JP2006057797A - Planetary gear type power device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide technology for setting specifications of a sun gear without depending on diameter and a material of a crank shaft. <P>SOLUTION: This planetary gear type power device 60 includes a driving shaft 61 to which the sun gear 72 is attached, a driven shaft 75 attached coaxially C with the driving shaft 61 and attached to a casing 17 rotatably, a supporting body 74 to which the driven shaft 75 is attached, a plurality of planetary gears 73, etc. mounted on the supporting body 74 rotatably and meshing with the sun gear 72, planetary gears 73, etc. attached to the casing 17 rotatably to mesh with these planetary gears 73, etc., and a braking means 78 provided in the casing 17 to stop rotation of a ring gear 76 or allow its rotation as main elements. The driving shaft 61 is provided with a tapered shaft part 121 at a shaft end, a boss member 71 is fitted into the tapered shaft part 121, the gun gear 72 is formed in the boss member 71, and the boss member 71 is fixed to the driving shaft 61 by a fixing bolt 82. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improvement in a structure for attaching a sun gear attached to a drive shaft that receives a driving force of an engine in a planetary gear type power unit.

Conventionally, a planetary gear type power unit that transmits power by combining a sun gear, a planetary gear, and a ring gear is known (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 6-70602 (FIG. 4)

Patent document 1 is demonstrated based on the following figure.
FIG. 10 is a diagram for explaining the basic configuration of the prior art. A planetary gear type power unit 200 includes a crankshaft 201 of an engine having a sun gear 202 formed at an end thereof, and the crankshaft 201 is rotatable on a coaxial line. The arranged driven shaft 203, the support 204 attached to the driven shaft 203, and a plurality of planetary gears 205... The same shall apply hereinafter) and a ring gear 206 meshed with these planetary gears 205. The sun gear 202 is formed directly on the end of the crankshaft 201 of the engine.

  However, since the sun gear is formed directly on the end of the crankshaft of the engine, the strength and outer diameter of the sun gear are determined by the material and outer diameter of the crankshaft, and the specifications of the sun gear can be freely changed. There is a problem that can not be. In addition, when the outer diameter of the sun gear is large, the entire outer diameter of the crankshaft must be increased, resulting in waste of material.

  It is an object of the present invention to provide a technique that enables the specification of the sun gear to be set regardless of the diameter and material of the crankshaft.

  According to the first aspect of the present invention, there is provided a drive shaft for receiving a driving force of an engine with a sun gear attached thereto, a driven shaft rotatably arranged on the same axis as the drive shaft, a support attached to the driven shaft, and the support In a planetary gear type power unit comprising a plurality of planetary gears that are freely rotatable and meshed with the sun gear, and a ring gear that is meshed with these planetary gears, the drive shaft has a tapered shaft portion at the shaft end. A boss member is fitted to the taper shaft portion, a sun gear is formed on the boss member, and the boss member is fixed to the drive shaft with a fixing bolt.

  The invention according to claim 2 is characterized in that the sun gear includes an engagement portion with which the removal tool is engaged to disengage the receiving surface from the tapered surface.

  In the invention according to claim 1, since the tapered shaft portion is formed at the shaft end of the drive shaft, and the boss member having the sun gear is fitted to the tapered shaft portion, the sun gear can be accurately positioned on the drive shaft. In addition, since the boss member is fixed to the drive shaft by the fixing bolt, the sun gear can be firmly fixed to the drive shaft.

  Since the sun gear is separated from the drive shaft, it is possible to increase the degree of freedom of specifications (also referred to as specifications) such as the material of the sun gear, the module, and the number of teeth as compared with the case where the sun gear is directly created on the drive shaft. it can.

  Conventionally, when the outer diameter of the sun gear is increased, the drive shaft and the sun gear are integrated with each other. Therefore, it is necessary to increase the crankshaft diameter by an amount corresponding to the increased outer diameter.

However, according to the present invention, it is not necessary to increase the crankshaft diameter, and the size of the boss member may be increased.
Since there is no need to increase the crankshaft diameter, there is an advantage that the waste of the crankshaft material can be reduced. In addition, the number of crankshaft processing steps can be reduced.

In the invention according to the second aspect, since the engagement of the tapered surface has a high degree of close contact, some disengagement tool is required to disengage the sun gear from the drive shaft.
Since the engaging portion for engaging the detaching tool is provided in a part of the sun gear, the sun gear can be easily detached from the drive shaft using the detaching tool.
As a result, there is an advantage that the maintainability of the sun gear can be improved.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals. “Front”, “rear”, “left”, “right”, “upper”, and “lower” indicate directions viewed from the driver of the vehicle.

