JP6726925B2 - Eccentric swing type speed reducer - Google Patents

Description

The present invention relates to an eccentric rocking type reduction gear transmission.

Patent Document 1 discloses an eccentric rocking type reduction gear transmission.

The eccentric oscillating type reduction gear device includes an internal gear and an external gear that is inscribed in the internal gear while oscillating, and takes out relative rotation between the internal gear and the external gear as an output.

The internal gear has a configuration including an internal gear main body, a pin groove formed in the internal gear main body, and a pin member arranged in the pin groove. The pin member constitutes the internal teeth of the internal gear, and can rotate while being arranged in the pin groove.

In Patent Document 1, a technique of applying a chemical conversion coating to the tooth surface of the external gear is proposed.

JP-A-62-132068 (FIG. 1)

However, Patent Document 1 applies the chemical conversion coating to the external teeth of the external gear of the eccentric oscillating reduction gear, and particularly discloses an example of applying the chemical conversion coating to the pin groove of the internal gear. There wasn't.

The present invention has been made in view of such a conventional situation, and is an eccentric oscillating type deceleration that can perform more efficient operation in terms of applying a low friction coating to the pin groove of the internal gear. The challenge is to obtain a device.

According to the present invention, an internal gear has an internal gear main body, a plurality of pin grooves formed in the internal gear main body and having a substantially semicircular cross section perpendicular to the axis, and rotatably arranged in each of the plurality of pin grooves. Pin member,
A eccentrically oscillating speed reducer device having a low friction coating is applied to the pin grooves, said Rinsanman
The root-mean-square roughness Rq obtained on the basis of the roughness measured in the axial direction of the pin groove after the gun coating is set to 0.5 μm or more and 2.5 μm or less to solve the above problems. It has been resolved.

As will be described in detail later, with this configuration, by applying the low-friction coating, it is possible to further improve the operation efficiency.

According to the present invention, it is possible to obtain an eccentric oscillating speed reducer capable of performing highly efficient operation in terms of applying a low-friction coating to a pin groove of an internal gear.

Sectional drawing which shows the whole structure of the eccentric oscillating type reduction gear device which concerns on an example of embodiment of this invention. Enlarged cross-sectional view of the main part of the internal gear body of the internal gear of FIG. Graph after 6 hours showing the relationship between operating efficiency and root mean square roughness Rq Familiar graph showing the relationship between operating efficiency and root mean square roughness Rq

Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

First, the overall configuration of an eccentric rocking type reduction gear transmission according to an example of an embodiment of the present invention will be described.

FIG. 1 is a cross-sectional view showing the overall configuration of the eccentric rocking type reduction gear transmission.

The input shaft 12 of this eccentric rocking type reduction gear G is integrated with a motor shaft 14A of a motor 14. A crankshaft 20 having two eccentric portions 18 is connected to the input shaft 12 via a key 16.

The axis C18 of each eccentric portion 18 is eccentric with respect to the axis C12 of the input shaft 12. In this example, the eccentric phase difference of the eccentric part 18 is 180 degrees. A roller bearing 22 is arranged on the outer circumference of the eccentric portion 18. Two external gears 24 are swingably incorporated on the outer circumference of the roller bearing 22. Two external gears 24 are provided in parallel in the axial direction because it is intended to secure the necessary transmission capacity and improve the rotational balance. The external gears 24 are internally meshed with the internal gears 30, respectively.

That is, in this eccentric oscillating reduction gear G, the crankshaft 20 for oscillating the external gear 24 has a radial center of the device (the axial center C12 of the input shaft 12 and the axial center C30 of the internal gear 30). It is an eccentric oscillating type speed reducer called "center crank type" arranged coaxially.

The internal gear 30 is arranged in the internal gear main body 32 integrated with the casing 28 (a casing main body 52 which will be described later), the pin groove 34 formed in the internal gear main body 32, and the pin groove 34. And an outer pin (pin member) 36. The outer pin 36 constitutes an inner tooth of the internal gear 30. The number of internal teeth of the internal gear 30 (the number of external pins 36) is slightly larger than the number of external teeth of the external gear 24 (in this example, only 1). The configuration of the internal gear 30 and its manufacturing method will be described in detail later.

The external gear 24 has a plurality of through holes 24A formed at a position offset from its axis (same as the axis C18). The inner pin 40 is fitted in the through hole 24A. The inner pin 40 is press-fitted and fixed to the inner pin holding hole 42A of the flange body 42 arranged on the axial side portion of the external gear 24. The flange body 42 is integrated with the output shaft 44. The output shaft 44 is supported by a pair of tapered roller bearings 46.

