The present invention relates to a railway vehicle gear unit (hereinafter, referred to as “gear unit”).
A conventional gear unit is configured by including a large gear that is fixed to an axle, that is formed with a diameter larger than the diameter of a small gear fixed to a small-gear shaft, and that engages with the small gear, and a gearbox that accommodates therein the small gear and the large gear. The gear unit is installed on a truck frame, and transmits a rotational torque from a traction motor to the axle to rotatably drive wheels mounted on the axle. At the bottom of the gearbox, a necessary amount of lubricant oil is stored. This lubricant oil is carried up by rotations of the large gear by using a lubrication method referred to as “oil splash lubrication method”. A part of this lubricant oil, carried up by rotations of the large gear, is supplied to an engaging portion between the large gear and the small gear, bearings provided on both sides of the large gear, bearings provided on both sides of the small gear, and other parts.
In a conventional technique described in Patent Literature 1 mentioned below, a labyrinth structure is provided, for example, at a boundary portion between a small-gear shaft and a gearbox in order to prevent lubricant oil in a gear unit from leaking to the outside and to prevent outside dust and the like from entering the gear unit. This labyrinth structure utilizes a centrifugal force generated by rotations of a rotary shaft and a pressure difference between the inside and outside of the gear unit to prevent leakage of the lubricant oil.
However, the gear unit according to the conventional technique represented by Patent Literature 1 mentioned above has the following problems. Generally, a gear unit is mounted under the floor of a vehicle. Therefore, depending on the ambient environment including wind, rain, snow, and the like, wind, rain, snowmelt, and the like sometimes enter the interior of the gear unit through a labyrinth structure, and are mixed into lubricant oil. Furthermore, water, generated by internal condensation due to a temperature difference between the inside and outside of the gear unit, is sometimes mixed into the lubricant oil. Because the labyrinth structure is provided in the gear unit as described above, the water having been mixed into the lubricant oil remains inside without being discharged to the outside. The water and the lubricant oil are then agitated by rotations of the large gear, thereby causing the lubrication performance of the lubricant oil to be gradually reduced. Therefore, there is a possibility of adversely affecting bearing rotations and the like.
An object of the present invention is to provide a railway vehicle gear unit that can suppress degradation of the lubrication performance of lubricant oil.
In order to solve the above problems and achieve the object, the present invention is a railway vehicle gear unit that is constituted by accommodating, in a gearbox, a small gear that is mounted on a rotary shaft of a traction motor provided on a truck frame of a railway vehicle, and a large gear that is mounted on an axle provided on the truck frame and that engages with the small gear to transmit a torque, wherein on an inner surface of the gearbox in a circumferential direction of the large gear, a water removing device that removes water included in lubricant oil carried up within the gearbox is installed.
According to the present invention, a water removing device that has an absorbent accommodated therein is provided in a space within a gear unit; therefore, degradation of the lubrication performance of lubricant oil can be suppressed.
Exemplary embodiments of a railway vehicle gear unit according to the present invention will be explained below in detail with reference to the drawings. The present invention is not limited to the embodiments.
