JP6632866B2 - Gear device - Google Patents

Description

  The present invention relates to a gear device, and more particularly to a gear device suitable for a gear device for a moving object such as an aircraft, an automobile, or an industrial vehicle, in which the diameter of the gear is larger than the shaft diameter.

  For example, in a traveling transmission for industrial vehicles, as shown in FIG. 1, the rotational speed of the engine is reduced by the transmission and transmitted to the axle. A general transmission for industrial vehicles will be described with reference to FIG.

  As shown in the figure, output shafts 2 and 3 connected to an axle are driven to rotate by an engine 4, and a parallel shaft gear device 1 is installed between the two.

  In such a configuration, when the output shaft 2 is rotationally driven and the vehicle moves forward, the rotational driving force is transmitted as follows. That is, for example, when the engine 4 rotates, the input shaft 5 is driven to rotate. By bringing the clutch 6 into the connected state, the gear 7A, the gear 8A, and the output shaft 2 are driven to rotate in this order.

  Next, when the output shaft 3 is rotationally driven and the vehicle moves forward, the rotational driving force is transmitted as follows. That is, for example, when the engine 4 rotates, the input shaft 5 is driven to rotate. By bringing the clutch 6 into the connected state, the gear 7A, the gear 9A, and the output shaft 3 are driven to rotate in this order.

  When the vehicle moves backward, the rotational driving force is transmitted as follows. That is, when the engine 4 rotates, the input shaft 5 is driven to rotate. By bringing the clutch 6 into the connected state, the gear 7C, the gear 10, the gear 8C, and the output shaft 2 are driven to rotate in this order.

  The gear group used in the gear device 1 is required to have high torsional rigidity in order to suppress a decrease in torsional natural frequency. On the other hand, there is a need to reduce the weight of the components of the gear device 1 by reducing the thickness for the purpose of improving fuel efficiency. However, in general, a lightweight hollow gear has low torsional rigidity.

  For such a problem, for example, there is a technique described in Patent Document 1. In this patent document 1, a gear having a beam configured to be inclined in a direction opposite to the rotation direction of the gear is used for a web connecting both a rim having teeth and a boss fitted to a shaft. It describes that it is possible to produce a lightened gear that maintains torsional rigidity.

JP 2004-360923 A

  However, the lightening gear described in Patent Document 1 is a resin gear used for a copying machine and the like, which is integrally formed by injection molding. Since it is made of steel and has a large gear diameter and tooth width, a rim having teeth, a web provided with a hollow portion, and a boss fitted to a shaft are integrally processed to produce a hollow gear that maintains torsional rigidity. It is difficult to create.

  The present invention has been made in view of the above points, and an object thereof is, for example, a gear device for a moving body that includes a gear having a larger diameter than a shaft diameter in a gear device for a moving body. Another object of the present invention is to provide a gear device capable of easily manufacturing a web provided with a hollow portion while maintaining torsional rigidity.

In order to achieve the above object, the gear device of the present invention includes a rim made of a steel alloy material for machine structure or a carbon steel material for machine structure having a plurality of teeth all around, and a circular plate material. A plurality of webs made of alloy steel for machine structure or carbon steel for machine structure to be fixed, and a boss made of alloy steel for machine structure or carbon steel for machine structure connecting the web and the shaft. In the web, a plurality of lightening portions are formed, and in a plane perpendicular to the axis of the gear, a beam formed between adjacent lightening portions is formed from an arbitrary point P on a circle on the outer circumference of the web. Of the tangents drawn to the circle on the inner circumference of the web, a line group in which a straight line in which the angle α formed between the point P as a starting point and the speed vector v at the time of forward rotation of the gear becomes an obtuse angle is arranged in the web, It is characterized by becoming.

  According to the present invention, for example, in a gear device for a moving body, even a gear device having a gear diameter larger than the shaft diameter, a web provided with a hollow portion while maintaining torsional rigidity. Can be easily obtained.