In this embodiment, the inner roller 48 is fitted on the inner pin 40 as a sliding promoting member. A part of the inner roller 48 is in contact with the inner peripheral surface of the through hole 24A of the external gear 24. The outer diameter of the inner roller 48 is smaller than the inner diameter of the through hole 24A, and a maximum gap corresponding to twice the eccentric amount of the eccentric portion 18 is provided between the inner roller 48 and the inner peripheral surface of the through hole 24A. Has been secured. Since the inner pin 40 (and the inner roller 48) penetrates the external gear 24, it moves in synchronization with the rotation of the external gear 24.

On the other hand, the casing 28 of the eccentric rocking type reduction gear transmission G has a casing main body 52 for accommodating the reduction gear mechanism portion 50 and an output casing body 54 for accommodating the output shaft 44. An anti-load side cover 56 (also functioning as a motor cover) is arranged on the axial main load side of the casing body 52, and a load side cover 57 is provided on the axial load side of the output casing body 54. It is arranged. The eccentric rocking type reduction gear G is fixed to a fixing member by a bolt (not shown) through a bolt hole 58A of the leg portion 58.

The eccentric oscillating speed reducer G has the above-described configuration, and rotates the motor shaft 14A of the motor 14 to rotate the two eccentric portions 18 of the crankshaft 20 connected to the input shaft 12. .. Then, the external gear 24 oscillates and meshes with the internal gear 30 (specifically, the external pin 36 forming the internal teeth of the internal gear 30). As a result, each time the input shaft 12 rotates once and the external gear 24 oscillates once, the external gear 24 has a difference in the number of teeth between the internal gear 30 and the external gear 24 (in this example, 1). Rotate by the amount of (teeth). As a result, this rotation component can be transmitted to the flange body 42 via the inner pin 40 and the inner roller 48, and the output shaft 44 integrated with the flange body 42 can be decelerated and rotated.

Next, the configuration near the internal gear 30 will be described in detail.

FIG. 2 is an enlarged cross-sectional view of a main part of the internal gear body 32 of the internal gear 30 of FIG.

As described above, the internal gear 30 includes the internal gear main body 32, the pin groove 34 formed in the internal gear main body 32, and the external pin (pin) that is arranged in the pin groove 34 and constitutes an internal tooth. Member) 36. The internal gear body 32 of the internal gear 30 is integrated with the casing body 52. That is, the internal gear main body 32 is the same member as the casing main body 52. In the present specification, for the sake of convenience, the internal gear body 32 will be collectively referred to.

The internal gear main body 32 is entirely formed of a substantially ring-shaped member. A step portion 32A for forming a spigot portion with the anti-load side cover 56 and a step portion 32B for constituting a spigot portion with the output casing body 54 are formed on both axial sides of the internal gear body 32. Has been done.

On the inner circumference of the internal gear body 32, pin grooves 34 are formed at equal intervals in the circumferential direction and for the number of teeth of the internal teeth, respectively, over the entire axial length. The pin groove 34 is formed of a groove whose cross section perpendicular to the axis has a substantially semicircular shape. In the pin groove 34, an outer pin (pin member) 36 that constitutes an internal tooth of the internal gear 30 is rotatably arranged.

In FIG. 1, reference numeral 32F is a bolt hole for connecting the counter-load side cover 56 and the output casing body 54 to the internal gear main body 32, and in FIG. 2, reference numeral 35 is an O-ring groove.

Hereinafter, the configuration of the pin groove 34 will be described in more detail together with the description of the surface texture thereof.

The inventors of the present invention are concerned with the roughness of the pin groove 34 of the internal gear main body 32 of the eccentric oscillating speed reducer G, that is, the pin groove 34 in which the external pin 36 forming the internal teeth of the internal gear 30 is arranged. The surface roughness of the pin groove 34) and the operation efficiency were tested. Specifically, first, the machining method is changed, or even with the same machining method, the tool specifications are changed and the feed rate is changed to obtain the pin grooves 34 having various roughnesses, and the roughness and the operation efficiency are obtained. The relationship with (%) was investigated. Next, a low-friction coating was applied to the pin groove 34 of each roughness, and the relationship between the roughness after applying the low-friction coating and the operating efficiency η was investigated.

In this test, the root mean square roughness Rq is measured as an index of roughness. The root mean square roughness Rq is the root mean square roughness (the square of the value of the height component at each position of the roughness curve, which is obtained for the reference length in the roughness curve defined in JIS B0601. Roughness is the average of the square root.

