CN1034985A

CN1034985A - Worm and worm-wheel gearing

Info

Publication number: CN1034985A
Application number: CN 88109079
Authority: CN
Inventors: 田中隆
Original assignee: Tanashin Denki Co Ltd
Current assignee: Tanashin Denki Co Ltd
Priority date: 1988-02-12
Filing date: 1988-10-05
Publication date: 1989-08-23
Also published as: JPH01121746U; CN2035413U

Abstract

A kind of Worm and worm-wheel gearing that is constituted by the worm and wheel engagement, near the helical tooth terminal of worm screw, be provided with in conjunction with projection, on the part of worm gear, be provided with braking part, interlock by worm and wheel rotates, make this in conjunction with projection from axially and parallel direction and braking part mesh, can make this worm screw stall.Also the terminal of above-mentioned helical tooth can be constituted thisly, or a part of tooth of worm gear 6 be eliminated, on this part, form in conjunction with projection in conjunction with projection, but this structure simplified design and reducing cost.

Description

Worm and worm-wheel gearing

The present invention relates to a kind of like this Worm and worm-wheel gearing, on worm screw, be provided with, and braking part is set on worm gear, and worm screw is stopped by they are in contact with one another in conjunction with projection.

Worm and worm-wheel gearing mostly uses as the actuating unit with deceleration effectiveness, but is applicable to that also example is the VTR(Video/tape/recorder) loading and unloading unit for cassette.

In loading and unloading unit for cassette, when cassette was inserted into assigned position in the tape cassette holder, sensor was a starter motor after it is detected, so the rotatory force of motor just passes to the worm screw of Worm and worm-wheel gearing, the worm gear reducer that is engaged with was rotated.This rotatory force of worm gear passes to the forked parts that have matching relationship with the tape cassette holder, make the tape cassette holder at first along the horizontally-guided body cause substantially horizontal in portion, then, move, till the cassette loading position of regulation along the vertically-guided body toward vertical lower.At this moment detect the position of tape cassette holder again by sensor, thereby stop to power to motor.

When taking out cassette, make the motor counter-rotating, loading and unloading unit for cassette is carried out and aforementioned opposite action, and when the tape cassette holder is retracted into initial position, just detect its position, and stop to power to motor by sensor.

In above-mentioned loading and unloading unit for cassette, even one detect the position of tape cassette holder, just stop immediately, but because the inertia of rotatable parts to the motor power supply, be difficult to allow motor stall at once.For this reason, the general rotation transmission way, slip gear is set, rotates with the excess of stroke that absorbs motor from motor to worm screw.

Now, some problems that exist in the Worm and worm-wheel gearing for prior art are example with its situation that is applied to loading and unloading unit for cassette, are illustrated.As previously mentioned, drive the motor of worm screw,, thereby normally to the rotation transmission way of worm screw, slip gear is set at motor even stop to its also not stall at once of power supply.Yet, even taked such measure, because the rotatory force that motor inertia causes can pass to worm screw by slip gear, therefore the helical tooth that has the worm screw of rotatory force, the worm-gear tooth forcing in the release position to stop produced sting the food phenomenon, give the helical tooth of worm screw and worm-gear tooth with violent impact load.So, in the design of worm and wheel, need consider after fully withstanding such harsh conditions, also should leave enough surpluses, thereby bring difficulty to design work.In addition, such result has also brought expensive problem.

The present invention's purpose is to adopt very simple structure to solve above-mentioned these problems.

Worm and worm-wheel gearing of the present invention adopts such structure, near the helical tooth terminal of worm screw, be provided with in conjunction with projection, simultaneously, on the part of worm gear, braking part is set, interlock rotation by worm and wheel, this is contacted with braking part from axial and parallel direction in conjunction with projection, thereby make the worm screw stall.

With above-mentioned Worm and worm-wheel gearing, the occasion that for example is used for the loading and unloading unit for cassette of VTR, when the tape cassette holder arrives the release position and stops after the motor power supply, worm screw and motor one cause inertia were rotated further, because contacting with the braking part of worm gear from axial and parallel direction in conjunction with projection of worm screw just can make worm screw stop.

