JP2634102B2 - Gearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission capable of converting a rotary motion into a linear reciprocating motion or a rotary reciprocating motion.

[0002]

2. Description of the Related Art Conventionally, there has been known an apparatus capable of selectively converting a rotary motion into a linear reciprocating motion and a rotary reciprocating motion (see Japanese Patent Application Laid-Open No. 62-196463).

As shown in FIG. 9, this device includes a first eccentric cam 1 for linear reciprocating motion that rotates eccentrically with the forward rotation of the drive source, and a rotary reciprocating motion that rotates eccentrically with the reverse rotation of the drive source. Eccentric cam 2 and a cam follower 3 that reciprocates linearly or reciprocally according to the first eccentric cam 1 or the second eccentric cam 2. Is converted into a linear reciprocating motion (see FIG. 10) or a rotary reciprocating motion (see FIG. 11).

The first eccentric cam 1 and the second eccentric cam 2 are connected to each other in the axial direction with their respective central axes shifted, forming an outer eccentric cam 4. The rotation of the drive source is transmitted to the outer eccentric cam 4 by the rotational movement of the inner eccentric cam 5 inserted into the through hole 4a penetrating the outer eccentric cam 4 in the axial direction.

[0005] The inner eccentric cam 5 is formed by a cylindrical body in which a gear shaft 5a for transmitting the rotation of the driving source is eccentrically arranged, and the first eccentricity is determined by the position of the inner eccentric cam 5 in the through hole 4a. When one of the cams 1 and the second eccentric cam 2 is eccentric, the other is coaxial, and when one is coaxial, the other is eccentric.

[0006]

However, in order to form such an eccentric state or a coaxial state, the inner eccentric cam 5 needs to be larger in diameter than the gear shaft 5a. Through-hole 4a allowing movement of cam 5
Since the diameter of the eccentric cam 5 must be larger than that of the inner eccentric cam 5, there is a limit in reducing the diameter of the first eccentric cam 1 and the second eccentric cam 2, and the entire mechanism including the outer eccentric cam 4 and the inner eccentric cam 5 There is a problem that it is difficult to reduce the size.

Further, the outer eccentric cam 4 provided with the through hole 4a
There is a limit to the reduction of the diameter in the same manner in terms of physical strength.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a transmission device capable of reducing the diameter of a cam and the entire mechanism.

[0009]

In order to achieve the above object, a transmission device according to the present invention comprises inserting a gear shaft of a gear rotated by a drive source into an elongated hole provided at a central portion of a cam body. A cam body is attached to the gear shaft so as to be rotatable with respect to the gear shaft and movably along the elongated hole, and the cam body is connected along the gear shaft and has a cylindrical shape having different center axes. A cam follower formed by a first eccentric cam and a second eccentric cam and having a first engaging portion and a second engaging portion is engaged with the first engaging portion to engage with the first eccentric cam.
When the engaging portion is engaged with the second eccentric cam, attached to the cam body, and the cam body is moved to one side along the elongated hole to position the gear shaft at one end of the elongated hole, When the center axis of one eccentric cam and the gear shaft are coaxial, and the cam body is moved to the other side along the long hole to position the gear shaft at the other end of the long hole, the second eccentric cam When the center axis and the gear shaft are coaxial and the first eccentric cam and the gear shaft are coaxial and the cam body is rotated about the gear shaft, the cam follower rotates and reciprocates, When the cam body is rotated about the gear shaft with the second eccentric cam and the gear shaft being coaxial with each other, the cam follower is a transmission device in which the cam follower reciprocates linearly. A locking portion is provided on one side of the gear, and is engaged with the locking portion, The cam body is moved along the elongated hole by the rotation of the gear, and then the cam body is rotated in the same direction as the gear around the gear shaft, and the cam body is rotated by forward / reverse rotation of the drive source. A cam mechanism having a different moving direction in the elongated hole is provided.