The root-mean-square roughness Rq can be a conceptual index close to the average roughness on the mountain side (height direction) of the peaks and valleys when the surface roughness of the pin groove 34 is captured in a cross section. It is considered that the operation efficiency has a large correlation with the friction coefficient, and the friction coefficient has a large correlation with the roughness on the mountain side. Therefore, in this test, the root mean square roughness Rq is adopted as an index of the roughness. .. In this test, a manganese phosphate coating is used as the low friction coating.

In this test, a boring process, a gear shaper process, a barrel process, a honing process, and a skiving process are adopted in order to obtain the pin grooves 34 of various surface roughness (root mean square roughness Rq). ..

The boring process adopted in this test is the so-called "boring", and the prepared hole pre-processed with a drill etc. is enlarged with a single blade (single point cutting tool) to increase the pin groove. It is a process for forming 34.

Further, the gear shaper machining adopted in this test is a machining in which a tool called a pinion cutter is reciprocated, and when the work advances in one direction, the work (internal gear body 32) is cut and returned. ..

Further, the barrel processing adopted in this test is a processing in which an abrasive, a work (internal gear main body 32) and a working fluid are put in a container called a barrel and the surface is finished by rotating or vibrating. is there. Incidentally, also in the barrel processing, a preliminary hole processing such as a drill or a gear shaper processing is performed in advance as a preprocessing.

The honing process used in this test is a process of precisely grinding (grinding) the inner circumference of a pre-formed hole by boring using a tool called a horn to which multiple grindstones are attached. That is. ..

The skiving process adopted in this test is created by a speed difference generated by rotating a tool called a skiving cutter and a work (internal gear main body 32) at an angle (for example, synchronous rotation). It is processing. In order to form the pin groove 34 of the internal gear main body 32 in the present embodiment by skiving, for example, in the processing machine described in Utility Model Registration No. 3181136, the pin groove 34 according to the present embodiment can be processed. The processing machine can be used by appropriately performing necessary customization (specifically, customizing the tool so as to machine an arc shape).

The diameter of the circular arc of the pin groove 34 to be tested is 6.0 mm, the axial length is 40.5 mm, and the material of the internal gear body 32 is FC200. The material of the outer pin 36 is SUJ2, which is processed by grinding. The surface roughness of the outer pin 36 is about Rq 0.2 μm in terms of root mean square roughness.

The test conditions (test process) are as follows.
(A) First, the pin groove 34 is processed on the casing main body 52 by various processing methods to manufacture a plurality of types of internal gears 30 without a low friction coating (having different roughness). Similarly, the pin groove 34 is processed in the casing main body 52 by various processing methods, and a plurality of types of internal gears 30 having low friction coatings (having different roughness) are manufactured.

Then, the root mean square roughness Rq of each of the internal gear 30 without the low friction coating and the internal gear 30 with the low friction coating is measured before the operation.

Further, both the internal gear 30 without the low friction coating and the internal gear 30 with the low friction coating, the operating efficiency η is measured after continuous operation for 6 hours and after the familiar operation is completed. ..

Here, “after the familiar operation is completed” means “after a lapse of time from the start of operation until the temperature change of the outer periphery of the casing 28 becomes 1° C./hr or less”. In short, after the familiar operation is completed, "the temperature of the outer circumference of the casing 28 rises by starting the operation, the temperature rise gradually becomes gentle, and the temperature rises in 1 hour becomes 1°C or less. It means "after being thermally stable".
(B) Roughness measurement was performed in the axial direction of the pin groove 34 using "Form Talysurf PGI840" manufactured by TAYLOR HOBSON to obtain a roughness curve, and a root mean square roughness based on the roughness curve. Get Rq.
(C) Regarding the accuracy of the traverse unit, "driving speed: 0.25 mm/sec", "measurement take-in interval: 0.125 µm", "stylus pressure: 80 mgf", and filter setting "form: LS line" , "Filter: Gaussian", "Cutoff (Lc): 0.8 mm", "Cutoff (Ls): 0.0025 mm", "Bandwidth: 300:1". For stylus specifications, "Tip radius : 2 μm” and “shape: 60° cone” to measure the roughness.

