JP2006058387A - Gear mechanism and camera having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce noise made by the collision of the teeth of gears by providing a mechanism for adjusting the meshing depth in a gear mechanism. <P>SOLUTION: The gear mechanism for transmitting driving force through a gear train has the adjusting mechanisms 5b and 6b for adjusting the meshing depth of the 1st and the 2nd gears 2 and 3a meshing with each other in the gear train. Both of the 1st and the 2nd gears 2 and 3a are spur gears, and the gear train GT includes an adjusting gear member 3 including the 2nd gear 3a and a worm part 3b coaxially and integrally rotating with the 2nd gear 3a, and a worm wheel 4a meshing with the worm part 3b. The adjusting mechanisms 5b and 6b positionally adjust the adjusting gear member 3 in the rotary shaft direction (direction X) of the worm wheel 4a. As a result, the meshing depth of the 1st and the 2nd gears 2 and 3a is adjusted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gear mechanism for transmitting power by a gear train and a camera having the gear mechanism, and measures against vibration and noise are taken.

  As a gear mechanism used for a camera, there is a mechanism that transmits a driving force of a single motor to each part by a gear train, drives a lens, a finder, a flash device, and feeds a film. Especially in the thing of patent document 1, the vibration and noise resulting from the backlash of a shaft part and its fitting part are aimed at by urging | biasing the axial part of the worm which comprises a gear train to radial direction. Yes.

JP 2002-207237 A

  In general, in a mechanism using a gear train, the impact sound generated when the teeth of the gears meshing with each other collide with each other increases, and this becomes more noticeable as the rotational speed of the gear increases. However, the noise reduction structure of Patent Document 1 does not reduce noise caused by this type of impact between teeth.

The gear mechanism according to the present invention is a mechanism that transmits a driving force via a gear train, and includes an adjustment mechanism that adjusts the meshing depth of first and second gears that mesh with each other in the gear train.
In particular, in the invention of claim 2, the first and second gears are both spur gears, and the gear train includes an adjustment gear member including a worm portion that rotates coaxially with the second gear and the second gear, and a worm. The adjustment mechanism is a mechanism for adjusting the position of the adjustment gear member in the direction of the rotation axis of the worm wheel.
In the invention of claim 3, the adjustment mechanism includes a cam portion that applies a force in the rotation axis direction of the worm wheel to the adjustment gear member, and a guide portion that guides the gear mechanism in the rotation axis direction in accordance with the operation of the cam member. Composed.
According to a fourth aspect of the present invention, the gear train is configured to transmit the driving force of the motor, and the guide portion is formed on a holding member that holds the motor.
In the invention of claim 5, the first gear is a gear that rotates at the highest speed in the gear train.
The camera according to the present invention has the gear mechanism.

  According to the present invention, since the meshing depth of the gears meshing with each other can be adjusted, it is possible to reduce the vibration and noise generated by the inappropriate meshing depth.

An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a view of the gear mechanism of the camera in this embodiment as seen from one direction, and FIGS. 2 and 3 are views as seen from the II-II and III-III lines. This gear mechanism transmits the driving force of the motor 1 by the reduction gear train GT to perform the camera operation. The camera operation includes driving of a taking lens and film feeding. If a transmission path switching mechanism is provided in the gear train GT, a plurality of types of operations can be performed with the driving force of a single motor 1. The gear train GT includes a pinion gear 2, an adjustment gear member 3, a gear member 4, and a plurality of gears (not shown) subsequent thereto.

  Reference numeral 5 denotes a holding member that holds the motor 1 and the adjustment gear member 3, and reference numeral 6 denotes a slide member that can slide in the Y direction with respect to the holding member 5. The holding member 5 and the slide member 6 have a pair of wall portions 5A and 5B: 6A and 6B, and the wall portions 6A and 6B of the slide member 6 are in contact with the outer sides of the wall portions 5A and 5B of the holding member 5, respectively. Yes. The guide pins 5a (FIG. 3) projecting from the walls 5A and 5B are engaged with Y-direction guide grooves 6a formed on the walls 6A and 6B, thereby guiding the slide of the slide member 6. .

  The motor 1 is fixed to the wall portion 5A of the holding member 5 with screws 7 with the wall portion 6A of the slide member 6 interposed therebetween. The output shaft 1a of the motor 1 passes through the walls 5A and 6A, and a pinion gear 2 is attached to the tip thereof by press-fitting. The wall 6A is provided with a hole through which the screw 7 penetrates and a hole (both not shown) that accommodates the protruding portion 1b of the motor 1, but these holes are sufficiently long in the Y direction. The slide is not disturbed.

  Further, guide walls (long grooves) 5b extending in the X direction perpendicular to the Y direction are formed on both wall portions 5A and 5B of the holding member 5, respectively, and on both wall portions 6A and 6B of the slide member 6, respectively. Are formed with cam grooves (long grooves) 6b extending obliquely. The guide groove 5b and the cam groove 6b constitute a cam mechanism for adjusting the position of the adjustment gear member 3.

  In the adjustment gear member 3, a spur gear portion 3a (input side) meshing with the pinion gear 2 and a worm portion 3b (output side) are integrally formed on the same axis, and the cam follower pin 3c is coaxial with the shaft at both ends. Protruding to. Both cam follower pins 3c pass through the pair of guide grooves 5b and are respectively engaged with the pair of cam grooves 6b, whereby the adjustment gear member 3 is rotatably supported.