[0010]

In the transmission according to the present invention, the locking portion is locked by the cam mechanism by the rotation of the gear to rotate the cam body, so that the rotation shaft of the first eccentric cam is coaxial with the gear shaft, that is, When the first eccentric cam is concentric with the shaft, the cam body is fixed in the first eccentric cam and the second eccentric cam is fixed in the eccentric state. Is rotated by rotating the cam body.
The rotation shaft of the eccentric cam is coaxial with the gear shaft,
When the eccentric cam is concentric with the shaft, the first eccentric cam and the second eccentric cam are fixed to the cam body. When the first eccentric cam and the gear shaft are made coaxial and the cam body is rotated about the gear axis, the cam follower reciprocates, and the second eccentric cam and the gear shaft are made coaxial to gear the cam body. When rotated about an axis, the cam follower reciprocates linearly.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a transmission according to the present invention will be described below with reference to the drawings.

In FIG. 1A, reference numeral 10 denotes a transmission, 1
Reference numeral 1 denotes a cam follower. The cam follower 11 includes a substantially cylindrical cam follower main body 12 and a cam follower main body 1.
And an output shaft 13 protruding from the upper surface of the output shaft 2.

The cam follower body 12 has a second
FIG. 1 (b) shows a contact surface (second engagement portion) 14 for vertical rotary reciprocating motion which contacts the tapered surface 18a of the eccentric cam 18.
As shown in FIG. 1, a contact surface (first engaging portion) 15 for horizontal linear reciprocating motion which comes into contact with an outer peripheral surface of a later-described first eccentric cam 17 is formed.

Reference numeral 16 denotes a cam, which is disposed inside the cam follower main body 12.

The cam body 16 includes a first eccentric cam 17, a second eccentric cam 18, and a first eccentric cam 17 which are connected along a gear shaft 23, which will be described later, and have different central axes.
The third cam 19 at the lower end of the third cam is integrally provided. The first eccentric cam 17 is for linear reciprocating motion, and the second eccentric cam 18 is for rotary reciprocating motion.

An elongated hole 20 penetrating in the direction of the longitudinal axis is provided at the center of the cam body 16.

The third cam 19 is provided with a ring-shaped guide portion 22 that extends over substantially half a circumference to form a curved elongated hole 21 (see FIG. 3B) between the third cam 19 and the first eccentric cam 17. ,
The guide portion 22 has a locking portion 2 (described later) at a diametrical position.
Steps 22a and 22b are formed as stoppers 5 in FIG. The third cam 19 functions as a cam mechanism.

A tapered surface 18a is formed on the outer peripheral surface of the second eccentric cam 18. In the drawing, a indicates the central axis of the first eccentric cam 17, and b indicates the central axis of the second eccentric cam 18. .

Reference numeral 23 denotes a face gear (gear), and a hole 23a is provided at the center of the face gear 23. A gear shaft 24 is inserted into the hole 23a, and the face gear 23 is rotatable with respect to the gear shaft 24. As shown in FIG. 2, the cam shaft 16 is attached to the gear shaft 24.
Are mounted so that the gear shaft 24 is inserted into the elongated hole 20 so as to be rotatable and movable along the elongated hole 20.

The face gear 23 has an L-shaped engaging portion 25 which is inserted into the elongated hole 21 and engaged with the guide portion 22 so as to protrude therefrom.

FIGS. 3 to 5 show the positional relationship among the cam body 16, the face gear 23 and the gear shaft 24. FIG.

The center axes a and b of the first eccentric cam 17 and the second eccentric cam 18 are, as shown in FIG.
9 is shifted by r1 with respect to the center 19a. And the third
As shown in FIG. 3B, the long hole 21 of the cam 19 is
R3-r1 and r4-r1 apart from the center axis a of the eccentric cam 17 and the center axis b of the second eccentric cam 18, respectively;
The third cam 19 is formed so as to pass through a position r2 away from the center 19a of the third cam 19.

As shown in FIGS. 4 and 5, the locking portion 25 is arranged at a position r5 shifted from the center of the face gear 23. These positional relationships are r2 = r3 = r4 = r5.

FIG. 6 shows the internal structure of the electric toothbrush 26 using the transmission 10 constituted by combining these members.

Reference numeral 27 denotes a main body case containing a driving mechanism, and reference numeral 28 denotes a charging battery for driving a motor (drive source) 29. Reference numeral 30 denotes a switch mechanism, and 31 denotes a knob for operating the switch mechanism 30. By operating this knob 31, as shown in FIG.
, The motor 29 can be rotated forward or backward.

