JP2005098339A - Reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reduction gear, removing a backing plate for closing a gear storing chamber in casing in a simple structure to decompose the inside of the casing, and securing the sealing performance of a fitting part of the backing plate to prevent leakage of grease injected into the gear storing chamber. <P>SOLUTION: In this reduction gear in which the gear storing chamber 3 in the casing 2 is closed by the backing plate 4, the inner peripheral wall 5 of the casing 2 is provided with an inner peripheral groove 18 to which the outer periphery of the backing plate 4 is fitted, and the outer periphery of the backing plate 4 is provided with two or more locking claws 22 removably locked in the inner peripheral groove 18 of the casing 2. An O-ring 23 fitted to the outer peripheral groove 24 of the backing plate 4 or soft resin 4a on the outer peripheral side by two-color forming is press-bonded to the inner peripheral groove 18 of the casing 2 to thereby secure the sealing performance of the backing plate 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a speed reducer for a motor drive unit used in a precision machine, and enables a base plate that closes a gear storage chamber in a casing to be removed with a simple structure and ensures sealing performance of a base plate mounting portion. It is related with the reducer made to do.

  Conventional reduction gears used for precision machines such as surveillance cameras and robots have a small and precise structure, making it difficult to disassemble the inside of the casing. When this occurs, the reduction gear itself has been replaced as a whole.

  That is, in the speed reducer used in the conventional precision machine, the base plate for closing the gear storage chamber in the casing is structured to be fixed to the casing by caulking, pin press fitting, screwing, etc. It is difficult to remove the base plate, and if abnormal noise or malfunction occurs as described above, a method is adopted in which the reducer is replaced instead of being inspected and repaired. It was.

  However, it is necessary to inspect the inside of the reducer in order to check the internal conditions when abnormal noise or noise occurs or to check for foreign matter contamination when an abnormal load occurs, and replace the reducer each time. If this is done, maintenance costs are also wasted, so a casing structure that can be disassembled is required even in a small reduction gear used in a precision machine.

Therefore, as described later, the present inventors have made it possible to disassemble the casing of the speed reducer by making the base plate that closes the gear housing chamber in the casing detachable by the locking claws. Invented the structure. And as a result of investigating the prior art regarding a latching claw, the following patent document 1 and patent document 2 were found.
Japanese Examined Patent Publication No. 63-259248 (4th, 5th page, FIG. 6) Japanese Patent Laid-Open No. 5-26304 (2nd and 3rd pages, FIGS. 1 and 3)

  By the way, the structure of Patent Document 1 relates to a reduction device with a torque limiter. As shown in FIG. 7, 32 is a motor, 33 is an output shaft of the motor, 34 is an output shaft of the reduction gear, 35 is an eccentric shaft, 36 Is a planetary gear, and the right half 37a of the housing 37 overhangs the left half 37b, and the outer periphery of the engagement protrusion 38 corresponding to the inner surface of the overhang of the right half 37a and the overhang of the left half 37b. Engagement holes 39 formed on the surface engage with each other to assemble the housing 37 integrally.

  However, the assembly structure of the housing 37 is assembled by a fitting structure without using screws, but the above structure does not consider the disassembly performance of the housing 37.

  The structure of Patent Document 2 relates to a hypocycloid speed reducer. As shown in FIGS. 8A and 8B, the substrate 40 is formed in a plate shape with a cylindrical body 41 projecting on one side. In the configuration in which the internal gear main body 42 is forcibly inserted into and integrated with the cylindrical body 41, the substrate 40 is provided in order to prevent relative movement in the axial direction between the cylindrical body 41 and the internal gear main body 42 of the substrate 40. The internal claw main body 42 is locked by the locking claw 43.

  Therefore, in the reduction gear of this patent document 2, since the gear structure having the sun gear 45 and the planetary gear 46 is not closed in the casing, the invention of this patent document 2 also has a casing disassembly structure. is not.

  Conventionally, small and precise reduction gears used in precision machines have not been provided with measures to prevent grease leakage. By using grease with high viscosity or grease with little temperature change, liquefaction is suppressed. Grease was prevented from leaking outside.

