JP2015190610A - Eccentric oscillation type speed reduction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an eccentric oscillation type speed reduction device capable of shortening time necessary for running-in operation.SOLUTION: In an eccentric oscillation type speed reduction device G, an internal tooth gear 30 includes an internal tooth gear body 32, a pin groove 34 formed in the internal tooth gear body 32, and an outer pin (pin member) 36 arranged in the pin groove 34. The root-mean-square roughness Rq of the surface of the pin groove 34 is 1.6 μm or less, or (level difference Rk of a core part+mean depth Rvk of a projection trough) of the surface of the pin groove 34 is 5.0 μm or less.

Description

  The present invention relates to an eccentric oscillating speed reducer.

  Patent Document 1 discloses an eccentric oscillating speed reduction device.

  The eccentric oscillating speed reduction device includes an internal gear and an external gear that is inscribed while swinging on the internal gear, and takes out the relative rotation of the internal gear and the external gear as an output.

  The internal gear includes an internal gear main body integrated with the casing, a pin groove formed in the internal gear main body, and a pin member arranged in the pin groove. The pin member can be rotated while being arranged in the pin groove, thereby facilitating meshing with the external gear.

  The pin groove is processed by gear shaper processing.

JP 2000-130521 A (FIGS. 3 and 5)

  The conventional eccentric oscillating speed reducer has a problem that the time required for the familiar operation is long when the so-called familiar operation is performed.

  The present invention has been made to solve such a conventional problem, and an object thereof is to provide an eccentric oscillating speed reduction device that can further reduce the time required for the familiar operation. .

  The present invention is an eccentric oscillating speed reduction device in which an internal gear includes an internal gear main body, a pin groove formed in the internal gear main body, and a pin member disposed in the pin groove. The above problem is solved by adopting a configuration in which the root mean square roughness Rq of the surface of the pin groove is 1.6 μm or less.

  Moreover, this invention is an eccentric rocking | fluctuation type reduction gear in which an internal gear has an internal gear main body, the pin groove formed in this internal gear main body, and the pin member arrange | positioned in this pin groove. And the said subject is solved by setting it as the structure whose (surface level difference Rk + average depth Rvk of a protrusion trough part) of the surface of the said pin groove is 5.0 micrometers or less.

  As will be described in detail later, with these configurations, the time required for the familiar operation in the eccentric oscillating speed reduction device can be further shortened.

  ADVANTAGE OF THE INVENTION According to this invention, the eccentric rocking | fluctuation type deceleration device which can shorten more the time required for a familiar operation can be obtained.

Sectional drawing which shows the whole structure of the eccentric rocking | fluctuation type deceleration device which concerns on an example of embodiment of this invention. Sectional drawing which shows the internal gear main body and pin groove | channel of the internal gear of the said eccentric rocking | swiveling type | formula speed reduction gear including a principal part expanded cross section in part The principal part expanded sectional view seen from the arrow III direction of FIG. A graph showing the relationship between the familiar operation time and the root mean square roughness Rq, and the familiar operation time and (level difference Rk of core portion + average depth Rvk of protruding valley portion). A graph showing the relationship between operating efficiency and root mean square roughness Rq, and operating efficiency (level difference Rk of core portion + average depth Rvk of protruding valley portion).

  Hereinafter, an example of an embodiment of the present invention will be described in detail based on the drawings.

  First, an overall configuration of an eccentric oscillating speed reduction device according to an example of an embodiment of the present invention will be described with reference to FIG.

  The input shaft 12 of the eccentric oscillating speed reduction device G is integrated with the motor shaft 14 </ b> A of the motor 14. A crankshaft 20 having two eccentric portions 18 is connected to the input shaft 12 via a key 16.