The operating efficiency η was measured as follows. First, the motor 14 is connected to the input shaft 12 of the eccentric oscillating speed reducer G, the brake device as a load is connected to the output shaft 44, and the legs 58 are fixed to a fixing member such as a floor. In this state, the load of the brake device is set to the rated torque of the eccentric oscillating reduction gear G, and the motor 14 is driven. Then, the input torque at the input shaft 12 and the output torque at the output shaft 44 were measured, and the operating efficiency η was obtained from the measurement result by the calculation formula of {output torque/(input torque×reduction ratio)}×100%.

The measurement results after continuous operation for 6 hours in this test are shown in FIG.

In FIG. 3, the plots filled in with black are the data of the test piece (pin groove 34) not applied with the low friction coating, and the plotted plots with white are the data of the test pieces provided with the low friction coating, respectively. Showing.

For convenience, the root mean square roughness Rq is classified into the following six groups based on the measured data and the findings described below.

First group: groove of 2.5 μm<Rq Second group: group of 1.8 μm≦Rq≦2.5 μm Third group: group of 1.2 μm≦Rq<1.8 μm Fourth group: 0.65 μm≦Rq <1.2 μm group Fifth group: 0.5 μm≦Rq<0.65 μm group Sixth group: Rq<0.5 μm group

Then, a sample having no manganese phosphate coating (a sample not having a manganese phosphate coating), which has a root mean square roughness Rq belonging to any one of the first to sixth groups, is a first sample. They are called no group to sixth no group. In addition, a sample having a manganese phosphate coating (a sample having a manganese phosphate coating), which has a root-mean-square roughness Rq belonging to any of the first to sixth groups, is a first group. The present group to the sixth present group are called.

First, the pin groove 34 is formed by boring, and the manganese phosphate coating is not applied, so that the root mean square roughness Rq exceeds 2.5 μm. The pin groove 34 of the first non-group B1 (black star mark: 3 pieces) were obtained. The operating efficiency ηB1 of the first no-group B1 after 6 hours was about 90.6 to 91.2%.

On the other hand, by forming the pin groove 34 by boring and applying the manganese phosphate coating, the root mean square roughness Rq after forming the coating (after applying the low friction coating) is more than 2.5 μm. A1 pin groove 34 (white star mark: 3 pieces) was obtained. The operating efficiency ηA1 of the first existence group A1 after 6 hours was about 91.0 to 91.1%.

As the next measurement step, the pin groove 34 is formed by gear shaper processing, and the manganese phosphate coating is not applied, so that the root mean square roughness Rq is 1.8 μm or more and 2.5 μm or less. 34 (black triangles ▲: 3 pieces) were obtained. The operating efficiency ηB2 of the second no-group B2 after 6 hours was about 91.2 to 91.7%.

On the other hand, by applying the manganese phosphate coating to the pin groove 34 formed by the gear shaper processing, the root mean square roughness Rq after the coating is formed (after the low friction coating is applied) is 1.8 μm or more and 2.5 μm or less. The pin groove 34 (white triangle mark Δ: 3 pieces) of the second existence group A2 was obtained. The operating efficiency ηA2 of the second existence group A2 after 6 hours was about 93.6 to 93.9%.

Further, as the next measurement step, the pin groove 34 is formed by gear shaper processing having tool specifications different from the gear shaper processing of the second non-group B2, and the root mean square roughness Rq is obtained by not applying the manganese phosphate coating. A pin groove 34 (black triangle mark ∘: 3) of the third non-group B3 having a size of 1.2 μm or more and less than 1.8 μm was obtained. In this test, the specific differences between the tool specifications of the second no-group B2 and the third no-group B3 are the blade angle of the tool and the presence/absence of coating on the blade (in the second no-group B2, coating). None). The operating efficiency ηB3 of the third non-group B3 after 6 hours was about 91.1 to 92.5%.

On the other hand, by applying the manganese phosphate coating to the pin groove 34 formed by the same gear shaper processing as the third non-group B3, the root mean square roughness Rq after the coating is formed (after the low friction coating is applied) is 1 The pin groove 34 (white triangle mark Δ: 3 pieces) of the third group A3 having a size of 0.2 μm or more and less than 1.8 μm was obtained. The operating efficiency ηA3 of the third existence group A3 after 6 hours was about 94.1 to 94.3%.

Further, as the next measurement step, the pin groove 34 is formed by barrel processing, and the manganese phosphate coating is not applied, so that the root-mean-square roughness Rq of 0.65 μm or more and less than 1.2 μm is included in the pin of the fourth non-group B4. Grooves 34 (black diamonds: 3 pieces) were obtained. The operating efficiency ηB4 of the fourth no-group B4 after 6 hours was about 92.7 to 93.6%.

