JPH11193851A - Reduction gear - Google Patents

Abstract

(57) [Summary] [Purpose] To effectively prevent seizure, noise, abnormally high temperature, and the like when the planetary gear 43 and the carrier 45 idle. [Structure] The first clutch 52 is connected to one side and the other side clutch piece is engaged with each other, and the second clutch 57 is disengaged by disengagement of the other side clutch piece 55 and the one side clutch piece 54. When you are, planetary gear 43, carrier 45,
The rotation (rotation, revolution) of the other clutch piece 55 is idling, but the idling speed of such rotation and revolution is substantially equal to or less than the rotation speed of the input shaft 27, so that seizure may occur. There is no.

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.

In order to solve such a problem, the present applicant has disclosed in Japanese Patent Application No. 9-333475, an input shaft that rotates by receiving a driving force, an input gear rotatably supported by the input shaft, and an input gear. A sun gear, an output gear meshing with the input gear, an internal gear provided to surround the sun gear, and a planet revolving around the sun gear while meshing with both the sun gear and the internal gear. Gears,
A carrier that rotatably supports the planetary gear, is connected to the input gear, and is interposed between the input shaft and the input gear, and a carrier that rotates at the same speed as the revolution of the planetary gear. A first clutch that couples the shaft and the input gear and disconnects the input gear from the input shaft when in the disengaged state; and a first clutch that is interposed between the input shaft and the sun gear when the connection state is established. A second clutch for connecting and disconnecting the sun gear from the input shaft when in a disconnected state;
Switching means for switching the first and second clutches so that one is in a disconnected state when the other is in a connected state, and the switching means switches the first clutch into a connected state;
By switching the second clutch to the disengaged state, the rotation of the input shaft is output from the output gear through the input gear, and on the other hand, by switching the second clutch to the connected state and the first clutch to the disengaged state by the switching means, the input A reduction gear is proposed in which the rotation of the shaft is reduced by a planetary gear reduction mechanism composed of a sun gear, an internal gear, a planetary gear, and a carrier, and then output from an output gear through an input gear.

However, in such a reduction gear transmission, the switching means switches the first clutch to the engaged state and the second clutch to the disengaged state to connect the input shaft and the input gear and to input the sun gear. When separated from the shaft, the rotation of the carrier rotating at the same speed as the input gear is increased by the planetary gear and transmitted to the sun gear, so that the sun gear idles at high speed, for example, 10,000 thousands rotations per minute. As a result, there is a problem that burn-in, noise, and abnormal heat generation may occur due to oil film breakage.

SUMMARY OF THE INVENTION An object of the present invention is to provide a speed reducer capable of effectively preventing seizure, noise, abnormally high temperature, and the like when a planetary gear and a carrier run idle.

[0007]

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 rotatably supported by the input shaft, and an input shaft that is connected to the input shaft and rotates integrally with the input shaft. Sun gear, an output gear meshing with the input gear, an internal gear provided to surround the sun gear, the sun gear, and revolving around the sun gear while meshing with both the internal gears. A planetary gear, a carrier rotatably supporting the planetary gear, and a carrier rotating at the same speed as the revolution of the planetary gear, and interposed between the input shaft and the input gear. A first clutch that connects the gears and disconnects the input gear from the input shaft when in a disconnected state, and is interposed between the carrier and the input gear; Noto Has a second clutch for disconnecting the input gear from the carrier, and switching means for switching the first and second clutches so that one of the first and second clutches is in the disconnected state when the other is in the connected state. By switching the clutch to the engaged state and the second clutch to the disengaged state, the rotation of the input shaft is output from the output gear through the input gear, while the second clutch is engaged and the first clutch is disengaged by the switching means. , The rotation of the input shaft 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 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 disengaged state by the switching means, the input shaft and the input gear are connected, so that the rotation of the input shaft is output from the output gear through the input gear, On the other hand, the input gear is separated from the carrier. At this time, the planetary gear revolves at a reduced speed around the sun gear while rotating at substantially the same speed as the sun gear by the sun gear rotating at the same speed as the input shaft. It rotates at the same speed as the revolution (low-speed rotation). Here, since the carrier is separated from the input gear as described above, the rotation (rotation, revolution) of the planetary gears and the carrier described above is idling, but the idling speed of such rotation and revolution is as described above. In this case, the input shaft is substantially equal to or less than the input shaft, and the occurrence of burn-in, noise, abnormally high temperature, etc. is effectively prevented. Next, when the second clutch is switched to the connected state and the first clutch is switched to the disengaged state by the switching means, the input gear is disconnected from the input shaft, while the input gear and the carrier are connected. At this time, similarly to the above, the planetary gear revolves at a reduced speed around the sun gear while rotating around the sun gear while rotating at substantially the same speed as the sun gear,
Also, the carrier is rotating at the same speed as the revolution of the planetary gear (low-speed rotation).
Is transmitted to the input gear at a constant speed because the input gear and the carrier are connected as described above. In this way, the rotation of the input shaft is greatly reduced by the planetary gear reduction mechanism including the sun gear, the internal gear, the planetary gear, and the carrier.
The output is output from the output gear through the input gear connected to the carrier.

