JP2000154849A - Reduction and device provided with gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase friction coefficient on a tightening face with a mating member, improve transmission torque, and make a reduction gear and a device provided with the reduction gear compact. SOLUTION: In this reduction gear, a friction coefficient between both connecting faces 11a and 32b is increased and a transmission torque is improved by applying shot treatment or thermal spraying treatment by a material containing tungsten on the tightening faces 11a, 32b tightened on mating members 51, 52. Moreover, a face member constituted by inserting a hard core material by an elastic material is arranged on the connecting face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed reducer which is used by being fastened to a robot or the like, and a device such as a robot provided with the speed reducer. And a speed reducer capable of achieving the following.

[0002]

2. Description of the Related Art Conventionally, in an industrial robot or the like, a motor having a high speed rotation and a low torque is generally used as a high torque power source by interposing a speed reducer in a power transmission path between the motor and the robot. ing. In such a speed reducer, bolts are used for fastening to a partner member (robot member). The allowable transmission torque in this case is given by the following equation (1).
Can be represented by T = F × (D / 2) × μ × n (1) where T: allowable transmission torque, F: bolt tightening force,
D: bolt mounting PCD, μ: coefficient of friction (μ = 0.15
(When oil adheres to the fastening surface), μ = 0.2 (when the fastening surface is degreased), n: number of bolts.

In order to increase the transmission torque between the speed reducer and the robot member, in equation (1), the bolt size is increased, the bolt tightening force F is increased, the bolt PCD (D) is increased, and the number of bolts is increased. increase the number n, use other joining means together (for example, knurling,
Countermeasures such as combined use of pins and application of an adhesive) can be considered.

However, in such a case, it is necessary to increase the shaft length in the output shaft bolting type in order to secure the fastening tap depth. Further, in the case of the output shaft through bolt tightening type, since the fastening bolt penetrates the strength member, it is necessary to increase the strength member in order to secure the strength of the strength member, which undesirably affects torsional rigidity.

In the case of (1), it is necessary to increase the outer diameter as the bolt PCD increases, which leads to an increase in the size of the speed reducer. Further, increasing the size of the speed reducer is not preferable because it leads to an increase in weight and reduces the payload of the robot. In addition, the same problem as described above occurs.

In addition, the above cases have a problem that the friction coefficient varies depending on the state of the fastening surface.

[0007] In addition, the above cases have their own problems. For example, when knurling is performed, a relatively large projection is formed on the fastening surface (mounting surface), and the projection is made to bite into the surface of the mating member to improve the coefficient of friction. If the fastening surface of the shaft is a shaft, and knurling is applied to the portion of the shaft that also serves as the sealing surface, the conventional sealing method using an O-ring leaks oil from the recess formed by the projection. Therefore, it is necessary to change the sealing material to a liquid sealing material, and the sealing operation becomes complicated, which is not preferable.

[0008] Further, in the case of using a β) pin together, in order to transmit torque using the pin, it is necessary to machine the joint surface and the mating member together. Occurs. In order to prevent the chips from entering the inside of the speed reducer, a masking operation is required for the speed reducer, and extra work increases, which is not preferable.

When γ) an adhesive is used together, the adhesive strength is greatly affected by the cleanliness of the fastening surface, so that a sufficient degreasing operation is required, and the operation is troublesome. Is adhered, so that remarkable difficulties occur when disassembling for maintenance or the like, which is not preferable.

[0010]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to increase the friction coefficient on a fastening surface with a mating member by a simple structure without impairing the characteristics of a speed reducer. It is an object of the present invention to provide a speed reducer that can improve transmission torque and can be downsized.

[0011]

SUMMARY OF THE INVENTION The present invention has been made by the inventors of the present invention as a result of intensive studies to achieve the above-mentioned object. By placing a surface member formed by sandwiching a hard core material such as a metal with an elastic material such as a rubber material between the fastening surface and a mating member,
This is based on the finding that it is effective to increase the coefficient of friction between the fastening surface and the mating member.