On the other hand, by applying the manganese phosphate coating to the pin groove 34 formed by barrel processing, the root mean square roughness Rq after the coating is formed (after the low friction coating is applied) is 0.65 μm or more and less than 1.2 μm. The pin grooves of the fourth group A4 (white diamonds: 3) were obtained. The operating efficiency ηA4 of the fourth existence group A4 after 6 hours was about 94.2 to 94.4%.

Further, as the next measurement step, the pin groove 34 is formed by honing and the manganese phosphate coating is not applied, so that the root-mean-square roughness Rq is 0.65 μm or more and less than 1.2 μm and is the pin of the fourth non-group B4. Grooves 34 (black circles: 3) were obtained. The operating efficiency ηB4 of the fourth no-group B4 after 6 hours was about 94.0 to 94.2%.

On the other hand, by applying the manganese phosphate coating to the pin groove 34 formed by the honing process, the root mean square roughness Rq after the coating is formed (after the low friction coating is applied) is 0.5 μm or more and less than 0.65 μm. The pin grooves 34 (white circles ◯: 3 pieces) of the fifth existence group A5 were obtained. As described above, the root mean square roughness Rq of the pin groove 34 obtained by the honing process when the manganese phosphate coating is not applied belongs to the fourth non-group B4, but the manganese phosphate coating is applied. As a result, the root mean square roughness Rq became the smoother pin groove 34 belonging to the fifth existence group A5. The operating efficiency ηA5 of the fifth existence group A5 after 6 hours was about 94.4 to 94.8%.

Further, as the next measurement step, the pin groove 34 of the sixth non-group B6 having a root mean square roughness Rq of less than 0.5 is formed by forming the pin groove 34 by skiving and not applying the manganese phosphate coating ( Black squares (3: 3) were obtained. The operating efficiency ηB6 of the sixth no-group B6 after 6 hours was about 93.8 to 94.1%.

On the other hand, by applying the manganese phosphate coating to the pin groove 34 formed by skiving, the sixth root-mean-square roughness Rq after the coating formation (after the low friction coating is applied) is less than 0.5 μm. The pin groove 34 (white square □: 3 pieces) of group A6 was obtained. The operating efficiency ηA6 of the sixth existence group A6 after 6 hours was about 94.2 to 94.7%.

In addition, FIG. 4 is a graph showing the data of the operation efficiency measured after the familiarization (after the familiarization operation is completed) similarly to FIG. 3. In the following description, verification will be performed based on the data of FIG. 3 described above, and in comparison with FIG. 3, the data of FIG. 4 after this familiarity will be appropriately referred to.

The following findings can be obtained from the data of each graph.

<Knowledge (1)>
A region where it can be said that there is a merit to apply the low friction coating to the pin groove 34 is a region where the root mean square roughness Rq after applying the low friction coating is 0.5 μm or more and 2.5 μm or less.

First, between the 1st existence group A1 whose root mean square roughness Rq after applying a low friction coating exceeds 2.5 μm, and the 2nd existence group A2-6th existence group A6 of 2.5 μm or less, The fact that there is the first threshold value S1 (2.5 μm) will be verified.

Referring to FIG. 3 (after 6 hours), the first-existing group A1 (white star mark ☆) in which the root mean square roughness Rq after the boring process and the low-friction coating exceeds 2.5 μm is In comparison with the first no-group B1 (black star), which does not have a low friction coating, no improvement in operating efficiency was observed (90.6-91.2% → 90.5-91.1). %). In other words, the area (the first existence group A1) where the root mean square roughness Rq after applying the low friction coating exceeds 2.5 μm (even if the low friction coating is applied at the cost and labor) It can be verified that there is no point in applying a low-friction coating, as no increase in operating efficiency was observed as compared with the case where no coating was applied.

On the other hand, in the second existence group A2 to the sixth existence group A6 in which the root mean square roughness Rq after applying the low friction coating is 2.5 μm or less (although there is a difference in degree), the low friction coating is used. The fact that the operating efficiencies ηA2 to ηA6 when applied is higher than the operating efficiencies ηB2 to ηB6 when the low friction coating is not applied is recognized (meaning that the low friction coating is applied).

From this, between the 1st existence group A1 whose root mean square roughness Rq after applying a low friction film exceeds 2.5 μm, and the 2nd existence group A2-6th existence group A6 of 2.5 μm or less. In addition, the first threshold S1 exists, and it can be verified that the low-friction coating has the advantage of being applied to the pin groove 34 having a root mean square roughness Rq of 2.5 μm or less after the low-friction coating is applied.

