JP2009041674A - Gear member, gear mechanism, and manufacturing method of gear member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gear member which does not produce variation of inside diameter and has high torque intensity even if two members are interconnected by press fitting and to provide a gear mechanism with the gear member and a manufacturing method of the gear member. <P>SOLUTION: The gear member 1 has a structure in which the connected part 11c of a small diameter gear 11 is inserted with force to the connected hole 12b of a large diameter gear 12. The inner peripheral surface of the connected hole 12b is flat and a groove portion 11b is formed in the outer peripheral face of the connected part 11c and when the connected part 11c of the small diameter gear 11 is press-fitted to the connected hole 12b of the large diameter gear 12, the inner peripheral face of the connected hole 12b is plastically deformed so as to disposed between the grooves 11b, the small diameter gear 11 and the large diameter gear 12 can be connected with high intensity. Further, when the connected part 11c is press-fitted into the connected hole 12b, a large load is not applied to the connected part 11c side and the inner diameter dimension of the connected part 11c never shrinks. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gear member formed by connecting a plurality of members, a gear mechanism including the gear member, and a method for manufacturing the gear member.

  In a reduction gear that reduces the rotational speed of a motor or the like, for example, a configuration using a stepped gear member that is coaxially provided with two gears having different diameters is known due to space limitations. However, with the gear member having such a configuration, it is difficult to integrally manufacture the two gears by cutting.

  Therefore, after the small-diameter gear and the large-diameter gear are separately manufactured by cutting, the small-diameter gear and the large-diameter gear are integrated by press-fitting the small-diameter gear coupling portion into the large-diameter gear coupling hole. Has been proposed. However, if the press-fitting allowance for press-fitting the small-diameter gear coupling portion into the large-diameter gear coupling hole is large, the torque strength between the small-diameter gear and the large-diameter gear can be increased. There is a problem that the connecting portion of the gear is deformed and the inner diameter of the small-diameter gear is reduced, and the gear member does not rotate smoothly in a state where the support shaft is passed through the gear member. In addition, if the press-fitting allowance for press-fitting the connecting portion of the small-diameter gear into the connecting hole of the large-diameter gear is small, fluctuations in the inner-diameter dimension of the small-diameter gear can be suppressed, but the small-diameter gear and the large-diameter gear There is a problem that the torque intensity is lowered.

Here, while a groove is formed on the outer peripheral surface of the connecting portion of the small-diameter gear, inner teeth are formed in the connecting hole of the large-diameter gear, and a groove formed on the outer peripheral surface of the connecting portion of the small-diameter gear, It has been proposed to fit an internal tooth formed in a connecting hole of a large-diameter gear (see Patent Document 1).
JP 61-31764 A

  However, the gear member described in Patent Document 1 has a problem in that it takes a lot of labor to form internal teeth in the connecting hole of the large-diameter gear. Moreover, in the structure which fits the groove | channel formed in the outer peripheral surface of the connection part of a small diameter gear, and the internal tooth of a large diameter gear, there exists a problem that it cannot connect firmly in an axial direction depending on processing precision.

  Further, in the configuration in which the groove formed on the outer peripheral surface of the connecting portion of the small-diameter gear and the internal teeth of the large-diameter gear are fitted, the inner diameter dimension of the small-diameter gear becomes small when the press-fitting allowance is large due to processing accuracy. Therefore, it is impossible to eliminate the problem that the gear member does not rotate smoothly while the support shaft is passed through the gear member.

  In view of the above problems, an object of the present invention is to provide a gear member that has high torque strength even when two members are connected by press-fitting and that does not vary in inner diameter even when formed in a cylindrical shape, and this gear member. The gear mechanism provided with this invention, and the manufacturing method of the said gear member.

  In order to solve the above-described problems, in the present invention, a first gear portion having a plurality of teeth formed on the outer peripheral surface, and a coaxial connecting portion with respect to the first gear portion are formed at positions shifted in the axial direction. In the gear member composed of the first member made and the second member having the connection hole into which the connection portion is fitted, an extension line of the tooth groove of the first gear portion is formed on the outer peripheral surface of the connection portion. A groove portion is formed at a position overlapping in the radial direction, and the inner peripheral surface of the connection hole is plastically deformed so as to enter between the groove portions.