  However, in the structure in which the base plate is detachable as in the present invention, it is necessary to ensure the sealing performance around the base plate.

  The present invention has been made in view of the above circumstances. In order to allow disassembly of the inside of the casing, the base plate that closes the gear storage chamber in the casing can be removed with a simple structure, and the gear storage chamber can be removed. An object of the present invention is to provide a reduction gear that ensures the sealing performance of the mounting portion of the base plate in order to prevent leakage of the injected grease.

  In order to solve the above problem, the speed reducer according to claim 1 of the present invention is a speed reducer that closes a gear storage chamber in a casing with a base plate, and the outer periphery of the base plate is fitted to the inner peripheral wall of the casing. On the other hand, an inner peripheral groove is formed on the outer periphery of the base plate, and locking claws that are detachably locked to the inner peripheral groove of the casing are formed at a plurality of locations on the outer periphery of the base plate. An O-ring is fitted into the formed outer peripheral groove, and the O-ring is press-fitted into the inner peripheral groove of the casing, thereby ensuring sealing performance around the base plate.

  According to a second aspect of the present invention, there is provided a speed reducer for closing a gear storage chamber in a casing with a base plate, wherein an inner peripheral groove for fitting an outer periphery of the base plate to an inner peripheral wall of the casing. On the other hand, a locking claw that is detachably locked to the inner peripheral groove of the casing is formed at a plurality of locations on the outer periphery of the base plate, and the peripheral portion of the hard resin that constitutes the main body of the base plate The soft resin formed by two-color molding is formed into a protruding shape, and the soft resin is pressure-bonded to the inner peripheral groove of the casing to ensure the sealing performance around the base plate. .

  Furthermore, the speed reducer according to claim 3 of the present invention is the speed reducer according to claim 1 or 2, wherein the locking claws formed at a plurality of locations on the outer periphery of the base plate are detachably attached to the inner peripheral groove of the front casing by elastic deformation. It is locked.

  According to the speed reducer of claim 1 of the present invention, since the locking claws that are detachably locked to the inner peripheral groove of the casing are formed at a plurality of locations on the outer periphery of the base plate, the base plate is the locking claw. Is fixed to the casing, and the base plate is detached from the casing by releasing the latching claw. By removing the base plate, the gear storage chamber in the casing is opened, and the inside of the casing can be disassembled. it can.

  In addition, the O-ring is crimped to the inner peripheral groove of the casing by the configuration in which the O-ring is fitted to the outer peripheral groove of the base plate that closes the casing of the reducer, thereby ensuring the sealing performance around the base plate. It is possible to prevent leakage of the grease injected into the gear storage chamber.

  Further, in the speed reducer according to claim 2 of the present invention, similarly to the case of claim 1, locking claws that are detachably locked to the inner peripheral groove of the casing are formed at a plurality of locations on the outer periphery of the base plate. Therefore, the base plate is fixed to the casing by the locking claws, and the base plate is removed from the casing by the release of the locking claws, and the gear storage chamber in the casing is opened by removing the base plate. be able to.

  Furthermore, the protruding shape of the soft resin is formed into the shape of the inner peripheral groove of the casing by forming the soft resin by the two-color molding on the peripheral portion of the hard resin constituting the main body of the base plate that closes the casing of the speed reducer. Thus, sealing performance around the base plate can be ensured, and leakage of grease injected into the gear housing chamber can be prevented.

  Embodiments of the present invention will be described below with reference to the drawings.

  The speed reducer 1 of the present embodiment is configured such that the gear storage chamber 3 in the casing 2 is closed with a base plate 4. In the present embodiment, the casing 2 is formed in a cylindrical shape (see FIG. 1A), but may have other shapes, and the base plate 4 is formed according to the inner diameter of the casing 2.

  The gear group in the gear housing chamber 3 is composed of a combination of a sun gear 8 provided coaxially with the output shaft 7 and a plurality of planetary gears 9 meshed with the sun gear 8. Is meshed with internal teeth 6 provided on the inner periphery of the casing 2. However, the present invention does not specify the gear configuration in the speed reducer, and can be applied to any speed reducer as long as the gear housing chamber 3 is closed by the base plate 4 even in other gear configurations. is there.