According to the present invention, since the friction coefficient can be improved at the fastening surface with the mating member, the transmission torque of the speed reducer can be increased without taking the above-mentioned measures (1) and (2). If the transmission torque is equivalent to the conventional one, the reduction gear can be downsized.

[0013] Further, a plurality of the fastening surfaces may be provided for fastening to a mating member different from the mating member. For example, one of the fastening surfaces is a fixed surface, and the speed reducer is fastened to a robot device or the like with the fixed surface. Then, the reduction gear can be fastened to a driven member such as a robot device by using the other fastening surface as an output surface.

Further, by means of a device such as a robot device provided with a speed reducer, wherein the speed reducer as described above is fastened on the fastening surface, rotational power from a power source is transmitted through the speed reducer. In this case, since the transmitted torque increases, for example, the driven member of the robot apparatus can be driven with high torque, which is preferable. In addition, when a certain transmission torque is obtained, a reduced gear can be fastened, which can contribute to weight reduction and downsizing of the robot device, which is preferable.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, first to third embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a speed reducer showing an embodiment of the present invention, FIG. 2 is a view of the speed reducer of FIG. 1 as viewed from the direction of arrow II, and FIG. 3 is a view of the speed reducer of FIG. FIG.

First, the reduction gear according to the present embodiment will be described. The speed reducer 10 shown in FIG. 1 has an outer periphery located at the outermost periphery of the entire speed reducer and a large number of pins 1 located at an inner periphery thereof.
2 and a pair of internal gears 11 constituting a pin gear, and two external gears having external teeth meshing with the pin gear on the inner periphery of the internal gear 11 and arranged to rotate the internal gear 11. The external gears 21 and 22 and the camshaft 23 in which the cam portions 23a and 23b are fitted via cam bearing holes 24 and 25 in cam mounting holes provided at eccentric positions on the plane of the external gears 21 and 22.
And both ends of the cam shaft 23 are tapered roller bearings 26, 27.
And a support block 31 for supporting through the support.

The support block 31 has a support member 32 on the left side of FIG. 1 and a disk member 33 on the right side, and the support member 32 and the disk member 33 are positioned, as shown in FIGS. It is fixed and integrated by a plurality of fastening members 35.

A plurality of rolling members 41 are arranged between the internal gear 11 and the support member 32, and a plurality of rolling members 42 are arranged between the internal gear 11 and the disc member 33, respectively. Accordingly, the internal gear 11 is rotatably supported by the support block 31.

An input spur gear 23c is fixed to the left end of the cam shaft 23 in FIG.
c is a concave portion 3 formed on the surface of the support member 32 as shown in the figure.
2a. As shown in FIG. 3, the camshafts 23 are arranged in a pair with the center of the internal gear 11 symmetrical.

The pair of cam shafts 23 have cam portions 23a,
23b is eccentric with respect to the axis of the camshaft 23, and the external gears 21 and 22 are rotated by the rotation of the cam portions 23a and 23b, and the two external gears 21 and 22 cooperate to form the internal gear 1
1 is rotated. In addition, external gear 2
The number of teeth 1 and 22 is one more than the number of pins 12 of the internal gear 11.
Only one is less.

As shown in FIGS. 1 to 3, fastening surfaces 11a and 11b for fastening the speed reducer to a partner member such as a robot member are formed on the outermost periphery of the internal gear 11; As shown in FIGS. 2 and 3, a plurality of fastening bolt holes 11c are formed to penetrate between 11a and 11b. The flat surface 32b (FIG. 3) of the support member 32 constitutes, for example, a fastening surface to which the driven member is fastened, and has a plurality of screw holes 32c for attaching the driven member and the like.

