing enlarged view of restrainer arrangement (020).

[0034] The restrainer arrangement (020) is designed to position on the interface of traction motor and its drive end gear enclosure (001). Also, the restrainer arrangement maintains axial distance with pinion (002) inwards face and does not circumscribe the pinion.

[0035] Partial components of the arrangement are static and are held together by means of bolts, screws, shrink fit or through welding. Rest of the components sit over the rotating shaft (003).
[0036] Restrainer arrangement (020) comprises five major components including splash guard (004), static retaining cap (005), rotating collar (006), stationary diverter (008) and compressible rubber sheet (009).

[0037] Static retaining cap (005), having grease pocket (019) on the inward side and labyrinths on the outward side, is bolted directly to the static frame. Outward side of static retaining cap (005) is also featured with Guiding pathways (011), Inverted tapered path (012), Tapered path (013), Inclined outlet hose (014) and Collecting chamber (024), for hindrance and diversion course for the leaked lube oil.

[0038] Stationary diverter (008) is static and has been made part with static retaining cap (005), through welding at 6’o clock position. However, the provision of mounting stationary diverter (008), is not limited to welding and can be bolted or made integral part with static retaining cap (005).

[0039] Rotating collar (006), is shrink fitted over the rotating shaft (003), with its inward labyrinths facing the outward labyrinths of static retaining cap (005). Also, circumferential steps are provided on the outward face of rotating collar (006).

[0040] Compressible rubber sheet (009), sits statically over the outward frontal face of static retaining cap (005) and is squeezed with splash guard (004).

[0041] Splash guard (004), featured with circumferential steps on splash guard (010), on inward face, is bolted with static retaining cap (005). However, the mounting provision of splash guard (004) is not limited to bolting and can be shrink fitted or any other holding arrangement can be suitably incorporated.

WORKING PRINCIPLE WITH FUNCTIONALITY:

[0042] The pinion (002) is mounted over or plugged into the extended length of rotor shafts (003), overhangs from the traction motor and is enclosed into the gear enclosure (001). Pinion meshes with the gear (007) to transmit motion from motor to wheel axle.

[0043] When the gear starts rotating, the sump oil (018) present in gear enclosure (001) automatically passes over the moving parts to provide an effective lubrication. In the process of splashing, the lube oil also hits the interface between the traction motor and the drive end gear enclosure.

[0044] Openings between static and rotary part, on the interface, provides the way for ingression of lube oil from high pressure zone of gear enclosure into the low pressure zone of traction motor. Ingression leads to mixing of lube oil with traction motor bearing grease and subsequent failure of traction motor, due to bearing seizure.

[0045] In the present invention, restrainer arrangement is designed to sit on the interface, with no openings directly exposed to parent splash lube oil (016). Additionally, for the child splash lube oil (017) that has lost the energy, due to collision, hindrance and diversion course has been provided on the arrangement, to divert it back into the enclosure, without reaching to traction motor bearing (021).

[0046] In the present invention, the static splash guard (004) directly faces the splashing oil in drive end gear enclosure. It reduces the quantum and tendency of inward flow-ability of lube oil, to minimum, by minimizing the cross section area of the opening between static and rotatory part (015).

[0047] In the opening between static and rotary part, surface friction of shaft and guard limits the ingression of lube into the arrangement.

[0048] Inward circumferential steps (010) on the splash guard face the outward circumferential steps of rotating collar (006) to accumulate and hinder the flow of leaked lube oil by reducing its pressure.

[0049] Compressible rubber sheet (009) sits statically over the outward frontal face of static retaining cap (005) and is squeezed with Splash guard (004). Compressed sheet disallows the leak of lube oil from the face joint.

[0050] The static retaining cap (005) has been provided with the provision of tapered path (013), circumferential guiding pathways (011) for accumulation of oil and allowing natural downwards flow of same due to surface tension.

[0051] The tapered path (013) below the diametrical chord of retaining cap has the tendency to let flow of lube oil towards base of splash guard (6’o clock position from the pinion side). At the bottom of the cap (from the pinion side), at 6’o clock position, an inverted tapered pathway (012) leads the way for leaked lube oil to collecting chamber (024) for the collection.

[0052] The tapered path above the diametrical chord of retaining cap has the tendency to let, flow of lube oil inside the motor. However, circumferential guiding pathways (011) on the retaining cap (005) at the guard side and at the collar side directs this lube oil to the inverted tapered pathway (012) which leads to collecting chamber (024).

[0053] Three walls (left: 011 a, circumferential: 011 b, right: 011 c) of the guiding pathways bind the lube oil and allow flow of lube oil in pre-defined gullies.
[0054] On the base of collecting chamber (024), an orifice adjoining inclined hose allows flow of accumulated lube oil back into the gear enclosure. The inclined hose (014) is designed in a manner that it neither directly faces the parent splashing oil (016) in the gear enclosure (001) nor faces the rotating element inside the motor.

[0055] Further, to block orifice and to diverge droplets of splashing oil, a stationary diverter has been introduced into the arrangement. The stationary diverter (008) allows outwards flow of leaked lube oil but restricts inwards flow parent splashing oil. The stationary diverter can be either bolted, welded or made integral part of the static retaining cap (005).

DISTINGUISHING FEATURES OF THE PRESENT INVENTION OVER PRIOR ARTS:
Prior Art Present Invention Remarks/Advantages
Static retaining cap and rotating collar are provided for sealing of gear enclosure lube oil with bearing grease. System of splash guard (004) with provision of inwards circumferential steps, compressible rubber sheet (009), modified static retaining cap (005) and rotating collar (006) with circumferential steps are provided for effective sealing and reduced failures.
1) Effective sealing on interface between traction motor and drive end gear enclosure.

