JPH11153200A - Reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decelerate rotation of an input shaft in an extensive area while simplifying structure, miniaturizing a device and making it low in cost. SOLUTION: At the time of maximum number of rotation to move a piston 60 to the other side, only a first clutch 52 comes to be in a connected state, and rotation of an input shaft 27 is output roughly at the same speed, but at the time of minimum number of rotation to move a moving body 61 to one side by a spring 64, and accordingly, rotation of the input shaft 27 is extensively reduced by a planetary gear speed reduction mechanism 47, and it is possible to extensively make reduction gear ratios of the both different from each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed reducer capable of changing a speed reduction ratio in a wide range.

[0002]

2. Description of the Related Art In recent years, a wide range of rotational speed control has been required for driving civil engineering and agricultural machines, such as hydraulic excavators and wheel loaders, by controlling the flow rate of supplied pressure oil and changing the tilting position of a swash plate, while being inexpensive. The use of a swash plate type hydraulic motor that can perform the rotation has been increased, but when the rotation of such a hydraulic motor is directly transmitted to the drive wheels of a hydraulic shovel or the like, the traveling speed of the hydraulic shovel or the like becomes too high. A speed reduction device capable of reducing the rotation at a high ratio is interposed between the hydraulic motor and the drive wheel to reduce the rotation speed of the drive wheel to an appropriate value.

[0003]

Recently, it has been considered to use such a speed reducer with a hydraulic motor as a drive for driving an asphalt finisher or the like that requires a wider range of speed control. Since such a reduction gear has a constant reduction ratio, there is a problem that the speed range is narrow and cannot be used.

SUMMARY OF THE INVENTION An object of the present invention is to provide a speed reducer capable of decelerating the rotation of an input shaft in a wide range while having a simple structure, small size, and low cost.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an input shaft that rotates by receiving a driving force, an input gear and a sun gear rotatably supported by the input shaft, and an output gear that meshes with the input gear. An internal gear provided so as to surround the sun gear, a planet gear that revolves around the sun gear while revolving around the sun gear while meshing with both the sun gear and the internal gear, and rotatably supports the planet gear. Along with
A carrier that is connected to the input gear and rotates at the same speed as the revolution of the planetary gear, is interposed between the input shaft and the input gear, and connects the input shaft and the input gear when in a connected state,
The first to disconnect the input gear from the input shaft when in the cutoff state
A clutch, interposed between the input shaft and the sun gear,
A second clutch that connects the input shaft and the sun gear when in the connected state, and disconnects the sun gear from the input shaft when in the disconnected state, and a second clutch in which one of the first and second clutches is in the connected state. Switching means for switching to the disengaged state, wherein the switching means switches the first clutch to the connected state and the second clutch to the disengaged state, thereby outputting the rotation of the input shaft from the output gear through the input gear, The switching means brings the second clutch into the connected state,
By switching the clutch to the disengaged state, the rotation of the input shaft can be achieved by decelerating the rotation of the input shaft by a planetary gear reduction mechanism including a sun gear, an internal gear, a planetary gear, and a carrier, and then outputting the output from the output gear through the input gear. .

When the first clutch is switched to the engaged state and the second clutch is switched to the disconnected state by the switching means, the input shaft and the input gear are connected, and the rotation of the input shaft is output from the output gear through the input gear. At this time, the rotation of the input shaft may be slightly reduced by the input and output gears meshing with each other, or may be transmitted at a constant speed. At this time, the carrier connected to the input gear rotates at the same speed as the input gear, so that the planetary gear and the sun gear rotate by receiving the rotation of the carrier (the planetary gear rotates and revolves, and the sun gear rotates. However, such rotation is idle because the sun gear is separated from the input shaft by the second clutch. Next, when the second clutch is switched to the connected state and the first clutch is switched to the disconnected state by the switching means, the input shaft and the sun gear are connected, and the rotation of the input gear is transmitted to the sun gear, and the sun gear is rotated. Rotate. As a result, the planetary gear meshing with the internal gear revolves around the sun gear while revolving around the sun gear. At this time, the revolution (low-speed rotation) of the planetary gear is taken out by the carrier, and the carrier is revolved with the revolution of the planetary gear. It rotates at low speed at high speed. In this way, the rotation of the input shaft is greatly reduced by the planetary gear reduction mechanism composed of the sun gear, the internal gear, the planetary gears, and the carrier, and then the output gear is transmitted through the input gear connected to the carrier in the same manner as described above. Is output. In this way, the rotation of the input shaft is output from the output gear at substantially constant speed (slightly reduced or not reduced) when the first clutch is switched to the engaged state and the second clutch is switched to the disconnected state. However, when the second clutch is switched to the engaged state and the first clutch is switched to the disengaged state, the speed is largely reduced by the planetary gear reduction mechanism, and the output is output from the output gear at substantially the same speed as the reduced rotation speed. Therefore, the speed reduction ratio of the two greatly differs, and as a result, the speed reduction range can be considerably widened. For this reason, the present speed reducer can be used for an asphalt finisher or the like that requires a wide range of speed control.

