JP2002021947A - Eccentric rocking type reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost eccentric rocking type reduction gear 24 and to simplify assembling work. SOLUTION: When an even number equal to larger than four crank shafts 50 are provided, the circumferential relative position relationship of through holes 46, 47 and outer teeth 40a, 41a of pinions 40, 41 is the same in both pinions 40, 41. Accordingly, the pinions 40 and 41 are both manufactured and assembled regardless of types, so that the manufacturing cost is reduced and the assembling work can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eccentric oscillating type speed reducer that performs deceleration by eccentrically rotating a pinion.

[0002]

2. Description of the Related Art A conventional eccentric oscillating speed reducer using a pinion includes, for example, a cylindrical body having internal teeth on an inner periphery, a cylindrical body housed in the cylindrical body, and an outer periphery having the number of teeth meshing with the internal teeth. A carrier having slightly less external teeth than the internal teeth, two pinions arranged in parallel in the axial direction, and a carrier having three pillars that penetrate these pinions in the axial direction and are spaced at equal angles in the circumferential direction; , While being disposed at equal intervals in the circumferential direction between adjacent pillars, and both ends are rotatably supported by the carrier,
A central portion inserted into the pinion, and three crankshafts for eccentrically rotating the pinion by rotating, and the eccentric rotation of the pinion is reduced by external and internal teeth to rotate the cylindrical body or the carrier at a low speed. Is known.

[0003]

However, in such a conventional eccentric oscillating speed reducer, three odd-numbered crankshafts which are equiangularly spaced in the circumferential direction respectively penetrate through two pinions. Therefore, the relative positions in the circumferential direction between the through holes for the crankshaft formed in these pinions and the external teeth of the pinions are different between the two, and as a result, when assembling the reduction gear, one pinion is replaced with the other pinion. This cannot be done if one tries to mount instead of the mounting position.

Therefore, each of the two pinions must be manufactured as a dedicated external gear. As a result, the entire reduction gear becomes expensive, and the assembling work is performed while selecting a pinion of a type that matches the mounting position. This has to be performed, and there is a problem that the assembling work is troublesome.

An object of the present invention is to provide an eccentric oscillating type speed reducer which is inexpensive and can be easily assembled.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cylindrical body having internal teeth on the inner periphery, and external teeth housed in the cylindrical body and meshing with the internal teeth on the outer periphery and having a slightly smaller number of teeth than the internal teeth. And a plurality of pinions arranged in parallel in the axial direction, a carrier having a plurality of pillar portions that penetrate these pinions in the axial direction, and are separated in the circumferential direction, A crankshaft that is arranged at equal angles and is rotatably supported at both ends by the carrier, while a center portion is inserted into the pinion and rotates the pinion eccentrically by rotating, and In the eccentric oscillating type speed reducer in which the cylindrical body or the carrier is rotated at a low speed by reducing the eccentric rotation by the external and internal teeth, the number of the crankshafts is set to four or more even numbers. It can be formed.

As described above, if the number of crankshafts is four or more, the relative position in the circumferential direction between the crankshaft through-hole and the external teeth of the pinion becomes the same in any pinion. It can be manufactured and assembled without worrying about the type of pinion, and the manufacturing cost is low,
Also, the assembling work can be simplified.

In addition, when the number of pillars of the crankshaft and the number of carriers are even or more than three or four, the pinion bridge formed radially outside the loose fitting hole for the pillar provided in the pinion. The length is shortened, the strength of the pinion is improved, and the strength of the drive unit and the support unit of the speed reducer is improved, so that the output torque can be improved.

According to the second aspect of the present invention, the symmetry of the pinion is increased, and the load acting on the crankshaft is substantially equal, so that the strength of the speed reducer is improved. Further, if configured as described in claim 3,
The number of driven external gears meshing with the driving external gears increases, and a large rotational torque can be transmitted. Also,
According to the structure described in claim 4, since the diameter of the driving external gear can be made small and the diameter of the driven external gear can be made large, the rotational driving force can be further greatly reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. 1, 2 and 3, 11
Is a fixed casing fixed to a traveling frame of a civil engineering construction machine (not shown), a storage chamber 12 is formed in the fixed casing 11, and the storage chamber 12 is rotatably supported by the fixed casing 11. A swash plate type hydraulic motor 14 having a rotating shaft 13 is accommodated. Reference numeral 15 denotes a cylindrical cylinder block into which the rotary shaft 13 is inserted and spline-connected. A plunger 17 is slidably inserted into each of a plurality of cylinder holes 16 formed in the cylinder block 15, and a shoe 18 is connected to the tip of each of the plungers 17.