It is a schematic structure figure showing the gear device for general mobiles. 1 is an exploded perspective view showing a minimum required configuration of a first embodiment of a gear device according to the present invention. It is a figure for explaining a web shape in Example 1 of a gear device of the present invention. FIG. 4 is an explanatory diagram for calculating a deflection of a web in which a beam is inclined in Embodiment 1 of the gear device of the present invention. FIG. 4 is an explanatory diagram for calculating a deflection of a web in which a beam is not inclined in Embodiment 1 of the gear device of the present invention. It is explanatory drawing which shows the calculation example of the bending of the web in Example 1 of the gear device of this invention. FIG. 3 is an explanatory diagram for defining a width of a beam forming a web in the first embodiment of the gear device of the present invention. It is a figure for explaining a web shape in Example 2 of a gear device of the present invention. It is an exploded perspective view showing Example 3 of the gear device of the present invention. FIG. 9 is an axial cross-sectional view illustrating a gear device according to a third embodiment of the present invention. FIG. 13 is an exploded perspective view showing another example of the gear device according to the third embodiment of the present invention. FIG. 13 is an exploded perspective view showing still another example of Embodiment 3 of the gear device of the present invention. FIG. 13 is an exploded perspective view showing still another example of Embodiment 3 of the gear device of the present invention. It is an axial sectional view showing Example 4 of a gear device of the present invention. It is an axial sectional view showing Example 5 of a gear device of the present invention. It is an axial sectional view showing Example 6 of a gear device of the present invention. It is an axial sectional view showing Example 7 of a gear device of the present invention.

  Hereinafter, a gear device of the present invention will be described based on the illustrated embodiment. In each embodiment, the same reference numerals are used for the same components.

  2 and 3 show a gear device according to a first embodiment of the present invention.

  As shown in FIG. 2, the gear device of the present embodiment includes a rim 14 having a plurality of teeth 14a all around and a web 15A. The web 15A is a circular plate made of, for example, an alloy steel material for a machine structure such as an SCM material or a carbon steel material for a machine structure such as an SC material, and is cut out as shown in FIG.

  That is, the web 15A is a point tangent of any point P on an inner circle 17 of the web 15A from an arbitrary point P on the outer circle 16 of the web 15A shown in FIG. Lightening portions 19 and 20 are formed such that a line having an obtuse angle α with the speed vector v at the time of forward rotation of the gear starting from P includes a beam 15A1 having a skeleton formed by a straight line 18 arranged in the web 15A. Is formed.

  As described above, since the beam 15A1 of the web 15A of the present embodiment is inclined in the rotation direction, it can support a tensile load.

  The conditions under which the support of the beam 15A1 by the tensile load is effective can be shown by calculation of the material dynamics. This will be described below with reference to FIGS.

First, the bending of the web 15A in which the beam 15A1 is inclined is calculated using FIG. Consider _one line P ₁ S ₁ of a group of lines serving as a skeleton of the beam 15A1 constituting the web 15A. Tangential load _{F t} and the normal direction load _{F n} is applied deflection beam 15A1 to the point _{P 1,} the point _{P 1} is moved to the point _{Q 1,} the web 15A deflects angle theta _1. Relationship such as the number 1 in the tangential direction load F _t and the normal direction load F _n.

Here, α is the pressure angle of the gear. At this time decomposes the tangential load F _t and the normal direction load F _n to bending load of tensile load and η direction ξ direction, the angle theta ₁ is assumed to be small, it is possible to calculate the angle theta ₁ . When the strain ξ direction is _ε ξ1, ε ξ1 is expressed as Expression 2.

Where φ is ΔO ₁ P ₁ S ₁ defined by Equation 3, E is the Young's modulus of the plate used for the web 15A, b is the thickness of the beam 15A1, and t is the thickness of the plate used for the web 15A.

r is the radius of the circle 17 on the inner circumference of the web 15A, and R is the radius of the circle 16 on the outer circumference of the web 15A. Since the strain ε _{ξ1 in the} ξ direction has a relationship represented by _Expression 4 with the displacement δ _ξ1 (| Q ₁ T ₁ |), the displacement δ _ξ1 is represented by _Expression 5.

