JPH0628394U - Pin gear reducer - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention improves the lubricity between a plurality of pins and the case, thereby eliminating the need for a troublesome surface treatment on the case, resulting in a low-cost and highly durable pin gear. The purpose is to provide a speed reducer. [Configuration] In the transmission path from the input shaft 13 to the output shaft 16,
A plurality of pins, each of which is composed of a case 11 having a plurality of pin mounting grooves 11a having a substantially semicircular cross section on an inner peripheral portion thereof and a plurality of cylindrical pins 41 mounted in the pin mounting grooves 11a of the case 11.
The pin gear 40 having internal teeth formed by 41 has a number of teeth slightly different from the number of teeth of the pin gear 40, and maintains a predetermined eccentricity with respect to the central axis of the pin gear 40 in a state of meshing with the pin gear 40. In a pin gear reducer in which an externally toothed gear 30 that is rotatable and a crankshaft 19 that rotates the externally toothed gear 30 while maintaining a predetermined eccentricity amount are arranged, a large number of minute recesses are formed on each surface of a plurality of pins 41. And a lubricant is interposed between the minute recess of the pin 41 and the case 11.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a pin gear reducer, and more particularly to a pin gear reducer having a pin gear that constitutes a differential gear reduction mechanism.

[0002]

[Prior art]

 Conventionally, a so-called planetary gear reduction mechanism is constructed by a pin gear in which a plurality of pins are arranged in a short cylindrical case at an equal pitch, and an external gear that meshes with the inner teeth of the pin gear that has a slightly different number of teeth. A configured pin gear reducer is known. In this type of pin gear reducer, the quality of the friction between the pin (internal teeth) meshing with the external gear and the case greatly affects the performance of the reducer. Surface treatment (for example, molybdenum disulfide coating treatment) is applied to form a hard coating with high lubricity on the inner peripheral part of the case, while the pins are mirror-finished on the outer peripheral surface. A lubricant is used for the pin to facilitate rotation of the pin during friction with the external gear and to prevent wear of the pin and the case.

[0003]

[Problems to be solved by the device]

 However, in such a conventional pin gear reducer, there is a problem in that the case, which is a large component, needs to be subjected to a surface treatment that takes a considerable amount of time, resulting in a high manufacturing cost. In addition, depending on the usage state of the pin gear reducer, the lubricant may not sufficiently enter the pressure contact portion between the plurality of pins and the case, and there is a problem that durability is likely to deteriorate.

Therefore, the present invention provides a pin gear reducer that is low in cost and excellent in durability by improving lubricity between a plurality of pins and a case, thereby eliminating the need for a complicated surface treatment on the case. The purpose is to do.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a case in which a plurality of pin mounting grooves having a substantially semicircular cross section are formed in the inner peripheral portion of a transmission path from an input shaft to an output shaft, and a pin mounting groove of the case. A pin gear composed of a plurality of cylindrical pins, and having a number of teeth slightly different from the number of teeth of the pin gear and maintaining a predetermined eccentricity with respect to the center axis of the pin gear while meshing with the pin gear. In a pin gear speed reducer in which a rotatable external gear and a crankshaft for rotating the external gear while maintaining the predetermined eccentricity are arranged, a large number of minute recesses are formed on each surface of the plurality of pins. A lubricant is interposed between the minute recesses of the pin and the case.

[0006]

[Action]

 In the present invention, a large number of minute recesses are formed on the surface of each of the plurality of pins, and a lubricant is interposed in the minute voids formed between the minute recesses and the case, so that the case and the plurality of pins are The lubricity of is improved. Therefore, a pin gear reducer with excellent durability can be obtained without subjecting the case to complicated surface treatment, and the manufacturing cost can be reduced.

[0007]

【Example】

 Hereinafter, the present invention will be described with reference to the drawings. 1 to 3 are views showing an embodiment of a pin gear reducer according to the present invention. In FIGS. 1 and 2, 10 is a support member such as a robot arm, 11 is a cylindrical case supported by this support member, 12 is a motor coaxially connected to one end of the case 11 (details are shown). No). The motor 12 rotates the input shaft 13 of the speed reducer. The rotation of the input shaft 13 is decelerated via the known first speed reducer 14 and second speed reducer 15, and the output shaft 16 rotates an external rotor (not shown). Is output to.

Specifically, the first reduction gear portion 14 serving as a transmission path from the input shaft 13 to the output shaft 16 has a plurality of small gears 17 fixed to the input shaft 13 and a plurality of (3 The large gear 18 and the rotation of the large gear 18 are taken into the second reduction gear unit 15. The second reduction gear portion 15 is supported by a plurality of crankshafts 19 to which large gears 18 are respectively connected, a rotation block 20 that rotatably supports both ends of the crankshafts 19, and a plurality of crankshafts 19. The external gear 30 has a predetermined number of teeth, and the internal pin gear 40 has a number of teeth slightly larger than the number of teeth of the external gear 30. Here, the rotation block 20 has a pair of plate portions 21 and 22 opposed to each other in the axial direction of the case 11 and a plurality of column portions 23 that integrally connect the pair of plate portions 21 and 22 with a bolt 23a. The outer peripheral portions of the plate portions 21 and 22 are rotatably supported by the case 11 via needle roller bearings (not shown). In addition, the external gear 30 is supported by the crankshaft 19 and meshes with the internal pin 41 of the internal pin gear 40 to rotate with a predetermined eccentricity with respect to the central axis of the internal pin gear 40 ( Revolution and rotation) is possible. Therefore, when the external gear 30 eccentrically moves (revolves) while meshing with the internal pin gear 40, the external gear 30 should rotate according to the difference in the number of teeth between the internal pin gear 40 and the external gear 30. As a result, the rotation block 20 rotates slowly, and the output shaft 16 integrally connected to the rotation block 20 rotates.