The operation of the illustrated speed reducer will be briefly described.
When a rotational force transmitted from a power source (not shown) rotates the pair of camshafts 23 via the input spur gear 23c, the cam portions 23a and 23b rotate eccentrically with respect to the axis of the camshaft 23 to revolve. I do. The two external gears 21 and 22 are pushed via the needle bearings 24 and 25 by the revolving motion of the cam portions 23a and 23b, and thereby, the external gears 21 and 22 are pushed.
22 rotates eccentrically with respect to the axis of the internal gear 11 and revolves. Then, the external teeth of the external gears 21 and 22 move over the pins 12 of the internal gear 11, whereby the internal gear 11 is pushed and rotated by one pitch of the pins 12. When the cam portions 23a and 23b make one rotation, the external teeth of the external gears 21 and 22 ride over one pin 12, so that the internal gear 11 is reduced in speed by the reciprocal of the number of pins 12.
Rotates. When the internal gear 11 is fixed,
The support block 31 rotates.

According to the above-described speed reducer, a large reduction ratio can be realized, a high-speed rotating low-torque motor can be used as a high-torque power source, and the torsional rigidity is large and a high-torque torque can be transmitted. Becomes

<First Embodiment> In the first embodiment, a thermal spraying process is performed on the fastening surfaces 11a and 11b and the flat surface (fastening surface) 32b shown in FIGS. is there. That is, using WC (tungsten carbide) as a thermal spraying material, the fastening surfaces 11a, 11b, and 32b are sprayed on the fastening surfaces 11a, 11b, and 32b to a thickness of several tens of μm by a known high-speed flame spraying method. WC
A sprayed film is formed. Such fastening surfaces 11a, 11b, 32
The following effects can be obtained by forming the sprayed film in b.

It is possible to increase the coefficient of friction up to about two to three times as compared with the conventional case. Therefore, the transmission torque in the reduction gear can be increased.

The friction coefficient is not affected by the degreasing state of the fastening surface. Therefore, it is possible to contribute to the improvement of the productivity of the speed reducer without taking time for the degreasing step of the fastening surface.

The fastening surface is not affected by the condition of the fastening surface--a constant friction coefficient can be obtained. Therefore, when attaching the speed reducer to the robot member or the like, the degreasing work is not required, and the working process and the adjusting process are simplified.

Even if the speed reducer is attached to and detached from a robot member or the like for adjustment or maintenance and the like, the high friction coefficient can be maintained on the fastening surface regardless of the number of times of attachment and detachment. Therefore, adjustment and maintenance are facilitated, and the service life of the speed reducer can be extended, and the usability is improved.

Since the sprayed film effectively protects the fastening surface, it is possible to prevent the fastening surface from being damaged. Therefore, handling, such as processing, transportation, and storage of the speed reducer, is facilitated, and special protection is not required for the fastening surface, so that no labor is required.

As described above, according to the speed reducer of the present embodiment, the coefficient of friction of the fastening surface with the robot member or the like can be increased, so that the characteristics of the speed reducer such as high torsional rigidity are not sacrificed at all. In addition, the transmission torque can be increased. Also,
When the transmission torque may be equal to the conventional one, the reduction gear can be reduced in size.

The thermal spraying materials include nickel, nickel graphite, molybdenum, copper, aluminum oxide, nickel alumina, aluminum tintanania, chromium oxide, zirconia, titanium dioxide, chromium carbide nichrome, tungsten carbide, tungsten, and titanium carbide. , Zirconium oxide, cobalt, and other metal materials and ceramics can be used, and a mixture of a plurality of these may be used. Above all, a material containing tungsten or a material coated with titanium is preferable, and tungsten carbide (WC) is particularly preferable. Further, a mixture of WC and one or more of the above materials is preferable. In addition, as the thermal spraying method, a known method such as arc thermal spraying, plasma thermal spraying, and wire explosive thermal spraying can be applied in addition to flame thermal spraying.