[0007] Further, according to the structure as described in claim 2, it can be used as a reduction gear that outputs an extremely low speed rotation. Further, with the structure as described in claim 3, the structure can be used as a reduction gear that outputs normal low-speed rotation while simplifying the structure. Further, with the configuration as described in claim 4, it can be used as a drive device capable of controlling a wide range of rotation speed. Further, according to the structure described in claim 5, the first and second clutches can be reliably switched with a simple structure.
Further, according to the structure described in claim 6, the transmission of the rotational driving force can be cut off inside the reduction gear transmission, and the transmission system after the input shaft can be freely rotated.

[0008]

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 attached to a traveling frame of an asphalt finisher, for example, and a storage chamber 13 is formed on one side of the fixed casing 11, and the storage chamber 13
Houses a swash plate type hydraulic motor 12 having a rotating shaft 14 rotatably supported by the fixed casing 11. Fifteen
Is a cylindrical cylinder block, into which the rotary shaft 14 is inserted and spline-coupled. Plungers 17 are slidably inserted into a plurality of cylinder holes 16 formed in the cylinder block 15, respectively.
18 are connected. Reference numeral 20 denotes a timing plate interposed between the cylinder block 15 and the fixed casing 11, and a supply / discharge hole 20a formed in the timing plate 20.
Connects a pair of supply / discharge passages (not shown) formed in the fixed casing 11 to the cylinder hole 16. In addition, 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 21 denotes a substantially ring-shaped swash plate disposed on the other side of the cylinder block 15, and an inclined surface 22 is formed on one end surface of the swash plate 21, and the shoe 18 slides on the inclined surface 22. I have. Further, two flat surfaces are formed on the other end surface of the swash plate 21, and a fulcrum member (not shown) is disposed on the boundary between these flat surfaces, whereby the swash plate 21 is provided. Can tilt between two tilting positions about the fulcrum member. Here, the tilting of the swash plate 21 is caused by the supply and discharge of pressure oil to and from the cylinder chamber 23 of the fixed casing 11,
This is performed by moving the piston 24 accommodated in the shaft in the axial direction. The tilting of the swash plate 21 changes the stroke of the plunger 17 in the cylinder block 15 in two stages, whereby the cylinder block 15, the rotating shaft
The number of rotations of 14 changes to two stages, and a wide range of rotation speed control is performed. The rotation shaft 14, the cylinder block 15, the plunger 17, the shoe 18, the timing plate 20, the swash plate 21, and the piston 24 as a whole have a two-stage rotation speed by changing the tilt position of the swash plate 21 to two stages. The hydraulic motor 12 having a rotating shaft 14 that changes to

Reference numeral 25 denotes a reduction gear having a hollow fixed case 26. The fixed casing 11 is fixed to one end of the fixed case 26. As a result, the hydraulic motor 12
Is attached to one side of the speed reducer 25. An input shaft 27 coaxial with the rotary shaft 14 is loosely fitted in the fixed case 26, and the other end of the rotary shaft 14 is inserted into a cylindrical joint member 28 into which one end of the input shaft 27 is inserted. Have been. The joint member 28, the rotating shaft 14, and the input shaft 27 are connected to each other by a spline connection.As a result, the rotating shaft 14 and the input shaft 27 are movable in the axial direction with respect to the joint member 28, Further, the input shaft 27 rotates by receiving the rotation driving force of the rotation shaft 14 transmitted through the joint member 28. A transmission member 29 having a substantially cylindrical shape is fitted to the outside of the input shaft 27 so as to be movable in the axial direction, and an input having a large number of external teeth 30 formed on the outer periphery of one side of the transmission member 29. A gear 31 is rotatably fitted, and a sun gear 33 having a large number of external teeth 32 formed on the outer periphery is rotatably fitted to the outside of the other side. As a result, the input gear 31 and the sun gear 33 are rotatably supported on the input shaft 27 via the transmission member 29, but the input gear 31 and the sun gear 33 rotate independently of each other. Can be. Numeral 34 denotes a plurality of output gears, here three output gears, each fixed to the other end of the crankshaft of the eccentric oscillating reduction gear described later.
Numeral 34 surrounds the input gear 31 from the outside and is arranged at equal distances in the circumferential direction. Reference numeral 35 denotes a number of external teeth formed on the outer periphery of each output gear 34, and the external teeth of these output gears 34
Reference numeral 35 meshes with the external teeth 30 of the input gear 31. Here, the number of the external teeth 35 of the output gear 34 is slightly larger than the number of the external teeth 30 of the input gear 31 as in this embodiment, and the rotation is slightly reduced by the input gear 31 and the output gear 34. Alternatively, the number of teeth of the input and output gears may be the same, and the rotation may be transmitted at a constant speed.

