JP6678538B2 - Internal gear and planetary gear - Google Patents

Description

  The present invention relates to an internal gear and a planetary gear device including the internal gear.

  The structure of the planetary gear device will be described with reference to FIG. The planetary gear device 700 includes an input shaft 701, a sun gear 702, a planetary gear 703, a bearing 704, a planetary shaft 705, a carrier 706, an internal gear 100C, and an output shaft 707. I have. In the above configuration, the planetary gear device 700 transmits the rotational driving force as described below. That is, for example, in the case of a planetary gear device for a gas turbine, when the input shaft 701 connected to the gas turbine is driven to rotate, the sun gear 702 integrated therewith also rotates at the same time, and the planetary gear meshing therewith. 703 is driven to rotate. Further, the internal gear 100C meshing with the planetary gear 703 is driven to rotate, and the output shaft 707 integrated therewith is driven to rotate.

  The lubricating oil circulates in the planetary gear device 700 as follows. The lubricating oil stored in the oil tank 710 is sucked up by the pump 711 and passes through the filter 712 in the process. The sucked lubricating oil is supplied to the sun gear 702 from the nozzle 713. The lubricating oil is scraped up by the planetary gear 703 meshing with the sun gear 702, and is also supplied to the internal gear 100C. The lubricating oil falls from the gap between the internal gear 100C and the carrier 706 and accumulates in the oil tank 710.

  The gas turbine planetary gear device is characterized in that it is driven at a high speed because it is rotationally driven by the gas turbine. Therefore, the pitch circumferential speeds of the sun gear, the planetary gears, and the internal gear are much higher than those of other industrial planetary gear devices, and as a result, the calorific value is large.

  As described in Non-Patent Document 1, the heat generation of the gear device is generated mainly by friction loss, lubricating oil stirring loss, and bearing loss due to gear meshing. Among the above factors, lubricating oil agitation loss and bearing loss occupy a large proportion and increase with an increase in the gear's pitch circumferential speed. Becomes larger.

  On the other hand, the heat generated inside the gear device is carried away by the lubricating oil cooled in the oil tank being supplied to the heat generating portion and flowing.

  Here, as shown in FIG. 15, in the case of the parallel shaft gear device 800, the lubricating oil (indicated by dots in FIG. 15) supplied from the oil supply nozzle 803 flows into the meshing portions of the gear pairs 801 and 802, and immediately. Since the oil is discharged from the engagement portion and falls into the oil tank 804, a large amount of heat is taken away by the lubricating oil, and the temperature is hardly increased.

  On the other hand, as shown in FIG. 16, in the case of the planetary gear device 700, the lubricating oil (indicated by dots in FIG. 16) supplied from the oil supply nozzle 713 flows into the meshing portion between the sun gear 702 and the planetary gear 703, and It is scraped up by the gear 703 and is also supplied to the internal gear 100C.

  Thereafter, the lubricating oil is separated into one that is discharged to the outside of the internal gear 100C and falls into the oil tank and one that stays inside the internal gear 100C. Therefore, the planetary gear device 700 has a smaller amount of heat carried away by the lubricating oil than the parallel shaft gear device 800 (see FIG. 15), and is easily heated. Therefore, in order to suppress the temperature rise of the planetary gear device 700, it is necessary to improve the dischargeability of the lubricating oil remaining inside the internal gear 100C.

  With respect to the above-mentioned problem with respect to the planetary gear device, for example, Patent Document 1 discloses that a columnar baffle unit extending in the rotation axis direction from a carrier is provided between adjacent planetary gears, and an opening is provided in the member in a radial direction. This describes a structure in which lubricating oil scattered around the planetary gear is collected, and the collected lubricating oil is discharged to the outside from a discharge hole of the ring portion of the internal gear.

WO 2015/50116

Neil E. A., and Stuart H. L., “Spur-Gear-System Efficiency at Part and Full Load”, NASA Technical Paper 1622, Technical Report 79-46, 1980.

  In the structure of the planetary gear device disclosed in Patent Document 1, a baffle unit structure is required between the planetary gears in order to collect lubricating oil between the planetary gears. However, there is a need for a planetary gear device that does not include a baffle unit and that has a structure that improves the lubricating oil discharge performance.

  Therefore, an object of the present invention is to provide an internal gear and a planetary gear device that improve the lubricating oil dischargeability.

In order to solve such a problem, an internal gear according to the present invention includes a cut rim, a web, and an annular portion that connects the rim and the web, and the annular portion has a flesh. have a cut-out portion, the lightening portion is centered point an arbitrary point on the normal line passing through the center point of any cylindrical surface on a plane perpendicular to the normal line, the bottom rotating on said annular portion A trapezoid which is perpendicular to the axis and which is symmetrical with respect to a line passing through the midpoint of the base, and a trapezoid which is 180 ° rotationally symmetric with respect to the trapezoid are arranged at equal intervals in the circumferential direction by projecting the figure projected on the annular portion. It is characterized by being a shape .

  A planetary gear device according to the present invention includes the above-described internal gear.

  ADVANTAGE OF THE INVENTION According to this invention, the internal gear and the planetary gear device which improve the discharge property of lubricating oil can be provided.

It is a sectional view of an internal gear concerning a 1st embodiment. It is sectional drawing of the internal gear which concerns on the modification of 1st Embodiment. It is a perspective view of an internal gear concerning a 1st embodiment, and a figure explaining a lightening structure of an annular part. It is sectional drawing of the internal gear concerning 2nd Embodiment. It is a perspective view of an internal gear concerning a 2nd embodiment, and a figure explaining a lightening structure of a ring part. It is sectional drawing of the internal gear concerning 3rd Embodiment. It is a perspective view of an internal gear concerning a 3rd embodiment, and a figure explaining a lightening structure of a ring part. It is sectional drawing of the internal gear concerning 4th Embodiment. It is a perspective view of an internal gear concerning a 4th embodiment, and a figure explaining a lightening structure of a ring part. It is sectional drawing of the internal gear concerning 5th Embodiment. It is a figure explaining a perspective view of an internal gear concerning a 5th embodiment, and a lightening structure of a ring part. It is sectional drawing of the internal gear concerning 6th Embodiment. It is a figure explaining the perspective view of the internal gear concerning 6th Embodiment, and the lightening structure of an annular part. It is sectional drawing of a planetary gear device. It is a figure explaining an oil supply structure in a parallel axis gear device. It is a figure explaining the oil supply structure in a planetary gear device.