  In the present invention, the gear member is configured by connecting the first member and the second member by press-fitting the connecting portion of the first member into the connecting hole of the second member. Here, even if the inner peripheral surface of the connecting hole is a flat surface, a groove is formed on the outer peripheral surface of the connecting portion, so when the connecting portion of the first member is press-fitted into the connecting hole of the second member Since the inner peripheral surface of the connecting hole undergoes plastic deformation so as to enter between the groove portions, the first member and the second member are connected with high torque strength and are also firmly connected in the axial direction. Moreover, since the groove part is formed in the outer peripheral surface of a connection part, even if the press-fitting allowance of a connection part and a connection hole is set large, the inner peripheral surface of a connection hole may enter between groove parts. Therefore, the first member and the second member can be reliably press-fitted. Further, on the outer peripheral surface of the connecting portion, the groove portion is formed at a position overlapping with the extension line of the tooth groove of the first gear portion in the radial direction, and the groove portion of such a structure is a gear cutting for forming the first gear portion. Since it can form by performing also with respect to the outer peripheral surface of a connection part, the manufacturing cost of a gear member can be reduced.

  The present invention is effective when applied to a case where at least the coupling portion is formed in a cylindrical shape in the first member. If comprised in this way, a gear member can be rotated to the surroundings of an axis line through a support shaft inside a connection part in a gear member. Even in this case, in the present invention, when the connecting portion of the first member is press-fitted into the connecting hole of the second member, plastic deformation occurs so that the inner peripheral surface of the connecting hole enters between the groove portions. Does not take a big load. For this reason, even if the press-fitting allowance with respect to the connecting hole is set to be large, the inner diameter dimension of the connecting portion is not reduced. Therefore, the support shaft can be reliably passed inside the connecting portion, and the gear member rotates smoothly around the support shaft. Further, even when the support shaft (rotary shaft) is press-fitted and fixed inside the connecting portion of the gear member, the inner diameter dimension of the connecting portion varies when the connecting portion of the first member is press-fitted into the connecting hole of the second member. Therefore, the support shaft (rotary shaft) can be reliably press-fitted and fixed inside the connecting portion.

  In the present invention, it is preferable that the outer diameter of the connecting portion is larger than the diameter of the root circle of the first gear portion. When such a configuration is adopted, the bottom portion of the groove portion is on an extension line of the tooth groove bottom portion of the first gear portion, and the diameter of an imaginary circle connecting the bottom portion of the groove portion is determined by the teeth of the first gear portion. A configuration equal to the diameter of the bottom circle can be employed. If comprised in this way, when forming a groove part in the outer peripheral surface of a connection part, it is only necessary to relatively move the tool for forming a 1st gear part, and a 1st member to an axial direction, and a tool, a 1st member, There is no need to shift the relative position in the radial direction. Therefore, since the groove portion can be efficiently formed on the outer peripheral surface of the connecting portion, the productivity can be improved. In addition, by setting the outer diameter of the connecting portion before grooving to a predetermined size, an optimum tooth gap is formed in the first gear portion by gear cutting, and the groove portion is formed in the connecting portion. After forming the groove portion, the groove portion having a depth suitable for press-fitting can be formed in the connecting portion without performing an additional process such as cutting the outer peripheral surface of the connecting portion to adjust the depth or press-fitting allowance of the groove portion. .

  In the present invention, the second member may include a second gear portion having a plurality of teeth formed on the outer peripheral surface. If comprised in this way, since the gear member to which this invention is applied is provided with two gear parts, it is the same as having arrange | positioned two single gears only by using one gear member to which this invention is applied. Demonstrate the function. Therefore, a gear mechanism can be incorporated even when space is limited.

  In the present invention, the first member and the second member may be formed of different materials, for example, the first member is made of metal and the second member is made of resin. However, when both the first member and the second member are made of metal, a gear member having extremely strong strength can be formed, which is suitable for use in a gear mechanism that applies a large torque such as a speed reducer. ing.

  At least one gear member according to the present invention is used for a gear mechanism. In this case, it is preferable that two or more gear members are used to form a speed reduction mechanism. Since the gear member according to the present invention has high torque strength, it is suitable for use in a gear mechanism to which a large torque such as a reduction gear is applied.