Reference numeral 38 denotes a substantially cylindrical hub rotatably supported by the fixed casing 11 and the fixed case 26 via a bearing 39. The hub 38 is connected to a drive wheel of the asphalt finisher. The other end of the hub 38 has a disc-shaped cover 40 for closing the opening of the other end of the hub 38.
The cover 40 is provided at its radially outer end with a protruding ring 41 serving as an internal gear. Here, the protruding ring 41 is arranged so as to surround the sun gear 33 from the outside, and a number of internal teeth 42 are formed on the inner periphery thereof.
Reference numeral 43 denotes a plurality of planet gears, which are three equidistantly arranged in the circumferential direction, here, three planet gears. A large number of external teeth 44 formed on the outer periphery of these planet gears 43 are external teeth of the sun gear 33. 32 and the internal teeth 42 of the protruding ring (internal gear) 41 are meshed. Reference numeral 45 denotes a carrier rotatably supported by the fixed case 26 and the cover 40. The plurality of carriers 45 are equidistant in the circumferential direction, here, the same number as the planetary gears 43 (3
Book). The planetary gears 43 are rotatably supported on the support shafts 46, respectively.As a result, the carrier 45 rotates when the planetary gears 43 revolve around the sun gear 33. Thus, the planetary gear 43 rotates at a constant speed. Further, the carrier 45 is connected to the input gear 31 by being spline-coupled to the external teeth 30 at one inner end thereof. As a result, the carrier 45 rotates at the same speed as the input gear 31. Becomes The sun gear 33, the internal gear (projecting ring) 41, the planetary gear 43, and the carrier 45 as a whole constitute a planetary gear reduction mechanism 47 that greatly reduces the rotation input to the sun gear 33 and outputs the rotation from the carrier 45. I do.

A substantially disk-shaped one-side clutch piece 50 whose other side is in contact with one end of the transmission member 29 is fitted to the outside of one side of the input shaft 27. The input shaft 27 is connected to the input shaft 27 by a spline connection. As a result, the one-side clutch piece 50 rotates at the same speed as the input shaft 27 and is movable in the axial direction of the input shaft 27. 51
Is a substantially ring-shaped other clutch piece disposed outside the one end of the input gear 31, and the other clutch piece 51 is located on the other side of the one clutch piece 50. Here, the other clutch piece 51 is connected to the input gear 31 by being spline-connected at its radial inner end to the external teeth 30. The one-side clutch piece 50 and the other-side clutch piece 51
When the one-side clutch piece 50 approaches the other-side clutch piece 51 and their teeth mesh with each other, the connected state is established, and the input shaft 27 and the input gear 31 are connected. 50
Is disengaged from the other clutch piece 51 when the teeth are disengaged from each other and the input gear 31 is moved to the input shaft.
Disconnect from 27. The above-mentioned one-side and other-side clutch pieces 50, 51
Is interposed between the input shaft 27 and the input gear 31 as a whole, connects the input shaft 27 and the input gear 31 when in a connected state, and disconnects the input gear 31 from the input shaft 27 when in a disconnected state. One clutch 52 is constituted.