  Hereinafter, embodiments for carrying out the present invention (hereinafter, referred to as “embodiments”) will be described in detail with reference to the drawings as appropriate. In each of the drawings, common portions are denoted by the same reference numerals, and redundant description will be omitted.

<< 1st Embodiment >>
The internal gear 100 according to the first embodiment will be described with reference to FIGS. FIG. 1 is a sectional view of the internal gear 100 according to the first embodiment. FIG. 2 is a cross-sectional view of the internal gear 100 according to a modification of the first embodiment. The internal gear 100 according to the first embodiment can be used for an internal gear 100C included in the planetary gear device 700 of FIG.

  As shown in FIG. 1, the internal gear 100 includes a rim 110 that is internally toothed, a web 120, and an annular portion 130 that connects the rim 110 and the web 120. 1 indicates the rotation axis R of the internal gear 100.

  The annular portion 130 is provided with a lightening portion 131 and a beam 132 formed between the lightening portions 131. In other words, the annular portion 130 includes the first annular portion 133 on the rim 110 side, the second annular portion 134 on the web 120 side, the first annular portion 133 and the second annular portion 134, And a beam 132 for connecting the two.

  In addition, the lightening portion 131 includes a first lightening portion 131a in which the rim 110 side is wider than the web 120 side and a second lightening portion 131b in which the web 120 side is wider than the rim 110 side. The ring portion 130 is configured to be alternately repeated at equal intervals in the circumferential direction. The beam 132 includes a first beam 132a and a second beam 132b. In other words, the first lightening portion 131a, the first beam 132a, the second lightening portion 131b, and the second beam 132b are repeatedly formed in the circumferential direction (rotation direction r2) of the annular portion 130 in this order. I have.

  The first lightened portion 131a has a shape in which fillets (rounded corners) are attached to the respective inner corners of a trapezoidal shape having a base extending in the circumferential direction of the annular portion 130, and the length of the base near the rim 110 is long. Is longer than the length of the base on the side of the web 120. The second lightening portion 131b has a shape in which fillets (rounded corners) are attached to inner corners of a trapezoid having a base extending in the circumferential direction of the annular portion 130, and the length of the base near the web 120 is long. Is longer than the length of the base on the side of the rim 110. The length of the bottom of the first lightening portion 131a on the rim 110 side is equal to the length of the bottom of the second lightening portion 131b on the side of the web 120, and the first lightening portion 131a is on the side of the web 120. Is equal to the length of the bottom of the second lightening portion 131b on the side of the rim 110, and the inner angle of the first lightening portion 131a on the side of the rim 110 and the web 120 of the second lightening portion 131b. The inner angles of the sides are equal. That is, the first lightening portion 131a and the second lightening portion 131b have a 180 ° rotationally symmetric relationship.

  The extending direction (center line) of the first beam 132a is not parallel to the rotation axis R, but is formed to be oblique to the rotation axis R. Similarly, the extending direction (center line) of the second beam 132b is not parallel to the rotation axis R but is formed to be oblique to the rotation axis R. Further, the first beam 132a is provided such that the end on the web 120 (second annular portion 134) side is closer to the first rotation direction r1 than the end on the rim 110 (first annular portion 133) side. On the other hand, in the second beam 132b, the end on the side of the web 120 (the second annular portion 134) is in a direction opposite to the first rotational direction r1 than the end on the side of the rim 110 (the first annular portion 133). It is provided on the side in the second rotation direction r2. That is, the beams 132 (132 a, 132 b) that are oblique to the rotation axis R are arranged in the annular portion 130 so that the directions thereof are alternated. The thickness of the beam 132 (132a, 132b) is constant.

  In the internal gear 100 shown in FIG. 1, the outer diameter of the annular portion 130 and the outer diameter of the rim 110 are illustrated as being equal (ie, flush), but are not limited thereto. Instead, they may be different. That is, the outer diameter of the annular portion 130 may be smaller than the outer diameter of the rim 110 (there may be a step).

  Further, the internal gear 100 is not limited to the configuration shown in FIG. 1, and may be provided with a boss 140 that is fitted to a rotating shaft (output shaft 707; see FIG. 14) as shown in FIG.

  Next, the shape of the lightening portion 131 (beam 132) of the internal gear 100 according to the first embodiment will be further described with reference to FIG. FIG. 3 is a perspective view of the internal gear 100 according to the first embodiment and a diagram illustrating a lightening structure of the annular portion 130.

  In FIG. 3, a plane P is an arbitrary cylindrical surface on the annular portion 130. Point O is the center point of cylindrical surface P. Line L is a normal passing through point O. The point Oq is an arbitrary point on the line L. The plane Q is a plane perpendicular to the line L with the point Oq as the center point.

  The quadrangle A1B1C1D1 on the surface Q is a trapezoid whose base is perpendicular to the rotation axis R (see FIG. 1) and is line-symmetric with respect to a line passing through the midpoint of the base. Further, the square A2B2C2D2 on the surface Q is a trapezoid that is 180 ° rotationally symmetric with respect to the aforementioned square A1B1C1D1.

  The side C1D1 and the side C2D2 on the surface Q are parallel, and the side A1B1 and the side A2B2 on the surface Q are parallel.

  The lightening portions 131 (131a, 131b) project the shape in which the vertices of the squares A1B1C1D1 and the squares A2B2C2D2 on the surface Q are chamfered or rounded (fillet) onto the surface P, and lighten the shape, and are equally spaced in the circumferential direction. Is repeated. However, it is not always necessary to provide chamfers and roundness, but it is preferable to provide them.

  Although the shape of the lightening portion 131 has been described as being a quadrangle (equilateral trapezoidal shape), the length of the side A1D1 and the length of the side A2D2 are 0, and the shape of the lightening portion 131 is a triangle (an isosceles triangle). ).