Next, between the sixth organic group A6 having a root mean square roughness Rq of less than 0.5 μm after applying the low friction coating and the fifth organic group A5 of 0.5 μm or more (less than 0.65 μm). , And that there is a second threshold value S2 (0.5 μm).

According to the graph of FIG. 3 after 6 hours, the operating efficiency ηB6 of the sixth non-group B6 (black square ■) without the low-friction coating is higher than the operating efficiency ηB6 of the low-friction coating. The operating efficiency ηA6 of the square □) is higher (increased from about 93.8 to 94.1% → about 94.2 to 94.7%).

However, according to the graph of FIG. 4 after familiarization, there is a difference between the operating efficiency ηB6 of the sixth non-group B6 where the low friction coating is not applied and the operating efficiency ηA6 of the sixth existence group A6 where the low friction coating is applied. unacceptable. It is related to the fact that the operating efficiency ηB6 (black square ■) of the sixth no-group B6 without the low-friction coating is “increased” in FIG. 4 after familiarization than in FIG. 3 after 6 hours. No. (93.8-94.1%→94.0-94.4%), the operation efficiency ηA6 of the sixth existence group A6 (white square □) provided with the low friction coating is shown in FIG. This is because the figure in FIG. 4 after the familiarity is “decreased” to the contrary (94.2 to 94.7%→94.2 to 94.4%).

As a result, in FIG. 4 after familiarization, there is almost no difference between the operating efficiency ηB6 of the sixth non-group B6 where the low friction coating is not applied and the operating efficiency ηA6 of the sixth existence group A6 where the low friction coating is applied. ing. In other words, the region where the root mean square roughness Rq is less than 0.5 μm due to the low friction coating (the sixth existence group A6) is the same as that in the operation (even if the low friction coating is applied with cost and effort). After being used for the most part, the operating efficiency is hardly improved as compared with the case where the low friction coating is not applied.

On the other hand, referring again to the graph of FIG. 3, the root mean square roughness Rq was 0.5 μm or more (less than 0.65 μm) due to the honing process and the low-friction coating. In comparison with the case where the low friction coating is not applied (the state of the fourth non-group B4), the operating group A5 has clear operating efficiency in FIG. 3 after 6 hours and in FIG. 4 after familiarization. (In FIG. 3, it is increased from 94.0 to 94.2%→94.4 to 94.8% by about 0.5%, and in FIG. 4, it is 93.9 to 94.0%→94. (Approximately 0.5% increase to 4-94.5%).

In other words, after 6 hours (FIG. 3) and after being familiar (FIG. 4), the fifth frictional group A5 with the low friction coating clearly shows an increase in operating efficiency from the state without the low friction coating. .. Further, in comparing the absolute values of the operating efficiencies ηA5 and ηA6, the operating efficiencies ηA5 of the fifth existence group A5 having the low friction coating applied the low friction coating after 6 hours and after familiarization. It is recognized that it is higher than the operating efficiency ηA6 of the sixth A6 group. Therefore, the fifth existence group A5 having the root mean square roughness Rq of 0.5 μm or more (less than 0.65 μm) due to the low friction coating applied has an advantage of applying the low friction coating.

From this, the second threshold value between the sixth existence group A6 having a root mean square roughness Rq of less than 0.5 μm and the fifth existence group A5 of 0.5 μm or more after the low friction coating is applied. It can be verified that the low friction coating having S2 has a merit to be applied only to the pin groove 34 having a root mean square roughness Rq of 0.5 μm or more.

Summing up the above verifications, it can be said that the merit of applying the low-friction coating to the pin groove 34 is that the root mean square roughness Rq after applying the low-friction coating is 0.5 μm or more and 2.5 μm or more. The knowledge (1) of the following regions (from the second group A2 to the fifth group A5) is obtained.

<Knowledge (2)>
Among the regions where the root mean square roughness Rq after applying the low friction coating obtained in the finding (1) is 0.5 μm or more and 2.5 μm or less, the region of 0.65 μm or more and 2.5 μm or less is low. The advantage of applying a friction coating is greater.

This finding (2) is, in short, the fifth existence group A5 having a root mean square roughness Rq (0.5 μm or more) of less than 0.65 μm after applying the low friction coating and the fourth existence of 0.65 μm or more. There is a third threshold value S3 (0.65 μm) between the group A5 and the second existence group A2, and with the third threshold value S3 as a boundary, the root mean square after applying the low friction coating. That is, the merit of applying the low-friction coating is greater on the region side of 0.65 μm or more than on the region side of Rq less than 0.65 μm. Hereinafter, this point will be verified.