  FIG. 1 is a side view of a front rotary working machine equipped with a planetary gear type power unit according to the present invention. The left and right traveling wheels 13 and 14 (only the reference numeral 13 on the near side is shown), and the left and right rotary working parts 15 and 16 arranged in front of these traveling wheels 13 and 14 (only the reference numeral 15 on the near side are shown). ), And cultivates the farm field with the rotary working units 15 and 16.

  The work machine 10 includes an engine 11 arranged at the upper part of the machine body, a power unit 12 attached to the lower part of the engine 11 via a clutch (braking means of the planetary gear type power unit according to the present invention), and the power unit 12 The rotary working units 15 and 16 (not shown) rotatably attached to the front part of the power unit 12 via left and right work drive shafts 15a and 16a (only the front side reference numeral 15a is shown) It comprises traveling wheels 13 and 14 (not shown) that are rotatably mounted via a drive shaft 13a and a right traveling drive shaft 14a (not shown), and a handle 18 that extends obliquely rearward and upward from the rear portion of the power unit 12. In addition, 17 is a clutch case part (casing) which accommodates a clutch, and is integrated with the case body 20 which covers the power unit 12, and forms a part of the case body 20.

  Here, 31 is a traveling auxiliary wheel attached to the front end of the power unit 12 so that the position can be adjusted vertically, 32 is a fender that covers the power unit 12 and the rotary working units 14 and 15, and 33 covers the engine 11. The engine cover, 34 is an air cleaner, 35 is a fuel tank filler cap, 36 is a shift lever, 37 is a differential lock lever, and 38 is a clutch lever.

  FIG. 2 is a plan view of a front rotary working machine equipped with the planetary gear type power unit according to the present invention. The working machine 10 includes a recoil starter knob 51 for starting the engine 11 at the right front portion of the handle 18; The throttle lever 52 for adjusting the output of the engine 11 and the above-described differential lock lever 37 are arranged, the power switch 53 for stopping the engine 11 is attached to the left rear portion of the handle 18, and the clutch lever 38 is attached to the rear portion of the handle 18. This shows that the shift lever 36 is extended rearward from the rear center of the power unit 12 (see FIG. 1).

FIG. 3 is a side view around the engine equipped with the planetary gear type power unit according to the present invention.
The engine 11 includes an aluminum alloy crankcase 43, a cylinder block 44 that is bolted to the crankcase 43 via a gasket (not shown), and a piston 46 that is slid onto a cylinder 45 formed in the cylinder block 44. A crankshaft 48 connected to the piston 46 via a piston rod 47 is a main component. A flywheel 49 is attached to one end of the crankshaft 48, and the other end of the crankshaft 48 is connected to the planetary gear according to the present invention. The drive shaft 61 of the power system 60 is used.

  The power transmission mechanism of the case member 20 has a pinion gear 64 attached to one end of the driven shaft 75 of the planetary gear type power unit 60, the pinion gear 64 and the gear 65 are meshed, and a sprocket 67a is attached to the gear shaft 65a of the gear 65. A chain 66a is extended forward from the sprocket 67a, the chain 66a is hung on a sprocket 19b attached to another shaft 19a, and a sprocket 19c attached to the other shaft 19a and work drive shafts 15a and 16a (not shown). The chain 19d is spanned between the attached sprockets 67b. Similarly, the sprocket 69a is attached to the gear shaft 65a of the gear 65, the chain 70a is extended behind the sprocket 69a, the chain 70a is stretched between the sprocket 69a and the sprocket 69b, and the sprocket 69b is attached to the intermediate shaft 68. A sprocket 69c is attached to the intermediate shaft 68, a sprocket 69d is also attached to the travel drive shaft 13a, and a chain 70b is spanned between the sprockets 69c and 69d.

  The power unit 12 has functions of transmitting and accelerating and decelerating power to the traveling wheels and the rotary working unit. The power unit 12 receives power from the engine 11 by the gear 65 and transmits power to the traveling drive shaft 13a and the work drive shaft 15a. Divide. In order to accelerate and decelerate the traveling wheels during forward travel, a reduction gear (not shown) is provided between the gear shaft 65a and the intermediate shaft 68. The chain 70b is used for power transmission during backward movement.

The travel drive shaft 13a is provided coaxially with the travel drive shaft 14a (not shown), but is connected to the travel drive shaft 14a via a differential gear (not shown). Thereby, the working machine 10 can perform a turning operation.
Further, the travel drive shafts 13a and 14a can be directly connected by the differential lock lever 37 (see FIG. 2). As a result, the work machine 10 can perform a straight-ahead operation.
The planetary gear type power device 60 is a device having a clutch function for turning on or off the engine power to the power device and a speed reducing function for engine rotation. This will be described in detail in the next figure.