A substantially disk-shaped clutch piece 54 whose one side is in contact with the other end of the transmission member 29 is fitted on the outside of the other end of the input shaft 27. The input shaft 27 and the input shaft 27 are connected by a spline connection. As a result, the other clutch piece 54 rotates at the same speed as the input shaft 27 and is movable in the axial direction of the input shaft 27. 55
Is a substantially ring-shaped one-side clutch piece disposed outside the other end of the sun gear 33, and the one-side clutch piece 55 is located on one side of the other-side clutch piece 54. Here, the one-side clutch piece 55 is connected to the sun gear 33 by a radially inner end portion being spline-coupled to the external teeth 32. The other clutch piece 54 and the one clutch piece 55
When the other clutch piece 54 approaches the one clutch piece 55 and the teeth mesh with each other, the other clutch piece 54 is connected to connect the input shaft 27 and the sun gear 33, while the other clutch piece 54 54
Is disengaged from the one-side clutch piece 55 and the teeth are disengaged from each other, and the sun gear 33 is connected to the input shaft
Disconnect from 27. The other side, one side clutch piece 54, 55 described above
Is interposed between the input shaft 27 and the sun gear 33 as a whole, connects the input shaft 27 and the sun gear 33 when in the connected state, and disconnects the sun gear 33 from the input shaft 27 when in the disconnected state. The two clutch 56 is constituted.

Reference numeral 60 denotes one clutch piece of the first clutch 52.
This piston is located on one side of 50
60 is inserted into the fixed case 26 and fitted to the outside of the input shaft 27, and can move in the axial direction of the input shaft 27. When the piston 60 moves to the other side to bring the one clutch piece 50 closer to the other clutch piece 51, the first
The clutch 52 is switched from the disconnected state to the connected state. 61
Reference numeral denotes a ring-shaped moving body disposed on the other side of the other clutch piece 54 of the second clutch 56. The moving body 61 is inserted into the cover 40 and floats outside the input shaft 27. The input shaft 27 can be fitted and can move in the axial direction of the input shaft 27. When the moving body 61 moves to one side to bring the other clutch piece 54 closer to the one clutch piece 55, the second clutch 56 is switched from the disengaged state to the connected state.

Reference numeral 62 denotes a hydraulic passage formed in the fixed casing 11 and the fixed case 26. One end of the hydraulic passage 62 is connected to a control hydraulic power source via a switching valve (not shown), and the other end is connected to the fixed case 26. And a cylinder chamber 63 formed between the piston and the piston 60, respectively. As a result, when high-pressure oil is supplied to the cylinder chamber 63 through the hydraulic passage 62, the oil is guided to one side of the piston 60 and presses the piston 60 toward the moving body 61 (to the other side). Move. When the piston 60 moves to the other side in this manner, the one clutch piece 50 of the first clutch 52 is pushed and approaches the other clutch piece 51, and the first clutch 52 is switched to the connected state, Other clutch piece 54 of second clutch 56
Is pushed by the one-side clutch piece 50 and the transmission member 29 to be separated from the one-side clutch piece 55, and the second clutch 56 is switched to the disengaged state. Reference numeral 64 denotes a spring interposed between the moving body 61 and the cover 40. The spring 64 applies an urging force toward the one side smaller than the pressing force of the piston 60 to the moving body 61, The body 61 is moved toward the piston 60 (to one side). As a result, when high-pressure oil is not guided to the piston 60, the spring 64 moves the moving body 61 to one side. When the moving body 61 moves to one side in this way, the second clutch 56 The other clutch piece 54 is pushed to approach the one clutch piece 55, the second clutch 56 is switched to the connected state, and the one clutch piece 50 of the first clutch 52 is connected to the other clutch piece 54, The first clutch 52 is switched to the disengaged state by being separated from the other clutch piece 51 by being pushed by the transmission member 29. Thus, the piston 60 and the moving body 61
The transmission member 29 interposed with the one-side clutch piece 50 and the other-side clutch piece 54 transmits the movement of either the piston 60 or the moving body 61 to the other, and transmits the first and second clutch pieces. The connection and disconnection states of the two clutches 52 and 56 are alternately switched. The transmission member 29, the piston 60, the moving body 61, the hydraulic passage 62, and the spring 64 as a whole are configured such that when one of the first and second clutches 52 and 56 is in the connected state, the other is in the disconnected state. The switching means 65 for switching is constituted, and the switching means 65 can reliably switch between the first and second clutches 52 and 56 while having a simple structure as described above.