  In the present invention, a first gear portion having a plurality of teeth formed on the outer peripheral surface, and a first member formed at a position where a coaxial connecting portion is shifted in the axial direction with respect to the first gear portion, In the manufacturing method of the gear member including the second member provided with the connecting hole into which the connecting portion is fitted, in the step of forming the second member, the inner peripheral surface of the connecting hole is made flat, In the step of forming one member, gear cutting for forming a tooth groove of the first gear portion is also performed on the outer peripheral surface of the connecting portion, and the extension line of the tooth groove of the first gear portion and the radial direction in the connecting portion. In the step of connecting the first member and the second member, the connecting portion is press-fitted into the connecting hole.

  In the present invention, when the connecting portion of the first member is press-fitted into the connecting hole of the second member, the inner peripheral surface of the connecting hole causes plastic deformation so as to enter between the groove portions, so the first member and the second member Is connected with high torque strength and is also firmly connected in the axial direction. Moreover, since the groove part is formed in the outer peripheral surface of a connection part, even if the press-fitting allowance of a connection part and a connection hole is set large, the inner peripheral surface of a connection hole may enter between groove parts. Therefore, the first member and the second member can be reliably press-fitted. Further, on the outer peripheral surface of the connecting portion, the groove portion is formed at a position overlapping with the extension line of the tooth groove of the first gear portion in the radial direction, and the groove portion of such a structure is a gear cutting for forming the first gear portion. Since it can form by performing also with respect to the outer peripheral surface of a connection part, the manufacturing cost of a gear member can be reduced.

  In the present invention, it is preferable that the hardness of the first member is higher than the hardness of the second member at the time of performing the connecting step. If comprised in this way, when the connection part of a 1st member is press-fit in the connection hole of a 2nd member, the inner peripheral surface of a connection hole will raise | generate a plastic deformation easily so that it may enter between groove parts.

  In the present invention, the first member and the second member are made of a metal material, the first member is subjected to a curing process before the connecting step, and the second member is It is preferable to perform a hardening process after a connection process. If comprised in this way, since hardness can be raised about both the said 1st member and the said 2nd member, slidability can be improved. Further, since the hardness of the first member is higher than the hardness of the second member during the press-fitting step, when the connecting portion of the first member is press-fitted into the connecting hole of the second member, The inner peripheral surface of the connecting hole tends to undergo plastic deformation so as to enter. Furthermore, since the hardening process is performed on the second member after the press-fitting step, the metal that has entered between the grooves can be hardened, and the first member and the second member can be firmly fixed.

  In the present invention, even if the inner peripheral surface of the connecting hole is a flat surface, a groove is formed on the outer peripheral surface of the connecting portion, so when the connecting portion of the first member is press-fitted into the connecting hole of the second member Since the inner peripheral surface of the connecting hole undergoes plastic deformation so as to enter between the groove portions, the first member and the second member are connected with high torque strength and are also firmly connected in the axial direction. Moreover, since the groove part is formed in the outer peripheral surface of a connection part, even if the press-fitting allowance of a connection part and a connection hole is set large, the inner peripheral surface of a connection hole may enter between groove parts. Therefore, the first member and the second member can be reliably press-fitted. Further, on the outer peripheral surface of the connecting portion, the groove portion is formed at a position overlapping with the extension line of the tooth groove of the first gear portion in the radial direction, and the groove portion of such a structure is a gear cutting for forming the first gear portion. Since it can form by performing also with respect to the outer peripheral surface of a connection part, the manufacturing cost of a gear member can be reduced. Furthermore, even when the connecting portion is formed in a cylindrical shape, when the connecting portion of the first member is press-fitted into the connecting hole of the second member, plastic deformation is performed so that the inner peripheral surface of the connecting hole enters between the groove portions. Therefore, a large load is not applied to the connection side. For this reason, even if the press-fitting allowance with respect to the connecting hole is set to be large, the inner diameter dimension of the connecting portion is not reduced.

  A gear member to which the present invention is applied, a gear mechanism provided with the gear member, and a method for manufacturing the gear member will be described with reference to the drawings.