In
In
In
The small-gear bearing cover 8 is detachably fixed by a bolt (not shown) or the like screwed into the traction-motor-side surface of the gearbox 5, taking into consideration of the maintainability of the small-gear bearing 6. An oil slinger 10 is provided between an inner peripheral portion 8a of the small-gear bearing cover 8 and an outer peripheral surface of the small-gear shaft 4. The oil slinger 10 and the small-gear bearing cover 8 constitute a labyrinth structure that utilizes a centrifugal force generated by rotations of the small-gear shaft 4 and a pressure difference between the inside and outside of the gear unit 100 to prevent the lubricant oil 11 within the gearbox 5 from leaking to the outside and to prevent outside dust from entering the gear unit 100. Although not shown in
The lubricant oil 11 stored at the bottom of the gear unit 100 is carried up by rotations of the large gear 1 by using a lubrication method referred to as “oil splash lubrication method”, and is supplied to an engaging portion between the large gear 1 and the small gear 3, the small-gear bearings 6 and 7, and other parts. However, the gear unit 100 is mounted under the floor of a railway vehicle (not shown), and therefore, depending on the ambient environment, wind, rain, snowmelt, and the like sometimes enter the interior of the gear unit 100 through the labyrinth structure. The water having entered the interior of the gear unit 100 is mixed into the lubricant oil 11. Furthermore, water generated by internal condensation due to a temperature difference between the inside and outside of the gear unit 100 is sometimes mixed into the lubricant oil 11. Because the labyrinth structure is provided in the gear unit 100 as described above, the water having been mixed into the lubricant oil 11 remains inside without being discharged to the outside. The water and the lubricant oil 11 are then agitated by rotations of the large gear 1, thereby causing the lubrication performance of the lubricant oil 11 to be gradually reduced. Therefore, there is a possibility of adversely affecting a rotational operation of the gear unit 100. In order to solve the problems as described above, the gear unit 100 according to the present embodiment includes a water removing device 12 that is detachably arranged in an empty space within the gearbox 5 as shown in
The configuration of the water removing device 12 is specifically explained below.
The surface of the cartridge 12a that faces an engagement portion 1a that is circumferentially provided on the large gear 1 is formed into a shape so as not to come into contact with the engagement portion 1a. The cartridge 12a includes an introduction portion 12e that introduces the lubricant oil 11, carried up by the large gear 1, to the absorbent 12b, and a discharge portion 12f that discharges the lubricant oil 11 from which water has been removed by the absorbent 12b.
The filter 12c is provided on the upper side of the water removing device 12, for example, and removes foreign matter included in the lubricant oil 11. The filter 12d is provided on the lower side of the water removing device 12, for example, and prevents particles and the like of the absorbent 12b from flowing out. The installation location of the filter 12c is not limited to the upper side of the water removing device 12 and may be at any location where the filter 12c is capable of taking in the lubricant oil 11 carried up by the large gear 1, such as on the lateral side of the water removing device 12.
The absorbent 12b removes water having been mixed into the lubricant oil 11. The lubricant oil 11 from which water has been removed is returned to the surface of the large gear 1 or to the bottom of the gearbox 5 through the filter 12d. As the absorbent 12b, it is preferable to use a material having a function of removing water in the lubricant oil 11 without affecting the lubricant oil 11, and a molecular sieve or the like is used.
Next, the installation location of the water removing device 12 is explained.
Within the gearbox 5, a space is formed as shown in
The empty spaces a1 and a2 are formed above the extended line of the line connecting the axle 2 and the small-gear shaft 4, for example, and are the spaces required for arranging the large gear 1 within the gearbox 5. The empty spaces b1 and b2 are formed below the extended line of the line connecting the axle 2 and the small-gear shaft 4, for example, and are a part of the space formed for storing the lubricant oil 11. The water removing device 12 shown in
Next, a method of fixing the water removing device 12 is explained.
In the gearbox 5 shown in
A gasket 15, which is a sealing member, is provided between the flange 14 and the cartridge 12a to prevent the lubricant oil 11 adhering to the water removing device 12 from leaking to the outside. Providing the gasket 15 makes it possible to prevent the lubricant oil 11 in the gear unit 100 from leaking to the outside through the flange 14.
In order for the gasket 15 to function effectively, the fastening members 13 are required to be fastened to the flange 14 with a predetermined fastening torque. However, there is a possibility that the fastening members 13 are stripped (spins freely) depending on the fastening torque. In order to prevent such a possibility and to hold the gasket 15 rigidly, the thickness t of the flange 14 in the direction from the outside to the inside of the gear unit 100 is formed larger than the thickness of the gearbox 5.