  As shown in FIGS. 1 (a) and 1 (b), a bearing member 12 that supports the output shaft 7 is fixed to one end portion of the casing 2 used in the speed reducer 1 of this embodiment via a bearing 10. Has been. That is, a circumferential step 2a is formed at the inner periphery of the casing 2 on the output shaft 7 side, and a circumferential step 12a formed on the outer periphery of the bearing member 12 is fitted into the step 2a. At the same time, the bearing member 12 is fixed to the end of the casing 2 by screwing the mounting screw 14 inserted into the mounting hole 13 formed near the end of the casing 2 into the screw hole 15 formed in the bearing member 12. Like to do.

  The bearing member 12 is formed with a shaft hole 16 through which the output shaft 7 is inserted through the bearings 10 and 10 arranged in parallel. A plurality of screw holes 17 are provided around the shaft hole 16 in the axial direction. , 17... Are formed, and the screw 31 inserted into the mounting hole 30a of the product 30 (see FIG. 3) to which the speed reducer 1 is to be attached is fastened to the screw hole 17 of the bearing member 12, whereby the speed reducer 1 is Can be fixed to.

  Further, as shown in FIG. 2, an inner peripheral groove 18 for fitting the outer periphery of the base plate 4 to the inner peripheral wall 5 of the casing 2 is formed outside the outermost planetary gear 9 a in the gear housing chamber 3. ing. As shown in FIG. 1 (b), the inner peripheral groove 18 is formed in the inner peripheral wall 5 of the casing 2 with a width for fitting a predetermined thickness of the base plate 4.

  As shown in FIG. 2, the base plate 4 to be fitted in the inner peripheral groove 18 has a circular outer periphery corresponding to the cylindrical shape of the casing 2. A shaft hole 19 for inserting the M drive shaft 20 (see FIG. 3) is formed.

  Further, as shown in FIGS. 1A and 1B, an annular groove 4c is formed on the outer surface of the base plate 4 along the vicinity of the outer periphery, and at the outer periphery of the base plate 4 as shown in FIG. An inclined locking claw 22 having an upward slope toward the outside is formed in a projecting shape at a plurality of required locations (4 locations in the present embodiment), so that each locking claw 22 has an annular groove. It has flexibility by an external force in the 4c direction, and is restored to its original protruding shape by releasing the external force.

  As shown in FIG. 2, the outer diameter of the base plate 4 is an outer diameter that can be inserted to such an extent that the outer periphery 22 a on which the locking claw 22 is not formed is in sliding contact with the inner peripheral wall 5 of the casing 2. . Therefore, as shown in FIG. 3, in order to insert the base plate 4 into the casing 2, a plurality of locking claws 22, 22... Protruding from the outer periphery of the base plate 4 by pushing the base plate 4 into the casing 2. Are inserted by being bent in the direction of the annular groove 4c of the casing 1, and when the respective locking claws 22, 22... Are fitted into the inner peripheral groove 18 of the casing 2, the inner periphery is restored by returning to the original protruding shape. A fixed state in which the groove 18 is locked is made.

  In addition, as shown in FIG. 2, an outer peripheral groove 24 for fitting the O-ring 23 is formed on the inner periphery of the base plate 4, and in the state where the O-ring 23 is fitted to the outer peripheral groove 24, When the main plate 4 is inserted into the casing 2, the locking claw 22 is pressed in close contact with the inner circumferential groove 18 in a state of being fitted to the inner circumferential groove 18 of the casing 2. The sealing performance around the base plate 4 can be ensured, and leakage of the grease injected into the gear housing chamber 3 can be prevented.