Reference numeral 19 denotes a cylinder block and a fixed casing.
A pair of supply / discharge holes 19a formed in the fixed casing 11 and a pair of supply / discharge passages (not shown) formed in the fixed casing 11 and the cylinder hole 16 are provided. And concatenate. Further, these supply / discharge passages are connected to a pump and a tank via a switching valve (not shown), and when the switching valve is switched, one of them becomes a supply side and the other becomes a discharge side.

Reference numeral 20 denotes a substantially ring-shaped swash plate disposed on the other side of the cylinder block 15. An inclined surface 20a is formed on one end surface of the swash plate 20, and the shoe 18 is formed on the inclined surface 20a.
Are in sliding contact. Further, two flat surfaces are formed on the other end surface of the swash plate 20, and a fulcrum member
The swash plate 20 can be tilted around the fulcrum member 21 between two tilt positions.

Here, the tilting of the swash plate 20 supplies and discharges pressure oil to and from the cylinder chamber 22 of the fixed casing 11,
This is performed by moving a piston 23 housed in 22 in the axial direction. The tilt of the swash plate 20 changes the stroke of the plunger 17 in the cylinder block 15 in two stages, whereby the rotation speed of the rotating shaft 13 changes in two stages, and a wide range of rotation speed control is performed. Will be

Reference numeral 24 denotes an eccentric oscillating reduction gear having a carrier 25, and an end plate provided at one end of the carrier 25 is integrated with the other end of the fixed casing 11. The carrier 25 has a plurality of columns 26 extending in the axial direction from one end plate portion (fixed casing 11) to the other side, and these columns 26 have an even number of four or more, in this case, four. Only books are provided, and they are arranged at equal angles in the circumferential direction. The carrier 25 has an end plate portion 27, and the end plate portion 27 is attached to the other end of the pillar portion 26 by a bolt 28.

Reference numeral 31 denotes a substantially cylindrical cylinder rotatably supported by the fixed casing 11 and the end plate 27 of the carrier 25 via a bearing 30. The cylindrical body 31 has a drive wheel of the civil engineering construction machine. Are connected. Reference numeral 32 denotes a disk-shaped cover fixed to the other end of the cylindrical body 31. The cover 32 closes the opening at the other end of the cylindrical body 31. Further, an even number of internal teeth pins 33 as internal teeth are provided on the inner circumference of the cylindrical body 31, and these internal tooth pins 33 extend in the axial direction and are arranged at equal angles in the circumferential direction.

At the center of the carrier 25, the rotating shaft 13
An input shaft 36 coaxial with the input shaft 36 is disposed, and the other end of the rotary shaft 13 is inserted into a cylindrical joint member 37 into which one end of the input shaft 36 is inserted. The joint member 37 and the rotating shaft 1
3. The input shaft 36 is connected to the input shaft 36 by a spline connection. As a result, the input shaft 36 rotates by receiving the rotational driving force of the rotary shaft 13 transmitted through the joint member 37.

Reference numeral 38 denotes a driving external gear provided integrally with the other end of the input shaft 36. The external teeth 38a of the driving external gear 38 mesh with the external teeth 39a of the four driven external gears 39. I have. Here, the driven external gear 39 has a larger diameter than the driving external gear 38, and as a result, the rotation of the input shaft 36 is reduced by the driving and driven external gears 38 and 39. These four driven external gears 39 surround the driving external gear 38 from the outside in the radial direction, and are arranged at equal angles in the circumferential direction.

A plurality of, here two, pinions 40, 41 are accommodated in the cylindrical body 31, and these pinions 40, 41 are arranged in parallel in the axial direction. These pinions 40, 41 have outer teeth 40a, 41a, which are slightly smaller than the number of teeth of the internal tooth pin 33 on the outer circumference, here, only one tooth is smaller.
The numbers a and 41a are both odd numbers.