Next, the operation of the gear unit 100 is explained. Power of the traction motor 20 is transmitted through the flexible shaft coupling 24 to the small-gear shaft 4, and the small gear 3 provided around the small-gear shaft 4 engages with the large gear 1 to rotate the large gear 1. The lubricant oil 11, stored at the bottom of the gearbox 5, is carried up by rotations of the large gear 1 and is supplied to the engaging portion between the large gear 1 and the small gear 3, bearings (not shown) provided on both sides of the large gear 1, the small-gear bearings 6 and 7 provided on both sides of the small gear 3, and other parts.
For example, when the large gear 1 rotates in the direction shown by an arrow C in
When the large gear 1 rotates in the direction shown by an arrow D, the amount of the lubricant oil 11 to be supplied to the absorbent 12b becomes smaller than the case when the large gear 1 rotates in the direction shown by the arrow C. However, because the traveling direction of a railway vehicle is reversed by reversing the rotation direction of the large gear 1, water having been mixed into the lubricant oil 11 is removed when the railway vehicle returns (that is, when the large gear 1 rotates in the direction shown by the arrow C).
Next, an example in which the shape of the gearbox 5 is changed is explained.
The gear unit 100 shown in
Empty spaces c1, c2, and d as shown in
The water removing device 12 shown in
Next, a method of fixing the water removing device 12 is explained.
In the gearboxes 5b and 5c shown in
The flange is formed with the opening and is also formed with holes (not shown) through which the fastening members 13 to be inserted toward the gearboxes 5b and 5c from the outside of the gearboxes 5b and 5c are insertable. Therefore, after the cartridge 12a is inserted through the opening formed in the flange, the fastening members 13 are screwed into the flange to fix the cartridge 12a to the gearbox 5b. By providing the flange on the gearbox 5b as described above, it is possible to replace the water removing device 12 easily. This flange may be provided on the surface which faces the side surface of the large gear 1 near the empty space c2. A gasket that is the same as the gasket 15 shown in
Next, the operation of the gear unit 100 shown in
For example, when the large gear 1 rotates in the direction shown by the arrow D in
When the large gear 1 rotates in the direction shown by the arrow C, the lubricant oil 11, pushed out of the engaging portion between the small gear 3 and the large gear 1, is also supplied to the absorbent 12b. Therefore, water having been mixed into the lubricant oil 11 is removed in the same manner as when the large gear 1 rotates in the direction shown by the arrow D.
When the water removing device 12 is installed in the empty space b1 or b2 shown in
The arrangement location of the water removing device 12 is not limited to the locations respectively shown in
Furthermore, the flange 14 is formed on the surface of the gearbox 5 shown in
Further, a flange (not shown) is formed on the surface of the gearbox 5b shown in
In a case where the performance of the absorbent 12b is reduced due to a long period of use, the water removing device 12 shown in
As explained above, the gear unit 100 according to the present embodiment is the railway vehicle gear unit 100 that is constituted by accommodating, in the gearbox (5, 5b, or 5c), the small gear 3 that is mounted on the rotary shaft of the traction motor 20 provided on the truck frame 30 of a railway vehicle, and the large gear 1 that is mounted on the axle 2 provided on the truck frame 30 and that engages with the small gear 3 to transmit a torque, wherein the water removing device 12 that removes water included in the lubricant oil 11 within the gearbox (5, 5b, or 5c) is installed on the inner surface of the gearbox (5, 5b, or 5c) in the circumferential direction of the large gear 1. Therefore, a water removing process is automatically performed by running the vehicle without carrying out any additional procedure such as providing, from the outside of the gear unit 100, power dedicated to removing water having been mixed into the lubricant oil 11. Accordingly, water having been mixed into the lubricant oil 11 is removed, and degradation of the lubrication performance of the lubricant oil 11 can be suppressed. As a result, overheating and burning of the engaging portion between the large gear 1 and the small gear 3, the small-gear bearings 6 and 7 provided on both sides of the small gear 3, and other parts are suppressed. This makes it possible to use the small-gear bearings 6 and 7 and other parts for a longer period of time.