  In order to mount the motor M after the base plate 4 is attached to the casing 2 as described above, the drive shaft 20 of the motor M is inserted into the shaft hole 25a at the center of the seating member 25 as shown in FIG. Then, after the mounting screw 26 is inserted into the mounting hole 25 c of the seating member 25 and fastened to the screw hole 29 of the motor M, the seating member 25 is inserted into the casing 2. At this time, the drive gear 21 fixed to the drive shaft 20 of the motor M meshes with the planetary gear 9a at the outermost end. On the other hand, the seating member 25 is fixed to the casing 2 by fastening the mounting screw 28 inserted into the mounting hole 27 formed near the outer end of the casing 2 into the screw hole 25b formed on the outer periphery of the seating member 25, and the motor M is attached to the casing 2.

  In FIG. 3, in order to disassemble the inside of the casing 2, the reducer 1 is removed from the product 30 by loosening the attachment screw 31 of the product 30 to which the reduction gear 1 is attached, and then the attachment screw 28 on the motor M side is removed. The seating member 25 is removed together with the motor M by loosening. In this state, a jig (not shown) is inserted through the shaft hole 19 of the base plate 4 from the outside and hooked inside, and this jig is pulled outward. By doing so, the respective locking claws 22, 22... Of the base plate 4 are bent inward of the annular groove 4c, and at the same time, the O-ring 23 is compressed by the inner peripheral wall 5 of the casing 2, and the base plate 4 is pulled out outward. It is. As a result, the gear housing chamber 3 is opened, and it becomes possible to disassemble and check the gear group, replace parts, and replenish grease.

  The speed reducer 1 of the present embodiment is similar to the first embodiment described above, in which the gear housing chamber 3 of the casing 2 is closed by the base plate 4 as shown in FIGS. 4 (a) and 4 (b). In this embodiment, the casing 2 is formed in a cylindrical shape, but other shapes are applicable as in the above embodiment, and the base plate 4 is formed according to the inner diameter of the casing 2. Is done.

  Further, the gear group in the gear housing chamber 3 is configured by a combination of a sun gear 8 and a plurality of planetary gears 9 as in the first embodiment, and each planetary gear is an inner tooth 6 provided on the inner periphery of the casing 2. Is in mesh.

  Further, also in this embodiment, as shown in FIG. 5, an inner peripheral groove 18 for fitting the outer periphery of the base plate 4 is formed on the inner peripheral wall 5 of the casing 2, and a plurality of outer peripheral grooves 4 on the outer periphery of the base plate 4 are formed. A locking claw 22 that is detachably locked to the inner circumferential groove 18 of the casing 2 is formed at a required location.

  In the above embodiment, the sealing performance around the base plate 4 is ensured by providing the O-ring 23 on the outer periphery of the base plate 4, but in this embodiment, as shown in FIG. It is set as the structure formed in the shape where the soft resin 4a by two-color molding protruded in the peripheral part of the hard resin 4b which comprises a main body. The outer diameter of the soft resin 4a has an outer diameter that is in close contact with the inner diameter of the inner peripheral groove 18 in a state of being fitted into the inner peripheral groove 18 of the casing 2 as shown in FIG.

  Therefore, in order to insert the base plate 4 having the soft resin 4a on the outer periphery thereof into the inner periphery of the casing 2, the soft resin 4a of the base plate 4 is attached to the inner peripheral wall 5 of the casing 2 as shown in FIG. When the outer diameter of the soft resin 4a is fitted into the inner peripheral groove 18 of the casing 2, the soft resin 4a is restored to the original outer diameter and is in close contact with the inner diameter of the inner peripheral groove 18. Crimped. As a result, sealing performance around the base plate 4 with respect to the inner circumferential groove 18 of the casing 2 can be ensured, and leakage of the grease injected into the gear housing chamber 3 can be prevented.

  Also in this embodiment, after the base plate 4 is attached to the casing 2 as described above, the drive shaft 20 of the motor M is inserted into the shaft hole 25a of the seating member 25 and the mounting hole 25c of the seating member 25 is inserted. After the mounting screw 26 is inserted and fastened to the screw hole 29 of the motor M, the seating member 25 is inserted into the casing 2 and the drive gear 21 is engaged with the planetary gear 9a at the outermost end. On the other hand, the mounting member 28 inserted into the mounting hole 27 of the casing 2 is fastened to the screw hole 25b of the seating member 25, whereby the seating member 25 is fixed to the casing 2 and the motor M is attached to the casing 2.