  Here, the area occupancy of the lightening portion 131 with respect to the annular portion 130 is preferably 40% or more from the viewpoint of lubricating oil discharge. On the other hand, from the viewpoint of the stress acting on the beam 132, it is preferable to set it to 65% or less. When it is necessary to ensure the rigidity and strength of the internal gear 100, the area occupancy of the lightening portion 131 with respect to the annular portion 130 may be designed to be 25% or more and less than 40%. Further, when it is necessary to further secure the rigidity and strength of the internal gear, even if the area occupancy of the lightening portion 131 with respect to the annular portion 130 is set to 10% or more and less than 25%, the lubricating oil discharge performance is slightly increased. The effect is obtained.

The internal gear 100 according to the first embodiment is preferably manufactured by the following procedure.
First, a gear blank is made from a column pipe of, for example, carbon steel for machine structure or alloy steel for machine structure. Next, the teeth are formed by, for example, hobbing or gear cutting with a rack cutter or a pinion cutter. Then, a lightening portion 131 is provided in the annular portion 130 using a machine tool. Thereafter, a heat treatment such as nitriding or tempering may be performed. Finally, a finish such as grinding or lapping may be applied to the tooth surface.

(Effects)
According to the internal gear 100 according to the first embodiment configured as described above, the following effects can be obtained.

  The lubricating oil supplied to the internal gear 100 is discharged from the rim 110 to the outside of the internal gear 100, the lubricating oil is discharged from the lightening portion 131 of the annular portion 130, and stays inside the internal gear 100. And what to do. In the case of a conventional internal gear, a hole (for example, a lead hole provided in a ring body in Patent Literature 1) is provided in the annular portion 130, but the area occupation ratio of the hole to the annular portion 130 is 10%. Because it is smaller than the lubricating oil discharged from the rim 110 side, it almost stays inside.

  On the other hand, in the internal gear 100 according to the first embodiment, since the area occupation ratio of the lightening portion 131 is 40% or more, the amount of lubricating oil retained inside the internal gear 100 is greatly reduced, and Emissions are improved. Thus, the amount of heat generated in the internal gear 100 carried away by the lubricating oil increases, and the cooling performance of the internal gear 100 improves. In addition, the lubricating oil that normally stays inside the internal gear 100 generates heat by encircling with the internal gear 100. The internal gear 100 according to the first embodiment improves the dischargeability of the lubricating oil, so that the amount of co-rotation decreases, and heat generation due to stirring of the lubricating oil can be suppressed. By obtaining the above effects, the temperature rise of the internal gear 100 can be suppressed. In particular, the internal gear 100 according to the first embodiment can be suitably used for a planetary gear device for a gas turbine that generates a large amount of heat.

  Further, by forming the lightening portion 131 in the annular portion 130, the rigidity and strength of the internal gear 100 are reduced. On the other hand, in the internal gear 100 according to the first embodiment, the reduction can be suppressed by setting the shape of the lightening portion 131 (in other words, the shape of the beam 132) to the above-described configuration.

  That is, as shown in FIG. 3, when the torque T is applied to the internal gear 100, the load F acting on the annular portion 130 can be decomposed into the load Ft in the bending direction of the beam 132 and the load Fn in the tensile compression direction. In addition, since the load can be supported even in the tension compression direction in which the amount of deflection is smaller than the bending direction, a decrease in the torsional rigidity of the internal gear 100 can be suppressed. In addition, since the inclination direction of the beam 132 with respect to the rotation axis is alternate, a tensile load and a compressive load act alternately, and the directivity of the axial deflection of the annular portion 130 is reduced or reduced, and the axial direction of the internal gear 100 is reduced. Stiffness can also be suppressed.

<< 2nd Embodiment >>
The internal gear 200 according to the second embodiment will be described with reference to FIG. FIG. 4 is a sectional view of the internal gear 200 according to the second embodiment. The internal gear 200 according to the second embodiment can be used for an internal gear 100C included in the planetary gear device 700 of FIG.

  As shown in FIG. 4, the internal gear 200 includes a rim 210 cut inward, a web 220, an annular portion 230 connecting the rim 210 and the web 220, a boss 240 fitted with a rotating shaft, It is provided with. Note that the boss 240 may not be provided. 4 indicates the rotation axis R of the internal gear 200.

  The annular portion 230 is provided with a lightening portion 231 and a beam 232 formed between the lightening portions 231. In other words, the annular portion 230 includes the first annular portion 233 on the rim 210 side, the second annular portion 234 on the web 220 side, the first annular portion 233 and the second annular portion 234. And a beam 232 for connecting the two.

  Here, the internal gear 200 according to the second embodiment differs from the internal gear 100 according to the first embodiment (see FIG. 2) in that the shape of the lightening portion 231 formed in the annular portion 230 is different. I have. In other words, the configuration of the beam 232 is different. Other configurations and manufacturing procedures are the same, and redundant description will be omitted.

  The lightening portion 231 is formed by equipping the first lightening portion 231a, the second lightening portion 231b, the third lightening portion 231c, and the fourth lightening portion 231d at equal intervals in the circumferential direction of the annular portion 230. Are alternately repeated. Further, the beam 232 includes a first beam 232a, a second beam 232b, a third beam 232c, and a fourth beam 232d. In other words, in the circumferential direction of the annular portion 230, the first lightening portion 231a, the first beam 232a, the second lightening portion 231b, the second beam 232b, the third lightening portion 231c, the third beam 232c, The fourth lightening portion 231d and the fourth beam 232d are repeatedly formed in this order.

  The first lightening portion 231a has, on the side of the rim 210, a side extending in the circumferential direction of the annular portion 230 and a side extending in the direction of the rotation axis R. The angle between these two sides is 90 °. It has a shape in which a fillet (rounded corner) is attached to each interior angle of a right triangle. The second lightening portion 231b has, on the side of the rim 210, a side extending in the circumferential direction of the annular portion 230 and a side extending in the direction of the rotation axis R. The angle between these two sides is 90 °. It has a shape in which a fillet (rounded corner) is added to each inner angle of a right triangle, and the first lightening portion 231a is a line with respect to a line extending in the direction of the rotation axis R (the center line of the first beam 232a). It has a symmetrical relationship. The third lightening portion 231c has a side extending in the circumferential direction of the annular portion 230 and a side extending in the direction of the rotation axis R on the side of the web 220, and the angle between these two sides is 90 °. It has a shape in which a fillet (rounded corner) is added to each inner angle of a right triangle, and has a 180 ° rotationally symmetric relationship with the second lightening portion 231b. The fourth lightening portion 231d has, on the side of the rim 210, a side extending in the circumferential direction of the annular portion 230 and a side extending in the direction of the rotation axis R. The angle between these two sides is 90 °. It has a shape in which fillets (rounded corners) are added to each inner angle of the right triangle, and the third lightening portion 231c is a line with respect to a line extending in the direction of the rotation axis R (the center line of the third beam 232c). It has a symmetrical relationship.