  The axes O2 and O3 of the eccentric portion 18 are eccentric with respect to the axis O1 of the input shaft 12, respectively. In this example, the eccentric phase difference of the eccentric portion 18 is 180 degrees. A roller bearing 22 is disposed on the outer periphery of the eccentric portion 18. Two external gears 24 are swingably incorporated on the outer periphery of the roller bearing 22. The reason why the two external gears 24 are provided in parallel in the axial direction is to ensure the necessary transmission capacity and improve the rotational balance. The external gears 24 are internally meshed with the internal gear 30. That is, in the eccentric oscillating speed reduction device G, the crankshaft 20 for oscillating the external gear 24 has a radial center of the device (the axis O1 of the input shaft 12 and the axis O1 of the internal gear 30). It is an eccentric oscillating type speed reducer called a “center crank type” arranged coaxially).

  The internal gear 30 is disposed in the internal gear main body 32 integrated with the casing 28 (a casing main body 52 described later), a 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 internal tooth of the internal gear 30. The number of internal teeth (the number of external pins 36) of the internal gear 30 is slightly larger (only 1 in this example) than the number of external teeth of the external gear 24. The configuration of the internal gear 30 and the manufacturing method thereof will be described in detail later.

  The external gear 24 is formed with a plurality of through holes 24A at positions offset from the axis (same as the axes O2 and O3). An inner pin 40 is fitted into the through hole 24A. The inner pin 40 is press-fitted and fixed in the inner pin holding hole 42 </ b> A of the flange body 42 disposed on the side in the axial direction 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, an inner roller 48 is fitted on the inner pin 40 as a sliding acceleration member. A gap corresponding to twice the amount of eccentricity of the eccentric portion 18 is secured between the inner roller 48 and the inner peripheral surface of the through hole 24 </ b> A of the external gear 24. 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 oscillating speed reduction device G has a casing body 52 that houses the speed reduction mechanism 50 and an output casing body 54 that houses the output shaft 44. An anti-load side cover 56 (which also functions as a motor cover) is disposed on the axially opposite load side of the casing body 52, and a load-side cover 57 is disposed on the axial load side of the output casing body 54. Has been placed. The eccentric oscillating speed reduction device G is fixed to a fixing member by a bolt (not shown) through a bolt hole 58A of the leg portion 58.

  The internal gear main body 32 of the internal gear 30 is integrated with the casing main body 52. That is, the internal gear main body 32 is the same member as the casing main body 52. In this specification, for convenience, the internal gear body 32 is referred to as a unit. The configuration of the internal gear 30 will be described in detail later.

  The eccentric oscillating speed reduction device G has the above-described configuration, and rotates the two eccentric portions 18 of the crankshaft 20 connected to the input shaft 12 by rotating the motor shaft 14A of the motor 14. . Then, the external gear 24 meshes with the internal gear 30 (specifically, the external pin 36 constituting the internal teeth of the internal gear 30) while swinging. Thus, every time the input shaft 12 rotates once and the external gear 24 swings once, the external gear 24 has a difference in the number of teeth between the internal gear 30 and the external gear 24 (1 in this example). Rotate as much as the 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 rotated at a reduced speed.

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

  FIG. 2 is a cross-sectional view of the internal gear main body 32 partially including an enlarged cross section of a main part. 3 is an enlarged cross-sectional view of a main part viewed from the direction of arrow III in 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 pins (pins) arranged in the pin groove 34 and constituting the internal teeth. Member) 36. The entire internal gear main body 32 is composed of a substantially ring-shaped member. On both side portions in the axial direction of the internal gear main body 32, a step portion 32A for forming an inlay portion with the anti-load side cover 56 and a step portion 32B for forming an inlay portion with the output casing body 54 are formed. Has been. That is, the internal gear main body 32 includes an axial central portion (hereinafter referred to as an axial central portion) 32C having a large radial thickness, and an axial end portion having a radial thickness smaller than the radial thickness of the axial central portion 32C. (Hereinafter, shaft end portions) 32E1 and 32E2 are provided.