The adjacent pinions 40 and 41 are engaged with the internal pin 33 of the cylindrical body 31 in a state where the phases are shifted from each other by 180 degrees. For example, when the outer teeth 40a at the upper end of the pinion 40 mesh with the inner pins 33 at the upper end most deeply, the outer teeth 41a at the lower end of the pinion 41 are
33 is the most deeply engaged. As a result, the symmetry of the pinions 40 and 41 is increased, and the force generated 180 degrees apart at the deepest meshing portion of the pinions 40 and 41 is caused by an even number of crankshafts as described later. Acting symmetrically about the axis, which
The strength of is improved.

The pinions 40, 41 are formed with the same number (four) of loose fitting holes 44, 45 in the circumferential direction as the column portions 26, respectively. The loose fitting holes 44, 45 of these pinions 40, 41 are formed. , 45
Each of the column portions 26 of the carrier 25 penetrates in the axial direction in a loosely fitted state. Here, since three loose fitting holes as described above are conventionally formed, the length of the bridge of the pinion formed radially outward from the loose fitting holes becomes longer, which facilitates deformation. And the strength of the pinion was low, but as in this embodiment, the loose fitting holes 44 and 45
When four are formed, the length L of the bridge 42 is shortened, and the strength of the pinions 40 and 41 is improved.

In the pinions 40 and 41, through holes 46 and 47 are formed at equal angles in the circumferential direction, respectively. The number of these through holes 46 and 47 is an even number of four or more, here only four. Have been. These through-holes 46 and 47 are arranged at a circumferentially intermediate point between two adjacent loose fitting holes 44 and 45.

Reference numeral 50 denotes an even number of four or more crankshafts, here, four crankshafts having the same number as the through holes 46, 46. One end of each of the crankshafts 50 has an end plate (fixed casing 11).
The other end is rotatably supported by the end plate 27 via a bearing 49. Each crankshaft 50 has two eccentric portions 51, 52 eccentric at an equal angle from the center axis of the crankshaft 50 at the axial center thereof.
Are 180 degrees out of phase in the circumferential direction. The eccentric portions 51 and 52 are inserted into the through holes 46 and 47 of the pinions 40 and 41 with the roller bearing 53 interposed therebetween.

The driven external gear 39 is spline-coupled to the other end of the crankshaft 50. In this way, the driven external gear 39 is attached to all of the crankshaft 50, and the driven external gear 39 If one drive external gear 38 is meshed with the external gear 38, the number of driven external gears 39 meshing with the drive external gear 38 is increased, so that a large rotational torque can be transmitted.

The drive rotation applied to the input shaft 36 is reduced by the drive and driven external gears 38 and 39 and transmitted to the crankshaft 50. When the crankshaft 50 rotates around the central axis, the eccentric portion 51 and 52 rotate eccentrically in the through holes 46 and 47, and eccentrically rotate (revolve) the pinions 40 and 41 in a state where the phases are shifted by 180 degrees. At this time, the internal tooth pin 33
Is slightly different from the number of the external teeth 40a and 41a (here, the number of the external teeth 40a and 41a is smaller by one than the number of the internal teeth pins 33). It rotates at low speed due to eccentric rotation.

Here, the pillar 26 and the crankshaft 50 are connected to the conventional 3
From the book, if there are four as in this embodiment, the speed reducer 24
The strength of the drive unit and the support unit is improved, and as a result, the output torque can be improved by about 25% with the same volume design. Further, as described above, if the pinions 40 and 41 are engaged with each other with a phase difference of 180 degrees, and the number of the crankshafts 50 is an even number of four, the symmetry of the pinions 40 and 41 is increased and acts on the crankshaft 50. The load sharing becomes substantially equal, and thereby the strength of the speed reducer 24 is improved.

Next, the operation of the first embodiment of the present invention will be described. When the pressure oil from the pump is supplied to any one of the cylinder holes 16 through the supply / discharge holes 19a of the timing plate 19, the plunger 17 in the cylinder hole 16 projects toward the swash plate 20 and presses the inclined surface 20a. However, at this time, since the tip of the plunger 17 is engaged with the inclined surface 20a via the shoe 18, the circumferential component of the pressing force acts on the plunger 17, whereby the shoe 18 moves on the inclined surface 20a. Sliding,
The rotation shaft 13 and the input shaft 36 are driven and rotated.