  The extending direction (center line) of the first beam 232a is parallel to the rotation axis R. Similarly, the extending direction (center line) of the third beam 232c is parallel to the rotation axis R. On the other hand, the extending direction (center line) of the second beam 232b is not parallel to the rotation axis R, but is formed to be oblique to the rotation axis R. Similarly, the extending direction (center line) of the second beam 232b is not parallel to the rotation axis R, and is formed to be oblique with respect to the rotation axis R. Further, the second beam 232b is provided such that the end on the web 220 (second annular portion 234) side is closer to the first rotation direction r1 than the end on the rim 210 (first annular portion 233) side. On the other hand, in the fourth beam 232d, the end on the side of the web 220 (the second annular portion 234) is in a direction opposite to the first rotational direction r1 than the end on the side of the rim 210 (the first annular portion 233). It is provided on the side in the second rotation direction r2. That is, the beams 232 (232 b, 232 d) that are inclined with respect to the rotation axis R are arranged in the annular portion 230 so that the directions thereof are alternately arranged, and the beams 232 that are parallel to the rotation axis R therebetween. (232a, 232c) are arranged respectively.

  Next, the shape of the lightening portion 231 (beam 232) of the internal gear 200 according to the second embodiment will be further described with reference to FIG. FIG. 5 is a perspective view of the internal gear 200 according to the second embodiment and a diagram for explaining a lightening structure of the annular portion 230.

  In FIG. 5, a plane P is an arbitrary cylindrical surface on the annular portion 230. Point O is the center point of cylindrical surface P. Line L is a normal passing through point O. The point Oq is an arbitrary point on the line L. The plane Q is a plane perpendicular to the line L with the point Oq as the center point.

  The triangle A1B1C1, triangle A2B2C2, triangle A3B3C3, and triangle A4B4C4 on the surface Q are congruent triangles. The triangle A1B1C1 is a right-angled triangle whose side B1C1 is perpendicular to the rotation axis R (see FIG. 4) and whose side A1C1 is parallel to the rotation axis R (see FIG. 4). The triangle A1B1C1 and the triangle A2B2C2 are symmetric with respect to a line parallel to the side A1C1 (side A2C2). The triangles A2B2C2 and A3B3C3 are 180 ° rotationally symmetric. The triangles A3B3C3 and A4B4C4 are symmetric with respect to a line parallel to the side A3C3 (side A4C4).

  The lightening portion 231 (231a, 231b, 231c, 231d) projects a shape in which a vertex of each of the triangles A1B1C1, A2B2C2, A3B3C3 and A4B4C4 on the surface Q is chamfered or rounded (fillet) onto the surface P. Lightening is repeated at regular intervals in the circumferential direction. However, it is not always necessary to provide chamfers and roundness, but it is preferable to provide them.

(Effects)
According to the internal gear 200 according to the second embodiment configured as described above, the following effects can be obtained.

  As with the internal gear 100 according to the first embodiment, the internal gear 200 according to the second embodiment has improved lubricating oil discharge performance and can suppress a decrease in torsional rigidity and axial rigidity. Further, the internal gear 200 according to the second embodiment is provided with the beam 232 (232a, 232c) parallel to the rotation axis R, so that the internal gear 200 is more axially movable than the internal gear 100 according to the first embodiment. The rigidity can be increased.

<< 3rd Embodiment >>
The internal gear 300 according to the third embodiment will be described with reference to FIG. FIG. 6 is a sectional view of the internal gear 300 according to the third embodiment. The internal gear 300 according to the third embodiment can be used for the internal gear 100C provided in the planetary gear device 700 of FIG.

  As shown in FIG. 6, the internal gear 300 includes a rim 310 cut inward, a web 320, an annular portion 330 connecting the rim 310 and the web 320, a boss 340 fitted to the rotating shaft, It is provided with. Note that the boss 340 may not be provided. 6 shows the rotation axis R of the internal gear 300.

  Further, the annular portion 330 is provided with a lightening portion 331 and a beam 332 formed between the lightening portions 331. In other words, the annular portion 330 includes the first annular portion 333 on the rim 310 side, the second annular portion 334 on the web 320 side, the first annular portion 333 and the second annular portion 334. And a beam 332 for connecting the two.

  Here, the internal gear 300 according to the third embodiment differs from the internal gear 100 according to the first embodiment (see FIG. 2) in that the shape of the lightening portion 331 formed in the annular portion 330 is different. I have. In other words, the configuration of the beam 332 is different. Other configurations are the same, and redundant description will be omitted.

  The lightening portion 331 is configured by alternately repeating the first lightening portion 331a and the second lightening portion 331b at equal intervals in the circumferential direction of the annular portion 330. Further, the beam 332 includes a first beam 332a and a second beam 332b. In other words, the first lightening portion 331a, the first beam 332a, the second lightening portion 331b, and the second beam 332b are repeatedly arranged in the circumferential direction of the annular portion 330.

  The first lightening portion 331a has a shape in which three circles having the same diameter are partially overlapped, and is formed so as to form an equilateral triangle when connecting the centers of the circles. Of the three sides of this equilateral triangle, the side on the rim 310 side extends in the circumferential direction of the annular portion 230. The second lightening portion 331b has a 180 ° rotationally symmetric relationship with the first lightening portion 331a.

  The first beam 332a extends so as to be oblique to the rotation axis R. Similarly, the second beam 332b extends obliquely with respect to the rotation axis R. The first beam 332a has a web 320 (second annular portion 334) side end that is closer to the second rotation direction r2 than a rim 310 (first annular portion 333) side end. On the other hand, the end of the second beam 332b on the web 320 (second annular portion 334) side is provided closer to the first rotation direction r1 than the end of the rim 310 (first annular portion 333) side. That is, the beams 332 (332a, 332b) extending obliquely with respect to the rotation axis R are arranged in the annular portion 330 so that the directions thereof are alternated.