Reference numeral 68 denotes an eccentric oscillating reduction gear provided on the other side of the fixed casing 11, and the reduction gear 68 is attached to one side of the reduction gear 25. This reduction gear 68 has a large number of internal gear pins 69 provided on the inner periphery of the hub 38,
These internal teeth pins 69 extend in the axial direction and are arranged at equal distances in the circumferential direction. Numeral 70 denotes two disc-shaped pinions housed in the hub 38, and the outer periphery of each pinion 70 meshes with the internal tooth pins 69 and has slightly less teeth than the number of the internal tooth pins 69. A number of external teeth 71 are formed. Further, a plurality of penetrating loose fitting holes 72 and a plurality of penetrating shaft holes 73 are formed in each pinion 70, respectively.
The other end of the fixed casing 11 is loosely fitted in the loose fitting hole 72. Reference numeral 74 denotes a plurality (three) of crankshafts extending in parallel with the rotary shaft 14 and the input shaft 27. The crankshafts 74 are rotatably supported by the fixed casing 11 and the fixed case 26. Each crankshaft 74 has two eccentric portions 75 eccentric in the opposite direction from the central axis of the crankshaft 74, and these eccentric portions 75 are inserted into shaft holes 73 of the pinion 70. When the crankshaft 74 rotates around the center axis, the eccentric portions 75 of the crankshafts 74 eccentrically rotate in the shaft holes 73 of the pinion 70 to cause the pinion 70 to eccentrically revolve.
At this time, since the number of the external teeth 71 is slightly smaller than the number of the internal teeth pins 69, the hub 38 is greatly decelerated by the eccentric revolving motion of the pinion 70 and rotates at a low speed. The above-described internal tooth pin 69, pinion 70, and crankshaft 74 as a whole constitute the eccentric oscillating reduction gear 68 which reduces the rotation of the crankshaft 74 by the pinion 70 that rotates eccentrically and outputs it to the hub 38. Since the reduction gear 68 can reduce the rotation of the crankshaft 74 at a high ratio, such a reduction gear 68 is attached to the reduction gear 25 as described above, and the reduction gear 25 is attached to the crankshaft 74. If the output gear 34 is connected, it can be used for deceleration of an asphalt finisher or the like that requires extremely low-speed rotation. In this embodiment, the variable-speed hydraulic motor 12 is attached to the reduction gear 25 as described above, and the input shaft 27 of the reduction gear 25 is connected to the rotating shaft 14 of the hydraulic motor 12. Therefore, it is suitable as a drive device for an asphalt finisher or the like that requires a wide range of rotation speed control.

1, 2, 4, and 5, reference numeral 79 denotes a through hole formed in the cover 40 and coaxial with the input shaft 27. One end of the through hole 79 has the other end of the input shaft 27. Is inserted. Reference numeral 80 denotes a cap screwed into the other side of the through hole 79. The cap 80 rotatably supports the other end of the input shaft 27 via a ball 81. Reference numeral 82 denotes a blocking member having one side inserted into the through hole 79 instead of the cap 80, and an outer periphery of one side of the blocking member 82 is a cylindrical surface.
In addition, a screw hole 83 that can be screwed to the other end of the input shaft 27 is formed on one end surface thereof. And the piston 60
When the supply of the pressurized oil is stopped, after inserting one side of the blocking member 82 into the through hole 79, the blocking member 82 is rotated by a knob 84 provided on the other side of the blocking member 82. The other end of the input shaft 27 is gradually pulled into the screw hole 83 while being screwed, whereby the input shaft 27 is forcibly moved in the axial direction toward the other side, and A gap is formed in At this time, the piston 60, the one-side clutch piece 50 of the first clutch 52, the transmission member 29, the other-side clutch piece 54 of the second clutch 56, and the moving body 61 are pushed by the step surface 27a of the input shaft 27.
Also moves together with the input shaft 27 toward the moving body 61 (the other side) while opposing the spring 64. When the input shaft 27 is pulled into the screw hole 83 until it comes into contact with the bottom wall of the screw hole 83 as shown in FIG. 5, the movement of the input shaft 27 stops. At this time, the other clutch piece 54 of the second clutch 56 is disengaged from the one clutch piece 55, but the one clutch piece 50 of the first clutch 52 cannot approach until it engages with the other clutch piece 51, As a result, both clutches 52 and 56 are in the disconnected state. When both the clutches 52 and 56 are in the disengaged state by the interruption member 82 in this way, the transmission of the rotational driving force is interrupted inside the reduction gear 25, so that the transmission system after the input shaft 27 can be freely rotated. Yes, this allows
Asphalt finisher can be towed.