The internal pin gear 40 has a plurality of pin mounting grooves 11a having a substantially semicircular cross section formed on the inner peripheral portion thereof, and a plurality of pin mounting grooves 11a mounted on the case 11. The pin mounting groove 11a of the case 11 is, for example, an exposed surface of the material of the material of the case 11 which has been cut or ground / polished. The plurality of pins 41 are pre-processed to have a predetermined diameter (for example, polished to have a predetermined surface roughness), and then the surface is subjected to a special surface processing to have a predetermined depth (several μm or less) as shown in FIG. The large number of minute concave portions 41a are randomly formed. Then, by applying a lubricant (for example, gear oil or grease) (not shown) to the surface of the pin 41, this lubricant is interposed between the many minute recesses 41a and the surface of the pin mounting groove 11a of the case 11. I am letting you. As the special surface processing, for example, special barrel polishing or shot peening can be used, and the Sk value which is a parameter of the surface roughness of the pin 41 forming the minute recess 41a is set to about -1 or less. I like to do it. The parameter Sk value is a value indicating the skewness of the surface roughness distribution curve, and the Sk value is zero for a symmetrical distribution such as a Gaussian distribution. The parameter Sk value is set to about -1 or less because the shape and distribution of the minute recesses 41a are within a range advantageous for oil film formation depending on the processing conditions.

In the present embodiment configured as described above, a large number of minute recesses 41a are formed on the respective surfaces of the plurality of pins 41, and between the minute recesses 41a and the surface of the pin mounting groove 11a of the case 11. By interposing a lubricant in the minute voids formed in the case 11, the lubricity between the case 11 and the plurality of pins 41 is enhanced. Therefore, even if the case 11 is not subjected to a troublesome conventional surface treatment and the pin mounting groove 11a of the case 11 is exposed on the material, the wear of the pin 41 and the case 11 can be suppressed, and the durability is improved. It is possible to obtain an excellent low-cost pin gear reducer.

In particular, the surface roughness parameter Sk value of the pin 41 is set as described above, and the minute concave portion 41 suitable for forming the lubricating oil film between the pin 41 and the case 11 is quantitatively managed and formed. By doing so, the lubricity of the pin 11 and the case 11 can be sufficiently enhanced, and the variation of the lubrication performance can be eliminated, so that the reliability of the pin gear reducer can be improved.

It is needless to say that the pin mounting groove 11a of the case 11 may be subjected to an appropriate surface treatment instead of being the material exposed surface, and by combining them, a reduction gear with higher durability is realized. You can also do it.

[0013]

[Effect of device]

 According to the present invention, a large number of minute recesses are formed on the surface of each of a plurality of pins, and a lubricant is interposed in the minute voids formed between the minute recesses and the case, so that Since the lubricity with the pin is enhanced, the pin gear reducer can be made excellent in durability without subjecting the case to troublesome surface treatment, and the manufacturing cost can be reduced. Further, the surface of the pin mounting groove on the case side can be appropriately processed to provide a pin gear speed reducer having more excellent durability.

[Brief description of drawings]

FIG. 1 is a front sectional view showing the overall configuration of an embodiment of a pin gear reducer according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

3A and 3B are views showing the pin, in which FIG. 3A is a perspective view thereof, and FIG.
FIG. 6 is a diagram schematically showing the minute recess.

[Explanation of symbols]

 11 Case 11a Pin mounting groove 13 Input shaft 16 Output shaft 19 Crankshaft 30 External gear 40 Pin gear 41 Pin 41a Minute recess

Claims (1)

[Scope of utility model registration request] 1. A plurality of pin mounting grooves (1) having a substantially semicircular cross section are formed on an inner peripheral portion in a transmission path from an input shaft (13) to an output shaft (16).
1a) and a plurality of cylindrical pins (41) mounted in the pin mounting grooves (11a) of the case (11), and the plurality of pins (41) form internal teeth. The pin gear (40) has a number of teeth slightly different from the number of teeth of the pin gear (40) and has a predetermined eccentricity with respect to the central axis of the pin gear (40) in a state of meshing with the pin gear (40). External gear that can be kept and rotated (3
0), and a crankshaft (19) for rotating the external gear (30) while maintaining the predetermined eccentricity amount, in a pin gear reducer, a large number of each of the plurality of pins (41) on the surface. Minute recess
A pin gear reducer characterized in that (41a) is formed, and a lubricant is interposed between the minute recess (41a) of the pin (41) and the case (11).