  Next, the shape of the lightening portion 331 (beam 332) of the internal gear 300 according to the third embodiment will be further described with reference to FIG. FIG. 7 is a perspective view of the internal gear 300 according to the third embodiment and a diagram illustrating a lightening structure of the annular portion 330.

  In FIG. 7, a plane P is an arbitrary cylindrical surface on the annular portion 330. Point O is the center point of cylindrical surface P. Line L is a normal passing through point O. The point Oq is an arbitrary point on the line L. The plane Q is a plane perpendicular to the line L with the point Oq as the center point.

  Each of the circles A1B1C1 on the surface Q has a portion where (the circle A1 and the circle B1, the circle B1 and the circle C1, and the circle C1 and the circle A1) overlap, and also has a portion where all the (circle A1B1C1) overlap. , A straight line connecting the center of the circle B1 and the center of the circle C1 is perpendicular to the rotation axis R (see FIG. 4). The aggregate of the circles A2B2C2 on the surface Q is an aggregate that is 180 ° rotationally symmetric with the aggregate of the circles A1B1C1 described above.

  The lightening portion 331 (331a, 331b) projects an outer peripheral line formed of an aggregate of the circles A1B1C1 and an aggregate of the circles A2B2C2 on the surface Q onto the surface P, and lightens the outer periphery. At regular intervals.

The internal gear 300 according to the third embodiment is preferably manufactured by the following procedure.
First, a gear blank is made from a column pipe of, for example, carbon steel for machine structure or alloy steel for machine structure. Next, the teeth are formed by, for example, hobbing or gear cutting with a rack cutter or a pinion cutter. Then, a lightening portion 331 is provided in the annular portion 330 by drilling using a tool having the same diameter as the circles A1 and C2. Thereafter, a heat treatment such as nitriding or tempering may be performed. Finally, a finish such as grinding or lapping may be applied to the tooth surface.

(Effects)
According to the internal gear 300 according to the third embodiment configured as described above, the following effects can be obtained.

  The internal gear 300 according to the third embodiment improves the drainage of the lubricating oil and suppresses the reduction in torsional rigidity and axial rigidity, similarly to the internal gear 100 according to the first embodiment. In addition, the internal gear 300 according to the third embodiment can form the lightening portion 331 only by simple drilling, so that the processing cost and processing time are lower than those of the internal gear 100 according to the first embodiment. Can be reduced.

<< 4th Embodiment >>
The internal gear 400 according to the fourth embodiment will be described with reference to FIG. FIG. 8 is a sectional view of the internal gear 400 according to the fourth embodiment. The internal gear 400 according to the fourth embodiment can be used for the internal gear 100C included in the planetary gear device 700 of FIG.

  As shown in FIG. 8, the internal gear 400 includes a rim 410 cut inward, a web 420, an annular portion 430 connecting the rim 410 and the web 420, a boss 440 fitted to the rotating shaft, It is provided with. Note that the boss 440 may not be provided. 8 indicates a rotation axis R of the internal gear 400.

  Further, the annular portion 430 is provided with a lightening portion 431 and a beam 432 formed between the lightening portions 431. In other words, the annular portion 430 includes the first annular portion 433 on the rim 410 side, the second annular portion 434 on the web 420 side, and the first annular portion 433 and the second annular portion 434. And a beam 432 for connecting the two.

  Here, the internal gear 400 according to the fourth embodiment differs from the internal gear 100 according to the first embodiment (see FIG. 2) in that the shape of the lightening portion 431 formed in the annular portion 430 is different. I have. In other words, the configuration of the beam 432 is different. Other configurations and manufacturing procedures are the same, and redundant description will be omitted.

  The lightening portion 431 is configured by alternately repeating the first lightening portion 431a and the second lightening portion 431b at equal intervals in the circumferential direction of the annular portion 430. Further, the beam 432 includes a first beam 432a and a second beam 432b. In other words, in the circumferential direction of the annular portion 430, the first lightening portion 431a, the first beam 432a, the second lightening portion 431b, and the second beam 432b are repeatedly formed in this order.

  The first lightening portion 431a has a shape in which fillets (rounded corners) are attached to the respective inner corners of the trapezoid having a base extending in the circumferential direction of the annular portion 430, and the length of the base on the side of the rim 410 is long. Is longer than the length of the base on the side of the web 420. The second lightening portion 431 b has a shape in which fillets (rounded corners) are attached to the respective inner corners of the trapezoid having the base extending in the circumferential direction of the annular portion 430, and the length of the base on the side of the web 420. Is longer than the length of the base on the side of the rim 410. Here, the first lightening portion 131a and the second lightening portion 131b of the internal gear 100 according to the first embodiment have a 180 ° rotationally symmetric relationship, whereas the inner lightening portion according to the fourth embodiment. The first lightening portion 431a and the second lightening portion 431b of the gear 400 have different shapes.

  The extending direction (center line) of the first beam 432a is not parallel to the rotation axis R and is formed to be oblique to the rotation axis R. Similarly, the extending direction (center line) of the second beam 432b is not parallel to the rotation axis R but is formed to be oblique to the rotation axis R. Further, the first beam 432a is provided such that an end on the web 420 (second annular portion 434) side is closer to the first rotation direction r1 than an end on the rim 410 (first annular portion 433) side. On the other hand, the end of the second beam 432b on the web 420 (second annular portion 434) side is provided closer to the second rotational direction r2 than the end of the rim 410 (first annular portion 433). That is, the beams 432 (432 a, 432 b) that are oblique to the rotation axis R are arranged in the annular portion 430 so that the directions thereof are alternated. Note that the thickness of the beam 432 (432 a, 432 b) is not constant, but becomes larger or thinner in the direction of the rotation axis R.

  Next, the shape of the lightening portion 431 (beam 432) of the internal gear 400 according to the fourth embodiment will be further described with reference to FIG. FIG. 9 is a perspective view of the internal gear 400 according to the fourth embodiment and a diagram illustrating a lightening structure of the annular portion 430.

  In FIG. 9, a plane P is an arbitrary cylindrical surface on the annular portion 430. Point O is the center point of cylindrical surface P. Line L is a normal passing through point O. The point Oq is an arbitrary point on the line L. The plane Q is a plane perpendicular to the line L with the point Oq as the center point.