A pinion 32 is press-fitted into the shaft of the motor 29.
It is fixed to. The face gear 2 is provided on the frame 34.
3, the cam body 16 and the cam follower 11 are mounted by a gear shaft 24, and the face gear 23 and the cam body 16 are rotatably mounted. 36 is a fixing piece to which the gear shaft 24 is fixed. Reference numeral 37 denotes a cradle, in which a bearing 38 is sealed, and 39, a cradle, in which the bearing 4 is mounted.
0 is enclosed.

Each bearing 3 of the receiving table 37 and the receiving table 39
8 and 40 through the output shaft 13 to receive the pedestals 37 and 39.
Is attached to the frame 34 with screws 42 (FIG. 6).
(A)).

Next, an operation of converting the rotary motion into a rotary reciprocating motion and an operation of converting the rotary motion into a linear reciprocating motion by the transmission device 10 will be described.

First, the knob 31 is operated to turn on the switch mechanism 30 so that the motor 29 rotates forward. When the switch mechanism 30 is turned on, electric power is supplied from the battery 28, the motor 29 rotates forward, and the rotation of the pinion 32 due to the forward rotation of the motor 29 causes the face gear 23 to rotate.

The rotation of the face gear 23 causes the locking portion 25 of the face gear 23 to abut on one end 21a of the groove 21 of the third cam 19 and be fixed, as shown in FIG. Rotate. The rotation of the cam body 16 causes the first
The rotating shaft of the eccentric cam 17 is coaxial with the gear shaft 24,
That is, the first eccentric cam 17 and the gear shaft 24 are concentric.

At this time, the gear shaft 24 is located at the end opposite to the one end 21a in the elongated hole 20 so that r5 = r3, so that the cam body 16 has the first eccentric cam 17 in the concentric state. Second
The eccentric cam 18 is fixed in an eccentric state, and the cam follower 11
Make a reciprocating rotation.

The rotary reciprocating motion of the cam follower 11 causes the output shaft 1 rotatably supported by the bearings 38 and 40 to rotate.
The toothbrush 43 attached to the tip of the output shaft 13 is caused to rotate and reciprocate.

At this time, since the first eccentric cam 17 is in the concentric state, the first eccentric cam 17 always rotates at the same position.

On the other hand, by operating the knob 31, the switch mechanism 30 is turned on so that the motor 29 rotates in the reverse direction. When the switch mechanism 30 is turned on, power is supplied from the battery 28, the motor 29 rotates in the reverse direction, and the rotation of the pinion 32 due to the reverse rotation of the motor 29 causes the face gear 23 to rotate.

By the rotation of the face gear 23, the locking portion 25 of the face gear 23 goes through the state shown in FIG. 8A and the state shown in FIG. 8C, and the other end of the groove 21 of the third cam 19. The cam body 16 is fixed while being in contact with the cam 21b. The rotation of the cam body 16 causes the rotation shaft of the second eccentric cam 18 to be coaxial with the gear shaft 24, that is, the second eccentric cam 1
8 and the gear shaft 24 are concentric.

At this time, since the gear shaft 24 is located at the end opposite to the other end 21b in the elongated hole 20 and r5 = r4, the cam body 16 has the first eccentric cam 17 in the eccentric state. , Second
The eccentric cam 18 becomes concentric, and the cam follower 11 reciprocates linearly.

The linear reciprocating motion of the cam follower 11 causes the output shaft 1 rotatably supported by the bearings 38 and 40 to rotate.
3, the toothbrush 43 attached to the tip of the output shaft 13 is linearly reciprocated.

At this time, since the second eccentric cam 18 is in the concentric state, the rotational force of the cam follower 11 is restricted, and a linear reciprocating motion without rotational motion can be obtained.

The gear shaft 24 is mounted on the face gear 2.
When the cam body 16 is rotated by the rotation of the third rotation, the cam body 16 linearly moves in the long hole 20. The length of the long hole 20 required to allow the movement of the gear shaft 24 depends on the movement distance of the gear shaft 24. The diameter is added.