On the other hand, the displacement δ _η1 (| T ₁ P ₁ |) in the η direction is expressed as in _Expression 6.

and ξ direction of displacement [delta] _.xi.1, combined displacement of η direction displacement _{δ η1 δ 1 (| Q 1} P 1 |) is expressed as Equation 7. Further, since the angle θ ₁ is very small, the angle θ ₁ is expressed as in Expression 8.

Next, the bending of the web 15A in which the beam 15A1 is not inclined is calculated using FIG. Consider one line P ₂ S ₂ of a group of lines serving as a skeleton of the beam 15A1 constituting the web 15A. Tangential load _{F t} and the normal direction load _{F n} is Hari applied 15A1 deflection point _{P 2,} the point _{P 2} is moved to the point _{Q 2,} the web 15A deflects angle theta _2. In this case, the displacement δ _{ξ2 in the} ξ direction is represented by _Expression 9.

On the other hand, the displacement δ _{η2 in the} η direction is expressed as in _Expression 10.

Since the angle theta ₂ is very small, the angle theta ₂ to the ξ direction of displacement [delta] _{[xi] 2,} is expressed as the number 11 with a combined displacement [delta] ₂ of the η direction displacement [delta] _.eta.2.

FIG. 6 shows a calculation example of the angles θ ₁ and θ ₂ obtained by the above formula. The angle when the inclination φ of the beam is 0 is θ ₂ , and the angle at other φ is θ ₁ . From the figure, θ ₁ is smaller than θ ₂ , so the present invention is effective.

  The web structure in which the beam 15A1 supports a tensile load as in this embodiment is particularly effective when the length L of the beam 15A1 is extremely large as compared with the thickness b. This will be described below with reference to FIG.

  FIG. 7 is an explanatory diagram that defines the width of the beam 15A1 constituting the web 15A of FIG.

  In FIG. 2, when the thickness of the web 15A is t and the thickness is b, when the thickness b of the web 15A is larger than the thickness t and the beam cross section is rectangular, the secondary radius k of the cross section of the beam 15A1 is , 12

Here, the effect of the slenderness ratio L / k, which is an index of the ease of buckling of the beam 15A1, on the yield stress σ _Y and the buckling limit stress σ _cr of the plate used for the web 15A will be considered. The yield stress σ _Y takes a constant value with respect to the slenderness ratio L / k.

On the other hand, the buckling limit stress σ _cr is a stress defined by Expression 17, and when a stress larger than the buckling limit stress σ _cr is applied to the beam 15A1, the beam 15A1 buckles.

As shown in FIG. 7, in a region where the slenderness ratio L / k is large, the buckling limit stress σ _cr takes a smaller value than the yield stress σ _Y, and therefore, the tensile strength is smaller than the structure in which a compressive load is applied to the beam 15A1. A structure in which a load is applied shows higher strength.

  It is particularly effective to provide a web 15A such that the beam 15A1 supports a tensile load on a gear having an extremely large slenderness ratio L / k in a gear group of a gear device for a moving body, as in this embodiment. is there.

  According to the present embodiment, a web provided with a hollow portion can be easily manufactured while maintaining torsional rigidity even with a gear having a gear diameter larger than the shaft diameter. And a gear device capable of doing so.

  FIG. 8 shows another example of the web shape as Embodiment 2 of the gear device of the present invention.

  The web 15B of the present embodiment shown in the figure is a projection of a point P on the circle 21 on the outer circumference of the web 15B and a point S on the circle 22 on the inner circumference of the web 15B shown in FIG. Lightening portions 24 and 25 are provided so as to include a beam 15B1 having a non-straight line (a curved surface, a non-straight line partially including a straight line) 23 as a skeleton. 23, the angle β formed by the line OP lowered from the shaft center O to the point P and the speed vector v at the time of forward rotation of the gear starting from the point P is the line drawn from the shaft center O to the point S and the speed vector v Is smaller than the angle γ formed by

  In other words, assuming that the rotation direction of the web 15B is positive, the line OP lowered from the point P, which is the intersection of the non-linear line 23 serving as the skeleton of the beam 15B1 and the circle on the outer periphery of the web 15B, to the axial center O is the reference. The angle β formed by the line I may be larger than the angle γ formed by the line OS lowered from the intersection S of the non-linear line 23 and the inner circumferential circle of the web 15B to the axis center O and the reference line I.