Again referring to FIG. 3, the operating efficiency ηA5 of the fifth existing group A5 (white circles ○) in which the root mean square roughness Rq after applying the low friction coating was less than 0.65 μm was low. Although it is higher than the operating efficiency ηB4 after 6 hours in the state of the fourth no-group B4 (black circle ●) without the friction coating, the degree of increase is not large (as described above). , 94.0-94.2% → 94.4-94.8%: increase of about 0.5%). Then, referring to FIG. 4 after familiarization with the same region, the same degree is obtained and the increase is not so great (as described above, 93.9 to 94.0%→94.4 to 94.5%). : About 0.5% increase).

On the other hand, referring to FIG. 3, after 6 hours of the fourth existence group A4 (white rhombus ◇) having a root mean square roughness Rq of 0.65 μm or more (less than 1.2 μm) after applying the low friction coating. The operating efficiency ηA4 of No. 4 is much higher (92.7 to 93.6) than the operating efficiency ηB4 (black diamonds ◆) of the fourth no-group B4 after 6 hours without the low friction coating. % → 94.2 to 94.4%: increase of about 1.0%). That is, in the fourth existence group A4, the increase rate of the operating efficiency ηA5 after 6 hours when the low friction coating is applied is larger than in the fifth existence group A5. Then, referring to FIG. 4 in the same region, the operating efficiency ηA4 after acclimatization of the fourth existing group A4 is compared with the operating efficiency ηB4 after acclimatization of the fourth non-group B4 without the low friction coating, Similarly, it is also greatly increased (92.5-93.0% → 93.9-94.2%: about 1.0% increase). In other words, the rate of increase in the operating efficiency ηA4 in the region of the fourth existing group A4 is obviously higher than the rate of increase in the operating efficiency ηA5 in the region of the fifth existing group A5 even after familiarization.

From this, between the fifth existence group A5 whose root mean square roughness Rq after applying the low friction coating is less than 0.65 μm and the fourth existence group A4 of 0.65 μm or more, There is a threshold value S3, and the low-friction coating has 0.65 μm or more (fourth existence group A4) from the region side of less than 0.65 μm (fifth existence group A5) with the third threshold value S3 as a boundary. It can be verified that the region side has a greater merit of applying the low friction coating.

That is, in the region where the root mean square roughness Rq after applying the low friction coating obtained in the finding (1) is 0.5 μm or more and 2.5 μm or less, the region of 0.65 μm or more and 2.5 μm or less is It is possible to obtain the finding (2) that the merit of applying the low friction coating is greater.

<Knowledge (3)>
Among the regions where the root mean square roughness Rq after applying the low friction coating obtained in the finding (2) is 0.65 μm or more and 2.5 μm or less, a region of 1.2 μm or more and 2.5 μm or less (third , The second group A3, A2) has a greater merit of applying the low friction coating.

In both FIG. 3 (after 6 hours) and FIG. 4 (after familiarization), the root mean square roughness Rq after applying the low-friction coating to the pin groove 34 obtained by the gear shaper machining is 1.2 μm or more. The operating efficiencies ηA3 and ηA2 of the second existence groups A3 and A2 are increased by about 2% as compared with the operating efficiencies ηB3 and ηB2 of the third and second non-groups B3 and B2 where the low friction coating is not applied. Therefore, the rate of increase is extremely large. In other words, the operating efficiencies ηA3 and ηA2 in the regions of the third and second groups A3 and A2 are apparently in the region of the fourth group A4 both in FIG. 3 after 6 hours and in FIG. 4 after familiarization. The rate of increase is greater than the efficiency ηA4.

From this, between the fourth existence group A4 whose root mean square roughness Rq after applying the low friction coating is less than 1.2 μm and the third and second existence groups A3 and A2 of 1.2 μm or more. , There is a fourth threshold value S4 (1.2 μm), and with the fourth threshold value S4 as a boundary, the root mean square roughness Rq after applying the low friction coating is less than the area side of less than 1.2 μm. It can be verified that the advantage of applying the low-friction coating is greater on the region side of 1.2 μm or more.

That is, in the region where the root mean square roughness Rq after applying the low friction coating obtained in the finding (2) is 0.65 μm or more and 2.5 μm or less, a region of 1.2 μm or more and 2.5 μm or less ( The knowledge (3) is obtained that the third and second groups A3 and A2) have a greater merit of applying the low-friction coating.