The rotation of the input shaft 36 is transmitted to the crankshaft 50 after being reduced by the driving external gear 38 and the driven external gear 39, and the rotational driving force transmitted to the crankshaft 50 is as described above. Then, the pinions 40 and 41 are eccentrically revolved in the cylindrical body 31. Thereby, the rotation of the input shaft 36 is greatly reduced and transmitted to the cylindrical body 31.

If the number of crankshafts 50 is four or more, as described above, the through holes 46 and 47 and the pinions 40 and 41
Of the outer teeth 40a and 41a in the circumferential direction
40 and 41 are the same. As a result, both pinions
Even if you exchange while turning over 40, 41, both pinions 4
0 and 41 are the same as the original state. As a result, pinion 4
Both 0 and 41 can be manufactured and assembled without worrying about the type thereof, the manufacturing cost can be reduced, and the assembling work can be simplified.

Next, a second embodiment of the present invention will be described. In this embodiment, as shown in FIG. 4, two of the crankshafts 50, which are furthest apart in the circumferential direction, are four crankshafts 50 in this case. The driven external gear 55 is attached only to the drive external gear 55, and the drive external gear 56 meshes with the two driven external gears 55. By doing so, the first
The surrounding space is larger than that of the embodiment, and as a result, the driving external gear 56 has a small diameter, while the driven external gear 55 has a large diameter without worrying about interference between the driven external gears 55. Can be. As a result, the rotational driving force can be significantly reduced. Other configurations and operations are the same as those of the first embodiment.

Although four crankshafts 50 are provided in the above-described embodiment, six crankshafts may be provided in the present invention. In the above-described embodiment,
While the cylindrical body 31 is rotatable, the carrier 25 is fixed, and the rotation input to the crankshaft 50 is reduced by the pinions 40 and 41 and output to the cylindrical body 31. The body may be fixed and the carrier may be rotatable, and the rotation input to the crankshaft may be reduced by a pinion and output to the carrier.

[0031]

As described above, according to the present invention, the eccentric oscillating speed reducer can be made inexpensive, the assembling work can be simplified, and the output torque can be improved.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a first embodiment of the present invention.

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

FIG. 3 is a sectional view taken along the line BB of FIG. 1;

FIG. 4 is a sectional view similar to FIG. 3, showing a second embodiment of the present invention.

[Explanation of symbols]

 24: Eccentric oscillating reduction gear 25 ... Carrier 26 ... Column 31 ... Cylindrical body 33 ... Internal teeth 38 ... Driving external gear 39 ... Driven external gear 40, 41 ... Pinion 40a, 41a ... External teeth 50 ... Crankshaft

Claims (4)

[Claims] 1. A cylindrical body having internal teeth on its inner periphery, and external teeth which are housed in the cylindrical body, mesh with said internal teeth on the outer periphery, and have a slightly smaller number of teeth than said internal teeth, and are arranged in parallel in the axial direction. A plurality of pinions, and while penetrating these pinions in the axial direction, and a carrier having a plurality of pillars separated in the circumferential direction, while being arranged at equal angular intervals from each other in the circumferential direction between adjacent pillars, A crankshaft that eccentrically rotates the pinion by rotating and rotating the pinion at the center, while the both ends are rotatably supported by the carrier, and the eccentric rotation of the pinion is reduced by external and internal teeth An eccentric oscillating type speed reducer in which a cylindrical body or a carrier is rotated at a low speed, wherein the number of the crankshafts is four or more and an even number. 2. The reduction gear according to claim 1, wherein adjacent pinions are engaged with the cylindrical body in a state where the phases are shifted by 180 degrees. 3. A driven external gear is mounted on all of the crankshafts, a driven external gear is meshed with the driven external gears, and a rotational driving force is transmitted from the driven external gear to the crankshaft via the driven external gears. The speed reducer according to claim 1, wherein 4. A driven external gear is mounted on only two of the crankshafts which are furthest apart in the circumferential direction, and a driven external gear is meshed with these driven external gears. 2. The reduction gear according to claim 1, wherein the rotational driving force is transmitted to the crankshaft via a gear.