  Here, the radial thickness means the thickness of the internal gear main body 32 (the radial thickness from the inner peripheral surface to the outer peripheral surface). In this embodiment, the radial distance from the inner peripheral surface to the outer peripheral surface of the portion where the pin groove 34 is not formed is the radial thickness. Since the inner circumference of the internal gear main body 32 is parallel to the shaft, the thickness in the radial direction depends on the outer diameter of the internal gear main body 32 (in this example, the shaft central portion 32C is d32C and the shaft end portion 32E1. 32E2 is a concept that matches the magnitude of d32E1 and d32E2).

  In this embodiment, the radial thickness of the shaft center portion 32C is W32C, and the radial thicknesses of the shaft end portions 32E1 and 32E2 are W32E1 and W32E2, and W32C> W32E1 = W32E2. Hereinafter, the shaft end portions 32E1 and 32E2 may be simply referred to as the shaft end portion 32E, and the radial thicknesses W32E1 and W32E2 may be simply referred to as W32E.

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

  In the figure, reference numeral 35 denotes an O-ring groove, reference numeral 32B1 denotes a chamfered portion of the stepped portion 32B, and 32F denotes a bolt hole for connecting the anti-load side cover 56 and the output casing body 54 to the internal gear main body 32. It is.

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

  The inventors relate to a pin groove 34 in which the pin groove 34 of the internal gear main body 32 of the eccentric oscillating reduction gear G, that is, the outer pin 36 constituting the internal teeth of the internal gear 30 is rotatably arranged. A test was conducted. Specifically, the pin groove 34 having a plurality of surface properties was formed by variously changing the manufacturing method of the pin groove 34, and the relationship between each surface property and the required familiar operation time Hr was investigated.

  Here, the familiar operation time Hr indicates an operation performed before the operation as the original eccentric oscillating speed reduction device. The familiar operation is sometimes performed to ensure a predetermined operation efficiency at the time of shipment or after delivery, but it is an issue to reduce the necessary time as much as possible. In addition, after delivery, the normal operation may be performed without performing the familiar operation. In this case, the initial stage of the normal operation corresponds to the familiar operation. In the present embodiment, the familiar operation time Hr is defined as “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 other words, the familiar operation time Hr in this test is “the temperature of the outer periphery of the casing 28 is increased by starting the operation, and the temperature increase gradually becomes 1 ° C. or less. It is defined as “the time until it becomes thermally stable”.

  The result is shown in FIG. FIG. 4A shows the relationship between the root mean square roughness Rq of the pin groove 34 and the required familiar operation time Hr. In this test, in order to obtain pin grooves 34 having various root-mean-square roughness Rq, machining methods by gear shaper processing (● mark), barrel processing (◯ mark), and skiving processing (◎ mark) were adopted. Yes.

  Here, the gear shaper machining refers to a machining method in which a tool called a pinion cutter is reciprocated to repeat the process of cutting and returning the workpiece (internal gear main body 32) when moving in one direction. The barrel processing here refers to a processing method in which an abrasive, a workpiece (internal gear main body 32), and a working fluid are placed in a container called a barrel, and the surface is finished by rotating or vibrating. . In barrel machining, pin groove machining by gear shaper machining or the like is performed in advance as pre-machining.

  Further, skiving processing here means “processing that creates a tool called a skiving cutter and a work (internal gear main body 32) at a certain angle (for example, synchronous rotation), and is generated by a generated speed difference. Method ". In order to form the pin groove 34 of the internal gear main body 32 in the present embodiment by skiving, for example, the machining of the pin groove 34 according to the present embodiment is performed on the processing machine described in Utility Model Registration No. 3181136. The processing machine can be used by performing necessary customization as appropriate (specifically, the tool is customized so that the arc shape can be machined).

  The arc diameter 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 main 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 approximately the root mean square roughness Rq of 0.2 μm.