Further, according to the structure as described in claim 2, it can be used as a reduction gear for outputting an extremely low speed rotation. Further, according to the third aspect, the axial length of the reduction gear transmission can be reduced.
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.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. 1 and 2, reference numeral 11 denotes a fixed casing mounted on a traveling frame of, for example, an asphalt finisher. A storage chamber 13 is formed on one side of the fixed casing 11, and the fixed casing 11 is provided in the storage chamber 13. A swash plate type hydraulic motor 12 having a rotating shaft 14 rotatably supported by 11 is housed therein. Reference numeral 15 denotes a cylindrical cylinder block into which the rotary shaft 14 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 (the other end) of the plunger 17. Reference numeral 20 denotes a timing plate interposed between the cylinder block 15 and the fixed casing 11,
A supply / discharge hole 20 a 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. In addition, two flat surfaces are formed on the other end surface of the swash plate 21,
A fulcrum member (not shown) on the boundary between these flat surfaces
Is arranged, whereby the swash plate 21 can be tilted between two tilt positions around the fulcrum member. Here, the tilting of the swash plate 21 is performed by supplying and discharging pressure oil to and from the cylinder chamber 23 of the fixed casing 11 and moving the piston 24 housed in the cylinder chamber 23 in the axial direction.
The tilt of the swash plate 21 changes the stroke of the plunger 17 in the cylinder block 15 in two stages, thereby changing the number of rotations of the cylinder block 15 and the rotating shaft 14 to two stages, thereby allowing a wide rotation. Numerical 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. This constitutes the hydraulic motor 12 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.An input gear 31 having a large number of external teeth 30 formed on the outer periphery of the transmission member 29 is provided outside the transmission member 29. It is rotatably fitted. As a result, this input gear 31
Is rotatably supported via a transmission member 29. The input shaft 27 on the other side of the transmission member 29 is fitted with a sun gear 33 having a large number of external teeth 32 formed on the outer periphery.The sun gear 33 is spline-coupled to the input shaft 27, so that the input The shaft 27 is movably supported in the axial direction and is connected to the input shaft 27 so as to rotate integrally therewith. Numeral 34 denotes a plurality of, here three, output gears each fixed to the other end of the crankshaft of the eccentric oscillating type reduction gear described later. These output gears 34 surround the input gear 31 from the outside and It is arranged equidistant in the direction. Reference numeral 35 denotes a large number of external teeth formed on the outer periphery of each output gear 34.
Are engaged 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 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. 43
Are a plurality of planetary gears, here three planetary gears, equidistantly arranged in the circumferential direction, and a large number of external teeth 44 formed on the outer periphery of these planetary gears 43 are external teeth 32 of the sun gear 33. And the internal teeth 42 of the protruding ring (internal gear) 41. A carrier 45 is provided between the fixed case 26 and the cover 40.The carrier 45 is provided on one side end plate 46 provided on one side of the planetary gear 43 and on the other side of the planetary gear 43. The other end plate 47, and a plurality of end plates fixed to the one end plate 46 and the other end fixed to the other end plate 47 and equidistant in the circumferential direction, here the same number (three) as the planetary gears 43 And a support shaft 48 of The support shaft 48 has the planetary gear
43 are rotatably supported, and as a result, the carrier 45 rotates at the same speed as the revolution of the planetary gear 43 when the planetary gear 43 is rotating while revolving around the sun gear 33. Will do. The sun gear 33, the internal gear (projecting ring) 41, the planetary gear 43, and the carrier 45 as described above constitute a planetary gear reduction mechanism 49 that largely reduces the rotation input to the sun gear 33 and outputs the rotation from the carrier 45. I do.