  In the figure, 55 is a spark plug, 56 is an intake (exhaust) valve, 57 is a head cover, 59 is a recoil starter, and 85 is a ball bearing.

  FIG. 4 is a side cross-sectional view of the planetary gear type power unit according to the present invention. The planetary gear type power unit 60 includes a drive shaft 61 (the other end of the crankshaft 48) disposed along the vertical line C and the drive shaft 61. A boss member 71 attached to the tip (lower part) of the shaft 61; a sun gear 72 formed on the boss member 71; three planetary gears 73 meshed with the sun gear 72; and these planetary gears 73. A plate-like and circular (disk-like) support 74 that rotatably supports, a driven shaft 75 that is attached to the support 74 and arranged coaxially with the drive shaft 61, and three planetary gears 73. A ring gear 76 that meshes and surrounds the planetary gears 73, braking means (clutch) 78 that stops or allows the rotation of the ring gear 76, a sun gear 72, the planetary gears 73, a support 74, and a ring gear. 6 and the casing 17 described above covering the consist sump lubricating oil 79. into the casing 17.

  The casing 17 includes a steel ball (ball) 81... (Only one is shown) that rotatably supports the ring gear 76, a locking portion 99 that locks an end portion 98 a of an elastic clip, which will be described later, and a driven shaft 75. Is provided with a ball bearing 85 for rotatably supporting the oil and an oil seal 86 for sealing the lubricating oil 79.

The driven shaft 75 is a member in which a male spline 87 for attachment to the support 74 is provided at one end, and a pinion gear 64 that transmits power to the power unit 12 (see FIG. 1) is provided at the other end. It is arranged coaxially with C.
The ring gear 76 includes a brake drum 89 that constitutes one part of the braking means 78.
The lubricating oil 79 sets the oil level 81 below the ring gear 76 or the planetary gear 73... And above the support 74.

  The support body 74 includes a disk-shaped support plate 92 and a center boss 93 to which the driven shaft 75 is attached by extending from the lower surface of the support plate 92.

  The support plate 92 includes support shafts 95 that rotatably support the planetary gears 73, and the center boss 93 is supported by a female spline 87 provided on the center boss 93 for attaching the driven shaft 75 and the root. A pulley body 97 for increasing the frictional resistance of the body 74 and an elastic clip 98 fitted in the outer peripheral groove 97a of the pulley body 97 are provided. The tip 98a of the elastic clip 98 was embedded in the casing 17.

  The planetary gear type power unit 60 forms a sun gear 72 below a drive shaft 61 arranged along the vertical line C, and meshes at least three planetary gears 73... With these sun gears 72. 73 is disposed below the planetary gears 73, and the driven shaft 75 extends coaxially with the drive shaft 61 from the support 74, and the planetary gears 73. Is surrounded by a ring gear 76, the ring gear 76, the planetary gear 73..., The support 74 and the sun gear 72 are surrounded by the casing 17, and braking means capable of arbitrarily braking the ring gear 76 between the casing 17 and the ring gear 76. 78, when the braking means 78 is used for braking, the power of the drive shaft 61 is decelerated and transmitted to the driven shaft 75, and when not braked, the ring gear 76 is idled. The power of the shaft 61 to as not transmitted to the driven shaft 75. The oil level 81 of the lubricating oil 79 accumulated in the casing 17 is set below the ring gear 76 and above the support 74. A fixing bolt 82 fixes the boss member 71 to the drive shaft 61.

  That is, the planetary gear type power unit 60 includes a drive shaft 61 to which a sun gear 72 is attached, a driven shaft 75 that is coaxially connected to the drive shaft 61 and rotatably attached to the casing 17, and the driven shaft 75. An attached support 74, a plurality of planetary gears 73 that are rotatable on the support 74 and meshed with the sun gear 72, and a casing 17 that meshes with the planetary gears 73 are rotatable. , And a braking means 78 provided on the casing 17 for stopping or allowing the rotation of the ring gear 76 as main elements. The drive shaft 61 includes a tapered shaft portion 121 having a tapered surface 121a at the shaft end. A boss member 71 is fitted to the tapered shaft portion 121, and a sun gear 72 is formed on the boss member 71. The boss member 71 is fixed with a fixing bolt 82.

  By the way, in a planetary gear type power unit that includes a sun gear, a planetary gear, and a ring gear and includes braking means for transmitting power or not transmitting power, the power of the input shaft is not transmitted to the output shaft by spinning the ring gear. Even in such a case, some continuous looping occurs, and it is preferable if this continuous loop can be reduced.