2) Reduced possibility of bearing failures.

Absence of Splash guard provides extra cross section for passage of lube oil into the traction motor. Splash guard (004) with inwards circumferential steps has been introduced to block splashing gear enclosure lube oil.
Reduces quantity of lube oil encountered by labyrinths
Sealing through labyrinths only. Sealing through hindrance, guided pathways, diversion and labyrinths.
Reduced dependency on labyrinths efficiency.
No guided pathways Provision of guiding pathways (011), inverted collecting chamber (024), inclined hose (014) on Static Retaining Cap (005).
Directional pathways to allow flow of oil back into the motor.
Outlet open to splashing Outlet allows outwards flow but restricts inwards flow parent (016)/ child (017) splashing oil.
Reduced ingression.

ADVANTAGES:

[0056] The successful development of hindrance and diversion system on the interface of traction motor and drive end gear enclosure allows to resolve issues related to seizure in traction motor.

[0057] The development also reduces the dependency on labyrinths efficiency.
[0058] Reduced failures related to oil ingression and labyrinths dimensional impermissibility, will result in enhanced life of traction motor and hence reduced maintenance cost.

TEST RESULT

[0059] Traction motor, with existing arrangement (prior art) when tested on wheel axle set, for long hours (more than 200 hours), oil ingression was observed on dismantling the motor.
[0060] However, when the same traction motor, with arrangement as per present invention, was tested on same wheel axle set and with same operating condition, for long hours (more than 200 hours), no oil ingression was observed on dismantling the motor.

[0061] This shows that, present invention performs better than the prior art.

REFERENCE NUMERALS

gear enclosure 001
Pinion 002
rotor shaft 003
splash guard 004
static retaining cap 005
rotating collar 006
Gear 007
stationary diverter 008
Compressible rubber sheet 009
Circumferential steps on splash guard 010
Guiding pathways on Static retaining cap 011
Inverted tapered path on Static retaining cap 012
Tapered path on Static retaining cap 013
Inclined outlet hose on Static retaining cap 014
Opening b/w static and rotary components 015
parent splash lube oil 016
child splash lube oil 017
sump oil 018
grease pocket 019
restrainer arrangement 020
traction motor bearing 021
Collecting chamber 024

[0062] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[0063] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[0064] 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 particulars claim containing such 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, 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 analogues 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.). In those instances where a convention analogous to “at least one of A, B, or 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, 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”.
[0065] The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.

[0066] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.

[0067] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.

[0068] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
, Claims:WE CLAIM:

1. Restrainer arrangement (020) with hindrance and diversion course on the interface of traction motors and its drive end enclosure (001), wherein the Restrainer arrangement (020) comprising of components including splash guard (004), static retaining cap (005), rotating collar (006), stationary diverter (008) and compressible rubber sheet (009); in which
the Splash guard (004) with Circumferential steps on splash guard (010), on inward face, is connected with static retaining cap (005),
the static retaining cap (005), having grease pocket (019) on the inward side and labyrinths on the outward side, is connected to the static frame,
the Rotating collar (006), is shrink fitted over rotating shaft (003), with its inward labyrinths facing the outward labyrinths of the static retaining cap (005), in which circumferential steps are provided on outward face of the rotating collar (006),
the Stationary diverter (008) is static and is part of static retaining cap (005),
the Compressible rubber sheet (009), sits statically over the outward frontal face of said static retaining cap (005) and is squeezed with the splash guard (004).

2. The Restrainer arrangement as claimed in claim 1, wherein the restrainer arrangement (020) maintains axial distance with pinion (002) inwards face and does not circumscribe the pinion, in which Partial components of the arrangement are static and rest of the components sit over the rotating shaft (003).

3. The Restrainer arrangement as claimed in claim 1 or 2, wherein the pinion (002) is mounted over or plugged into the extended length of rotor shafts (003), overhangs from the traction motor and is enclosed into the gear enclosure (001), in which Pinion meshes with the gear (007) to transmit motion from motor to wheel axle.

4. The Restrainer arrangement as claimed in claims 1-3, wherein when the gear starts rotating, the sump oil (018) present in gear enclosure (001) automatically passes over the moving parts to provide an effective lubrication.

5. The Restrainer arrangement as claimed in claims 1-4, wherein the splash guard (004) faces the splashing oil and encloses rotating collar to reduce the quantity of lube oil encountered by the labyrinths, wherein the splash guard (004) allows minimal passage area for the lube oil between rotor shaft and splash guard (015).

6. The Restrainer arrangement as claimed in claims 1-5, wherein the mounting provision of splash guard (004) includes bolting, shrink fitting or any holding arrangement.

7. The Restrainer arrangement as claimed in claims 1-6, wherein the splash guard (004) is having provision of inwards circumferential steps with corresponding circumferential steps of the rotatable collar (006).

8. The Restrainer arrangement as claimed in claims 1-7, wherein outward side of static retaining cap (005) is featured with guiding pathways (011), Inverted tapered path (012), Tapered path (013), Inclined outlet hose (014) and Collecting chamber (024), for hindrance and diversion course for the leaked lube oil.

9. The Restrainer arrangement as claimed in claims 1-8, wherein the Stationary diverter (008) is part of said static retaining cap (005), through welding at 6’o clock position, alternatively the stationary diverter (008) is bolted/made integral part with the static retaining cap (005).

10. The Restrainer arrangement as claimed in claims 1-9, wherein the stationary diverter (008) allows outward flow of leaked lube oil but restricting inwards flow splashing oil, wherein exposed passage b/w static and rotary components (015) is offset from the gap between rotating collar and static retaining cap, providing U-shaped hindrance path for leaked oil.