Next, the operation of the first embodiment of the present invention will be described. When pressure oil is supplied to one of the cylinder holes 16 through the supply / discharge hole 20a, the plunger 17 in the cylinder hole 16 projects toward the swash plate 21 and presses the inclined surface 22. Since the tip is engaged with the inclined surface 22 via the shoe 18, the circumferential component of the pressing force acts on the plunger 17, whereby the plunger 17,
The shoe 18 slides on the inclined surface 22 to integrally rotate the plunger 17, the cylinder block 15, the rotating shaft 14, and the input shaft 27.

Here, when it is desired to rotate the hub 38 at the highest rotational speed, the amount of pressure oil supplied to the cylinder hole 16 of the hydraulic motor 12 is maximized, and the tilt angle of the swash plate 21 is reduced. And the stroke of the plunger 17 is shortened, whereby the rotation speed of the cylinder block 15 and the rotary shaft 14 is maximized in combination with the supply of the maximum amount of pressure oil. At the same time, high pressure oil is supplied through the hydraulic passage 62 to the cylinder chamber 63.
And guide it to one side of the piston 60. As a result, the piston 60 moves together toward the other side while pressing the one-side clutch piece 50 of the first clutch 52, and engages the one-side clutch piece 50 and the other-side clutch piece 51 to connect the first clutch 52. State. At this time, the other clutch piece of the second clutch 56
Since the moving force of the one-side clutch piece 50 is transmitted via the transmission member 29, the 54 moves to the other side integrally with the one-side clutch piece 50 and the transmission member 29. As a result, the other-side clutch piece 54 is separated from the one-side clutch piece 55 and disengaged, and the second clutch 56 is brought into a disengaged state. When the first clutch 52 enters the connected state as described above, the input shaft 27
And the input gear 31 are connected, and the rotation of the input shaft 27 is output from the output gear 34 to the crankshaft 74 through the input gear 31. At this time, the input and output gears 31 and 34 meshing with each other. As a result, the rotation of the input shaft 27 is output to the crankshaft 74 only by being slightly reduced, so that the rotation is output from the reduction gear 25 at the maximum rotation speed. As described above, the rotation of the input shaft 27 is output from the output gear 34 at a substantially constant speed. This rotation is thereafter reduced at a high ratio in the speed reducer 68 and output to the hub 38 as described above. As a result, the hub 38 rotates at the maximum rotational speed. At this time, since the carrier 45 of the reduction gear 25 connected to the input gear 31 rotates at the same speed as the input gear 31, the planetary gear 43 and the sun gear 33
Receives the rotation of the carrier 45 and rotates (the planetary gear 43 rotates and revolves, and the sun gear 33 rotates). Such rotation is performed by the second clutch 56 in which the sun gear 33 is in the disconnected state as described above. Since it is separated from the input shaft 27, it idles.

On the other hand, when the hub 38 is rotated at the lowest rotational speed, the amount of pressure oil supplied to the cylinder hole 16 of the hydraulic motor 12 is minimized and the swash plate 21 is tilted at a large angle. By tilting the plunger 17 in a certain direction to increase the stroke of the plunger 17, the rotation speed of the cylinder block 15 and the rotating shaft 14 is minimized in combination with the supply of the minimum amount of pressure oil. At the same time, the supply of pressure oil to the cylinder chamber 63 through the hydraulic passage 62 is stopped, and the moving body 61,
The other clutch piece 54 of the second clutch 56 is replaced with the one clutch piece 55
Move closer to. As a result, the second clutch 56
The other clutch piece 54 and the one clutch piece 55 mesh with each other, and the second clutch 56 is connected. At this time, the moving force of the other clutch piece 54 is transmitted to the one clutch piece 50 of the first clutch 52 via the transmitting member 29, and thus the other clutch piece 54 and the transmitting member 29 are integrated with each other. Move to one side. As a result, the one-side clutch piece 50 is
As a result, the first clutch 52 is disengaged from the clutch 51. Then, when the second clutch 56 is connected as described above, the input shaft 27 and the sun gear 33 are connected,
The rotation of the input shaft 27 is transmitted to a sun gear 33,
Rotate 33. Thereafter, the rotation of the sun gear 33 is transmitted to the planetary gear 43 to rotate the planetary gear 43. At this time, the projecting ring 41 meshing with the planetary gear 43 and the hub 38 together with the hub 38 have a minimum rotation speed as described later. Therefore, the planetary gear 43 revolves around the input shaft 27 at a low speed. Since the revolution (low-speed rotation) of the planetary gear 43 is taken out by the carrier 45, the carrier 45 rotates at a low speed at the same speed as the revolution of the planetary gear 43. In this way, the rotation of the input shaft 27 is significantly reduced by the planetary gear reduction mechanism 47, and then transmitted to the input gear 31 connected to the carrier 45.The low-speed rotation transmitted to the input gear 31 is The speed is slightly reduced by the input / output gears 31 and 34 in the same manner as described above, and is output to the crankshaft 74 of the speed reducer 68. Thereafter, this rotation is further reduced at a high ratio in the speed reducer 68 as described above, and output to the hub 38. As a result, the hub 38 rotates at the minimum rotation speed.