  The square A1B1C1D1 on the surface Q is a trapezoid (equilateral trapezoid) whose base A1D1 is perpendicular to the rotation axis R (see FIG. 8) and is line-symmetric with respect to a line passing through the midpoint of the base. The square A2B2C2D2 on the surface Q is a trapezoid (equilateral trapezoid) whose base A2D2 is perpendicular to the rotation axis R (see FIG. 8) and is line-symmetric with respect to a line passing through the midpoint of the base. Further, the square A1B1C1D1 has a long base on the side of the rim 410, and the square A2B2C2D2 has a long base on the side of the web 420.

  Note that the sides C1D1 and C2D2 on the surface Q are not parallel, and the sides A1B1 and A2B2 on the surface Q are not parallel.

  The lightening portions 431 (431a, 431b) project the shape in which the vertices of the squares A1B1C1D1 and A2B2C2D2 on the surface Q are chamfered or rounded (fillet) onto the surface P, and lighten the shape, and are equally spaced in the circumferential direction. Is repeated. However, it is not always necessary to provide chamfers and roundness, but it is preferable to provide them.

(Effects)
According to the internal gear 400 according to the fourth embodiment configured as described above, the following effects can be obtained.

  The internal gear 400 according to the fourth embodiment improves the drainage of lubricating oil and suppresses a decrease in torsional rigidity, similarly to the internal gear 100 according to the first embodiment. Further, the internal gear 400 according to the fourth embodiment changes the thickness of the beam 432 (432a, 432b) along the rotation axis R, and adjusts the amount of change to provide rigidity in the radial direction (translational direction). Can be adjusted.

<< 5th Embodiment >>
An internal gear 500 according to a fifth embodiment will be described with reference to FIG. FIG. 10 is a cross-sectional view of the internal gear 500 according to the fifth embodiment. The internal gear 500 according to the fifth embodiment can be used for the internal gear 100C included in the planetary gear device 700 of FIG.

  As shown in FIG. 10, the internal gear 500 includes a rim 510 cut inward, a web 520, an annular portion 530 connecting the rim 510 and the web 520, a boss 540 fitted to the rotating shaft, It is provided with. Note that the boss 540 may not be provided. 10 indicates the rotation axis R of the internal gear 500.

  The annular portion 530 is provided with a lightening portion 531 and a beam 532 formed between the lightening portions 531. In other words, the annular portion 530 includes a first annular portion 533 on the side of the rim 510, a second annular portion 534 on the side of the web 520, a third annular portion 535 therebetween, and a first annular portion. A portion 533 is connected to the third annular portion 535, and a beam 532 is connected to connect the third annular portion 535 and the second annular portion 534.

  Here, the internal gear 500 according to the fifth embodiment differs from the internal gear 100 according to the first embodiment (see FIG. 2) in that the shape of the lightening portion 531 formed in the annular portion 530 is different. I have. In other words, the configuration of the beam 532 is different. Other configurations are the same, and redundant description will be omitted.

  The lightening portion 531 connects the first lightening portion 531a and the second lightening portion 531b on the side of the rim 510 (between the first annular portion 533 and the third annular portion 535). Are alternately repeated in the circumferential direction at equal intervals, and on the side of the web 520 (between the third annular portion 535 and the second annular portion 534), the third lightening portion 531c and the fourth lightening portion 531d are provided. And are alternately repeated at regular intervals in the circumferential direction of the annular portion 530. The beam 532 includes a first beam 532a, a second beam 532b, a third beam 532c, and a fourth beam 532d. In other words, on the rim 510 side (between the first annular portion 533 and the third annular portion 535), in the circumferential direction of the annular portion 530, the first lightening portion 531a, the first beam 532a, The second lightening portion 531b and the second beam 532b are repeated in this order, and the third lightening portion 531c and the third beam 532c are provided on the web 520 side (between the third annular portion 535 and the second annular portion 534). , A fourth lightening portion 531d and a fourth beam 532d in this order.

  The first lightening portion 531a has a shape in which a fillet (rounded corner) is attached to each inner corner of a triangle having a base whose bottom side extends in the circumferential direction of the annular portion 530. The second lightening portion 531b has a 180 ° rotationally symmetric relationship with the first lightening portion 531a.

  The third lightening portion 531c has a 180 ° rotationally symmetric relationship with the first lightening portion 531a. Alternatively, the third lightening portion 531c has a line-symmetric relationship with the first lightening portion 531a and a line (center line of the third annular portion 535) extending in the direction of the rotation axis R. The fourth lightening portion 531d has a 180 ° rotationally symmetric relationship with the third lightening portion 531c.

  The extending direction (center line) of the first beam 532a is not parallel to the rotation axis R, but is formed to be oblique to the rotation axis R. Similarly, the extending direction (center line) of the second beam 532b is not parallel to the rotation axis R but is formed to be oblique to the rotation axis R. The first beam 532a has a web 520 (second annular portion 534) -side end provided closer to the first rotation direction r1 than a rim 510 (first annular portion 533) -side end. On the other hand, the end of the second beam 532b on the side of the web 520 (second annular portion 534) is provided closer to the second rotational direction r2 than the end of the rim 510 (first annular portion 533). That is, in the annular portion 530, the beams 532 (532a, 532b) that are inclined with respect to the rotation axis R are arranged so that their directions are alternated. Similarly, in the annular portion 530, beams 532 (532c, 532d) that are oblique to the rotation axis R are arranged so that their directions are alternated.

  Next, the shape of the lightening portion 531 (beam 532) of the internal gear 500 according to the fifth embodiment will be further described with reference to FIG. FIG. 11 is a perspective view of the internal gear 500 according to the fifth embodiment and a diagram illustrating a lightening structure of the annular portion 530.

  11, the plane P is an arbitrary cylindrical surface on the annular portion 530. Point O is the center point of cylindrical surface P. Line L is a normal passing through point O. The point Oq is an arbitrary point on the line L. The plane Q is a plane perpendicular to the line L with the point Oq as the center point.