The test conditions are as follows.
(A) Measured in a state after the internal gear 30 is manufactured (after the pin groove 34 is processed) and before the eccentric oscillating speed reduction device G is operated (a state where the eccentric gear is not operated).
(B) Using “Form Talysurf PGI840” manufactured by TAYLOR HOBSON, the roughness is measured in the axial direction of the pin groove 34 to obtain a roughness curve, and the root mean square described later based on the roughness curve The roughness Rq, the level difference Rk of the core part, and the average depth Rvk of the protruding valley part are obtained.
(C) The traverse unit accuracy is “drive speed: 0.25 mm / sec”, “measurement capture interval: 0.125 μm”, “stylus pressure: 80 mgf”, and the filter setting is “form: LS line”. ”,“ Filter: Gaussian ”,“ Cutoff (Lc): 0.8 mm ”,“ Cutoff (Ls): 0.0025 mm ”,“ Bandwidth: 300: 1 ”. : 2 μm ”,“ Shape: 60 ° cone ”, roughness was measured.

  Note that the root mean square roughness Rq is the root mean square roughness (the value of the height component at each position of the roughness curve) obtained with respect to the reference length in the roughness curve defined in JIS B0601. (Roughness obtained by averaging the squares and taking the square root).

  Then, by changing the processing method, or by changing the cutting tool or changing the feed speed even in the same processing method, various root mean square roughness Rq is obtained for the surface of the pin groove 34, and the root mean square roughness Rq is obtained. And the correlation with the familiar operation time Hr.

  From the graph of FIG. 4 (A), until the root mean square roughness Rq is about 1.5 μm, the familiar operation time Hr gradually decreases as the root mean square roughness Rq increases. (Both values are maintained below 400 hours). In this embodiment, skiving processing (◎ mark) and barrel processing (○ mark) enable processing of the root mean square roughness Rq of this portion.

  However, when the root mean square roughness Rq is about 1.5 μm, the familiar operation time Hr starts to increase, and the root mean square roughness Rq becomes larger than 1.6 μm (indicated by a dotted line in FIG. 4A). The familiar operation time Hr is rapidly increasing (from 500 hours to a level exceeding 800 hours). This result can be grasped as numerically clearly supporting that “the conventional operation (gear shaper processing: mark) has a long familiar operation time Hr”. From the graph of root mean square roughness Rq-familiar operation time Hr in FIG. 4 (A), in order to shorten the familiar operation time Hr, the root mean square roughness Rq of the pin groove 34 should be 1.6 μm or less. Is preferable.

  Note that, when the root mean square roughness Rq of the pin groove 34 is 1.6 μm or less, the variation in the familiar operation time Hr is small. This indicates that the individual difference for each product is small. In other words, when the root mean square roughness Rq is 1.6 μm or less, a favorable result of a certain level or more can be stably obtained with respect to the familiar operation time Hr (regardless of the manufacturing method).

  On the other hand, the graph of FIG. 4B represents the relationship between the “level difference Rk of the core part” + “the average depth Rvk of the protruding valley part” and the familiar operation time Hr. Both the “level difference Rk of the core part” and the “average depth Rvk of the protruding valley part” are JIS B0671-2 or JIS B0671-2 with respect to the roughness curve obtained according to JIS B0671-1. It is one of the roughness indicators defined in detail in other provisions cited. Hereinafter, “level difference Rk of the core part” + “average depth Rvk of the protruding valley part” is simply referred to as (Rk + Rvk). In the figure, the ● mark indicates gear shaper processing, the ○ mark indicates barrel processing, and the ◎ mark indicates skiving processing.

  From the graph of FIG. 4B, the familiar operation time Hr gradually decreases (less than 400 hours) until (Rk + Rvk) is close to 5.0 μm (indicated by the dotted line in FIG. 4B). Is maintained). However, if it exceeds 5.0 μm, the familiar operation time Hr rapidly increases, and it is understood that it takes about 500 hours to 800 hours. In this test, it is skiving processing (バ レ ル mark) and barrel processing (◯ mark) that enables processing with a surface roughness of (Rk + Rvk) of 5.0 μm or less. Note that when the (Rk + Rvk) of the pin groove 34 is 5.0 μm or less, the variation in the familiar operation time Hr is small. In other words, when (Rk + Rvk) is 5.0 μm or less, a favorable result of a certain level or more is stably obtained with respect to the familiar operation time Hr.