(Whole structure of gear mechanism)
1A and 1B are a plan view and a configuration diagram of a gear mechanism to which the present invention is applied, respectively. As shown in FIGS. 1A and 1B, the gear mechanism 100 according to the present embodiment includes a reduction mechanism that transmits the rotation of the driving shaft 51 to the output shaft 56 while reducing the rotation between the pair of end plates 101 and 102. It is composed. FIGS. 1A and 1B show an example in which the driving shaft 51 and the output shaft 56 are arranged on the same axis, and four support shafts 52 to 55 are arranged around the output shaft 56. is there. In FIG. 1 (b), the support shafts 52 and 53 are located on the same axis and the support shafts 54 and 55 are located on the same axis, but as shown in FIG. 1 (a). Each of the support shafts 52 to 55 is held at both ends by the end plates 101 and 102 or a ground plate (not shown) around the output shaft 56. Further, in FIG. 1B, illustration of bearings for the driving shaft 51 and the output shaft 56 is omitted, but the driving shaft 51 and the output shaft 56 can each rotate about an axis.

  As shown in FIG. 1B, the gear 2 is fixed to the driving shaft 51 so as to be rotatable integrally with the driving shaft 51. On the outer periphery of the support shaft 52, a stepped gear 3 in which a large-diameter gear 3a and a small-diameter gear 3b are integrally formed coaxially is rotatably supported. A stepped gear member 1c is fixed to the support shaft 53 by press fitting, and the support shaft 53 functions as a rotation shaft. A stepped gear member 1a is fixed to the support shaft 54 by press fitting, and the support shaft 54 functions as a rotation shaft. A stepped gear member 1e is fixed to the support shaft 55 by press fitting, and the support shaft 55 functions as a rotation shaft. The output shaft 56 includes a stepped gear 4 in which a large-diameter gear 4 a and a small-diameter gear 4 b are integrally formed coaxially, a stepped gear member 1 b, and a stepped gear member 1 d. The gear 5 is disposed on the output shaft 56 so as to be rotatable integrally with the output shaft 56.

  In the gear mechanism 100 configured as described above, the rotation of the driving shaft 51 includes the gear 2, the stepped gear 3, the stepped gear 4, the gear member 1a, the gear member 1b, the gear member 1c, the gear member 1d, the gear member 1e, The gears 5 are transmitted in this order while being decelerated toward the gear 5 and output from the output shaft 56.

  Therefore, among the gears, the stepped gear 3 and the stepped gear 4 have only a relatively small torque applied thereto, so that an inexpensive resin gear can be used. In addition, about the gear 2 arrange | positioned at the front | former stage side, the spur gear made from a brass is used from a viewpoint of ensuring press-fit strength. In contrast, since a large torque is applied to the gear 5 at the final stage, a metal spur gear is used. Further, since a relatively large torque is applied to the gear members 1a to 1e arranged on the relatively rear side, a resin gear cannot be used. However, a composite gear as shown in the gear members 1a to 1e is made of metal. In this case, when the small diameter gear portion is formed by the hob cutter, the large diameter gear portion becomes an obstacle. Therefore, about the gear members 1a-1e, the structure demonstrated with reference to FIG. 2 and FIG. 3 is employ | adopted.

(Configuration of gear members 1a to 1e)
2 (a), 2 (b), 2 (c) and 2 (d) are respectively a sectional view of a gear member to which the present invention is applied, a sectional view of a small diameter gear used for the gear member, and a large diameter gear used for the gear member. FIG. 2D is a cross-sectional view of FIG. 2 and a side view of the small-diameter gear. In FIG. Moreover, since the fundamental structure of the gear members 1a-1e is the same, in the following description, the gear members 1a-1e are demonstrated as the gear member 1 without distinguishing.

  As shown in FIG. 2A, the gear member 1 (gear members 1a to 1e) of the present embodiment includes a cylindrical small-diameter gear 11 (first member) and a disk-shaped large-diameter gear 12 (second member). In this embodiment, both the small diameter gear 11 and the large diameter gear 12 are made of the same metal material (for example, carbon steel SUM24L, carbon steel S45C, etc.).

