GB2231447A - Insulated bearing assembly in a traction motor for electric rolling stock - Google Patents

Insulated bearing assembly in a traction motor for electric rolling stock Download PDF

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Publication number
GB2231447A
GB2231447A GB8923110A GB8923110A GB2231447A GB 2231447 A GB2231447 A GB 2231447A GB 8923110 A GB8923110 A GB 8923110A GB 8923110 A GB8923110 A GB 8923110A GB 2231447 A GB2231447 A GB 2231447A
Authority
GB
United Kingdom
Prior art keywords
running gear
axles
traction motor
rolling stock
electric rolling
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB8923110A
Other versions
GB2231447B (en
GB8923110D0 (en
Inventor
Tetsuji Andoh
Jirou Tajimi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Publication of GB8923110D0 publication Critical patent/GB8923110D0/en
Publication of GB2231447A publication Critical patent/GB2231447A/en
Application granted granted Critical
Publication of GB2231447B publication Critical patent/GB2231447B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K5/00—Casings; Enclosures; Supports
    • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
    • H02K5/16—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields
    • H02K5/173—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields using bearings with rolling contact, e.g. ball bearings
    • H02K5/1732—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields using bearings with rolling contact, e.g. ball bearings radially supporting the rotary shaft at both ends of the rotor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/52—Bearings with rolling contact, for exclusively rotary movement with devices affected by abnormal or undesired conditions
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C35/00—Rigid support of bearing units; Housings, e.g. caps, covers
    • F16C35/04—Rigid support of bearing units; Housings, e.g. caps, covers in the case of ball or roller bearings
    • F16C35/06—Mounting or dismounting of ball or roller bearings; Fixing them onto shaft or in housing
    • F16C35/07—Fixing them on the shaft or housing with interposition of an element
    • F16C35/073—Fixing them on the shaft or housing with interposition of an element between shaft and inner race ring
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2202/00—Solid materials defined by their properties
    • F16C2202/30—Electric properties; Magnetic properties
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2326/00—Articles relating to transporting
    • F16C2326/10—Railway vehicles

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Power Engineering (AREA)
  • Motor Or Generator Frames (AREA)
  • Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
  • Rolling Contact Bearings (AREA)
  • General Details Of Gearings (AREA)

Abstract

Running gear for electric rolling stock has a traction motor 17 whose rotor shaft is arranged to have at least a portion at which the shaft bearing 15 makes contact made of an electrically insulating material 19. The electrically insulating material prevents erosion of the bearing by the electric current supplied to the axles 3. <IMAGE>