  From these tests, in order to shorten the familiar operation time Hr, the surface becomes 1.6 μm or less if the root mean square roughness Rq is used as an index, and 5.0 μm or less if (Rk + Rvk) is used as an index. It can be said that it is preferable to process it so as to be rough. As a processing method for obtaining the pin grooves 34 having these surface roughnesses, skiving processing or barrel processing can be employed.

  In this embodiment, with respect to the familiar operation time Hr, good results were obtained by skiving and barrel processing, and good results were not obtained by gear shaper processing. However, what is important in relation to the familiar operation time Hr is the root mean square roughness Rq, the level difference Rk of the core part, and the average depth Rvk of the protruding valley part, not the processing method. Even if the machining method is the same, if the machining conditions (for example, tool feed rate), tool shape, tool accuracy, etc. change, the root mean square roughness Rq, the core level difference Rk, and the average depth of the protruding valleys The value of Rvk also changes. Therefore, for example, even in gear shaper processing, the root mean square roughness Rq may be 1.6 μm or less and (Rk + Rvk) may be 5.0 μm or less. There is a possibility that the roughness Rq becomes larger than 1.6 μm and (Rk + Rvk) becomes larger than 5.0 μm. That is, in the present invention, the processing method of the pin groove 34 is not particularly limited.

  On the other hand, FIG. 5A is a graph showing the relationship between the root mean square roughness Rq and the operating efficiency η. As in FIG. 4, the mark ● is for gear shaper processing, the mark ○ is for barrel processing, and the mark ◎ is for skiving.

  Here, a method for measuring the operating efficiency η will be described. 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 leg portion 58 is 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 speed reducer 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 are measured. From the measurement result, the operation efficiency η is calculated by a calculation formula of {output torque / (input torque × reduction ratio)} × 100%.

  As apparent from the graph of FIG. 5A, when the root mean square roughness Rq is smaller than 0.5 μm (shown by a dotted line in FIG. 5A), the operation efficiency η is rapidly improved ( For example, at 0.4 μm or less, an operating efficiency η of 94.0 to 94.5% or more is obtained). However, as the root mean square roughness Rq approaches 0.5 μm, the operating efficiency η rapidly decreases. When the root mean square roughness Rq is 0.5 μm or more, only less than 93.5% is obtained in any of the test examples. It is not done. Note that the root mean square roughness Rq and the operating efficiency η are not particularly correlated at 0.5 μm or more (even if the root mean square roughness Rq changes, the operating efficiency η increases or decreases accordingly. Is not necessarily). From these results, if the operation efficiency η is taken into consideration, the root mean square roughness Rq is preferably 0.5 μm or less. Note that, when the root mean square roughness Rq is 0.5 μm or less, the variation in the operation efficiency η is small (if the root mean square roughness Rq is 0.5 μm or less, the operation efficiency η is stably above a certain level. Favorable results have been obtained).

  This qualitative tendency is also shown in the relationship between (Rk + Rvk) and operating efficiency η, as shown in the graph of FIG. That is, when (Rk + Rvk) is smaller than 1.4 μm (shown by a dotted line in FIG. 5B), the operating efficiency η is rapidly improved (for example, 94.0 or less at 1.3 μm or less). An operating efficiency of 94.5 or more is obtained η). However, when (Rk + Rvk) is 0.5 μm or more, (Rk + Rvk) and the operating efficiency η have little correlation, and even if (Rk + Rvk) changes, the operating efficiency η is not 93.5% at the maximum. . From this result, if the operation efficiency η is taken into account, (Rk + Rvk) is preferably 1.4 μm or less. In addition, when (Rk + Rvk) is 1.4 μm or less, the variation in the operation efficiency η is small (if (Rk + Rvk) is 1.4 μm or less, a preferable result that is stable or higher is obtained with respect to the operation efficiency η. )

  After all, considering the test results of FIGS. 4 and 5, in order to shorten the familiar operation time Hr, if the root mean square roughness Rq is used as an index, it is preferably 1.6 μm or less, and (Rk + Rvk) is used as an index. In that case, 5.0 μm or less is preferable. As a processing method, skiving processing or barrel processing is adopted in the present embodiment.