  Even with such a gear device having the web shape of the present embodiment, the same effect as that of the first embodiment can be obtained.

  Next, various gear units derived from the gear units described in the first and second embodiments will be described below.

  9 and 10 show a gear device according to a third embodiment of the present invention.

  As shown in FIGS. 9 and 10, the gear device 30 of this embodiment includes a rim 31 having a plurality of teeth 31 a all around, two upper and lower webs 32 and 33, and a boss 34. The rim 31 having a plurality of teeth 31a around the entire circumference is a member made of, for example, an alloy steel material for a machine structure such as an SCM material or a carbon steel material for a machine structure such as an SC material. For example, the teeth are cut into involute teeth.

  On the other hand, the webs 32 and 33 are circular plates made of, for example, an alloy steel material for a machine structure such as an SCM material or a carbon steel material for a machine structure such as an SC material. Each of the beams 32A1 and 33A1 having the skeleton 18 is provided, and the upper portion of the web 32 and the lower portion of the web 33 are provided so that the lightening portions 19 and 20 have the same position as the same position. I have.

  However, the webs 32 and 33 adjust the number and the assembly phase according to the torsional rigidity required of the gear device 30. For example, as shown in FIG. 11, five webs 32, 33, 35, 36 and 37 are formed. The gear device 30 may be provided, or may be a gear device 30 in which the phases of the web 32 and the web 33 are different as shown in FIG. That is, the gear device 30 may be configured such that the lightening portions 19 and 20 are located at different positions between the upper web 32 and the lower web 33.

  When the gear device 30 rotates in both directions, a plurality of webs may be provided upside down. For example, as shown in FIG. 13, one of the three webs 32, 38 and 33 may be provided with one web 38 located at the center upside down with the other two webs 32 and 33.

  Further, ribs (not shown) or the like may be provided between the rim 31 and the webs 32, 33, 35, 36, 37, and 38 for the purpose of securing the strength in the axial direction. The boss 34 is a member made of, for example, an alloy steel material for a machine structure such as an SCM material or a carbon steel material for a machine structure such as an SC material.

  When the gear device 30 rotates in the forward direction, the beams 32A1, 33A1, 35A1, 36A1, 37A1, and 38A1 having the straight line 18 as a skeleton support a tensile load and exhibit high torsional rigidity. When the gear device 30 rotates in the reverse direction, the plurality of beams 38A1 of the web 38 provided upside down as shown in FIG. 12 support the tensile load.

  The gear device 30 shown in FIG. 9 is manufactured, for example, by the following procedure. First, a gear blank of the rim 31 having teeth is manufactured from a pillar material as a raw material. In addition, the bosses 34 are manufactured from column members having different diameters. Then, for example, the circular plate material is cut out by cutting or wire electric discharge machining to produce webs 32 and 33.

  As shown in FIG. 10, the rim 31 and the webs 32 and 33, and the webs 32 and 33 and the boss 34 are fillet or re-welded, and in the cooling process after welding, martensite formation is performed in order to suppress cracking. It is desirable to use a marquenche which is rapidly cooled to a temperature and air-cooled after the temperature distribution is made uniform, or a martemper which is rapidly cooled to just below a martensite formation temperature and maintained at a constant temperature thereafter. After that, refining or annealing is performed to recover the mechanical properties of the welds deteriorated by welding and to remove residual stress. Alternatively, for example, the rim and the web may be fastened by shrink fitting or cold fitting. Further, for example, the bolts may be fastened by bolts. Next, for example, teeth are formed by hobbing, rack cutting, pinion cutting, or the like, and heat treatment such as induction hardening, carburizing, nitriding, or carbonitriding is performed. Finally, for example, a finishing process such as grinding or lapping may be performed on the tooth surface.