  The gear member 4 is formed by integrally forming a worm wheel portion 4a (input side) and a spur gear portion 4b (output side) coaxially, and is rotatably held by a holding member (not shown). The worm wheel portion 4a meshes with the worm portion 3b of the adjustment gear member 3, thereby transmitting the rotation of the adjustment gear member 3 to the spur gear portion 4b. The rotation of the spur gear portion 4b is transmitted to the driven object via a gear train (not shown). Here, the shaft angle of the worm part 3b and the worm wheel part 4a is a right angle.

Next, the position adjustment of the adjustment gear member 3 will be described.
The adjustment of the position of the adjustment gear member 3 in the X direction corresponds to the adjustment of the inter-axis distance between the pinion gear 2 and the spur gear portion 3a, and the meshing depth of both the gears 2 and 3a is adjusted by adjusting the inter-axis distance. It will be. In general, when the gears are too shallowly engaged, the collision noise between the teeth increases due to the large backlash between the teeth, and when the engagement is too deep, a collision noise between the tooth tip and the tooth bottom occurs. By adjusting the meshing depth to an appropriate state that is not too shallow and not too deep, noise and vibration can be minimized.

  For adjustment, when the slide member 6 is slid in the Y direction, a force in the X direction acts on the cam follower pin 3c via the cam groove 6b, and the cam follower pin 3c is guided in the guide groove 5b and moves in the X direction. As a result, the adjustment gear member 3 moves in the same direction. 4 to 6 show an example of adjustment, FIG. 4 shows before adjustment, and FIGS. 5 and 6 show after adjustment. Before the adjustment, the line connecting the shafts of both gears 2 and 3a is parallel to the Y direction. At this time, the distance between the shafts of both gears is the shortest (C in FIG. 6) and the meshing depth is the deepest. When the slide member 6 is slid downward, the adjusting gear member 8 is moved to the right by the action of the cam. As a result, the inter-shaft distance becomes D (> C), and the meshing depth is equal to the difference between D and C. Becomes shallower.

  Here, it is clear that the noise at the meshing portion of the gear increases as the rotational speed of the gear increases, so adjusting the meshing depth between the low-speed rotating gears does not make much sense, and the gear rotates as fast as possible. It is desirable to adjust the meshing depth between each other. The adjustment mechanism of this embodiment adjusts the meshing depth between the pinion gear 2 that rotates at the highest speed in the gear train and the spur gear portion 3a that meshes with the pinion gear 2, and has the highest noise reduction effect. However, the adjustment of the meshing depth is not limited to the highest speed gears.

  Furthermore, the adjusting mechanism can adjust only the meshing depth of the gears 2 and 3a by using a worm gear without affecting the meshing depth of other gears. That is, by adjusting the position of the adjustment gear member 3, not only the spur gear portion 3a but also the worm portion 3b moves integrally in the X direction, but since the moving direction is the rotational axis direction of the worm wheel portion 4a, the worm portion 3b. The distance between the shafts of the worm wheel portion 4a and the worm wheel portion 4a does not change, and the meshing depth of the gears 3b and 4a is unchanged.

  In addition, although the adjustment mechanism using a cam mechanism was shown above, this is not limited to a cam mechanism, For example, the mechanism using a spring and a press screw may be sufficient. Further, although the description has been given with respect to the gear mechanism of the camera, the present invention can also be applied to a gear mechanism used in equipment other than the camera as long as gear noise reduction is required. Furthermore, the drive source is not limited to a motor, and may be one that transmits a driving force by manual operation, for example.

The figure which shows the gear mechanism of the camera in one Embodiment. II-II sectional view taken on the line of FIG. III-III sectional view taken on the line of FIG. It is a figure explaining the adjustment method of meshing depth, and shows the state before adjustment. It is a figure explaining the adjustment method of meshing depth, and shows the state after adjustment. The figure which shows the difference in the center distance (meshing depth) before and after adjustment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Pinion gear 3 Adjustment gear member 3a Spur gear part 3b Worm part 3c Cam follower pin 4 Gear member 4a Worm wheel part 4b Spur gear part 5 Holding member 5A, 5B Wall part 5b Guide groove 6 Slide member 6A, 6B Wall part 6b Cam groove 7 screw

Claims (6)

In a gear mechanism that transmits driving force through a gear train,
A gear mechanism comprising an adjusting mechanism for adjusting a meshing depth of first and second gears meshing with each other in the gear train.   Each of the first and second gears is a spur gear, and the gear train meshes with the worm portion and an adjustment gear member including a worm portion that rotates coaxially with the second gear and the second gear. The gear mechanism according to claim 1, further comprising: a worm wheel, wherein the adjustment mechanism is a mechanism that adjusts a position of the adjustment gear member in a rotation axis direction of the worm wheel.   The adjustment mechanism includes a cam portion that applies a force in the rotation axis direction of the worm wheel to the adjustment gear member, and a guide portion that guides the gear mechanism in the rotation axis direction in accordance with the operation of the cam member. The gear mechanism according to claim 2, wherein:   The gear mechanism according to claim 3, wherein the gear train is configured to transmit a driving force of a motor, and the guide portion is formed on a holding member that holds the motor.   The gear mechanism according to any one of claims 1 to 4, wherein the first gear is a gear that rotates at a highest speed in the gear train.   A camera comprising the gear mechanism according to claim 1.

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