Description

RUNNING GEAR FOR AN ELECTRIC ROLLING STOCK BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a running gear for an electric rolling stock, and, more particularly, to a running gear for an electric rolling stock capable of preventing electric erosion of the traction motor thereof.
Description of the Related Art Fig. 1 is a plan view which illustrates an essential portion of a conventional running gear for an electric rolling stock. Referring to the drawing, wheels 2 capable of running on a track 1 are integrally secured to the corresponding two ends of axles 3. A pair of axles 3 is supported by a bogie transom 4 with an axle box (not shown). Traction motors 5 are mounted on this bogie transom 4, thus, the rotation therefrom being transmitted to the axles 3 through coupling devices consisting of gear coupling 6 and reduction devices 7. Contacts 8 are arranged to be brought into contact with the axles 3. The electric connection is established by grounding lines 9 between these contacts 8 and the bogie transom 4. An end of a coil of the armature of the traction motor 5 is also connected to the corresponding contact 8.
In the thus-structured running gear, an electric current introduced to the traction motor 5 from a stringing (omitted from illustration) through a pantegraph passes through a route formed between contacts 8 and the track 1 via the axles 3 and wheels 2 The conventional running gear is structured as described above and an electric current is arranged to be introduced into the axles 3 through the contacts 8.
Tharef ore, when the contact resistance of the contact 8 inereases, an electric current passes to the bearing means of the traction motor 5 due to the potential difference generated to the product of this contact resistance and the above-described electric current.
As d result, electric erosion generates, causing the bearing to be damaged.
Then, this phenomenon wila be described with reference to Figs. 1 and 2.
Fig. 2 is a partial cross-sectional view of an electric motor, for example, the traction motor 5.
Referring to the drawing, a frame 10 is secured to a bogie transom 4, this frame 10 indluding a stator 11.
A bearing box 12 is fastened with bolts 13 to the two end of the frame 100 Bearing means 15 are secured to the front portions of the bearing box 12. A rotator shaft 14 to which a stator 16 is secured can be rotatably held by the bearing means 15. The traction motor 5 is, at the frame portion 10 thereof, secured to the bogie transom 4, and the rotator shaft 14 of the traction motor 5 is connected to a gear coupling 6.
Therefore, a closed circuit: the contact 8 - axle 3 - reduction device 7 - gear coupling 6 - rotator shaft 14 - bearing means 15 - bearing box 12 - frame 10 - bogie transom 4 - grounding line 9 - contact 8 is present so that a portion of the above-described contact potential difference is arranged to be applied to the bearing means 15. When the contact potential difference is small level, the bearings means 15 maintains its insulation by the oil film thereon.
However, when this contact potential difference exceeds a certain level, the above-described insulation is lost, causing an electric current to be supplied to the bearings means 15. As a result, electric erosion is generated.
SUMMARY OF THE INVENTION The present invention is established in order to overcome the above-described problem. An object of the present invention therefore is to obtain a running gear for an electric rolling stock in which electric erosion of the bearing means of the traction motor due to the supply of electricity to the axles can be prevented.
In order to achieve the above object, according to one aspect of the present invention, there is provided a running gear for an electric rolling stock comprises: a bogie transom; axles rotatably supported by the bogie.transom, the axles having wheels secured thereto; a traction motor having a frame secured to the bogie frame, bearing means secured to the frame and a rotator shaft supported by the bearing means; a coupling device capable of transmitting rotation of the rotator shaft of the traction motor to the axles; and a grounding device capable being brought into contact with the axles and establishing passages through which an electric current can flow between the axles and the bogie transom, wherein at least a portion of the rotator shaft of the traction motor which is positioned to contact with the bearing means is made of an electrically insulating material.
BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view which illustrates a running gear for an electric rolling stock according to the conventional and present invention; Fig 2 is a partial cross-sectional view which illustrates a traction motor for a conventional running gear for an electric rolling stock; and Fig. 3 is a partial cross-sectional view which illustrates a traction motor for a running gear for an electric rolling stock according to an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT A running gear for an electric rolling stock according to the present invention, as shown in Figs. 1 and 3, comprises: a bogie transom 4; axles 3 rotatably supported by the bogie transom 4 and having wheels 2 fitted thereto; electric motors such as traction motors 17 secured to the bogie transom 4; coupling devices consisting of gear coupling 6 and reduction devices 7, the coupling devices capable of transmitting the rotation of rotators 18 of the traction motors 17 to the axles 3; and grounding means, for example, grounding lines 9 which establish passages through which an electric current passes between the axles 3 and the bogie transom 4.
The traction motor 17 includes: a frame 10 secured to the bogie transom 4, the frame 10 having a stator 11 secured thereto; bearing means 15 provided in a bearing box fastened at the two ends of the frame 10 by bolts 13; and a rotator shaft 18 rotatably held by the bearing means 15, the rotator shaft 18 having a rotator 16 secured thereto and the rotator shaft as well being connected to the coupling device. The difference from the conventional running gear shown in Fig. 2 lines in a rotator shaft 18. That is, the rotator shaft 18 has an insulating layer 19 which serves as an electrically insulating material in the portion thereof at which the bearing means 15 comes contact. This insulating layer 19 needs to exhibit sufficient electricity insulating strength and also needs to exhibit sufficient mechanical strength so as to serve as the rotator shaft 18.Therefore, it is preferable to employ a structure that is arranged such that alumina or titanium ceramic film is formed to have a thickness about 0.5 mm by a molten liquid spray method. However, the film thickness of the level described above is sufficient to create a resistance of several tens MQ or more. Therefore, a sufficient difference from the contact resistance (about several tens of mQ to few hundred of mQ) at the contact 8 can be assured. Therefore, when contact resistance of the contact 8 is increased and a high voltage is thereby applied between the frame 10 of the traction motor 17 and the rotator shaft 18, the large portion of the above-described voltage is applied to the insulating layer 19, causing the bearing means 15 to be protected from the application of the voltage. As a result, its insulation can be maintained. Consequently, the electric erosion of the bearing means 15 can be prevented.
The material and the shape of the insulating layer 19 is not limited to those according to the above-described embodiment. It can be variously selected. For example, the overall body of the rotator 18 may be made of, for example, ceramics.