  As shown in FIGS. 2B and 2D, the small diameter gear 11 is formed with a shaft hole 11e extending with the same inner diameter in the axial direction. A first gear portion 11a having a plurality of teeth on the outer peripheral surface is formed on one end side in the axial direction of the small-diameter gear 11, while the other end side in the axial direction of the small-diameter gear 11 is on the outer peripheral surface. The connection part 11c provided with the groove part 11b is formed. Here, the tooth groove of the first gear portion 11 a and the groove portion 11 b extend linearly in parallel with the axial direction of the small-diameter gear 11.

  In this embodiment, the outer diameter d1 of the connecting portion 11c is smaller than the tooth tip diameter d4 of the first gear portion 11a, and a step portion 11d is formed at the boundary portion between the first gear portion 11a and the connecting portion 11c. Yes. Further, the outer diameter d1 of the connecting portion 11c is set larger than the diameter d2 of the root circle of the first gear portion 11a.

  Here, the groove part 11b is formed in the position which overlaps with the extended line of the tooth groove of the 1st gear part 11a in a radial direction. In this embodiment, since the bottom of the groove 11b is located on the extension line of the tooth bottom of the first gear portion 11a, the groove 11b and the tooth groove of the first gear 11a are continuous, and the bottom of the groove 11b is The diameter d5 of the virtual circle to be connected is equal to the diameter d2 of the root circle of the first gear portion 11a.

  As shown in FIG. 2C, the large-diameter gear 12 includes a second gear portion 12a having a plurality of teeth formed on the outer peripheral surface, and the connecting portion 11c of the small-diameter gear 11 is press-fitted in the center. A connecting hole 12b is formed. The inner diameter d3 of the connecting hole 12b is set slightly smaller than the outer diameter d1 of the connecting portion 11c and smaller than the tooth tip circle diameter d4 of the first gear portion 11a. Moreover, the inner peripheral surface of the connection hole 12b is a flat surface.

  When the gear member 1 shown in FIG. 2A is manufactured using the small-diameter gear 11 and the large-diameter gear 12 configured as described above, the connecting portion 11c of the small-diameter gear 11 is connected to the connecting hole 12b of the large-diameter gear 12. The step 11d of the small diameter gear 11 and the inner peripheral edge of the large diameter gear 12 are brought into contact with each other. Thereby, the gear member 1 in which the small diameter gear 11 and the large diameter gear 12 are integrated as shown in FIG. 2A can be obtained.

(Manufacturing method of gear member)
Next, the manufacturing method of the gear member 1 will be described with reference to FIG. 3 in addition to FIG. 2, and the configuration of the gear member 1 will be described in detail. FIG. 3 is an explanatory view showing a method for manufacturing the small-diameter gear 11 constituting the gear member 1 to which the present invention is applied.

  In manufacturing the gear member 1, first, the large-diameter gear 12 described with reference to FIG. In the step of forming the large-diameter gear 12, the inner peripheral surface of the connecting hole 12b is made flat.

  On the other hand, in order to manufacture the small-diameter gear 11 shown in FIGS. 2B and 2D, first, as shown in FIG. 3A, a metal cylindrical blank 111 is manufactured. The blank 111 is configured with two barrel portions 111a and 111b having different diameters on the outer peripheral surface, and the outer diameter of the barrel portion 111a (the tip circle of the first gear portion 11a shown in FIG. 2B). The diameter d4) is larger than the outer diameter of the trunk portion 111b (the outer diameter d1 of the connecting portion 11c shown in FIG. 2B).

  Next, after aligning the cutting edge of the hob cutter 9 with a virtual line L1 extending in parallel with the central axis of the blank 111, the hob cutter 9 and the blank 111 are relatively moved in parallel with the central axis of the blank 111, Gear cutting is performed. As a result, as shown in FIG. 3B, a tooth groove of the first gear portion 11a is formed in the body portion 111a, and a groove portion 11b is formed on the extension portion of the tooth groove of the gear portion 11a in the body portion 111b. Is formed. The rotation speed of the hob cutter 9 is set to 4000 to 6000 rpm, for example.