Next, an example of a robot apparatus in which the above-described speed reducer is attached to a mating member will be described with reference to FIGS. In the example of FIG. 4, the robot member 51 of the robot apparatus is connected to the fastening surface 1 of the internal gear 11 of the speed reducer 10 shown in FIGS.
1a by a plurality of fastening bolts 51a for fastening, and the driven member 52 of the robot apparatus is fastened to the fastening surface 32b of the support member 32 of the speed reducer 10 by a plurality of fastening bolts 52a.
It is attached and fastened by. A hole is formed in the robot member 51, and the disk member 33 and the like of the speed reducer 10 enter the hole.

In the example shown in FIG. 4, the WC sprayed layer is formed on each of the fastening surfaces 11a and 32b as described above, and is formed between the fastening surface 11a and the fastening surface 51b of the robot member and between the fastening surface 32b and the fastening surface 32b. The friction coefficient between the driving member 52 and the fastening surface 52b is large. For this reason, the rotational torque from the power source such as the motor input from the input spur gear 23c is efficiently transmitted to the driven member 52 via the speed reducer 10, and the driven member 52 is rotationally driven with high torque. be able to. If a constant torque is sufficient, the reduction gear can be reduced in size, so that the robot device can be reduced in weight and size.

In the example shown in FIG. 5, the robot member 51 of the robot apparatus is attached and fastened to the fastening surface 11b of the internal gear 11 of the speed reducer 10 shown in FIGS. 1 to 3 by a plurality of fastening bolts 51a. Has the same configuration as that of FIG. Further, a hole is formed in the robot member 51, and the left portion of the speed reducer 10 in the drawing enters into the hole and penetrates. In FIG. 5, the WC sprayed layer is formed on each of the fastening surfaces 11b and 32b as described above, so that the fastening surface 11b is fastened to the fastening surface 51c of the robot member and the fastening surface 32b is fastened to the driven member 52. The friction coefficient with the surface 52b is large. Therefore, the same effect as in the example of FIG. 4 can be obtained.

<Second Embodiment> In a second embodiment, a shot process is performed on the fastening surfaces 11a, 11b and 32b shown in FIGS. The shot process is a surface treatment method in which a large number of projectiles such as small particles made of steel or the like are projected onto a surface to be processed at a high speed, thereby processing the surface to be processed to form a uniform rough surface. The following effects can be obtained by applying a pressurized air blast method as the shot projection method and optimizing the projection material, the projection time, the projection angle of the projection material in the projection direction with respect to the surface to be processed, and the like.

The friction coefficient is 1.5 to 2 compared with the conventional case.
It is possible to increase up to about twice. Therefore, the transmission torque in the reduction gear can be increased.

The fastening surface is not affected by the condition of the fastening surface--a constant friction coefficient can be obtained. Therefore, when attaching the speed reducer to the robot member or the like, the degreasing work is not required, and the working process and the adjusting process are simplified.

The surface roughness of the fastening surface should be within a range where there is no problem in sealing with the O-ring when the O-ring is arranged (Ra6).
８8 μm), so there is no adverse effect of shot processing.

Even if the speed reducer is attached / detached from the robot member or the like for adjustment or maintenance, and the attachment / detachment is repeated within the practical number of attachment / detachment assumed for the robot speed reducer, the fastening surface is not affected by the number of attachment / detachment It is possible to maintain a high coefficient of friction. Therefore, adjustment and maintenance are facilitated, and the service life of the speed reducer can be extended, and the usability is improved.

The surface roughness of the fastening surface by the shot processing of the present embodiment can be optimized by experiments and the like.

As described above, according to the speed reducer of the present embodiment, the coefficient of friction of the fastening surface with the robot member and the like can be increased, so that the characteristics of the speed reducer such as high torsional rigidity are not sacrificed at all. In addition, the transmission torque can be increased. Also,
When the transmission torque may be equal to the conventional one, the reduction gear can be reduced in size.

Further, the speed reducer 1 having the above-described shot processing applied to the fastening surface 11a or 11b and the fastening surface 32b.
0 can be attached and fastened to the robot device in the same manner as in FIGS. 4 and 5, whereby the same effect as in FIGS. 4 and 5 can be obtained.