Claims (7)

Claims,
1. A running gear for electric rolling stock comprising: a bogie frame; axles rotatably supported by said bogie frame, said axles having wheels secured thereto; a traction motor having a motor frame secured to said bogie frame, bearing means secured to said motor frame and a rotor shaft supported by said bearing means; a coupling device capable of transmitting rotation of said rotor shaft of said traction motor to said axles; and grounding means capable of being brought into contact with said axles and establishing pathways through which an electric current can flow between said axles and said bogie frame. wherein at least a portion of said rotor shaft of said traction motor which is positioned to contact with said bearing means is made of an electrically insulating materia10
2. Running gear according to claim 1 wherein said electrically insulating material comprises alumina or titan ceramics.
3. Running gear according to claim 2 wherein said alumina or titania ceramics are prepared by a liquid spraying method.
4. Running gear according to claim 2 or 3 wherein the thickness of said ceramics is about O.5mm.
5. Running gear according to claim 1, 2, 3. or 4 wherein the resistance of said electrical insulating material is several tens of Mnor more.
6. Running gear according to any preceding claim wherein the overall body of said rotor is made of ceramics.
7. Running gear for electric rolling stock.
substantially as herein described with reference to Figure 3 of the drawings.
GB8923110A 1989-05-10 1989-10-13 Improvements in or relating to running gear for an electric rolling stock Expired - Fee Related GB2231447B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5366489U JPH02146959U (en) 1989-05-10 1989-05-10

Publications (3)

Publication Number Publication Date
GB8923110D0 GB8923110D0 (en) 1989-11-29
GB2231447A true GB2231447A (en) 1990-11-14
GB2231447B GB2231447B (en) 1993-08-25

Family

ID=12949120

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8923110A Expired - Fee Related GB2231447B (en) 1989-05-10 1989-10-13 Improvements in or relating to running gear for an electric rolling stock

Country Status (3)

Country Link
JP (1) JPH02146959U (en)
ES (1) ES2019492A6 (en)
GB (1) GB2231447B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004068676A1 (en) * 2003-01-13 2004-08-12 Siemens Aktiengesellschaft Electric machine comprising a bearing system
US6936943B2 (en) 2003-10-08 2005-08-30 Mcmillan Electric Company Member for reducing leakage current through a bearing of an electric motor
EP2436943A1 (en) * 2010-10-01 2012-04-04 ALSTOM Transport SA Rolling bearing protection device
EP3772802A1 (en) * 2019-08-05 2021-02-10 Bombardier Transportation GmbH Drive system; traction motor shaft and motor with a traction motor shaft

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002247798A (en) * 2001-02-20 2002-08-30 Sanyo Denki Co Ltd Fan motor
JP2006115672A (en) * 2004-10-18 2006-04-27 Nidec Shibaura Corp Structure having countermeasure against electrolytic corrosion of brushless dc motor

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1573913A (en) * 1977-01-27 1980-08-28 Boatman P J F Insulating bearing housings
GB1591560A (en) * 1977-11-22 1981-06-24 Heemaf Nv Electric machine

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1573913A (en) * 1977-01-27 1980-08-28 Boatman P J F Insulating bearing housings
GB1591560A (en) * 1977-11-22 1981-06-24 Heemaf Nv Electric machine

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004068676A1 (en) * 2003-01-13 2004-08-12 Siemens Aktiengesellschaft Electric machine comprising a bearing system
US6936943B2 (en) 2003-10-08 2005-08-30 Mcmillan Electric Company Member for reducing leakage current through a bearing of an electric motor
EP2436943A1 (en) * 2010-10-01 2012-04-04 ALSTOM Transport SA Rolling bearing protection device
FR2965597A1 (en) * 2010-10-01 2012-04-06 Alstom Transport Sa DEVICE FOR PROTECTING A BEARING BEARING
CN102624137A (en) * 2010-10-01 2012-08-01 阿尔斯通运输股份有限公司 Rolling bearing protection device
RU2570979C2 (en) * 2010-10-01 2015-12-20 Альстом Транспорт Текнолоджис Protection device of journal roller bearing
EP3772802A1 (en) * 2019-08-05 2021-02-10 Bombardier Transportation GmbH Drive system; traction motor shaft and motor with a traction motor shaft

Also Published As

Publication number Publication date
GB2231447B (en) 1993-08-25
GB8923110D0 (en) 1989-11-29
JPH02146959U (en) 1990-12-13
ES2019492A6 (en) 1991-06-16

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Legal Events

Date Code Title Description
746 Register noted 'licences of right' (sect. 46/1977)

Effective date: 19951107

PCNP Patent ceased through non-payment of renewal fee

Effective date: 19961013