A substantially ring-shaped one-side clutch piece 50 whose other side is in contact with one end of the transmission member 29 is fitted on one outer side of the input shaft 27. The input shaft 27 is connected 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.
Reference numeral 51 denotes a substantially ring-shaped other clutch piece disposed outside one side 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-side clutch piece 51 has a radially inner end portion which is
Are connected to the input gear 31 by spline connection. 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 connection state is established and the input shaft 27 and the input gear 31 are connected. Piece
When the tooth 50 is separated from the other clutch piece 51 and disengaged from each other, the input gear 31 is disconnected from the input shaft 27 in the cutoff state. One side, the other side clutch piece 50 described above,
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 in a connected state, and disconnects the input gear 31 from the input shaft 27 in a disconnected state. The first clutch 52 is configured.

Reference numeral 54 denotes a substantially ring-shaped one-side clutch piece serving as one clutch piece disposed outside the other end of the input gear 31. The one-side clutch piece 54 has an inner end in the radial direction. The input gear is splined to the external teeth 30
Linked to 31. Reference numeral 55 denotes a substantially ring-shaped other-side clutch piece serving as the other clutch piece disposed on the other side of the one-side clutch piece 54, and the other-side clutch piece 55 is the carrier 45, specifically, a one-side end plate. Axial hole formed in 46
It is inserted into 56 and its axially outer end is connected to the axial hole 56 by a spline. If the other clutch piece 55 is inserted into the axial hole 56 formed in the one end plate 46 of the carrier 45 in this way, the two can overlap with each other to reduce the axial length of the reduction gear transmission 25.
The inner end of the other clutch piece 55 in the radial direction is sandwiched between the transmission member 29 and the sun gear 33 from both sides. For this reason, the other clutch piece 55 rotates at the same speed as the carrier 45 and moves in the axial direction to be able to approach and separate from the one clutch piece 54. The other-side clutch piece 55 and the one-side clutch piece 54 are connected to each other when the other-side clutch piece 55 approaches the one-side clutch piece 54 and meshes with each other. gear
When the other clutch piece 55 is separated from the one clutch piece 54 and disengaged from each other, the input gear 31 is disconnected from the carrier 45 when the other clutch piece 55 is disengaged from the carrier 45. The above-described one-side and other-side clutch pieces 54 and 55 are interposed between the carrier 45 and the input gear 31 as a whole, and connect the carrier 45 and the input gear 31 when connected.
A second clutch 57 that disconnects the input gear 31 from the carrier 45 when in the disconnected state is configured.

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
Is a ring-shaped moving body disposed on the other side of the sun gear 33, and this moving body 61 is inserted into the cover 40, is loosely fitted to the outside of the input shaft 27, and is It can move axially. When the moving body 61 moves to one side together with the sun gear 33 to bring the other clutch piece 55 closer to the one clutch piece 54, the second clutch 57 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 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 55 of second clutch 57
Is pushed by the one-side clutch piece 50 and the transmission member 29 to be separated from the one-side clutch piece 54, and the second clutch 57 is switched to the disengaged state. At this time, the sun gear 33 and the moving body 61 are pushed by the one-side clutch piece 50 and the transmission member 29 and move to the other side. 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 the high-pressure oil is not guided to the piston 60, the spring 64 moves the moving body 61,
The sun gear 33 is moved to one side.
1. When the sun gear 33 moves to one side, the other clutch piece 55 of the second clutch 57 is pushed and approaches the one clutch piece 54, the second clutch 57 is switched to the connected state, and the first clutch 52, the one-side clutch piece 50 is the other-side clutch piece.
55, being pushed by the transmission member 29 and separated from the other clutch piece 51, the first clutch 52 is switched to the disengaged state. As described above, the transmission member 29 interposed between the piston 60 and the moving body 61 together with the one-side clutch piece 50, the sun gear 33, and the other-side clutch piece 55 includes one of the piston 60 and the moving body 61. Is transmitted to the remaining other, and the first and second clutches 52,
Alternately switches between the 57 connected and disconnected states. Transmission member 29, piston 60, moving body 61, hydraulic passage 62, spring described above
64 as a whole constitutes switching means 65 for switching the first and second clutches 52 and 57 so that one of them is in the disconnected state when the other is in the connected state, and the switching means 65 is simple as described above. First and second clutch 5
Switching between 2, 57 can be performed reliably.