  Therefore, by setting the oil level 81 of the lubricating oil 79 stored in the casing 17 below the ring gear 76 or the planetary gear 73... And above the support 74, the resistance of the ring gear 76 due to the lubricating oil 79 is reduced. be able to. As a result, the ring gear 76 can be easily rotated, and the continuous rotation can be reduced.

  In addition, an elastic clip 98 is provided on the driven shaft 75 or the support 74 in order to suppress the continuous rotation of the driven shaft 75 with respect to the rotation of the drive shaft 61 when the braking means 78 is opened.

FIG. 5 is an explanatory view of the braking means of the planetary gear type power unit according to the present invention.
The braking means (clutch) 78 includes an anchor pin 101 attached to the casing 17, a pair of brake shoes 102, 102 supported by the anchor pin 101, and a brake formed on the ring gear 76 for contacting these brake shoes 102, 102. Drum 89, return springs 108, 108 biased between brake shoes 102, 102, operating cam 103 for expanding the diameter of brake shoes 102, 102, connecting lever 104 connected to this operating cam 103, and this connecting lever The cable 106 is connected to the clutch 104 via a buffer spring 105, and the tip of the cable 106 is connected to the clutch lever 38. The brake shoes 102 and 102 include brake pads 102 a and 102 a that are applied to the ring gear 76.

  That is, the braking means 78 pulls the clutch lever 38 toward the handle 18 as indicated by the arrow a, rotates the connecting lever 104 as indicated by the arrow b, and rotates the operating cam 103 as indicated by the arrow b. The diameters of the brake shoes 102 and 102 are increased, the brake drum 89 (ring gear 76) is tightened by these brake shoes 102 and 102, and the ring gear 76 is stopped, whereby the support 74 (see FIG. 4) is rotated to drive the driven shaft. 75, and the clutch shoe 38 is released to release the brake shoes 102, 102 from the brake drum 89 (ring gear 76), so that the ring gear 76 is idled and power is transmitted to the support 74. It is intended not to be transmitted.

  6 is a cross-sectional view taken along line 6-6 of FIG. It shows that the elastic clip 98 is engaged with the formed V-shaped groove 96. The tip 98a of the elastic clip was embedded in the casing 17 and fixed.

Since the elastic clip 98 is engaged with the V-shaped groove 96, the elastic clip 98 can play a role of preventing rotation of the pulley body 97 with a predetermined frictional resistance.
In this embodiment, the V-shaped groove 96 is formed on the outer periphery of the pulley body 97. In addition, the driven shaft 75 (see FIG. 4) or the support 74 may be formed.

  FIG. 7 is a side view of a boss member according to the present invention. Engage with engaging portions 124 and 125 formed for engaging, engaging surfaces 135 and 136 formed for applying a tool during assembly, and tapered shaft 121 at the tip of drive shaft 61 (see FIG. 4). And a bolt hole portion 128 connected to the taper receiving surface 122 and penetrating toward the sun gear surface 127.

By providing the engaging portions 124 and 125, the boss member 71 can be easily disassembled.
Further, by providing the engagement surfaces 135 and 136, the boss member 71 (sun gear 72) and the fixing bolt 82 can be easily assembled.

  FIG. 8 is a view taken in the direction of the arrow 8 in FIG. Indicates.

FIG. 9 is a diagram for explaining the removal of the boss member from the drive shaft by the removal tool.
(A) shows the state which fixed the boss | hub member 71 provided with the sun gear 72 to the taper shaft part 121 formed in the axial end of the drive shaft 61 with the fixing bolt 82. FIG.

  (B) shows that the T-type wrench 131 that fits the mounting / demounting size of the fixing bolt 82 is inserted into the head of the fixing bolt 82, rotated several times in the direction of FIG. X, and the fixing bolt 82 is loosened. It is sufficient that the boss member 71 can be detached from the taper shaft portion 121 simply by removing the fixing bolt 82, but there are cases where it is not possible to easily remove the boss member 71 because the degree of close contact with the taper shaft portion 121 is high.

(C) shows that the removal tool 132 is set on the boss member 71.
The shaft tip 133 of the detachment tool 132 is inserted into the head of the fixing bolt 82, the claws 134, 134 of the detachment tool 132 are engaged with the engagement portions 124, 125, and the detachment tool 132 is rotated in the Y direction in FIG. The taper receiving surface 122 that is in close contact with 121 is removed.
Since the shaft tip 133 has a conical shape, a chamfered portion 137 of a hexagonal hole provided at the head of the fixing bolt 82 is formed according to the conical shape of the removal tool 132.