Then, considering and taking into account the operating efficiency η, if the root mean square roughness Rq is used as an index, 0.5 μm or less is more preferable, and if (Rk + Rvk) is used as an index, 1.4
It is more preferable that the thickness is μm or less. As a processing method, skiving processing is employed in the present embodiment.

  That is, if attention is paid to the processing method, in the present embodiment, the familiar operation time Hr is short and the operation efficiency η is high when the pin groove 34 is formed by skiving. That is, according to skiving, the root mean square roughness Rq can be set to 1.6 μm or less, and can be further reduced to 0.5 μm or less in consideration of the operation efficiency η. Met. In the skiving process, (Rk + Rvk) can be set to 5.0 μm or less, or can be further reduced to 1.4 μm or less in consideration of operating efficiency η.

  Note that “differentiation” focusing on these processing methods is based solely on the test results in the present embodiment. As described above, what is important with respect to the familiar operation time Hr and the operation efficiency η is the value of the root mean square roughness Rq, the level difference Rk of the core part, and the average depth Rvk of the protruding valley part itself. (Even if the processing method is the same, the root mean square roughness Rq and (Rk + Rvk) change if the processing conditions and the like change).

  According to another test conducted by the inventors, in this eccentric oscillating speed reducer G, the radial depth of the pin groove 34 is not uniform, and is partly between the pin groove 34 and the outer pin 36. When a gap is formed, the gap can be used as a lubricant introduction part or a holding part, and the lubricity between the pin groove 34 and the outer pin 36 can be further improved. Thereby, the operation efficiency η can be further increased.

  On the other hand, in the skiving process, a large radial load is applied to the internal gear main body 32 from the tool side at the time of processing, but if a radial load is applied to a part of the internal gear main body 32 in the axial direction from the radial inside, The toothed gear main body 32 is easily elastically deformed radially outward. This elastic deformation is significantly generated at the shaft end portion 32E having a small radial thickness W32E (low rigidity) than the shaft center portion 32C having a large radial thickness W32C (high rigidity). Further, the shaft end portion 32E of the pin groove 34 is generated more significantly than the shaft center portion 32C of the pin groove 34.

  Therefore, in the eccentric oscillating speed reducer G according to this embodiment, as shown in FIGS. 2 and 3, the set cutting allowance at the central portion of the shaft is more difficult to deform as the elastic deformation is exceeded. The set cutting allowance at the shaft end portion that is more easily deformed is set to be large. That is, the set cutting allowance of the pin groove 34 at the shaft end portion 32E is made larger than the set cutting allowance of the pin groove 34 at the shaft center portion 32C beyond the amount that cancels the influence of elastic deformation during processing. Yes. X = Y + H + α, where X is the set cutting allowance at each part of the shaft end 32E, Y is the set cutting allowance at the shaft center part 32C, and H is the amount of elastic deformation at each part of the shaft end 32E during processing. It is to set to. In the present embodiment, “α” is set so that the radial depth of the pin groove 34 after the completion of machining gradually increases toward the outside in the axial direction.

  With this configuration, it is possible to realize a configuration in which a slight gap is ensured between the shaft end portion 32E and the outer pin 36 while canceling the influence of elastic deformation more appropriately. As a result, since the generated gap δ34 can function as a lubricant introduction part or a holding part, the familiar operation time Hr can be further shortened, and the operation efficiency η can be further improved. Further, when a strong load is applied, the outer pin 36 can bend, so that the meshing surface pressure at the contact portion between the pin groove 34 and the outer pin 36 and between the outer pin 36 and the external gear 24 is excessive. The rise can be suppressed, and both the reduction of backlash and the reduction of the meshing surface pressure can be achieved at the same time (of course, either one of them may be designed more importantly).