As described above, the rotation of the input shaft 27 is substantially constant (here, slightly reduced) from the output gear 34 when the first clutch 52 is switched to the engaged state and the second clutch 56 is switched to the disengaged state. When the second clutch 56 is switched to the connected state and the first clutch 52 is switched to the disengaged state, the speed is largely reduced by the planetary gear reduction mechanism 47, and then the rotation speed is substantially equal to the reduced rotation speed. Since the output is output from the output gear 34, the speed reduction ratio of the two greatly differs, and as a result, the speed reduction range can be considerably widened. For this reason, the present speed reducer can be used for an asphalt finisher or the like that requires a wide range of speed control.

In the case where the asphalt finisher or the like equipped with such a speed reducer breaks down and needs to be pulled, the cap 80 and the ball 81 are taken out from the through hole 79, and then the one side of the blocking member 82 is removed. The block is inserted into the through hole 79, and the blocking member 82 is manually rotated by the knob 84. As a result, the other end of the input shaft 27 is gradually pulled into the screw hole 83 while being screwed into the input shaft 27, the piston 60, and the first clutch.
The one-side clutch piece 50, the transmission member 29, the other-side clutch piece 54 of the second clutch 56, and the moving body 61 are forcibly moved to the other side integrally. And, the input shaft 27 has a screw hole 83
When the clutches 52 and 56 are retracted into the screw hole 83 until they come into contact with the bottom wall, both clutches 52 and 56 are switched to the disconnected state. When both the clutches 52 and 56 are in the disengaged state by the interruption member 82 in this manner, the transmission of the rotational driving force is interrupted inside the reduction gear transmission, so that the transmission system after the input shaft 27 can be freely rotated. As a result, the asphalt finisher can be towed.

FIGS. 6 and 7 show a second embodiment of the present invention. In this embodiment, the eccentric oscillating speed reducer 68 in the first embodiment is omitted, and the output gear
The outer teeth 90 of the output gear 88
Forming a large number of internal teeth 91 meshing with the output gear
88 is rotatably supported by a plurality of support shafts 93 fixed to a fixed casing 92. Also, by inserting one end of the input shaft 95 into the other end of the rotating shaft 94 of the hydraulic motor 12 and spline-joining, these rotating shafts 94,
The input shaft 95 is directly connected. By doing so, the rotation of the output gear 88 is directly transmitted to the hub 89 while being reduced at a low ratio, that is, while being reduced at the ratio of the number of the external teeth 30 of the input gear 31 to the number of the internal teeth 91 of the hub 89. Machines that require normal low-speed rotation while simplifying the structure, such as hydraulic excavators,
It can be used for wheel loaders and the like. In addition, when towing a hydraulic shovel equipped with such a reduction gear, for example, as shown in FIG. 8, instead of the cap 80, the blocking member 82 is inserted into the through hole 79 and rotated, and Second
By setting both of the clutches 52 and 56 to the disconnected state, transmission of the rotational driving force is interrupted inside the reduction gear transmission. Other configurations and operations are the same as those of the first embodiment.

In the above-described embodiment, the one clutch piece 50 is moved to the other side by the piston 60 and the spring 64 is moved to the other side.
Although the other clutch piece 54 is moved to one side by the above, in the present invention, the one clutch piece 50 is moved to the other side by the spring, and the other clutch piece is moved by the piston.
54 may be moved to one side,
The other clutch pieces 50 and 54 may both be moved by the piston. Further, in the above-described embodiment, the protruding ring 41 as an internal gear is formed on the cover 40. However, in the present invention, it may be formed on the hub, or the internal gear may be provided as a separate component, and the internal ring may be provided. The gear may be fixed to the cover or the hub. further,
In the above-described embodiment, the number of rotations of the rotary shaft 14 is changed to two steps by changing the tilt angle of the swash plate 21 to two steps. In the present invention, the number of rotations is changed to three steps. You may.