  Next, as shown in FIG. 3B, the hob cutter 9 and the blank 111 are relatively moved in the circumferential direction, and then the gear cutting described with reference to FIG. 3A is repeated. As a result, in the region shifted in the axial direction on the outer peripheral surface of the blank 111, the tooth groove of the first gear portion 11a and the groove portion 11b are formed over the entire periphery of the blank 111, and FIGS. As shown, the small-diameter gear 11 including the first gear portion 11a and the connecting portion 11c is formed in a region shifted in the axial direction.

  Next, the hardness and wear resistance of the small-diameter gear 11 are improved by subjecting the small-diameter gear 11 to heat treatment and surface hardening treatment by salt bath soft nitriding. On the other hand, the surface hardening process is not performed on the large-diameter gear 12.

  Next, in the connecting step, the connecting portion 11c of the small diameter gear 11 is press-fitted into the connecting hole 12b of the large diameter gear 12, and the connecting portion 11c of the small diameter gear 11 is inserted into the large diameter gear 12 as shown in FIG. The gear member 1 fitted into the connecting hole 12b is formed.

  Finally, the large diameter gear 12 is subjected to heat treatment and surface hardening treatment by salt bath soft nitriding. At that time, the entire gear member 1 is subjected to surface hardening treatment, and the gear member 1 is completed.

(Main effects of this form)
As described above, the gear member 1 according to the present embodiment connects the small-diameter gear 11 and the large-diameter gear 12 by press-fitting the coupling portion 11c of the small-diameter gear 11 into the coupling hole 12b of the large-diameter gear 12. The member 1 is configured. Here, even if the inner peripheral surface of the connecting hole 12b is a flat surface, since the groove portion 11b is formed on the outer peripheral surface of the connecting portion 11c, the press-fitting allowance between the connecting portion 11c and the connecting hole 12b is set to be large. Even when the connecting portion 11c of the small-diameter gear 11 is press-fitted into the connecting hole 12b of the large-diameter gear 12, the inner peripheral surface of the connecting hole 12b undergoes plastic deformation so as to enter between the groove portions 11b. Moreover, since the hardness of the small-diameter gear 11 is higher than the hardness of the large-diameter gear 12 at the time when the small-diameter gear 11 and the large-diameter gear 12 are connected, the connecting portion 11c of the small-diameter gear 11 is connected to the large-diameter gear 12. When press-fitted into the connecting hole 12b, the inner peripheral surface of the connecting hole 12b is likely to undergo plastic deformation so as to enter between the groove portions 11b. Therefore, the small-diameter gear 11 and the large-diameter gear 12 are coupled with high torque strength and are also firmly coupled in the axial direction. Therefore, the gear mechanism 100 shown in FIG. 1 can be used as the gear member 1a to the gear member 1e to which a large torque is applied. In addition, since the small-diameter gear 11 and the large-diameter gear 12 are formed of separate members and are firmly connected, the gear ratio between the small-diameter gear 11 and the large-diameter gear 12 is set large, and the reduction ratio is increased. You can also

  Further, when the connecting portion 11c of the small-diameter gear 11 is press-fitted into the connecting hole 12b of the large-diameter gear 12, plastic deformation occurs so that the inner peripheral surface of the connecting hole 12b enters between the groove portions 11b. Does not take a big load. Moreover, since the hardness of the small-diameter gear 11 is higher than the hardness of the large-diameter gear 12 when the small-diameter gear 11 and the large-diameter gear 12 are coupled, the coupling portion 11c of the small-diameter gear 11 is coupled to the large-diameter gear 12. When press-fitted into the hole 12b, the inner peripheral surface of the connecting hole 12b is likely to be plastically deformed so as to enter between the grooves 11b, and a large load is not applied to the connecting part 11c side. For this reason, even if the coupling part 11c is set to have a large press-fitting allowance for the coupling hole 12b, the inner diameter dimension of the coupling part 11c does not shrink. Therefore, the support shaft can be surely passed through the inside of the connecting portion 11c, and when the gear member 1 is used as the stepped gear members 1b and 1d, the stepped gear members 1b and 1d are connected to the support shaft 56. Rotates smoothly around. Further, when the gear member 1 is used as the stepped gear members 1a, 1c, and 1e, the support shafts 54, 53, and 55 (rotating shafts) can be reliably press-fitted and fixed inside the gear members 1a, 1c, and 1e. it can.