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, respectively. When the crankshaft 74 rotates around the central axis, the eccentric portions 75 of the crankshaft 74
The eccentric rotation of the pinion 70 causes the pinion 70 to eccentrically revolve, but 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. Rotating at low speed. Internal tooth pin described above
The 69, the pinion 70, and the crankshaft 74 as a whole constitute the eccentric oscillating reduction gear 68 which reduces the rotation of the crankshaft 74 by the eccentrically rotating pinion 70 and outputs the reduced speed 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, as described above, the variable speed hydraulic motor 12 is connected to the speed reducer 25.
And the input shaft 27 of the speed reducer 25 is connected to the rotating shaft 14 of the hydraulic motor 12, so that it is suitable as a drive device for an asphalt finisher or the like that requires a wide range of rotation speed control.

Reference numeral 79 denotes a through hole formed in the cover 40 and coaxial with the input shaft 27. The other end of the input shaft 27 is inserted into one side of the through hole 79. 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. Then, after removing the cap 80, the first and second clutches 52 and 57 can be switched to the disengaged state by grasping the other end of the input shaft 27 and pulling it out slightly to the other side in the axial direction. In this way, the drive system on the hub 38 side with respect to the input gear 31 can be in a free state.

Next, the operation of the embodiment of the present invention will be described. When the pressure oil is supplied to any 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,
At this time, since the tip of the plunger 17 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 and the shoe 18 become inclined. The plunger 17, the cylinder block 15, the rotary shaft 14, and the input shaft 27 are integrally rotated by sliding on the top 22.

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 57
Since the moving force of the one-side clutch piece 50 is transmitted via the transmission member 29, the 55 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 55 is separated from the one-side clutch piece 54 and disengaged, and the second clutch 57 is brought into a disconnected 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. Thus, the rotation of the input shaft 27 is substantially constant speed,
Here, the rotation is output at a maximum rotation speed from the reduction gear 25 because it is output to the crankshaft 74 after being slightly decelerated. In this manner, the rotation of the input shaft 27 is output from the output gear 34 at a substantially constant speed.
As described above, the speed is reduced at a high ratio and output to the hub 38. In such a state, the hub 38 rotates at the maximum rotational speed. At this time, the planetary gear 43 is
Receiving rotation force from the sun gear 33 rotating at a constant speed and rotating at substantially the same speed as the sun gear 33,
Revolved around the sun gear 33 at a reduced speed, limited by the internal teeth 42 of 41. At this time, the revolution of the planetary gear 43 is transmitted to the carrier 45 via the support shaft 48, whereby the carrier 45 rotates at the same speed as the revolution (low-speed rotation) of the planetary gear 43. Here, since the second clutch 57 is switched to the disengaged state as described above and the carrier 45 is disconnected from the input gear 31, the planetary gear 43 and the carrier 4 described above are separated.
5. The rotation (rotation, revolution) of the other clutch piece 55 is idling, but the idling speed of such rotation and revolution is almost equal to or less than that of the input shaft 27 as described above, and seizure, noise, abnormal The generation of high temperature and the like is effectively prevented.