  If attention is paid to the point of “resolving the problem due to the effect of elastic deformation during skiving”, the set cutting allowance when performing skiving does not necessarily offset the effect of elastic deformation during machining. There is no need to increase it beyond minutes. For example, the size may be increased by just offsetting the influence of elastic deformation during processing. Thus, pin grooves having a uniform radial depth can be formed while the pin grooves of the internal gear are being processed by skiving. Further, a technique of “skiving the pin groove in a state where the reinforcing member is fitted to the radially outer side of the axial end portion of the pin groove” is also effective. As a result, the elastic deformation of the internal gear main body during processing is substantially suppressed, so even when trying to form a gap between the pin groove and the outer pin, or when trying to make the gap zero, more Pin grooves controlled with high dimensional accuracy can be formed by skiving.

  As described above, the present invention can obtain many merits when the pin groove of the internal gear body of the internal gear is processed by skiving, but the present invention It does not specifically limit about whether it forms by such a processing method. As long as the desired root mean square roughness Rq, core level difference Rk, and average depth Rvk of the protruding valley are obtained, it is not limited to skiving processing, barrel processing, and gear shaper processing, and various processing methods are adopted. it can. For example, in an application in which the improvement of the operation efficiency η is not so required, processing that can reduce the root mean square roughness Rq of the surface of the pin groove to 1.6 μm or less, or (Rk + Rvk of the surface of the pin groove) ) Can be 5.0 μm or less, for example, gear shaper processing and barrel processing may be used in combination.

  Further, in the above-described embodiment, the “center crank type” eccentric oscillating speed reduction device provided with one crankshaft at the center in the radial direction of the device is exemplified as the eccentric oscillating speed reduction device. However, the eccentric oscillating speed reduction device includes a plurality of crankshafts at positions distant from the shaft center of the device, and rotates the plurality of crankshafts in synchronization to thereby swing the external gear. A "type" eccentric oscillating speed reducer is also known. According to the present invention, 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. As long as it has a configuration including a pin member, it can be similarly applied.

  Moreover, in the said embodiment, the inner tooth comprised so that an outer roller might be externally fitted as a sliding promotion member also with respect to an outer pin, as the inner roller was externally fitting as an inner pin as a sliding promotion member An eccentric oscillating speed reducer having a gear is also known. In this case, a pin groove in which the outer roller is disposed is formed in the internal gear main body. The present invention can be similarly applied to a pin groove in which such an outer roller is disposed by regarding the outer roller as a pin member of the present invention.

G: Eccentric oscillating speed reducer 12 ... Input shaft 18 ... Eccentric portion 20 ... Crank shaft 24 ... External gear 30 ... Internal gear 32 ... Internal gear body 32C ... Shaft center portion 32E ... Shaft end portion 34 ... Pin groove 36 ... Outer pin (pin member)
44 ... Output shaft Rq ... Root mean square roughness Rk ... Level difference of core part Rvk ... Average depth of protruding valley part Hr ... Familiar operation time η ... Operating efficiency

Claims (4)

The internal gear is an eccentric oscillating speed reducer having an internal gear main body, a pin groove formed in the internal gear main body, and a pin member disposed in the pin groove,
The root mean square roughness Rq of the surface of the pin groove is 1.6 μm or less. In claim 1,
The root mean square roughness Rq of the surface of the pin groove is 0.5 μm or less. The internal gear is an eccentric oscillating speed reducer having an internal gear main body, a pin groove formed in the internal gear main body, and a pin member disposed in the pin groove,
The eccentric oscillating speed reducer characterized in that the surface of the pin groove has a (level difference Rk of the core part + average depth Rvk of the protruding valley part) of 5.0 μm or less. In claim 3,
The eccentric oscillating speed reducer characterized in that the surface of the pin groove has a level difference Rk of the core portion + an average depth Rvk of the protruding valley portion of 1.4 μm or less.

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