  Further, on the outer peripheral surface of the connecting portion 11c, the groove portion 11b is formed at a position overlapping the extension line of the tooth groove of the first gear portion 11a in the radial direction, and the groove portion 11b having such a structure forms the first gear portion 11a. Therefore, the gear member 1 can be manufactured at a lower cost because the gear cutting process can be performed on the outer peripheral surface of the connecting portion 11c.

  Furthermore, since the outer diameter d1 of the connecting portion 11c is larger than the diameter d2 of the tooth bottom circle of the first gear portion 11a, the bottom portion of the groove portion 11b is on the extension line of the tooth bottom portion of the first gear portion 11a, A configuration in which the diameter d5 of the imaginary circle connecting the bottom of the groove 11b is equal to the diameter d2 of the root circle of the first gear portion 11a can be employed. That is, since the outer diameter d1 of the connecting portion 11c before the groove processing is set larger than the diameter d2 of the root circle of the first gear portion 11a, when forming the groove portion 11b on the outer peripheral surface of the connecting portion 11c, A tooth groove can be formed in the first gear portion 11a only by relatively moving the hob cutter 9 and the small-diameter gear 11 for forming the one gear portion 11a in the axial direction, and the groove portion can be formed on the outer peripheral surface of the connecting portion 11c. Since 11b can be formed, it is not necessary to shift the relative position of the hob cutter 9 and the small-diameter gear 11 in the radial direction. Therefore, since the groove part 11b can be efficiently formed in the outer peripheral surface of the connection part 11c, a construction period can be shortened and productivity can be improved.

  In addition, the outer diameter of the trunk portion 111a shown in FIG. 3A (the tip diameter d4 of the first gear portion 11a shown in FIG. 2B) is the outer diameter of the barrel portion 111b (FIG. 2B). Since the outer diameter d1) of the connecting portion 11c is set larger than the outer diameter d1), an optimum tooth gap is formed in the first gear portion 11a by gear cutting, and after the groove portion 11b is formed in the connecting portion 11c, the connecting portion 11c is connected. The groove portion 11b having a depth suitable for press-fitting can be formed in the connecting portion 11c without performing an additional process such as adjusting the depth and press-fitting allowance of the groove portion 11b by cutting the outer peripheral surface of the portion 11c.

  The small-diameter gear 11 may be formed of a material different from that of the small-diameter gear 11 and the large-diameter gear 12 such as the metal and the large-diameter gear 12 are made of resin. Since all of the large-diameter gears 12 are made of metal, the gear member 1 having extremely strong strength can be configured and is suitable for use in the gear mechanism 100 to which a large torque such as a reduction gear is applied.

[Modification]
In the above embodiment, both the small diameter gear 11 and the large diameter gear 12 are made of metal. However, depending on the magnitude of applied torque, the small diameter gear 11 may be made of metal and the large diameter gear 12 may be made of resin. Good.

  Moreover, in the said form, the bottom part of the groove part 11b exists on the extension line | wire of the tooth groove bottom part of the 1st gear part 11a, and the diameter d5 of the virtual circle which connects the bottom part of the groove part 11b is made into the diameter of the tooth base circle of the 1st gear part 11a. 4A, the groove portion 11b is formed at a position overlapping the extension line of the tooth groove of the first gear portion 11a in the radial direction, as shown in FIG. 4A, but the bottom portion of the groove portion 11b is A configuration that is deeper than the bottom of the tooth groove of the first gear portion 11a, that is, a configuration in which the diameter d5 of the imaginary circle that connects the bottom of the groove 11b is smaller than the diameter d2 of the bottom circle of the first gear portion 11a is adopted. May be. Further, as shown in FIG. 4B, the groove 11b is formed at a position that overlaps the extension line of the tooth groove of the first gear portion 11a in the radial direction, but the bottom of the groove 11b is the first gear portion 11a. A configuration that is shallower than the bottom of the tooth gap, that is, a configuration in which the diameter d5 of the imaginary circle connecting the bottom of the groove 11b is larger than the diameter d2 of the bottom circle of the first gear portion 11a may be employed.

