DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
METHOD TO MINIMIZE STRUCTURE VIBRATIONS IN A DRIVING MOTOR CAR OF THREE PHASE ELECTRICAL MULTIPLE UNIT

Applicant:
BEML Limited
A company Incorporated in India under the Companies Act, 1956
Having address:
BEML Soudha, 23/1, 4th Main,
Sampangirama Nagar, Bengaluru - 560 027,
Karnataka, India

The following specification particularly describes the invention and the manner in which it is to be performed.
CROSS REFERENCE TO RELATED APPLICATION AND PRIORITY
[001] The present Application claims priority to Indian Patent Application No. 202141018111 titled “METHOD TO ESTABLISH MAIN-COMPRESSOR INSTALLATION PROCESS-PARAMETERS TO MINIMIZE STRUCTURE VIBRATION IN 3-PHASE MEMU DM CAR” filed on April 19, 2021.
TECHNICAL FIELD
[002] The present invention relates to a method for determining the parameters to minimize structure vibrations in a driving motor and more particularly relates to minimizing structural vibration in a three phase mainline electric multiple unit (MEMU) driving motor car.
BACKGROUND
[003] During manufacturing of three phase MEMU cars, the major equipment’s like Main Transformer, EP unit and Battery Box are installed under slug position of the Body shell structure. Further, shell structure vibrations may be generated due to compressor running in the Driving Motor car in three Phase MEMU coaches. The vibrations are observed from a partition structure and fans mounted on a Roof. Further, it is observed that the main compressor is the source of vibration in the structure. To reduce the vibrations, there need to develop a method that may reduce structure vibration caused due to the main compressor.
OBJECT OF THE INVENTION
[004] The object of the invention is to provide a method to minimize structural vibration.
[005] Another object of the invention is to optimize a number of anti-vibration mounts and gap between a compressor frame and an underframe structure to minimize structural vibration.
[006] Yet another object of the invention is to study effect of installation design parameters on structure vibrations.

SUMMARY

[007] Before the present method is described, it is to be understood that this application is not limited to the particular machine or an apparatus and methodologies described, as there can be multiple possible embodiment that are not expressly illustrated in the present disclosure. It is also to be understood that the terminology used in the description is for the purpose of describing the particular version or embodiment only and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related method to minimize structure vibrations in a driving motor car of three phase electrical multiple unit and the aspects are further elaborated below in application detailed description. This summary is not intended to identify essential features of the proposed subject matter nor is it intended for use in determining or limiting the scope of the proposed subject matter.
[008] In an embodiment a method to minimize structure vibrations in a driving motor car is disclosed. The method comprises mounting, a compressor over a compressor frame and mounting, the compressor frame below at least one underframe structure. Further, the method comprises mounting, plurality of an anti-vibrating mount between a compressor frame and an under-frame structure of the driving motor (DM) car for maintaining a predefined gap between the compressor frame and the under-structure frame of the DM car to reduce transfer of vibration from the compressor frame.
[009] In an embodiment a method to optimize a gap between a compressor frame and an underframe structure is disclosed. The method comprising checking for damage of the main compressor and the underframe structure and isolating a compressor frame. The method further comprises placing a coach on a high rise and the compressor on a lifting table and installing the compressor below the underframe structure area of the mounting. Further, the method comprises lifting the compressor to bring the compressor closed to the underframe mounting area and aligning a compressor mounting hole to an underframe structure hole. The method further comprises inspecting an alignment and installing a requisite hardware in 16 diameter holes at four places and tightening with 60 NM torque. Once components are installed a second inspection may be performed and an electric connection may be checked. Further, an installed components may be tested, and a parameter may be recorded and checking at least one value.
STATEMENT OF INVENTION
[0010] Accordingly, the present invention discloses a method to minimize structure vibrations in a driving motor car is disclosed. The method comprises mounting, a compressor over a compressor frame and mounting, the compressor frame below at least one underframe structure. Further, plurality of an anti-vibrating mount is mounted between a compressor frame and an under-frame structure of the driving motor (DM) car for maintaining a predefined gap between the compressor frame and the under-structure frame of the DM car to reduce transfer of vibration from the compressor frame.
[0011] A number of plurality anti-vibrating mount is configured to be optimized based on an intensity of vibration generated by the compressor frame. The anti-vibrating mount is installed below the underframe structure of the DM car, wherein the anti-vibrating mount is configured with a mount with a flange, a STEM, locking plate, hexbolt M16, spring washer, hex bolt, spring washer M12 and a nyloc nut M12. The number of anti-vibrating mount and the gap between the compressor frame and the underframe structure is configured to be determined by Full factorial experiment, wherein the full factorial experiment considers experimental factors and control factor. The number of plurality anti-vibrating mount optimized to minimize the vibration are configured in a range 4 to 6. The distance between the compressor frame and the underframe structure is configured in a range 5mm to 7mm.