Since the chamfered portion 137 of the hexagonal hole is formed in accordance with the conical shape of the shaft tip 133 of the detaching tool 132, the conical slope and the chamfered portion 137 are in contact with each other, so that the detaching tool 132 is difficult to tilt during the detaching operation. Workability is improved.
In the present embodiment, the shape of the shaft tip of the detachment tool is a conical shape having a pointed protrusion, but may not be a conical shape. For example, you may form in a plane, without making a protrusion sharp.

As described above, the engagement of the tapered surface where the tapered shaft portion 121 and the taper receiving surface 122 are in close contact with each other has a high degree of close contact. Therefore, in order to disengage the sun gear 72 from the drive shaft 61, some disengagement tool is required. Necessary.
Therefore, in order to easily disengage the sun gear 72 from the drive shaft 61, an engaging portion 124 with which the disengaging tool 132 is engaged is provided in a part of the sun gear 72. By providing the engagement portion 124, the sun gear 72 can be easily detached from the drive shaft 61 using the removal tool 132.
As a result, the maintainability of the sun gear 72 can be improved.

Hereinafter, the operation of the present invention will be described.
Returning to FIG. 4, the drive shaft 61 includes a tapered shaft portion 121 at the shaft end, and a boss member 71 is fitted to the tapered shaft portion 121, and a sun gear 72 is formed on the boss member 71.
Since the taper shaft portion 121 is formed at the shaft end of the drive shaft 61 and the boss member 71 including the sun gear 72 is fitted to the taper shaft portion 121, the sun gear 72 can be accurately positioned on the drive shaft 61.

In addition, since the boss member 71 is fixed to the drive shaft 61 by the fixing bolt 82, the sun gear 72 can be firmly fixed to the drive shaft 61.
Since the sun gear 72 is separated from the drive shaft 61, the degree of freedom in specifications such as the material, module, and number of teeth of the sun gear 72 can be increased as compared with the case where the sun gear 72 is directly created on the drive shaft 61.
Conventionally, when the outer diameter of the sun gear 72 is increased, the drive shaft 61 and the sun gear 72 are integrated with each other. Therefore, it is necessary to increase the crankshaft diameter by an amount corresponding to the increased outer diameter.

However, according to the present invention, it is not necessary to increase the crankshaft diameter, and the size of the boss member 71 may be increased.
Since there is no need to increase the diameter of the crankshaft, material waste can be reduced. In addition, the number of crankshaft processing steps can be reduced.

  The planetary gear type power unit of the present invention is applied to a front rotary working machine in the embodiment, but may be applied to a general vehicle.

  The planetary gear type power unit of the present invention is suitable for a front rotary working machine.

It is a side view of the front rotary working machine which mounts the planetary gear type power unit concerning the present invention. It is a top view of the front rotary working machine which mounts the planetary gear type power unit concerning the present invention. 1 is a side view around an engine equipped with a planetary gear type power unit according to the present invention. It is side surface sectional drawing of the planetary gear type power unit which concerns on this invention. It is explanatory drawing of the braking means of the planetary gear type power plant which concerns on this invention. FIG. 6 is a sectional view taken along line 6-6 of FIG. It is a side view of the boss member concerning the present invention. FIG. 8 is a view taken in the direction of arrow 8 in FIG. 7. It is a figure explaining removing a boss member from a drive shaft by a detachment tool. It is a figure explaining the basic composition of the conventional technology.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 17 ... Casing, 60 ... Planetary gear type power unit, 61 ... Drive shaft, 71 ... Boss member, 72 ... Sun gear, 74 ... Support body, 75 ... Drive shaft, 76 ... Ring gear, 82 ... Fixing bolt, 121 ... Taper shaft part 121a ... taper surface, 122 ... taper receiving surface, 124, 125 ... engaging portion, 132 ... detachment tool.

Claims (2)

A drive shaft that receives the driving force of the engine with a sun gear attached thereto, a driven shaft that is rotatably arranged on the same axis as the drive shaft, a support that is attached to the driven shaft, and a rotary that is rotatable on the support and is attached to the sun gear. In a planetary gear type power unit comprising a plurality of meshed planetary gears and a ring gear meshed with these planetary gears,
The drive shaft includes a tapered shaft portion at a shaft end, a boss member is fitted to the tapered shaft portion, and the sun gear is formed on the boss member,
A planetary gear type power unit, wherein the boss member is fixed to the drive shaft with a fixing bolt.   2. The planetary gear type power unit according to claim 1, wherein the sun gear includes an engaging portion with which a removal tool is engaged to detach the receiving surface from the tapered surface.

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