  Furthermore, in the above embodiment, the groove portion 11b is formed at all positions that overlap the extension line of the tooth groove of the first gear portion 11a in the radial direction. However, as shown in FIG. 4C, the teeth of the first gear portion 11a are formed. The groove 11b may be formed only in a part of the position overlapping with the extended line of the groove in the radial direction.

  Furthermore, in the above embodiment, the tooth groove of the first gear portion 11a and the groove portion 11b are connected, but as shown in FIG. 4D, the teeth of the groove portion 11b and the first gear portion 11a are formed. You may employ | adopt the structure which is not connected with the groove | channel, or the structure where the groove part 11b is parted as shown in FIG.4 (e).

  The present invention can also be applied to a case where the connecting portion of the small diameter gear 11 is press-fitted into the connecting hole 12b of the large diameter gear 12 when the connecting portion 11c of the small diameter gear 11 is not cylindrical.

(A), (b) is the top view and block diagram of the gear mechanism to which this invention is applied, respectively. (A), (b), (c), (d) is a sectional view of a gear member to which the present invention is applied, a sectional view of a small-diameter gear used for the gear member, and a sectional view of a large-diameter gear used for the gear member, respectively. It is a figure and a side view of a small diameter gear. It is explanatory drawing which shows the manufacturing method of the small diameter gear used for the gear member to which this invention is applied. It is explanatory drawing which shows the modification of the small diameter gear used for the gear member to which this invention is applied.

Explanation of symbols

1 (1a to 1e) Gear member 11 Small diameter gear (first member)
11a 1st gear part 11b Groove part 11c Connection part 12 Large diameter gear (2nd member)
12a Second gear portion 12b Connecting hole 100 Gear mechanism

Claims (11)

A first gear portion having a plurality of teeth formed on the outer peripheral surface, a first member formed at a position where a coaxial connecting portion is displaced in the axial direction with respect to the first gear portion, and the connecting portion is fitted. In the gear member composed of the second member having the connecting hole to be joined,
On the outer peripheral surface of the connecting portion, a groove portion is formed at a position overlapping with an extension line of the tooth groove of the first gear portion in the radial direction,
An inner peripheral surface of the connecting hole is plastically deformed so as to enter between the groove portions.   The gear member according to claim 1, wherein at least the connection portion of the first member is formed in a cylindrical shape.   3. The gear member according to claim 1, wherein an outer diameter dimension of the connecting portion is larger than a diameter of a root circle of the first gear portion. The bottom of the groove is on an extension line of the tooth bottom of the first gear part,
4. The gear member according to claim 3, wherein a diameter of a virtual circle connecting the bottom portions of the groove portions is equal to a diameter of a tooth bottom circle of the first gear portion.   The gear member according to any one of claims 1 to 4, wherein the second member includes a second gear portion having a plurality of teeth formed on an outer peripheral surface thereof.   The gear member according to any one of claims 1 to 5, wherein the first member and the second member are made of metal.   A gear mechanism comprising at least one gear member according to any one of claims 1 to 6. Comprising two or more gear members,
The gear mechanism according to claim 7, wherein a speed reduction mechanism is constituted by the gear member. A first gear portion having a plurality of teeth formed on the outer peripheral surface, a first member formed at a position where a coaxial connecting portion is displaced in the axial direction with respect to the first gear portion, and the connecting portion is fitted. In the manufacturing method of the gear member composed of the second member having the connecting hole to be joined,
In the step of forming the second member, while keeping the inner peripheral surface of the connection hole flat,
In the step of forming the first member, gear cutting for forming a tooth groove of the first gear portion is also performed on the outer peripheral surface of the connecting portion, and an extension line of the tooth groove of the first gear portion is connected to the connecting portion. A groove is formed at a position overlapping in the radial direction,
In the connecting step between the first member and the second member, the connecting portion is press-fitted into the connecting hole.   The method for manufacturing a gear member according to claim 9, wherein at the time of performing the connecting step, the hardness of the first member is set higher than the hardness of the second member. The first member and the second member are made of a metal material,
The first member is subjected to a curing process before the connecting step,
The gear member manufacturing method according to claim 10, wherein the second member is subjected to a curing process after the connecting step.

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