Therefore, comprehensively judging the findings (1) to (3) so far, it can be said that the merit of applying the low friction coating to the pin groove 34 is that the root mean square roughness Rq after the low friction coating is formed. Is a pin groove 34 in a region of 0.5 μm or more and 2.5 μm or less, preferably 0.65 μm or more and 2.5 μm or less, and more preferably 1.2 μm or more and 2.5 μm. It can be said that the pin groove 34 is in the following region.

In this test, in order to obtain a predetermined roughness after the low-friction coating is applied to the formation of the pin groove 34, the pin groove 34 is formed by boring, gear shaping, barreling, honing, and skiing. It was formed by bing processing. However, the selection of these processing methods is only for obtaining the pin groove 34 of various roughness in this embodiment (main test). On the contrary, even if the machining methods are the same, if the machining conditions (for example, the tool feed speed), the tool specifications such as the tool shape and the tool accuracy, and the like change, the value of the root mean square roughness Rq changes. For example, even with the same gear shaper processing, the root mean square roughness Rq may be 1.2 μm or less, and may be 2.5 μm or more. In the present invention, the root mean square roughness Rq is used as an index of differentiation, and the processing method itself is not particularly limited. In addition to the above processing method, for example, a processing method such as shot peening may be adopted.

On the other hand, when the processing methods are different, for example, even when the low friction coating is not applied as in the case of the barrel processing and the honing processing, even if the root mean square roughness Rq is the same (both are 4 No group B4), the root mean square roughness Rq may be different after the low friction coating is applied. When a low friction coating is applied, it changes to Group A5 with No. 5).

In the present invention, the roughness (root mean square roughness Rq) after the low friction coating is applied to the pin groove is used as an index for differentiation. In other words, in the present invention, in addition to the method for processing the pin groove, the roughness when the low friction coating is not applied is not particularly limited.

Further, in the above embodiment, as the eccentric oscillating speed reducer, a "center crank type" eccentric oscillating speed reducer having one crankshaft in the radial center of the device has been illustrated. However, as an eccentric oscillating reduction gear, a plurality of crankshafts are provided at positions distant from the axis of the device, and the plurality of crankshafts are synchronously rotated to oscillate the external gear. "Type" eccentric oscillating speed reducers are also known. According to the present invention, even in such a distribution type eccentric oscillating speed reducer, the internal gear is arranged in the internal gear main body, the pin groove formed in the internal gear main body, and the pin groove. The pin member and the pin member are similarly applicable.

Further, in the above-described embodiment, the inner roller is externally fitted to the inner pin as the sliding promoting member, so that the inner roller is externally fitted to the outer pin as the sliding promoting member. Eccentric oscillating speed reducers having gears are also known. In this case, a pin groove in which the outer roller is arranged is formed in the internal gear body. The present invention can be similarly applied to a pin groove in which such an outer roller is arranged, by regarding the outer roller as the pin member of the present invention.

Further, although the manganese phosphate coating is applied as the low friction coating in the above embodiment, the low friction coating according to the present invention is not limited to the manganese phosphate coating. For example, it may be a solid lubricating coating. The solid lubricating coating herein refers to a treatment in which a solid lubricating agent such as molybdenum disulfide, PTFE, graphite or the like is dispersed in a coating material singly or in a composite and the coating is applied to an object to be treated.

G... Eccentric oscillating speed reducer 12... Input shaft 18... Eccentric part 20... Crank shaft 24... External gear 30... Internal gear 32... Internal gear main body 34... Pin groove 36... External pin (pin member)
Rq... root mean square roughness η... operating efficiency

Claims (3)

An internal gear has an internal gear main body, a plurality of pin grooves formed in the internal gear main body and having a substantially semicircular cross section at a right angle to the axis, and a pin member rotatably arranged in each of the plurality of pin grooves. An eccentric oscillating speed reducer having:
A manganese phosphate coating is applied to the pin groove,
An eccentricity characterized in that the root mean square roughness Rq obtained based on the roughness measured in the axial direction of the pin groove after applying the manganese phosphate coating is 0.5 μm or more and 2.5 μm or less. Swing type speed reducer. In claim 1,
The root mean square roughness Rq of the pin groove after applying the manganese phosphate coating is 0.6
An eccentric oscillating speed reducer having a thickness of 5 μm or more and 2.5 μm or less. In claim 1 or 2,
The root mean square roughness Rq of the pin groove after applying the manganese phosphate coating is 1.2.
An eccentric oscillating speed reducer having a size of not less than μm and not more than 2.5 μm.

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