Railway vehicle drive unit

Abstract

A railway vehicle drive unit ( 12 ) is a drive unit to rotatably drive a wheel ( 11 ) of a railway vehicle. More specifically, it includes a reducer housing ( 13 ) held on an inner diameter surface of the wheel ( 11 ), and integrally rotating with the wheel ( 11 ), an input side rotation member ( 14 ) connected to a drive source, a reducing mechanism ( 15 ) to reduce rotation speed of the input side rotation member ( 14 ) and transmit it to the reducer housing ( 13 ), a fixed member ( 23 ) arranged in the reducer housing ( 13 ) and connected and fixed to a vehicle body, axle bearings ( 24 ) and ( 25 ) to rotatably support the reducer housing 13 with respect to the fixed member ( 23 ), and lubricant oil circulating mechanisms ( 32 ) and ( 33 ) to circulate a lubricant oil between the reducing mechanism and the axle bearings ( 24 ) and ( 25 ).

1 . A railway vehicle drive unit to rotatably drive a wheel of a railway vehicle, comprising:
 a reducer housing held on an inner diameter surface of the wheel, and integrally rotating with the wheel;   an input side rotation member connected to a drive source;   a reducing mechanism to reduce rotation speed of said input side rotation member and transmit it to said reducer housing;   a fixed member arranged in said reducer housing, and connected and fixed to a vehicle body;   an axle bearing to rotatably support said reducer housing with respect to said fixed member; and   a lubricant oil circulating mechanism to circulate a lubricant oil between said reducing mechanism and said axle bearing.   
     
     
         2 . The railway vehicle drive unit according to  claim 1 , wherein
 said lubricant oil circulating mechanism circulates the lubricant oil by use of centrifugal force generated with the rotation of said input side rotation member.   
     
     
         3 . The railway vehicle drive unit according to  claim 1 , wherein
 said lubricant oil circulating mechanism includes a lubricant oil path radially penetrating an inside of said fixed member to return the lubricant oil from a radial outer side to a radial inner side.   
     
     
         4 . The railway vehicle drive unit according to  claim 3 , wherein
 said axle bearing is a tapered roller bearing including an inner ring fixed to an outer diameter surface of said fixed member, an outer ring fixed to an inner diameter surface of said reducer housing, and a plurality of tapered rollers arranged between said inner ring and said outer ring,   a seal member to seal said reducer housing is arranged between said reducer housing and said fixed member so as to be opposed to a large diameter side end of said tapered roller, and   an opening part of said lubricant oil path on the radial outer side is provided between said tapered roller bearing and said seal member.   
     
     
         5 . The railway vehicle drive unit according to  claim 4 , wherein
 said seal member has a lip part being slidably in contact with the outer diameter surface of said fixed member, and it is fixed to the inner diameter surface of said reducer housing, and integrally rotates with said reducer housing.   
     
     
         6 . The railway vehicle drive unit according to  claim 3 , wherein
 said input side rotation member has an eccentric part,   said reducing mechanism includes:   a revolution member rotatably supported with respect to said eccentric part, to execute revolution motion around a rotation axis of said input side rotation member;   a rotation regulation member to prevent rotation motion of said revolution member, allowing the revolution motion thereof; and   a periphery engagement member fixed to said reducer housing, to rotate said reducer housing at speed reduced with respect to said input side rotation member by engaging with a periphery of said revolution member, and   an opening part of said lubricant oil path on the radial inner side is provided in a position opposed to said eccentric part.   
     
     
         7 . The railway vehicle drive unit according to  claim 1 , wherein
 said reducing mechanism is held in a space sealed with the lubricant oil, and   said lubricant oil circulating mechanism is provided with a lubricant oil holding chamber communicating with said space sealed with said lubricant oil in such a manner that said lubricant oil can be moved between it and said space.   
     
     
         8 . The railway vehicle drive unit according to  claim 7 , wherein
 said lubricant oil holding chamber is arranged in said reducer housing, and   said space and said lubricant oil holding chamber are connected through a vent hole to uniform their internal pressures and a lubricant oil passage to uniform their oil surface heights.   
     
     
         9 . The railway vehicle drive unit according to  claim 7 , further comprising:
 a detecting means for detecting a state of the lubricant oil sealed in said space; and   a lubricant oil moving means for moving the lubricant oil between said space and said lubricant oil holding chamber, based on a detected result of said detecting means.   
     