<Third Embodiment> A third embodiment is directed to a robot apparatus having the same structure as that shown in FIGS. 4 and 5 in which the fastening surface 11a of the speed reducer 10 and the robot member 51 are arranged as shown in FIG. And between the fastening surface 32b and the fastening surface 52b of the driven member 52, respectively.
1, 62 are interposed. Also, as shown in FIG. 7, face members 61 and 62 are interposed between the fastening surface 11b of the speed reducer 10 and the fastening surface 51c of the robot member, and between the fastening surface 32b and the fastening surface 52b of the driven member 52, respectively. It was made. Therefore, the configuration of FIG. 6 is the same as that of FIG. 4 and the configuration of FIG. 7 is the same as that of FIG. 5, and therefore, the same portions are denoted by the same reference numerals and description thereof is omitted.

FIG. 8 is a longitudinal sectional view of the above-mentioned surface member 61. The surface member 61 includes a sheet-like hard core material 71 made of a metal material, and rubber materials 72a and 72 as elastic materials made of a rubber material which are disposed on both surfaces thereof and adhered with an adhesive.
b. As shown in FIG.
Is arranged between the fastening surface 11a of the robot member 51 and the fastening surface 51b of the robot member 51, and is configured to have a surface shape suitable for this, and a plurality of holes 71a through which a plurality of fastening bolts 52a penetrate.
Are formed. The surface member 62 has the same configuration as that of FIG. 8 except for the surface shape. The core 71 is
It is preferable to use a metal material such as steel.
A PCC material can be used, but is not limited thereto. As the rubber material, synthetic rubber, hard rubber, or the like can be used. The adhesive can be a thermosetting adhesive,
Other adhesives may be used.

Here, it is conceivable to simply sandwich the rubber member between the fastening surface of the speed reducer and the mating member. However, according to this method, the torsional rigidity of the speed reducer is reduced due to the elasticity of the rubber. . Further, since the rubber material has a characteristic of creeping when compressed, the problem of loosening of the fastening bolt is likely to occur with the passage of time, so that the fastening bolt needs to be retightened. In order to solve such a problem, in the present embodiment, rubber materials 72a, 72b which are relatively thin (several ten μm) are provided on both surfaces of a core material 71 made of a metal material.
As described above, the surface members 61 and 62 with which are joined are sandwiched between the fastening surface of the reduction gear and the mating member.
Thereby, the following effects can be obtained.

When only the rubber material is interposed, the torsional rigidity of the speed reducer is reduced due to the elasticity of the rubber. However, according to the surface member according to the present embodiment, since the rubber material is relatively thin, the torsional rigidity is reduced. Can be prevented from decreasing.

Since the friction coefficient between the fastening surface of the speed reducer and the mating member can be increased, the transmission torque can be increased without sacrificing the characteristics of the speed reducer such as high torsional rigidity. Further, when the transmission torque may be equal to the conventional one, the reduction gear can be downsized.

Since the rubber layer of the rubber material cuts into the unevenness of the fastening surface, the surface member has a sealing property and plays a role as a sealing material. Therefore, it is necessary to apply another sealing means such as an O-ring or a sealant. Is eliminated, workability is improved, and it is possible to contribute to improvement in productivity.

According to the surface member of the present embodiment, since the rubber material is relatively thin, the creep angle is minimized, so that the problem of loosening of the fastening bolt over time can be solved. No additional tightening is required, and workability is improved.

The rubber material of the face member makes it possible to cut off the vibration, to obtain a vibration-proof / sound-proofing effect in a robot device equipped with a speed reducer, and the speed reducer itself can preferably have a vibration damping function.

Since the insulating rubber is used as the rubber material, the rubber material has electrical insulation, so that it can be applied to the case where the robot device needs the electrical insulation of the reduction gear.