The aforesaid structure according to the present invention, when near the helical tooth terminal of worm screw, being provided with in conjunction with projection, on the part of worm gear, braking part is set again, interlock by this worm and wheel rotates, this is contacted from axial and parallel direction with braking part in conjunction with projection, thereby make the worm screw stall, like this, even after the worm gear stall, when also having the part driving force to pass to worm screw, also need not misgivings bring harsh load can for the mate of this worm and wheel, therefore, can reach worm and wheel is designed easily, and initial desired purpose such as can reduce cost.

The diagrammatic illustration of relevant accompanying drawing is as follows:

Accompanying drawing is depicted as one embodiment of the invention, Fig. 1 is for observing the structure diagram of the loading and unloading unit for cassette of VTR mechanical device from the side, Fig. 2 is the planimetric map of above-mentioned loading and unloading unit for cassette, Fig. 3 is the oblique drawing of Worm and worm-wheel gearing, and Fig. 4 shows the planimetric map that concerns between worm and wheel in the above-mentioned Worm and worm-wheel gearing.Among the figure, the meaning of number designation is:

The 5-worm screw; The 6-worm gear; The 7-Worm and worm-wheel gearing; The 16-helical tooth; The lower end of 16a-helical tooth (in conjunction with projection); 17-is in conjunction with projection; 18a, 18b-braking part.

Fig. 1 to Fig. 4 is the embodiment that Worm and worm-wheel gearing of the present invention is applied to the loading and unloading unit for cassette of VTR.

Fig. 1 is the side view of VTR mechanical device, on main body side plate 1, is provided with continuously and makes tape cassette holder 2 insert horizontal guide groove 3 and the vertical guide slot 4 that the position directs into the cassette loading position from cassette.In addition, on aforementioned body side plate 1, the worm gear 6 that is provided with worm screw 5 and is meshed with it, the two constitutes Worm and worm-wheel gearing 7.

The rotatory force of motor 8 passes to above-mentioned worm screw 5 by slip gear 9.Gearwheel 10 and worm gear 6 interlocks on this gearwheel 10, integrally are equipped with the forked parts 11 that constitute bifilar shape.

In addition, in the side of above-mentioned tape cassette holder 2, saliently be provided with aforementioned levels guide groove 3 and vertical guide slot 4 in match in conjunction with pin 12, this in conjunction with pin 12 by the bifilar shape part clamping of above-mentioned forked parts 11.

In addition, on the main body side plate of relative one side, be provided with above-mentioned horizontal guide groove 3, vertical guide slot 4 too and the gearwheel 10 of forked parts 11 is housed.So just, constituted the structure that the gearwheel 10 of both sides is synchronized with the movement by synchromesh gear 13 and coupling shaft 14.

Therefore, aforementioned worm gear 6 is between certain angle (0 °～340 ° or 350 °), with combining pin 12 along horizontal guide groove 3 and vertical guide slot 4 guidings, make the tape cassette holder 2 that has inserted VTR cassette 15 from the loading position that the position moves to regulation that inserts shown in Figure 1 with the forked parts 11 of its interlock.

But, near an end (upper end) of the helical tooth 16 on the above-mentioned worm screw 5, be provided with in conjunction with projection 17.In addition, aforesaid worm gear 6 on the part that has reamed some teeth, then is provided with a pair of braking part 18a, the 18b of connection.

Above-mentioned helical tooth 16 and be set as follows: when worm screw 5 turns right in conjunction with the relation between projection 17 and braking

part

18a, 18b, make tape cassette holder 2 insert the position to the loading position direction guiding by forked parts 11 from cassette, and when tape cassette holder 2 just in time arrives the loading position of regulation, the lower end 16a of the helical tooth 6 of this worm screw 5 is contacted with the braking part 18a of worm gear 6; In addition, when worm screw 5 turns left, by forked parts 11 tape cassette holder 2 is inserted locality guiding from the loading position of regulation to cassette, and tape cassette holder 2 just in time arrive cassette insert the position time, the contacting of worm screw 5 in conjunction with the braking part 18b of projection 17 with worm gear 6.At this moment, though motor 8 rotates because of inertia has the excess of stroke to a certain degree, this excess of stroke is rotated and can be absorbed by slip gear 9.