Moreover, the water removing device 12 is arranged in the space (the empty space) a1, a2, or d formed above the extended line of the line connecting the axle 2 and the small-gear shaft 4 as shown in
Moreover, the water removing device 12 includes a casing (the cartridge 12a) that encloses the absorbent 12b, that is formed with the introduction portion 12e that introduces the lubricant oil 11 carried up by the large gear 1 to the absorbent 12b and the discharge portion 12f that discharges the lubricant oil 11 from which water has been removed by the absorbent 12b, and that is formed detachably on the gearbox 5, 5b, or 5c, the filter 12c that is provided in the introduction portion 12e and that removes foreign matter included in the lubricant oil 11, and the filter 12d that is provided in the discharge portion 12f and that prevents the absorbent 12b from flowing out of the cartridge 12a. In the gearbox (5, 5b, or 5c), the flange 14 is formed above or below the extended line of the line connecting the axle 2 and the small-gear shaft 4 and on the surface which faces the engagement portion 1a. The flange 14 includes the opening through which the cartridge 12a is insertable in the direction from the outside to the inside of the gearbox (5, 5b, or 5c). The cartridge 12a inserted through this opening is fixed to the flange 14 by the fastening members 13. Therefore, even in a case where a space for attaching/detaching the water removing device 12 cannot be ensured on the surface on the traction-motor side or on the counter traction-motor side of the gearbox (5, 5b, or 5c), for example, it is still possible to easily attach/detach the cartridge 12a from the side of the traveling direction of a train. Therefore, the absorbent 12b is replaceable without any additional work such as removing the lid 5a or separating the gearbox 5b from the gearbox 5c for replacing the absorbent 12b. As a result, it is possible to minimize the amount of work associated with the replacement of the absorbent 12b as required.
Moreover, the water removing device 12 includes the casing (the cartridge 12a) that encloses the absorbent 12b, that is formed with the introduction portion 12e that introduces the lubricant oil 11 carried up by the large gear 1 to the absorbent 12b and the discharge portion 12f that discharges the lubricant oil 11 from which water has been removed by the absorbent 12b, and that is formed detachably on the gearbox 5, 5b, or 5c, the filter 12c that is provided in the introduction portion 12e and that removes foreign matter included in the lubricant oil 11, and the filter 12d that is provided in the discharge portion 12f and that prevents the absorbent 12b from flowing out of the cartridge 12a. In the gearbox (5, 5b, or 5c), the flange 14 is formed above or below the extended line of the line connecting the axle 2 and the small-gear shaft 4 and on the surface which faces the side surface of the large gear 1. The flange 14 includes the opening through which the cartridge 12a is insertable in the direction from the outside to the inside of the gearbox (5, 5b, or 5c). The cartridge 12a inserted through this opening is fixed to the flange 14 by the fastening members 13. Therefore, even in a case where a space for attaching/detaching the cartridge 12a cannot be ensured on the side of the traveling direction of a train, for example, it is still possible to easily attach/detach the cartridge 12a from the surface on the traction-motor side or the counter traction-motor side of the gearbox (5, 5b, or 5c). Therefore, the absorbent 12b is replaceable without any additional work such as removing the lid 5a or separating the gearbox 5b from the gearbox 5c for replacing the absorbent 12b. As a result, it is possible to minimize the amount of work associated with the replacement of the absorbent 12b as required.
Furthermore, the gasket 15 that is a sealing member is provided between the flange 14 and the cartridge 12a. Therefore, even when the water removing device 12 is provided on the gearbox (5, 5b, or 5c), it is still possible to prevent the lubricant oil 11 in the gear unit 100 from leaking to the outside.
As described above, the present invention is mainly applicable to vehicle drive systems, and is particularly useful as an invention that can suppress degradation of the lubrication performance of lubricant oil.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2011/071149 | 9/15/2011 | WO | 00 | 3/12/2014 |