JPH041396Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a planetary gear mechanism, and more particularly to a planetary gear mechanism for power transmission drive of a telescopic fitting tube drive device that drives the shortening and extension of a telescopic fitting tube.

BACKGROUND ART Conventionally, for example, there are systems in which a telescopic fitting tube is used as an antenna or a corner pole of an automobile, and the antenna or corner pole is moved up and down by driving the telescopic fitting tube electrically. As a speed reduction mechanism for such a device, a planetary gear mechanism having a structure as shown in FIG. 4 is used.

The reduction ratio m of the planetary gear mechanism is angular velocity ω ₁ of the sun gear 15, ω ₂ the angular velocity of the driven gear 18, Ζ ₁ the number of teeth of the sun gear 15, Ζ 2 the number of teeth of the planetary gear 16, and Ζ ₂ the number of teeth of the fixed gear. If the number of teeth of gear 17 is Ζ ₃ and the number of gears of driven gear 18 is Ζ ₄ , then m=ω ₁ /ω ₂ =1+Z ₃ /Z ₁ /1+Z ₃ /Z ₄ .

Problems to be Solved by the Invention However, the planetary gear mechanism configured as described above has a fixed gear 17 and a driven gear 18 as shown in FIG.
The meshing pitch circle with the planetary gear 16 is the same, and the number of teeth is different, so that the planetary gear 16 and the fixed gear 17
and a fixed gear 17 for every tooth meshing with the driven gear 18.
Difference d between gear pitch distances between and driven gear 18
The driven gear 18 is moved by the amount shown in FIG.

Therefore, for example, when a high load is applied to the driven gear 18 to stop its motion, or when the driven gear 18 to which a high load has been previously applied is stopped, the fixed gear 17 and the driven gear 18 are attached to the planetary gear 16. Therefore, pressure contact forces are applied in opposite directions, and the pressure contact forces become a couple force in the tooth width direction of the planetary gear 16. In order to reverse and re-drive the stopped mechanism, it is necessary to apply a pressure force greater than the above pressure contact force, that is, normal drive. A motor with starting characteristics several times higher than that required is required.

In addition, when making a mechanism smaller, resin is most often used due to cost considerations, but when resin gears are used, the gears become elastically deformed due to the pressure contact force mentioned above. There were some problems, such as making it difficult to establish this organization.

The present invention has been made in view of the above points, and an object of the present invention is to provide a planetary gear mechanism that does not require a high starting torque motor.

Means for Solving the Problems The present invention revolves the planetary gears meshed with the sun gear and the fixed first internal gear by the rotation of the sun gear driven by a motor. The second gear has a difference in the number of teeth and meshes with the planetary gear.
In a planetary gear mechanism, the internal gear of the sun gear is rotated at a reduced speed according to the difference in the number of teeth.The protrusion provided on the sun gear is fixed to the rotation shaft of the motor and rotates at a predetermined angle under almost no load. The rotor is provided with a rotor that rotates to obtain a rotational force sufficient to start the sun gear and then comes into contact with the protrusion to rotate the sun gear.

Function The rotor is fixed to the motor shaft, and when the motor rotates, the rotor also rotates, and when it rotates by a predetermined angle, it collides with the protrusion provided on the sun gear, starting the sun gear. Rotate while pressing.

Embodiment FIG. 1 is a plan view of a telescopic fitting tube drive device using an embodiment of the present invention, and FIG. 2 is a sectional view of the device shown in FIG.

In FIGS. 1, 2, and 3, reference numeral 1 denotes a motor, which is fixed to a plate 2, and this plate 2 is fixed to a case 3. A sun gear 4 having a concave cross section is loosely fitted onto the rotating shaft 2a of the motor 1, and a rotor 14 is fixed in the concave portion of the sun gear 4. The rotor 14 is driven by the motor 1.
rotates clockwise or counterclockwise, and the sun gear 4 rotates clockwise or counterclockwise.
The sun gear 4 is rotated by contacting the protrusions 4a and 4b provided in the recesses of the sun gear 4. At this time, rotor 1
4 rotates in a substantially unloaded state until it comes into contact with the protrusions 4a and 4b, and obtains sufficient rotational force. sun gear 4
The number of teeth provided on the outer periphery is, for example, 36.

Planetary gears 5, 6, and 7 are meshed with the outer periphery of the sun gear 4, respectively. The number of teeth of each of the planetary gears 5, 6, and 7 is, for example, 32.

Each of the planetary gears 5, 6, and 7 meshes with a fixed gear 8, which is a first internal gear, and a driven gear 9, which is a second internal gear. The fixed gear 8 and the driven gear 9 are made to have the same distance between their axes as the planetary gears 5, 6, and 7 through displacement, respectively.

The fixed gear 8 is ring-shaped and has, for example, 102 teeth. The fixed gear 8 is located at the stepped portion 3a of the case 3.
The movement in the direction of arrow A is regulated by engaging with.
Further, a wavy spring 11 is provided between the fixed gear 8 and the case 10 fixed to the case 3, and the fixed gear 8 is moved by the arrow indicated by the wavy spring 11.
It is urged in the direction and pressed against the step portion 3a of the case 3, and is fixed to the case 3 by friction.