In above structure, when the cassette 15 of VTR is inserted into assigned position in the tape cassette holder 2, after sensor (unreceipted among the figure) detects is starter motor 8, and the rotatory force of motor 8 passes to the worm screw 5 of Worm and worm-wheel gearing 7, makes with worm gear 6 decelerations of worm screw 5 engagements to rotate.This worm gear 6 passes to this rotatory force forked parts 11 again, forked parts 11 make tape cassette holder 2 at first along horizontal guide groove 3 be directed to substantially horizontal in portion, then,,, it is directed to the cassette loading position of regulation towards vertical lower along vertical guide slot 4.So far, the position of tape cassette holder 2 detects through sensor (unreceipted among the figure) once more, and stops to motor 8 power supplies, simultaneously, shown in Fig. 3 (a), the terminal of the helical tooth 16 of worm screw 5, contact with the braking part 18a of worm gear 6 from axial and parallel direction, make worm screw 5 stalls.

At this moment, though motor 8 stall immediately after outage, and because of inertia generation rotation to a certain degree, but, this excess of stroke is rotated and can be absorbed by slip gear 9.

When taking out cassette 15, make motor 8 counter-rotatings, loading and unloading unit for cassette is carried out opposite action, when tape cassette holder 2 is retracted into initial position, just stop after by sensor it being detected to motor 8 power supplies, simultaneously, shown in Fig. 3 (b), contacting with the braking part 18b of worm gear 6 from axial and parallel direction in conjunction with projection 17 of worm screw 5 makes worm screw 5 stalls.

At this moment, the excess of stroke of motor 8 is rotated and is also absorbed by slip gear 9.

As mentioned above, since the structure taked be by near the lower end of the helical tooth on the worm screw 5 16 16a and this helical tooth upper end in conjunction with projection 17, contact with

braking part

18a, 18b on being arranged on worm gear 6 parts, make worm screw 5 stalls, like this, the excess of stroke that is produced by the inertia of motor 8 was rotated, when passing to worm screw 5, also can not produce the effect of the superfluous external force of impact force and so on the mate of worm screw 5 and worm gear 6 by slip gear 9.Therefore, can prevent the influence that the excess of stroke that the inertia by motor 8 causes is rotated, and cause the gear teeth of 16 pairs of worm gears 6 of helical tooth of worm screw 5 to sting the food phenomenon, so, multiple effect such as can obtain to design easily worm screw 5 and worm gear 6, can reduce cost.

Certainly, the present invention is not limited to the foregoing description, and all change forms can also be arranged.For example, in above embodiment, only near the upper end of helical tooth 16, be provided with worm screw 5 in conjunction with projection 17, bottom worm screw 5, the terminal of helical tooth 16 is had and combine the projection identical functions, but also can be two sides up and down the terminal part of spiral tooth 16 as in conjunction with projection, perhaps opposite, also can about two sides helical tooth 16 is provided with in conjunction with projection respectively.

Claims

1, a kind of Worm and worm-wheel gearing  rinse the drooping plan of an ancient small-mouthed wine vessel tomb dry up to tease to scrape carefully to rouse stop up Sha dirty system under the shoulder blade how to control the strange school of thin Shun   forget down thin by 5) spiral tooth terminal near be provided with in conjunction with projection (16a, 17), simultaneously, on the part of worm gear (6), be provided with braking part (18a, 18b); Interlock by this worm screw (5) and worm gear (6) rotates, can make above-mentioned in conjunction with projection (16a, 17) from axially and parallel direction contact with above-mentioned braking part (18a, 18b), and make this worm screw (5) stall.

2, Worm and worm-wheel gearing according to claim 1 is characterized in that: with the terminal part (16a) of the helical tooth (16) of above-mentioned worm screw (5) as above-mentioned in conjunction with projection.

3, Worm and worm-wheel gearing according to claim 1 is characterized in that: a part of tooth of above-mentioned worm gear (6) is eliminated, and form above-mentioned in conjunction with projection (18a, 18b) on this part.