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 tilt angle of the swash plate 21 is reduced. 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 sun gear 33 and the other clutch piece 55 of the second clutch 57 are moved closer to the one clutch piece 54. As a result, the other clutch piece 55 of the second clutch 57 and the one clutch piece 54 are engaged with each other, so that the second clutch 57 is connected. At this time, the one-side clutch piece 50 of the first clutch 52 is transmitted integrally with the other-side clutch piece 55 and the transmission member 29 because the moving force of the other-side clutch piece 55 is transmitted through the transmission member 29. Move to one side. As a result, the one-side clutch piece 50 is separated from the other-side clutch piece 51 and disengaged, the first clutch 52 is disconnected, and the input gear 31 is disconnected from the input shaft 27. On the other hand, when the second clutch 57 is engaged as described above, the input gear 31 and the carrier 45 are connected. At this time, similarly to the above, the planetary gear 43 revolves around the sun gear 33 at a reduced low speed while rotating at substantially the same speed as the sun gear 33, and the carrier 45 revolves around the sun gear 33 (low speed). Rotation) and the carrier rotates at the same speed.
Is transmitted to the input gear 31 at a constant speed because the input gear 31 and the carrier 45 are connected as described above. In this way, the rotation of the input shaft 27 is transmitted to the input gear 31 after being greatly reduced by the planetary gear reduction mechanism 49, and the low-speed rotation transmitted to the input gear 31 is output at a substantially constant speed. Is output to the crankshaft 74. 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, hub 38
Will rotate at the lowest speed.

As described above, the rotation of the input shaft 27 is output from the output gear 34 at substantially constant speed when the first clutch 52 is switched to the connected state and the second clutch 57 is switched to the disconnected state.
When the second clutch 57 is switched to the connected state and the first clutch 52 is switched to the disengaged state, the speed is greatly reduced by the planetary gear reduction mechanism 49, and the output from the output gear 34 is substantially equal to the reduced rotation speed. Therefore, the speed reduction ratios of the two greatly differ, 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 above-described embodiment, the one-side clutch piece 50 and the other-side clutch piece 55 are moved to the other side by the piston 60, and to the one side by the spring 64. May be moved to the other side by a piston, or may be moved to one side by a piston, or both the one-side and other-side clutch pieces 50 and 55 may 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 rotation speed of the rotary shaft 14 is changed in two steps by changing the tilt angle of the swash plate 21 in two steps.
You may make it change in steps.

[0024]

As described above, according to the present invention, it is possible to effectively prevent seizure, noise, abnormally high temperatures, and the like when the planetary gears and the carrier idle.

[Brief description of the drawings]

FIG. 1 is a front sectional view at the time of high-speed rotation showing an embodiment of the present invention.

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

[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 49 planetary gear reduction mechanism 52 first clutch 54 one clutch piece 55 other clutch piece 56 axial hole 57 second clutch 60 piston 61 moving body 62 hydraulic passage 64 spring 65 switching Means 68 ... Eccentric swing type reduction gear 70 ... Pinion 74 ... Crankshaft

Claims (5)

[Claims] An input shaft rotatable by a driving force; an input gear rotatably supported by the input shaft; a sun gear connected to the input shaft and rotating integrally with the input shaft; An output gear, an internal gear provided to surround the sun gear, the sun gear, a planetary gear that rotates while revolving around the sun gear while meshing with both the internal gear, and the planetary gear can rotate. And 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 in the connected state, and when in the disconnected state. A first clutch that disconnects the input gear from the input shaft, and is interposed between the carrier and the input gear, connects the carrier and the input gear when in the connected state, and disconnects the input gear from the carrier when in the disconnected state A second clutch, the first, second
Switching means for switching the clutch so that when one of the clutches is in the engaged state, the other is in the disengaged state, and the switching means switches the first clutch to the engaged state and the second clutch to the disengaged state, thereby providing an input shaft. Is output from the output gear through the input gear, while the switching means switches the second clutch to the connected state and the first clutch to the disengaged state, thereby rotating the input shaft to the sun gear, the internal gear, the planetary gear, A speed reducer, wherein the speed is reduced by a planetary gear speed reduction mechanism comprising 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 clutch according to claim 2, wherein the second clutch comprises one clutch piece connected to an input gear, and the other clutch piece which can be approached and separated from the one clutch piece and is connected when approached. The reduction gear transmission according to claim 1, wherein an axial hole is formed in the carrier, and the other clutch piece is inserted and connected into the axial hole. 4. A swash plate type hydraulic motor whose rotation speed changes to a plurality of stages by changing the tilt position of the swash plate to a plurality of positions, and wherein the input shaft is connected to a rotation shaft of the hydraulic motor. The reduction gear transmission according to 1. 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.