     
         10 . The railway vehicle drive unit according to  claim 9 , wherein
 said lubricant oil moving means is a pressure adjustment device to increase a pressure in said lubricant oil holding chamber under the condition that the detected result of said detecting means exceeds a threshold value, and decrease the pressure in said lubricant oil holding chamber under the condition that the detected result of said detecting means falls below the threshold value.   
     
     
         11 . The railway vehicle drive unit according to  claim 10 , wherein
 said lubricant oil holding chamber has a piston to separate its inside into a first region isolated from said space, and a second region communicating with said space, and   said pressure adjustment device increases or decreases the pressure in said lubricant oil holding chamber by moving said piston.   
     
     
         12 . The railway vehicle drive unit according to  claim 9 , wherein
 said detecting means is a temperature sensor to detect a temperature of the lubricant oil sealed in said space.   
     
     
         13 . The railway vehicle drive unit according to  claim 9 , wherein
 said detecting means is a rotation sensor to detect rotation speed of said input side rotation member.   
     
     
         14 . The railway vehicle drive unit according to  claim 9 , wherein
 said lubricant oil holding chamber is provided outside said reducer housing.   
     
     
         15 . The railway vehicle drive unit according to  claim 7 , wherein
 said lubricant oil holding chamber is provided with a filter device to filter the internal lubricant oil.   
     
     
         16 . The railway vehicle drive unit according to  claim 1 , wherein
 said reducing mechanism is held in a space sealed with the lubricant oil, and   said lubricant oil circulating mechanism comprises a lubricant oil transferring mechanism to transfer the lubricant oil from a bottom region to an upper region in said space, by use of at least one rotation of said reducer housing and said input side rotation member.   
     
     
         17 . The railway vehicle drive unit according to  claim 16 , wherein
 said lubricant oil transferring mechanism transfers the lubricant oil from the bottom region to the upper region in said space, by use of the rotation of said input side rotation member.   
     
     
         18 . The railway vehicle drive unit according to  claim 17 , further comprising a fixed member arranged in said reducer housing, and connected and fixed to the vehicle body, wherein
 said fixed member internally includes:   said lubricant oil transferring mechanism;   a lubricant oil supply path extending from said lubricant oil transferring mechanism toward the bottom region in said space, to supply the lubricant oil to said lubricant oil transferring mechanism, and   a lubricant oil discharge path extending from said lubricant oil transferring mechanism toward the upper region in said space, to discharge the lubricant oil from said lubricant oil transferring mechanism.   
     
     
         19 . The railway vehicle drive unit according to  claim 17 , wherein
 said lubricant oil transferring mechanism includes a first pump to pump up the lubricant oil in response to a positive rotation of said input side rotation member, and a second pump to pump up the lubricant oil in response to a negative rotation of said input side rotation member.   
     
     
         20 . The railway vehicle drive unit according to  claim 19 , wherein
 said first pump comprises a first drive gear having teeth around its outer diameter surface, and integrally rotating with said input side rotation member, and a first driven gear having teeth meshing with said first drive gear, around its inner diameter surface, and being rotatably supported by said fixed member, and rotating around a point shifted from a rotation center of said first drive gear to one horizontal direction, and   said second pump comprises a second drive gear having teeth around its outer diameter surface and integrally rotating with said input side rotation member at a position different from that of said first pump, and a second driven gear having teeth meshing with said second drive gear, around its inner diameter surface, and being rotatably supported by said fixed member, and rotating around a point shifted from a rotation center of said second drive gear to the other horizontal direction.   
     
     
         21 . The railway vehicle drive unit according to  claim 19 , wherein
 said first pump is composed of a drive gear having teeth around its outer diameter surface and integrally rotating with said input side rotation member, and a first driven gear having teeth meshing with said drive gear, around its outer diameter surface, and being rotatably arranged on one side of said drive gear in a horizontal direction, and   said second pump is composed of said drive gear, and a second driven gear having teeth meshing with said drive gear, around its outer diameter surface, and being rotatable arranged on the other side of said drive gear in the horizontal direction.   
     
