JPH0315874Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a gear transmission device that transmits power by combining various gears.

Conventional configuration and its problems A conventional gear transmission will be explained below.

FIG. 1 is a sectional view of a conventional gear transmission.
1 is a worm, which rotates together with the drive shaft 2. 3 is a drive source for driving the drive shaft 2, and in this conventional example, a drive motor is used. 4 is a worm gear that meshes with the worm 1, and 5 is a drive gear that meshes with the driven gear 6 and transmits the motion from the drive shaft 2 to the driven gear 6. The worm gear 4 and the drive gear 5 are respectively fitted into a rotating shaft 9 that is supported by bearings 8 and 8' provided in the gear box 7, and the worm gear 4 and the drive gear 5 rotate in conjunction with each other. . A driven gear 6 is fitted into a rotating shaft 11 supported by bearings 10, 10' provided in a gear box 7, and a lever 12 is fitted therein.

The operation of the conventional gear transmission configured as described above will be described below.

When the drive shaft 2 is driven by the drive source 3, the worm 1 rotates together with the drive shaft 2.
The rotation of the worm gear 4, which is meshed with the worm 1, rotates. The rotation of the worm gear 4 causes the rotation shaft 9 to rotate, and the drive gear 5 rotates accordingly.
rotate in conjunction. When the driving gear 5 rotates, the driven gear 6 meshing with the driving gear 5 rotates.
The rotation of the driven gear 6 causes the rotating shaft 11 to rotate, thereby causing the lever 12 to rotate. In this way, the power from the drive source 3 is transmitted to the lever 12, which is the intended transmitted device.

However, in the above configuration, the drive source 3
When the lever 12 is not being driven, the worm 1 is stopped, and since the worm 1 and the worm gear 4 are engaged with each other, the lever 12 can be driven by a drive means other than the drive source 3 (for example, manually). In this case, the worm 1 cannot be driven even by the rotation of the worm gear 4.

The operation of the conventional gear transmission will be explained in more detail below with reference to FIG. Worm 1 at the pitch point of worm 1 and worm gear 4
If the load applied perpendicularly to the tooth surface of the worm gear 4 is PZ, and the frictional force μPZ acts in the γ direction, the force P acting in the tangential direction of the pitch circle of the worm gear 4 is P=PZcosαcosγ−μPZsinγ, and the pitch of the worm 1 is The force PS acting in the tangential direction of the circle is PS＝PZcosαsinγ＋μPZcosγ≒P
(sinγ+μcosγ/cosγ−μsinγ) = P(γ+ρ) (however, cosα≒1, μ=
tanρ). Also, the torque M that should drive the worm 1
is M=Pα/2tan(γ+ρ) (where α is the pitch diameter of the worm), so the contact efficiency of the gears of the worm gear 4 is η
is η=tanγ/tan(γ+ρ). Therefore, the efficiency η' when the worm gear 4 rotates the worm 1 is η'=tan(γ-ρ)/tanγ, and when γ≦ρ, the worm gear 4 drives the worm 1. I can't let you. In this way, the friction coefficient μ on the tooth surface of the worm 1 is generally large, and the friction loss is large compared to other gears, so the efficiency η of the worm gear 4 is low, so the rotation of the worm gear 4 drives the worm 1. Therefore, warm 1
Even if an attempt is made to drive the lever 12 by a drive means other than the drive source 3 when the lever 12 is stopped, the lever 12 remains fixed and does not rotate because the worm gear 4 does not rotate. .

Purpose of the invention This invention solves the above-mentioned conventional problems.The worm stops by moving the integrated worm gear and drive gear to a position where the worm gear does not mesh with the worm. It is an object of the present invention to provide a gear transmission device capable of driving a transmitted device by a drive means other than a worm drive source even in a state in which the transmission device is driven by a drive source other than a worm drive source.

Structure of the invention The present invention is a gear transmission device in which a worm gear that rotates while meshing with a worm can be slid in the direction of the rotation axis of the worm gear. By shifting the gear and the drive gear, the transmitted device can be driven by a drive means other than the drive source even when the worm is stopped.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

FIGS. 3 and 4 are cross-sectional views of a gear transmission according to an embodiment of the present invention. In FIG. 3, 21 is a worm, which rotates together with the drive shaft 22. In FIG. 23 is a drive source for driving the drive shaft 22, and in this embodiment, a drive motor is used. 24 is a worm gear that meshes with the worm 21; 25 is a drive gear that meshes with the driven gear 26 and transmits the motion from the drive shaft 22 to the driven gear 26; the worm gear 24 and the drive gear 25 are integrally formed in a hollow It is fitted into the shaft 27. The hollow shaft 27 is fitted into a rotating shaft 30 which is supported by bearings 29 and 29' provided in the gear box 28, and is slidable in the direction of the rotating shaft 30. In addition, the elastic member 31 is a spring in this embodiment, and presses the hollow shaft 27 downwardly at the flange portion of the hollow shaft 27, so that the worm 21
The rotation of the worm gear 24, which engages with the worm 21, is ensured to rotate around the hollow shaft 27. Bearings 32, 3 provided in the gear box 28
A driven gear 26 and a lever 34 are fitted into a rotating shaft 33 which is supported by a shaft 2'.