    The triangle A1B1C1, triangle A2B2C2, triangle A3B3C3, and triangle A4B4C4 on the surface Q are congruent triangles. The triangle A1B1C1 is a triangle (an isosceles triangle or an equilateral triangle) whose base B1C1 is perpendicular to the rotation axis R (see FIG. 10) and is line-symmetric with respect to a line passing through the midpoint of the base. The triangles A1B1C1 and A2B2C2 are 180 ° rotationally symmetric, and the sides A1C1 and A2C2 are parallel.

  The triangle A3B3C3 is a triangle (an isosceles triangle or an equilateral triangle) whose base B3C3 is perpendicular to the rotation axis R (see FIG. 10) and is line-symmetric with respect to a line passing through the midpoint of the base. Is symmetrical about a line perpendicular to the rotation axis R. The triangles A3B3C3 and A4B4C4 are 180 ° rotationally symmetric, and the sides A3C3 and A4C4 are parallel. That is, the triangles A1B1C1 and A2B2C2 and the triangles A3B3C3 and A4B4C4 have a line-symmetric relationship with respect to a line perpendicular to the rotation axis R.

  The lightening portions 531 (531a, 531b, 531c, 531d) project a shape having chamfers or roundings (fillets) at the vertices of the triangles A1B1C1, A2B2C2, A3B3C3, and A4B4C4 on the surface Q onto the surface P. Lightening is repeated at regular intervals in the circumferential direction. However, it is not always necessary to provide chamfers and roundness, but it is preferable to provide them.

(Effects)
According to the internal gear 500 according to the fifth embodiment configured as described above, the following effects can be obtained.

  The internal gear 500 according to the fifth embodiment has improved lubricating oil discharge performance, as in the internal gear 100 according to the first embodiment, and the direction of the beam 532 is alternately inclined with respect to the rotation axis R. As a result, reductions in torsional rigidity and axial rigidity can be suppressed. Further, the internal gear 500 according to the fifth embodiment requires a processing cost and a processing time as compared with the internal gear 100 according to the first embodiment, but the length of the beam 532 can be shortened, so that the rigidity is improved. Can be increased.

<< 6th Embodiment >>
An internal gear 600 according to the sixth embodiment will be described with reference to FIG. FIG. 12 is a cross-sectional view of the internal gear 600 according to the sixth embodiment. The internal gear 600 according to the sixth embodiment can be used for the internal gear 100C provided in the planetary gear device 700 of FIG.

  As shown in FIG. 12, the internal gear 600 includes a rim 610 cut inward, a web 620, an annular portion 630 connecting the rim 610 and the web 620, a boss 640 fitted to the rotating shaft, It is provided with. Note that the boss 640 may not be provided. 12 indicates the rotation axis R of the internal gear 600.

  Further, the annular portion 630 is provided with a lightening portion 631 and a beam 632 formed between the lightening portions 631. In other words, the annular portion 630 includes the first annular portion 633 on the side of the rim 610, the second annular portion 634 on the side of the web 620, the first annular portion 633, and the second annular portion 634. And a beam 632 for connecting the two.

  Here, the internal gear 600 according to the sixth embodiment differs from the internal gear 100 according to the first embodiment (see FIG. 2) in that the shape of the lightening portion 631 formed in the annular portion 630 is different. I have. In other words, the configuration of the beam 632 is different. Other configurations and manufacturing procedures are the same, and redundant description will be omitted.

  The lightening portions 631 are alternately and repeatedly formed at equal intervals in the circumferential direction of the annular portion 630. In other words, in the circumferential direction of the annular portion 630, the lightening portion 631 and the beam 632 are repeatedly formed in this order.

  The lightening portion 631 has a shape in which a fillet (rounded corner) is attached to each inner corner of a rectangle whose base is inclined by a certain angle from the circumferential direction of the annular portion 630.

  The extending direction (center line) of the beam 632 is not parallel to the rotation axis R, but is formed to be oblique to the rotation axis R. The beam 632a has an end on the web 620 (second annular portion 634) side closer to the first rotation direction r1 than an end on the rim 610 (first annular portion 633) side.

  Next, the shape of the lightening portion 631 (beam 632) of the internal gear 600 according to the sixth embodiment will be further described with reference to FIG. FIG. 13 is a perspective view of the internal gear 600 according to the sixth embodiment and a diagram illustrating a lightening structure of the annular portion 630.

  In FIG. 13, a plane P is an arbitrary cylindrical surface on the annular portion 630. Point O is the center point of cylindrical surface P. Line L is a normal passing through point O. The point Oq is an arbitrary point on the line L. The plane Q is a plane perpendicular to the line L with the point Oq as the center point.

  The square ABCD on the surface Q is a rectangle whose base AD is inclined from the rotation axis R (see FIG. 12).

  The lightening portion 631 is formed by projecting a shape in which each vertex of the square ABCD on the surface Q is chamfered or rounded (fillet) onto the surface P, lightening the surface, and repeating the same at equal intervals in the circumferential direction. However, it is not always necessary to provide chamfers and roundness, but it is preferable to provide them.

(Effects)
According to the internal gear 600 according to the sixth embodiment configured as described above, the following effects can be obtained.

  The internal gear 600 according to the sixth embodiment can improve the dischargeability of lubricating oil and suppress the decrease in torsional rigidity, similarly to the internal gear 100 according to the first embodiment. Further, the internal gear 600 according to the sixth embodiment can form the lightening portion 631 only by simple processing, so that the processing cost and processing time are reduced as compared with the internal gear 100 according to the first embodiment. Can be reduced.

≪Modified example≫
The internal gears 100 to 600 and the planetary gear device including the internal gears 100 to 600 according to the present embodiment are not limited to the configuration of the above-described embodiment, and various modifications may be made without departing from the spirit of the invention. Is possible.

  Although the internal gear 200 according to the second embodiment has been described as being formed with the lightening portion 231 in triangular units, the present invention is not limited to this, and the lightening portion 231 may be formed in quadrilateral (rectangular trapezoidal) units. It may be formed.

  In the internal gear 500 according to the fifth embodiment, the lightening portion 531 is formed in units of triangles. However, the present invention is not limited to this, and the lightening portion 231 is formed in units of squares (trapezoids). It may be.

  In the internal gear 600 according to the sixth embodiment, the lightening portion 631 is formed in rectangular units. However, the present invention is not limited to this. The lightening portion 631 is formed in quadrangular (trapezoidal) units. It may be.