[0024]

As described above, according to the present invention, the rotation of the input shaft can be decelerated over a wide range while having a simple structure, small size, and low cost.

[Brief description of the drawings]

FIG. 1 is a front cross-sectional view illustrating a first embodiment of the present invention at the time of high-speed rotation.

FIG. 2 is an enlarged front sectional view of the reduction gear transmission.

FIG. 3 is a front sectional view at the time of low-speed rotation.

FIG. 4 is a front sectional view showing a state immediately before the input shaft is moved to the other side.

FIG. 5 is a front sectional view showing a state when the input shaft is moved to the other side.

FIG. 6 is a front sectional view at the time of high-speed rotation showing a second embodiment of the present invention.

FIG. 7 is a front sectional view at the time of low-speed rotation.

FIG. 8 is a front sectional view showing a state when the input shaft is moved to the other side.

[Explanation of symbols]

 12 ... Hydraulic motor 14 ... Rotating shaft 21 ... Swash plate 25 ... Reduction gear 27 ... Input shaft 29 ... Transmission member 31 ... Input gear 33 ... Sun gear 34 ... Output gear 38 ... Hub 41 ... Internal gear 43 ... Planetary gear 45 ... Carrier 47 planetary gear reduction mechanism 52 first clutch 56 second clutch 60 piston 61 moving body 62 hydraulic passage 64 spring 65 switching means 68 eccentric oscillating reduction gear 70 pinion 74 crankshaft 82 … Blocking member 89… Hub 91… Inner teeth

Claims (6)

[Claims] An input shaft that rotates by receiving a driving force, an input gear and a sun gear rotatably supported by the input shaft, an output gear meshing with the input gear, and a sun gear are provided. The internal gear, the sun gear, a planetary gear that rotates while revolving around the sun gear while meshing with both the internal gear, and rotatably supporting the planetary gear, and connected to the input gear, A carrier that rotates at the same speed as the revolution of the planetary gear, and is interposed between the input shaft and the input gear, connects the input shaft and the input gear when connected, and connects the input gear to the input shaft when disconnected. And a second clutch that is interposed between the input shaft and the sun gear for disconnecting the sun gear from the input shaft when the input shaft and the sun gear are connected in the connected state, and disconnected when the sun gear is disconnected. And a switching means for switching the first and second clutches so that one of the first and second clutches is in a disengaged state when the other is in a connected state. By switching to the disengaged state, the rotation of the input shaft is output from the output gear through the input gear. On the other hand, by switching the second clutch to the connected state and the first clutch to the disconnected state by the switching means, the rotation of the input shaft is reduced A speed reducer, wherein the speed is reduced by a planetary gear reduction mechanism including a sun gear, an internal gear, a planetary gear, and a carrier, and then output from an output gear through an input gear. 2. An eccentric oscillating type speed reducer for reducing the rotation of a crankshaft by a pinion for eccentric rotation and outputting the reduced speed to a hub, and the output gear is connected to the crankshaft of the eccentric oscillating type speed reducer. The reduction gear according to claim 1. 3. The output gear is provided with a hub surrounding the output gear and having inner teeth formed on the inner periphery and meshing with the external teeth of the output gear, wherein the hub transmits the rotation directly from the output gear. The reduction gear according to claim 1. 4. A swash plate type hydraulic motor having a rotating shaft whose rotation speed changes to a plurality of stages by changing the tilt position of the swash plate to a plurality of positions, and the input shaft is connected to the rotating shaft of the hydraulic motor. The reduction gear transmission according to claim 1, which is connected. 5. The switching means can be moved in the axial direction of the input shaft, and by the movement, a piston for switching the first clutch can be moved in the axial direction of the input shaft. A moving body that switches the second clutch, a hydraulic passage that guides the piston toward the moving body by introducing pressure oil to the piston, and a moving body that faces the piston by applying an urging force to the moving body. 2. The reduction gear transmission according to claim 1, further comprising a spring that is moved between the piston and the moving body, and a transmission member that transmits one of the movements to the other. 6. When the supply of pressure oil to the piston is stopped, the piston, the transmission member, and the moving body are forcibly moved toward the moving body against a spring, and both the first and second clutches are disengaged. 6. The reduction gear transmission according to claim 5, further comprising a blocking member for switching to a state.