Since the core material is a metal core, the rigidity is higher than when the surface member is formed only of the rubber material, the handling is easy, and the mounting line for automatically mounting the surface member is extremely automated. It becomes simple and can contribute to improvement of productivity.

As described above, according to the present embodiment, it is possible to improve the transmission torque of the reduction gear or to reduce the size thereof, and it is possible to provide a function not provided in the conventional reduction gear. This is preferable because the added value of the speed reducer increases.

Further, in the robot apparatus in which the speed reducer is fastened as shown in FIGS. 6 and 7, the rotational torque from a power source such as a motor input from the input spur gear 23c is efficiently received via the speed reducer 10. Because it is transmitted to the drive member 52,
The driven member 52 can be rotationally driven with high torque. If a constant torque is sufficient, the reduction gear can be reduced in size, so that the robot device can be reduced in weight and size.

Although a rubber material is used in the present embodiment, an elastic material other than the rubber material may be used.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to this.
Various modifications are possible within the scope of the technical idea of the present invention. For example, in the present embodiment, the speed reducer is capable of transmitting power at a relatively large speed reduction ratio by using an external gear that moves eccentrically. However, the present invention can also be applied to other types of speed reducers. Also,
The device for fastening the speed reducer is not limited to the robot device, and may be another industrial machine (a winch or the like). Also, FIG.
In FIG. 7, the fastening surface 11a or 11b and the fastening surface 3
Only one of 2b may be subjected to the shot processing or the thermal spray processing according to the present invention, and a surface member may be disposed. Alternatively, one of the fastening surfaces 11a or 11b and the fastening surface 32b may be a shot processing surface or a thermal spraying surface, and a surface member may be disposed on the other.

[0056]

According to the present invention, it is possible to increase the friction coefficient on the fastening surface with the mating member by a simple structure without impairing the characteristics of the speed reducer, to improve the transmission torque, and to reduce the size. Can be provided.

Further, according to the device provided with such a speed reducer, the driven member of the device can be driven with high torque, and a reduced speed reducer can be fastened, which contributes to the weight reduction and size reduction of the device.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a speed reducer according to an embodiment of the present invention.

FIG. 2 is a view of the speed reducer of FIG. 1 as viewed from an arrow direction II.

FIG. 3 is a view of the speed reducer of FIG. 1 as viewed from an arrow direction III.

FIG. 4 is a diagram showing a state where the speed reducer of FIG. 1 is attached to a robot device.

FIG. 5 is another view showing a state where the speed reducer of FIG. 1 is attached to a robot device.

FIG. 6 is a diagram showing a state in which the speed reducer of FIG. 1 is attached to a robot device using a surface member.

FIG. 7 is another view showing a state in which the speed reducer of FIG. 1 is attached to a robot device by using a surface member.

8 is a longitudinal sectional view of the surface member shown in FIGS. 6 and 7. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Reduction gear 11 Internal gear 11a, 11b Fastening surface 32 Support member 32b Fastening surface 51 Robot member (partner member) 52 Driven member (another partner member) 51a, 52a Fastening bolt 61, 62 Surface member 71 Core material (hard) Core material) 72a, 72b Rubber material (elastic material)

Claims (4)

[Claims] 1. A speed reducer having a fastening surface that is fastened to a mating member to reduce and transmit power from a power source, wherein the fastening surface is subjected to a shot process or a thermal spray process using a tungsten-containing material. A speed reducer characterized in that: 2. A speed reducer having a fastening surface that is fastened to a mating member for transmitting power from a power source at a reduced speed, wherein the speed reducer includes a surface member formed by sandwiching a hard core material with an elastic material. A speed reducer characterized by being arranged on a fastening surface. 3. The reduction gear according to claim 1, wherein a plurality of the fastening surfaces are provided for fastening to a mating member different from the mating member. 4. An apparatus provided with a speed reducer, wherein the speed reducer according to claim 1, 2, or 3 is fastened at the fastening surface.