The operation of the gear transmission of this embodiment configured as described above will be described below.

When the drive shaft 22 is driven by the drive source 23, the worm 21 rotates together with the drive shaft 22.
As the worm 21 rotates, the worm gear 24 meshing with the worm 21 rotates around the hollow shaft 27. Since the worm gear 24 and the drive gear 25 are fitted into the hollow shaft 27 as one body,
The worm gear 24 and the drive gear 25 rotate in conjunction with each other. When the drive gear 25 rotates, the drive gear 25
The driven gear 26 meshing with the driven gear 26 rotates, and the rotation of the driven gear 26 causes the rotating shaft 33 to rotate, thereby rotating the lever 34.

In this way, the power from the drive source 23 is transmitted to the lever 34, which is the intended transmitted device.
When the drive source 23 is stopped, the lever 34
Drive means other than the drive source 23 (for example, manual)
4, the worm gear 24 and the drive gear 25 are moved upward along the rotating shaft 30 while compressing the elastic member 31 together with the hollow shaft 27. The worm gear 24 is moved out of engagement with the worm 21 by manual shifting means or the like, and the driven gear 26 and the driving gear 25 are disengaged so that the rotating shaft 33 rotates freely. is driven by other driving means. The lever 34 is again driven by the drive source 23.
When driving the worm gear 24 and the drive gear 25 together with the hollow shaft 27, the moving means that moves the rotating shaft 30 upward is released, and the force of the compressed elastic member 31 causes the hollow The shaft 27 moves downward along the rotation shaft 30, and the worm gear 24 and the drive gear 25 return to their original positions, so that the worm 21 and the worm gear 24 mesh again, and the drive The gear 25 and the driven gear 26 mesh with each other, and the power from the drive source 23 is transmitted to the lever 34, which is a transmitted device.

As described above, according to this embodiment, the worm gear meshes with the worm on the hollow shaft that is fitted into the rotating shaft of the worm gear and is slidable in the direction of the rotating shaft, and the worm gear rotates around the hollow shaft integrally with the worm gear. By inserting a rotatable drive gear and making the hollow shaft slidable to a position where the worm and worm gear disengage, and by pressing the hollow shaft with an elastic member, when the worm is stopped, the hollow shaft The worm and worm gear can be easily disengaged by simply sliding the worm gear and drive gear, which are integrated together with the shaft, in the direction of the rotation axis, and the transmitted device can be easily disengaged by a drive means other than the drive source. The worm gear can be easily returned to its original meshing position with the worm, and the pressing force of the elastic member that fixes the hollow shaft is not applied directly to the worm gear and the driving gear. Therefore, the transmitted device can be driven without any problem by the rotation of the worm by the drive source.

Effects of the Invention The gear transmission device of the present invention has a worm gear that meshes with the worm, which is rotatable around the rotation axis of the worm gear integrally with the drive gear, and is slidable in the direction of the rotation axis. By making it possible to move the worm to a position where it does not engage with the worm, it is possible to very easily drive the transmitted device with a drive means other than the drive source even when the worm is stopped, and it is also possible to easily drive the transmitted device with a drive means other than the drive source. The transmitted device can be driven by this, which has great practical effects.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional gear transmission, FIGS. 2A and B are explanatory views of the same operation, and FIGS. 3 and 4 are sectional views of a gear transmission according to an embodiment of the present invention. 21... Worm, 23... Drive source, 24...
Worm gear, 25... Drive gear, 27... Hollow shaft, 30... Rotating shaft, 31... Elastic member.

Claims (1)

[Scope of utility model registration request] a worm gear that rotates by meshing with a worm rotated by a drive source; a hollow shaft that is fitted into the rotating shaft of the worm gear and is slidable in the direction of the rotating shaft; and a hollow shaft that is integrated with the worm gear and rotates; a driving gear that is fitted into a shaft and rotatable around the hollow shaft; a driven gear that meshes with the driving gear to transmit the rotation of the drive source; and a worm gear that meshes with the worm and drives the drive gear. an elastic member that biases the hollow shaft so that the hollow shaft is fixed at a position where the gear meshes with the driven gear; a transition means that moves the hollow shaft in the direction of the rotating shaft; a drive means for rotating the driven gear when the driven gear is in a position where it does not mesh with the worm gear; A gear transmission device characterized in that the driven gear can be rotated by the driving means when the driving gear integrated with the worm gear is moved to a position where it does not mesh with the worm. .