  In FIG. 6, in order to disassemble the inside of the casing 2, as in the first embodiment, the reducer 1 is removed from the product 30 by loosening the mounting screw 31 of the product 30, and then the mounting screw 28 on the motor M side. Is removed together with the motor M. In this state, a jig (not shown) is inserted through the shaft hole 19 of the base plate 4 from the outside and hooked inside, and this jig is pulled outward. As a result, the respective locking claws 22, 22... Of the base plate 4 bend inward of the annular groove 4c, and at the same time, the soft resin 4a on the outer periphery of the base plate 4 is compressed by the inner peripheral wall 5 of the casing 2, The main plate 4 is pulled out. As a result, the gear housing chamber 3 is opened, and it becomes possible to disassemble and check the gear group, replace parts, and replenish grease.

  INDUSTRIAL APPLICABILITY The present invention can be used for a reduction gear of a motor driving unit used for a precision machine such as a monitoring camera and a robot, and can be used for a reduction gear that requires disassembly during inspection and repair.

FIG. 2 relates to the speed reducer according to the first embodiment of the present invention, in which (a) is an end view of the speed reducer on the base plate side, and (b) is a cross-sectional view taken along line AA in (a). It is the perspective view of the base plate in Example 1 by this invention, and sectional drawing which shows a part of speed reducer. It is sectional drawing which shows the internal condition which fixed the motor to the reduction gear of Example 1 by this invention. It relates to the speed reducer of Embodiment 2 according to the present invention, (a) is an end view of the speed reducer on the base plate side, and (b) is a cross-sectional view taken along line BB in (a). It is sectional drawing which shows the perspective view of the base plate in Example 2 by this invention, and a part of reduction gear. It is sectional drawing which shows the internal condition which fixed the motor to the reduction gear of Example 2 by this invention. It is principal part sectional drawing of the conventional reduction gear. (a) is a perspective view of a conventional speed reducer, and (b) is a longitudinal sectional view thereof.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Reducer 2 ... Casing 2b ... Inner peripheral wall 3 ... Gear storage chamber 4 ... Base plate 4a ... Soft resin 4b ... Hard resin 4c ... Circular groove 5 ... Inner peripheral wall 6 ... Inner tooth 7 ... Output shaft 8 ... Sun gear 9 ... Planetary gear 9a ... outermost planetary gear 10 ... bearing 12 ... bearing member 14 ... mounting screw 16 ... shaft hole 18 ... inner peripheral groove 19 ... shaft hole 20 ... drive shaft 21 ... drive gear 22 ... locking claw 22a ... engagement Periphery 23 in which pawl is not formed ... O-ring 25 ... Seat member 25a ... Shaft hole 25c ... Mounting hole 26 ... Mounting screw 28 ... Mounting screw 30 ... Product 31 ... Mounting screw
M ... Motor

Claims (3)

In the speed reducer that closes the gear storage chamber in the casing with the base plate, an inner peripheral groove for fitting the outer periphery of the base plate is formed on the inner peripheral wall of the casing, and a plurality of locations on the outer periphery of the base plate A locking claw that is detachably locked to the inner peripheral groove of the casing is formed, and an O-ring is fitted into an outer peripheral groove formed on the outer periphery of the base plate. A speed reducer characterized by ensuring sealing performance around the base plate by being crimped to an inner circumferential groove. In the speed reducer that closes the gear storage chamber in the casing with the base plate, an inner peripheral groove for fitting the outer periphery of the base plate is formed on the inner peripheral wall of the casing, and a plurality of locations on the outer periphery of the base plate In addition, a locking claw that is detachably locked to the inner peripheral groove of the casing is formed, and a soft resin by two-color molding is formed on the periphery of the hard resin that constitutes the main body of the base plate. The speed reducer is characterized in that the soft resin is pressed into the inner peripheral groove of the casing to ensure the sealing performance around the base plate. 3. The speed reducer according to claim 1, wherein locking claws formed at a plurality of locations on the outer periphery of the base plate are detachably locked to an inner peripheral groove of the casing by elastic deformation.

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