BRIEF DESCRIPTION OF DRAWINGS
[0012] The foregoing summary, as well as the following detailed description of embodiment, is better understood when read in conjunction with the appended drawing. For the purpose of illustrating the disclosure, however, the disclosure is not limited to the specific methods and apparatus disclosed in the document and the drawing.
[0013] The detailed description is described with reference to the accompanying figure. In the figure, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawing to refer like features and components.
[0014] Figure 1A-Figure 1C shows existing mounting of the compressor below the under-structure frame of the DM car, in accordance with an embodiment of the present subject matter.
[0015] Figure 1C shows a main compressor fitted in the underframe and showing the gap between compressor frame and Underframe structure, in accordance with an embodiment of the present invention.
[0016] Figure 2A shows a process parameter to minimize structure vibration in a driving motor, in accordance with an embodiment of the present subject matter.
[0017] Figure 2B shows an anti-vibrating mount STEM hardware in accordance with an embodiment of the present subject matter.
[0018] Figure 2C shows gap between compressor frame and Underframe structure, in accordance with an embodiment of the present invention.
[0019] Figure 3 shows main effect plot for means illustrating various combinations of variables to get the desired output, in accordance with an embodiment of the present invention.
[0020] Figure 4 shows interaction plot for means illustrating various combinations of Interactions to get the desired output, in accordance with an embodiment of the present invention.
[0021] Figure 5 shows a flow chart for the method to minimize structural vibration, in accordance with an embodiment of the present invention.
[0022] Figure depicts various embodiments of the present disclosure for purpose of illustration only. Only skilled in the art will readily recognize from the following discussion 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
[0023] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words “comprising”, “having”, and “including,” and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items or meant to be limited to only the listed item or items. Although any systems or method similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary method to minimize structure vibrations in a driving motor car of three phase electrical multiple unit. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
[0024] Various modification to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to another embodiment. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated but is to be accorded the widest scope consistent with the principles and features described herein.
[0025] The present subject matter discloses a method to establish main-compressor installation process-parameters to minimize structure vibration in 3-phase MEMU DM car. The proposed system comprises anti vibrating mount to be installed between a compressor frame and an underframe structure of a DM car. Before mounting the anti-vibrating, number of anti-vibrating mounts (AVMs) required to minimize the vibrations is optimized and a gap between the compressor frame and the underframe structure of the DM car is optimized. Full factorial experiment may be used to determine the parameters to minimize the vibrations may be obtained by a full factorial experiment.
[0026] In an embodiment the full factorial experiment considers two factors. The first factor that may be consider is experimental factor and second factor considered may be control factors. In an embodiment experimental factor may comprise a number of anti-vibration mounts (AVMs) hardware and the gap between compressor frame and underframe structure of the DM car. The Control factor may comprise a mount hardware, a Material property, a train testing parameter, a Noise factors: an ambient condition (Temp, Humidity etc.), an operator fatigue, etc.
[0027] In an embodiment, referring to Figure 2A and Figure 2B in combination shows a system 200 configured to minimize the structural vibration of a in 3-phase MEMU DM car of the present invention. The compressor set up 200 comprises an anti-vibrating mount 210.
[0028] In an embodiment the anti-vibrating mount is mounted between the under compressor top mounting frame 204 and underframe structure of the DM car 214. A STEM 216 is configured to hold anti-vibrating mount rubber assembly to a mounting hardware. The hardware is configured with locking plate 218, hexbolt M16 220, spring washer 222, hex bolt 224, spring washer M12 226 and a nyloc nut M12 228. The hardware is configured for fastening Main compressor to the underframe structure of the DM car coach.
[0029] In embodiment a compressor (not shown in the figure) is mounted to the underframe structure of the driving motor car 202. In an embodiment the system 200 consist of a wire rope isolator 206 attached to the compressor top mounting frame 204 is configured to control vibration. The wire rope is made of a stainless-steel cable and retaining bars. An air pipe 208 is configured to allow a flow of compressor air. Further, the compressor set up comprises a blower motor 212 configured to operate the Main compressor.
[0030] In an embodiment, the number of AVMs and the gap between a compressor top mounting frame 204 and underframe structure of the DM car 214 is optimized by performing a factorial design experiment. The full factorial experiment considers two factors. The first factor that may be consider is an experimental factor and second factor considered may be a control factor. The experimental factor may comprise a number of anti-vibration mounts (AVMs) and the gap between compressor frame 204 and underframe structure of the DM car 214. The Control factor may comprise a mount hardware, a Material property, a train testing parameter, a Noise factors: an ambient condition (Temp, Humidity etc.), an operator fatigue, etc. Figure 1C clearly indicates that gap between the compressor frame 204 and the underframe structure of the DM car 214.