  The beam 632a that extends obliquely with respect to the rotation axis R has a web 620 (second annular portion 634) side end that is closer to the rim 610 (first annular portion 633) side end in the first rotational direction r1. However, the present invention is not limited to this, and the end of the web 620 (the second annular portion 634) is closer to the end of the rim 610 (the first annular portion 633). It may be provided on the side of the second rotation direction r2.

  The internal gear 200 according to the second embodiment and the internal gear 500 according to the fifth embodiment have been described as having a constant beam thickness. However, the present invention is not limited to this. The configuration of the internal gear 400 may be combined so as to change the thickness of the beam.

100, 200, 300, 400, 500, 600 Internal gear 110, 210, 310, 410, 510, 610 Rim 120, 220, 320, 420, 520, 620 Web 130, 230, 330, 430, 530, 630 Ring Parts 131, 231, 331, 431, 531, 631 Lightening parts 131a, 231a, 331a, 431a, 531a First lightening parts 131b, 231b, 331b, 431b, 531b Second lightening parts 231c, 531c Third lightening Part 231d, 531d Fourth lightening part 132, 232, 332, 432, 532, 632 Beam (beam part)
132a, 232a, 332a, 432a, 532a First beam 132b, 232b, 332b, 432b, 532b Second beam 232c, 532c Third beam 232d, 532d Fourth beam 133, 233, 333, 433, 533, 633 First circle Rings 134, 234, 334, 434, 534, 634 Second ring 535 Third ring 140, 240, 340, 440, 540, 640 Boss R Rotation axis r1, r2 Rotation

Claims (12)

A toothed rim, a web, and an annular portion connecting the rim and the web;
The annular portion has a lightening portion,
The lightening portion,
Any point on the normal passing through the center point of any cylindrical surface on the annular portion as a center point on a plane perpendicular to the normal,
A trapezoid whose base is perpendicular to the rotation axis and symmetrical with respect to a line passing through the midpoint of the base,
A trapezoid that is 180 ° rotationally symmetric with the trapezoid,
Internal gear you characterized by shapes projected onto the annular portion is a shape equally spaced in the circumferential direction. A toothed rim, a web, and an annular portion connecting the rim and the web;
The annular portion has a lightening portion,
The lightening portion,
Any point on the normal passing through the center point of any cylindrical surface on the annular portion as a center point on a plane perpendicular to the normal,
A first triangle whose base is a right-angled triangle perpendicular to the rotation axis;
A second triangle that is a right-angled triangle that is line-symmetric with respect to a side that is orthogonal to the base of the first triangle;
A third triangle that is a right-angled triangle that is line-symmetric with respect to a side that does not form a right angle of the first triangle;
The fourth triangle, which is a right-angled triangle that is line-symmetric with respect to the side perpendicular to the base of the third triangle, is a shape in which figures obtained by projecting the annular portion are arranged at equal intervals in the circumferential direction. the internal gear shall be the. A toothed rim, a web, and an annular portion connecting the rim and the web;
The annular portion has a lightening portion,
The lightening portion,
Any point on the normal passing through the center point of any cylindrical surface on the annular portion as a center point on a plane perpendicular to the normal,
A set of three circles, each of which has an overlapping portion, and a line connecting the two center points is perpendicular to the rotation axis;
The aggregate, a 180-degree rotationally symmetric aggregate,
Internal gear you characterized by shapes projected onto the annular portion is a shape equally spaced in the circumferential direction. A toothed rim, a web, and an annular portion connecting the rim and the web;
The annular portion has a lightening portion,
The lightening portion,
Any point on the normal passing through the center point of any cylindrical surface on the annular portion as a center point on a plane perpendicular to the normal,
A trapezoid whose base is perpendicular to the rotation axis and whose long base is on the side of the web;
A trapezoid whose base is perpendicular to the rotation axis and whose long base is on the side of the rim;
Internal gear you characterized by shapes projected onto the annular portion is a shape equally spaced in the circumferential direction. A toothed rim, a web, and an annular portion connecting the rim and the web;
The annular portion has a lightening portion,
The lightening portion,
Any point on the normal passing through the center point of any cylindrical surface on the annular portion as a center point on a plane perpendicular to the normal,
A first triangle whose base is an isosceles triangle perpendicular to the rotation axis;
A second triangle that is an isosceles triangle that is line-symmetric with respect to a side that is not the base of the first triangle;
A third triangle and a fourth triangle, which are isosceles triangles that are symmetrical about the first triangle and the second triangle with respect to a line perpendicular to a rotation axis;
Internal gear you characterized by shapes projected onto the annular portion is a shape equally spaced in the circumferential direction. A toothed rim, a web, and an annular portion connecting the rim and the web;
The annular portion has a lightening portion,
The lightening portion,
Any point on the normal passing through the center point of any cylindrical surface on the annular portion as a center point on a plane perpendicular to the normal,
Internal gear base has you characterized by a figure obtained by projecting a rectangular inclined from the rotation axis, the said annular portion is a shape arranged at equal intervals in the circumferential direction. A toothed rim, a web, and an annular portion connecting the rim and the web;
The annular portion has a lightening portion,
Internal gear you wherein the area occupancy rate for the annular portion of the lightening portion is 10% or more. A toothed rim, a web, and an annular portion connecting the rim and the web;
The annular portion has a lightening portion,
Internal gear you wherein the area occupancy rate for the annular portion of the lightening portion is 25% or more. A toothed rim, a web, and an annular portion connecting the rim and the web;
The annular portion has a lightening portion,
Internal gear you wherein the area occupancy rate for the annular portion of the lightening portion is 40% or more. A toothed rim, a web, and an annular portion connecting the rim and the web;
The annular portion, a plurality of lightening portions provided in the circumferential direction,
The beam part is
A first beam portion inclined with respect to the rotation axis, and a second beam portion inclined with respect to the rotation axis in a direction opposite to the first beam portion,
An internal gear, wherein a first beam portion and the second beam portion are arranged alternately. Any one of claims 1 to 6, characterized by further comprising a boss to be fitted with said rotary shaft, or the internal gear of claim 10.   A planetary gear device comprising the internal gear according to any one of claims 1 to 11.

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