  Even with such a configuration of the present embodiment, the same effect as that of the first embodiment can be obtained.

  FIG. 14 shows a gear device according to a fourth embodiment of the present invention.

  The gear device 40 of the present embodiment shown in FIG. 14 includes a rim 31 having a plurality of teeth 31a all around, two upper and lower webs 41 and 42, and a boss 34. Eight beams 41A1 and 42A1 each having the same straight line 18 as the skeleton as in the first embodiment are provided.

  Even with such a configuration of this embodiment, the same effect as that of the first embodiment can be obtained, and the number of beams may be adjusted according to the radial strength required of the gear device 40.

  FIG. 15 shows a fifth embodiment of the gear device of the present invention.

  The gear device 50 of the present embodiment shown in FIG. 15 includes a rim 31 having a plurality of teeth 31a all around, two upper and lower webs 51 and 52, and a boss 34. Each of the beams 51A1 and 52A1 has six beams 51A1 and 52A1 each having the same straight line 18 as the skeleton, but the shape of the lightening portion is different from the lightening portions 19 and 20 of the first example. ing.

  That is, the lightening portions 19a and 20a of the webs 51 and 52 of the present embodiment are different from the lightening portions 19 and 20 of the first embodiment in that the shapes of the lightening portions 19 and 20 are a combination of linear portions, whereas the curved portions or R The adjustment (chamfering) processing part and the straight part are combined.

  Even with such a configuration of the present embodiment, the same effects as those of the first embodiment can be obtained. Of course, if the webs 51 and 52 are provided with the straight lines 18 as the skeleton, the webs 51 and 52 can be thinned. The shape of the part does not matter.

  FIG. 16 shows a gear device according to a sixth embodiment of the present invention.

  The gear device 60 of the present embodiment shown in FIG. 16 includes a rim 31 having a plurality of teeth 31a all around, two upper and lower webs 61 and 62, and a boss 34. Although six beams 61A1 and 62A1 each having the same straight line 18 as the skeleton as in the first embodiment are provided, the thickness of the beams 61A1 and 62A1 is not uniform in the webs 61 and 62.

  That is, in the beams 61A1 and 62A1 of the webs 61 and 62 of this embodiment, one beam 61A1 and 62A1 is formed of a thin portion and a thick portion.

  Even with such a configuration of the present embodiment, the same effects as those of the first embodiment can be obtained. Of course, if the beams 61A1 and 62A1 of the webs 61 and 62 have the straight line 18 as a skeleton, the beam 61A1 can be obtained. And 62A1 may not be uniform in the webs 61 and 62.

  FIG. 17 shows a seventh embodiment of the gear device of the present invention.

  The gear device 70 of the present embodiment shown in FIG. 17 includes a rim 31 having a plurality of teeth 31a all around, two upper and lower webs 71 and 72, and a boss 34. Further, six beams 71A1 and 72A1 each having the same non-linear line 23 as the skeleton as in the second embodiment are provided.

  Even with such a configuration of the present embodiment, the same effect as that of the second embodiment can be obtained.

  Note that the present invention is not limited to the above-described embodiment, and includes various modifications. That is, the above-described embodiments have been described in detail in order to easily explain the present invention, and are not necessarily limited to those having all the configurations described above. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of one embodiment can be added to the configuration of another embodiment. Also, for a part of the configuration of each embodiment, it is possible to add, delete, or replace another configuration.

  1, 30, 40, 50, 60, 70 ... gear device, 2, 3 ... output shaft, 4 ... engine, 5 ... input shaft, 6 ... clutch, 7A, 7C, 8A, 8C, 9A, 10 ... gear, 14 , 31 ... rim, 14a, 31a ... teeth, 15A, 15B, 32, 33, 35, 36, 37, 38, 41, 42, 51, 52, 61, 62, 71, 72 ... web, 15A1, 15B1, 32A1 , 33A1, 35A1, 36A1, 37A1, 38A1, 41A1, 42A1, 51A, 52A1, 61A1, 62A1, 71A1, 72A1,..., Beam, 16, 21,... Straight lines, 19, 19a, 20, 20a, 24, 25: Lightening portion, 23: Non-linear, 34: Boss.