     
         22 . The railway vehicle drive unit according to  claim 17 , wherein
 said input side rotation member has an eccentric part,   said reducing mechanism comprises:   a revolution member rotatably supported with respect to said eccentric part, to execute revolution motion around a rotation axis of said input side rotation member;   a plurality of rotation regulation members to prevent rotation motion of said revolution member, allowing the revolution motion thereof;   a periphery engagement member fixed to said reducer housing, to rotate said reducer housing at speed reduced with respect to said input side rotation member by engaging with a periphery of said revolution member; and   a counterweight fitted and fixed to said input side rotation member with a phase so as to offset unbalance inertia coupling due to eccentric motion, and   said lubricant oil transferring mechanism is provided in said counterweight.   
     
     
         23 . The railway vehicle drive unit according to  claim 22 , wherein
 said counterweight includes a large diameter fun-shaped part, and a small diameter fun-shaped part having a radius smaller than that of said large diameter fun-shaped part and connected to said large diameter fun-shaped part in such as manner that their chords are in contact with each other, and   said lubricant oil transferring mechanism has an opening part in the chord of said large diameter fun-shaped part, and includes a circumferential oil path circumferentially extending in said large diameter fun-shaped part, and a radial oil path extending from said circumferential oil path toward an outer diameter surface of said large diameter fun-shaped part.   
     
     
         24 . The railway vehicle drive unit according to  claim 22 , wherein
 said counterweight includes a large diameter fun-shaped part, and a small diameter fun-shaped part having a radius smaller than that of said large diameter fun-shaped part and connected to said large diameter fun-shaped part in such as manner that their chords are in contact with each other, and   said lubricant oil transferring mechanism is a fin projecting from an end face of said large diameter fun-shaped part in a thickness direction.   
     
     
         25 . The railway vehicle drive unit according to  claim 23 , wherein
 said reducing mechanism has a plurality of said counterweights arranged in such a manner that phases of said large diameter fun-shaped parts differ from each other.   
     
     
         26 . The railway vehicle drive unit according to  claim 16 , wherein
 said lubricant oil transferring mechanism transfers the lubricant oil from the bottom region to the upper region in said space, by use of the rotation of said reducer housing.   
     
     
         27 . The railway vehicle drive unit according to  claim 26 , wherein
 said lubricant oil transferring mechanism is composed of concavo-convex parts formed in surfaces of said reducer housing, and a member rotating with the rotation of said reducer housing.   
     
     
         28 . The railway vehicle drive unit according to  claim 27 , wherein
 said concavo-convex part is a projection projecting from an inner diameter surface of said reducer housing and extending in a direction intersecting with a rotation direction of said reducer housing.   
     
     
         29 . The railway vehicle drive unit according to  claim 28 , wherein
 said projections are provided in a plurality positions in the inner diameter surface of said reducer housing, at regular intervals.   
     
     
         30 . The railway vehicle drive unit according to  claim 28 , wherein
 a wall surface of said projection opposed to a circumferential direction of said reducer housing is in contact with a tangent line of the inner diameter surface of said reducer housing, at an acute angle.   
     
     
         31 . The railway vehicle drive unit according to  claim 30 , wherein
 a cross-sectional shape of said projection perpendicular to a rotation axis of said reducer housing is an isosceles trapezoid having a long side and a short side parallel to each other, and said short side is arranged so as to be in contact with the inner diameter surface of said reducer housing.   
     
     
         32 . The railway vehicle drive unit according to  claim 28 , wherein
 said projection is formed in an inner diameter surface of an annular belt fixed in the inner diameter surface of said reducer housing.   
     
     
         33 . The railway vehicle drive unit according to  claim 27 , further comprising:
 a fixed member arranged in said reducer housing, and connected and fixed to the vehicle body; and   an axle bearing comprising an inner ring fixed to an outer diameter surface of said fixed member, an outer ring fixed to an inner diameter surface of said reducer housing, a plurality of rolling bodies arranged between said inner ring and said outer ring, and a retainer retaining an interval of said adjacent rolling bodies, and rotatably supporting said reducer housing with respect to said fixed member, wherein   said concavo-convex part is provided in at least one of said outer ring, said rolling body, and said retainer.   
     
     
         34 . The railway vehicle drive unit according to  claim 26 , further comprising:
 a fixed member arranged in said reducer housing, and connected and fixed to the vehicle body, and   an annular seal member fixed to an inner diameter surface of said reducer housing, to seal a space between said reducer housing and said fixed member, wherein   said lubricant oil transferring mechanism is a weir expanding from said seal member to a direction intersecting with a rotation direction of said reducer housing.