The driven gear 9 is ring-shaped, has a substantially U-shaped cross section, and has, for example, 99 teeth. The driven gear 9 is rotatably engaged with the fixed gear 8. Groove 9a (winding part) with U-shaped cross section of driven gear 9
A flexible tube 12 made of resin such as nylon is inserted into the tube and is wrapped around the driven gear 9. A fixing member 9b is provided in a part of the groove 9a as shown in FIG.
One end 12a of is fixed to the fixing member 9b. The flexible tube 12 is wound around the driven gear 9 approximately twice, for example, and the other end 12b is guided to the telescopic fitting tube 134 and fixed to the tip of the telescopic fitting tube 134. The base 13a of this telescopic fitting tube 13 is connected to the case 3.
Fixed.

Here, after the motor 1 is driven and the rotor 14 rotates in a substantially unloaded state for a predetermined angle until it collides with the protrusions 4a and 4b, the protrusion 4 of the sun gear 4
a and 4b, and starts the sun gear 4.
The sun gear 4 is moved to the second position while being pressed by the rotor 14.
When rotated clockwise in the figure, the planetary gear 5,
6 and 7 each rotate counterclockwise. Each of the planetary gears 5, 6, and 7 is a fixed gear 8 having a different number of teeth.
The fixed gear 8 is in mesh with the driven gear 9 and the driven gear 9, and the fixed gear 8 is fixed to the case 3 by friction. Therefore, the driven gear 9 rotates counterclockwise with respect to the fixed gear 8 due to the difference in the number of teeth (the difference in the number of teeth between the driven gear 9 and the fixed gear 8). At this time, the rotation reduction ratio of the driven gear 9 to the sun gear 4 is "126.5". By the clockwise rotation of the driven gear 9, the flexible tube 12 is sent out from the groove 9a of the driven gear 9, and the other end of the flexible tube 12 is connected to the telescopic fitting tube 13.
, and the telescopic fitting tube 13 is extended.

When the motor 1 is stopped in this state, the planetary gears 5, 6, and 7 are pushed into a narrow gap by the pitch difference between the fixed gear 8 and the driven gear 9. Therefore, pressing forces are applied to the planetary gears 5, 6, and 7 as reaction forces from the fixed gear 8 and the driven gear 9 from opposing directions, respectively.
Moreover, the pressing force becomes a couple force in the tooth width direction of the planetary gears 5, 6, and 7.

Therefore, when the next time the motor is reversely rotated to shorten the telescopic fitting tube, the motor is required to have a starting torque sufficient to overcome the pressing force of the planetary gear. Therefore, in order for the planetary gears 5, 6, and 7 to overcome the pressure contact force, the starting force of the motor is replaced with an impact force via the rotor 14, and the motor is started.

When the sun gear 4 is rotated counterclockwise by the motor 1, the driven gear 9 rotates counterclockwise with respect to the fixed gear 8 due to the difference in the number of teeth between the driven gear 9 and the fixed gear 8. As a result, the flexible tube 12 is wound around the groove 9a of the driven gear 9, the tip of the telescopic fitting tube 13 is pulled down, and the telescopic fitting tube 13 is shortened.

By the way, the slip torque of the friction between the fixed gear 8 and the case 3 caused by the wave spring 11 is W _T , the torque of the fixed gear 8 required to extend and contract the telescopic fitting tube 13 is P _T , and the driven gear 9 is Let M _T be the torque of motor 1 required to rotate it. At this time, the wavy spring 11 is selected so as to satisfy the following equation.

M _T > W _T > P _T Therefore, a large load is applied to the telescopic fitting tube 13, and even if the driven gear 9 stops rotating even though the motor 1 is rotating, the fixed gear 8 continues to rotate. .
Therefore, the rotation of the motor 1 does not stop, and there is no risk that the motor 1 will generate heat and be damaged. Further, even when the rotation of the motor 1 is stopped, the telescopic fitting tube 13 can be manually extended and contracted.

In this way, the sun gear 4, the planetary gears 5, 6,
A large reduction ratio can be obtained with a small number of gears (7, fixed gear 8, and driven gear 9), and because the number of gears is small, transmission efficiency is improved, assembly workability is good, and downsizing is possible. .

Effects of the invention As described above, according to the invention, the starting force of the motor is replaced with an impact force via the rotor, and the impact force collides with the projection of the recess of the sun gear, so that the starting mechanism uses a motor with a high starting torque. Easy to do without
It also has the advantage of allowing the use of gears made of resin that are prone to elastic deformation.

[Brief explanation of drawings]

Fig. 1 is a plan view with the case removed of a device using an embodiment of the present invention, Fig. 2 is a sectional view of the device shown in Fig. 1, and Fig. 3 is a device using an embodiment of the present invention. 4 is a diagram showing a gear train of an example of a planetary gear mechanism, and FIG. 5 is a diagram showing the relationship between the planetary gear, fixed gear, and driven gear. 1...Motor, 4...Sun gear, 4a, 4b...
...Protrusion, 5, 6, 7... Planetary gear, 8... Fixed gear (first internal gear), 9... Driven gear (second internal gear), 14... Rotor.

Claims (1)

[Claims for Utility Model Registration] Due to the rotation of a sun gear driven by a motor, planetary gears meshed with the sun gear and a fixed first internal gear are made to revolve, and relative to the first internal gear. In a planetary gear mechanism that has a difference in the number of teeth and that causes a second internal gear that meshes with the planetary gear to decelerate and rotate according to the difference in the number of teeth, the protrusion provided on the sun gear; It is fixed to the rotating shaft of the motor, and rotates by a predetermined angle under almost no load due to the rotation of the rotating shaft of the motor, and after obtaining sufficient rotational force to start the sun gear, comes into contact with the protrusion. A planetary gear mechanism comprising a rotor that rotates the sun gear.