Claims (14)

A rim comprising a machine structural alloy steels or carbon steels for machine structural use steel having a plurality of teeth all around, made from a circular plate, alloy steels for machine structural fixed to the rim or the mechanical structural carbon steel A plurality of webs made of steel , and a boss made of alloy steel for machine structure or carbon steel for machine structure connecting the web and the shaft,
A plurality of lightening portions are formed on the web, and a beam formed between adjacent lightening portions in a plane projection perpendicular to the axis of the gear is formed from an arbitrary point P on a circle on the outer periphery of the web. Of the tangents drawn to the circle on the inner circumference of the web, a line group in which a straight line in which the angle α formed by the speed vector v at the time of forward rotation of the gear starting from the point P is an obtuse angle is arranged in the web is a skeleton. A gear device comprising: The gear device according to claim 1,
A gear device provided with a gear, wherein a beam formed between the hollow portions of the web is inclined in a rotation direction. The gear device according to claim 1 or 2,
The gear device according to claim 1, wherein the web includes an upper web and a lower web, and the lightening portions of the upper web and the lower web are located at the same position. The gear device according to claim 1 or 2,
The gear device according to claim 1, wherein the web includes an upper web and a lower web, and the lightening portions of the upper web and the lower web are located at different positions. The gear device according to claim 1 or 2,
The gear device according to claim 1, wherein the web includes five webs, and the lightening portions of each of the five webs are located at the same position. The gear device according to claim 1 or 2,
The gear device according to claim 1, wherein the web includes three webs, and one web is provided upside down with respect to the other webs. The gear device according to claim 6,
A gear device, wherein the web located at the center of the three webs is provided upside down with respect to the other webs. The gear device according to any one of claims 1 to 7,
A gear device characterized in that the shape of the hollow portion of the web is a shape obtained by combining linear portions. The gear device according to any one of claims 1 to 7,
A gear device, wherein a shape of the hollow portion of the web is a shape obtained by combining a curved portion or a chamfered portion with a straight portion. The gear device according to claim 1 or 2,
The gear device according to claim 1, wherein the beam of the web is formed of a thin portion and a thick portion. The gear device according to any one of claims 1 to 10,
A gear device, wherein a rib is provided between the web and the rim. A rim comprising a machine structural alloy steels or carbon steels for machine structural use steel having a plurality of teeth all around, made from a circular plate, alloy steels for machine structural fixed to the rim or the mechanical structural carbon steel A plurality of webs made of steel , and a boss made of alloy steel for machine structure or carbon steel for machine structure connecting the web and the shaft,
A plurality of lightening portions are formed on the web, and a beam formed between adjacent lightening portions in the projection plane perpendicular to the axis of the gear is formed by a point P on the web outer circumference circle and the web inner circumference. An angle β formed between a line OP drawn from the axis center O to the point P and a speed vector v at the time of forward rotation of the gear starting from the point P, with a non-linear SP smoothly connecting the points S on the circle Is smaller than an angle γ formed by a line drawn from the shaft center O to the point S and the velocity vector v. A rim having a plurality of teeth all around, a plurality of webs made of a circular plate material and fixed to the rim, and a boss connecting the web and a shaft,
A plurality of lightening portions are formed on the web, and a beam formed between adjacent lightening portions in a plane projection perpendicular to the axis of the gear is formed from an arbitrary point P on a circle on the outer periphery of the web. Of the tangents drawn to the circle on the inner circumference of the web, a line group in which a straight line in which the angle α formed by the speed vector v at the time of forward rotation of the gear starting from the point P is an obtuse angle is arranged in the web is a skeleton. and,
The gear device is characterized in that the web is composed of three webs, and one web is provided upside down with respect to the other webs . The gear device according to claim 13 ,
A gear device, wherein the web located at the center of the three webs is provided upside down with respect to the other webs.

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