[0031] In an embodiment the data collected from the factorial experiment is analysed by Minitab 14 software. Referring to Figure 3, a main effect plot is disclosed. Significant change in vibration value may be observed when number of AVMs may be changed from 4 to 6. Further, a significant change in the vibration value may be observed when the gap between compressor frame and underframe structure of the DM car 214 may be maintained between 5 mm to 7 mm. However, the aforesaid range may vary based on variation of the size of compressor and the DM car
[0032] Further, figure 4, shows an interaction plot plotted for number of the AVMs and the gap between the compressor frame 104 and the underframe structure of the DM car 214. A significant interaction may be observed between 5mm and 7mm a Gap line.
[0033] In an embodiment Figure 5 shows, a method 500 for optimizing the distance between the underframe structure of the DM car 214 and the compressor frame to minimize the structural vibration, the step comprising: checking for damage of the main compressor and the underframe structure of DM car 214, isolating a compressor frame, placing a coach on a high rise and the compressor on a lifting table, installing the compressor below the underframe structure of DM car 214 area of the mounting, lifting the compressor to bring the compressor closed to the underframe mounting area, aligning the compressor mounting hole to an underframe structure hole, inspecting the alignment, installing a requisite hardware in 16 dia hole at four places and tightening with 60 NM torque, performing a second inspection, checking electric connection may be checked, the testing the installed components and recording the parameters and checking at least one value.
[0034] In an embodiment a method to minimize structure vibrations in a driving motor car comprises mounting, a compressor over a compressor frame and mounting, the compressor frame (204) below at least one underframe structure (202). Further, plurality of an anti-vibrating mount (210) is mounted between a compressor frame (204) and an under-frame structure of the driving motor (DM) car (214) for maintaining a predefined gap between the compressor frame (204) and the under-structure frame of the DM car (214) to reduce transfer of vibration from the compressor frame (204).
[0035] A number of plurality anti-vibrating mount (210) is configured to be optimized based on an intensity of vibration generated by the compressor frame (204).
[0036] The anti-vibrating mount (110) is installed below the underframe structure of the DM car (214), wherein the anti-vibrating mount (210) is configured with a mount with a flange (216), a STEM 218, locking plate 220, hexbolt M16 222, spring washer 224, hex bolt 226, spring washer M12 128 and a nyloc nut M12 130.
[0037] The number of anti-vibrating mount and the gap between the compressor frame (204) and the underframe structure (114) is configured to be determined by Full factorial experiment, wherein the full factorial experiment considers experimental factors and control factor.
[0038] The number of plurality anti-vibrating mount optimized to minimize the vibration are configured in a range 4 to 6.
[0039] The distance between the compressor frame and the underframe structure (114) is configured in a range 5mm to 7mm.
[0040] In one implementation, the process is applicable for fitment of Main Compressor Model No. RR 20070OF(M) to Drg No.070314080, 1750 LPM Oil Free. Further, the process is applicable for Underframe manufactured as per drawing no. 849-41004 & 849-41001 using IRSM 41: 97 grade raw material.
[0041] Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features.
[0042] Some embodiments of the method may minimize the structural vibration in DM cars.
[0043] Some embodiments of the method may determine the parameter to control the vibration values.
REFERENCE NUMERALS
Part Number Part Name
202 Underframe compressor mounting bracket assay
204 Compressor top mounting frame
206 Wire rope isolator
208 Air pipe
210 Anti-vibrating mount system
212 Blower motor
214 Underframe structure of a Driving motor car
216 Flange
218 a STEM
220 locking plate
222 hexbolt M16
224 spring washer
226 hex bolt
228 spring washer M12
230 a nyloc nut M12
,CLAIMS:1. A method to minimize structure vibrations in a driving motor car, comprising:
mounting, a compressor over a compressor frame;
mounting, the compressor frame (204) below at least one underframe structure (202); and
mounting, plurality of an anti-vibrating mount (210) between a compressor frame (204) and an under-frame structure of the driving motor (DM) car (214) for maintaining a predefined gap between the compressor frame (204) and the under-structure frame of the DM car (214) to reduce transfer of vibration from the compressor frame (204).
2. The method to minimize structure vibrations in a driving motor car as claimed in claim1, wherein a number of plurality anti-vibrating mount (210) is configured to be optimized based on an intensity of vibration generated by the compressor frame (204).
3. The method to minimize structure vibrations in a driving motor as claimed in claim 1, wherein the anti-vibrating mount (110) is installed below the underframe structure of the DM car (214), wherein the anti-vibrating mount (210) is configured with a mount with a flange (216), a STEM 218, locking plate 220, hexbolt M16 (222), spring washer (224), hex bolt (226), spring washer M12 (228) and a nyloc nut M12 (230).
4. The method to minimize structure vibrations in a driving motor as claimed 1, wherein the number of anti-vibrating mount and the gap between the compressor frame (204) and the underframe structure (114) is configured to be determined by Full factorial experiment, wherein the full factorial experiment considers experimental factors and control factor.
5. The method to minimize structure vibrations in a driving motor as claimed in claim 1, wherein the number of plurality anti-vibrating mount optimized to minimize the vibration are configured in a range 4 to 6
6. The method to minimize structure vibrations in a driving motor as claimed in claim 1, wherein the distance between the compressor frame and the underframe structure (114) is configured in a range 5mm to 7mm.