On the other hand, for example, in the device shown in the conventional example, the gear shaft 5a for transmitting the rotation of the driving source has an inner eccentric cam 5 formed of a columnar body arranged eccentrically.
However, since the rotary shaft moves in the through hole 4a, the through hole 4a required to allow the movement of the gear shaft 5a is obtained by adding the diameter of the gear shaft 5a and the thickness of the cylindrical body to the moving distance of the gear shaft 5a. It must be formed in a circular shape having a different diameter.

Therefore, in the transmission 10 according to the present invention, a structure for allowing the movement of the gear shaft 24, compared with the device shown in the conventional example, is provided with a long hole having a long diameter smaller by at least the thickness of the cylindrical body. Since it can be set to 20,
The diameter of the first eccentric cam 17 and the second eccentric cam 18 can be reduced, and further, the entire mechanism having the cam body 16 can be reduced in size.

The downsizing of the entire mechanism is effective especially for an electric toothbrush or the like where space requirements are severe, and brings great merits.

[0043]

In the transmission according to the present invention, the gear shaft of the gear rotated by the drive source is inserted into an elongated hole provided at the center of the cam body, and the cam body is rotatable with respect to the gear shaft. The cam body is formed by a first cylindrical eccentric cam and a second cylindrical eccentric cam which are connected along the gear shaft and have different central axes from each other. A cam follower having a first engaging portion and a second engaging portion, wherein the first engaging portion is engaged with the first eccentric cam, and the second engaging portion is engaged with the second eccentric cam. Attaching to the cam body, moving the cam body to one side along the elongated hole to position the gear shaft at one end of the elongated hole,
A center axis of the first eccentric cam and the gear shaft are coaxial;
When the cam body is moved to the other side along the elongated hole and the gear shaft is positioned at the other end of the elongated hole, the center axis of the second eccentric cam and the gear shaft are coaxial, and the first eccentric When the cam and the gear shaft are made coaxial and the cam body is rotated about the gear shaft, the cam follower rotates and reciprocates, and the second eccentric cam and the gear shaft are made coaxial and the cam body is rotated. When the cam follower is rotated about the gear shaft, the cam follower linearly reciprocates, and a locking portion is provided on one side of the gear on the side facing the cam body. Engaging, moving the cam body along the elongated hole by rotation of the gear, and then rotating the cam body about the gear axis in the same direction as the gear, and forward / reverse rotation of the drive source. The moving direction of the cam body in the elongated hole differs depending on It is characterized in that a beam mechanism.

For this reason, the forward / reverse rotation of the drive source makes it possible to reduce the diameter of the cam in the transmission device capable of obtaining rotational and linear reciprocating motion, and also to reduce the size of the entire mechanism.

[Brief description of the drawings]

FIG. 1 shows a main part of a transmission according to the present invention,
(A) is an exploded perspective view, (b) is a perspective view of a cam follower.

FIG. 2 is a perspective view of a cam body and a face gear.

3A and 3B show a cam body, wherein FIG. 3A is an explanatory diagram showing a relationship between a first eccentric cam and a second eccentric cam and an elongated hole, and FIG. 3B is an explanatory diagram of a third cam.

FIG. 4 is a plan view showing a relationship between a locking portion and a gear shaft in the face gear.

FIG. 5 is an explanatory sectional view showing a relationship between a cam body and a gear shaft.

6A and 6B show an electric toothbrush, wherein FIG. 6A is a longitudinal sectional view, FIG. 6B is a sectional view of another longitudinal section without the toothbrush mounted, FIG. 6C is a transverse sectional view of a switch mechanism, and FIG. () Is a cross-sectional view of another cross section.

FIG. 7 is a circuit diagram of a switch mechanism.

8A and 8B show a positional relationship between a gear shaft moving in an elongated hole and a cam body, wherein FIG. 8A is an explanatory diagram showing a state where the gear shaft is located at the center, and FIG. FIG. 7C is an explanatory view of a rotary reciprocating state, and FIG. 9C is an explanatory view of a linear reciprocating state in which a gear shaft is located at the other end.

9A and 9B show a main part of a conventional transmission, wherein FIG. 9A is an exploded perspective view and FIG. 9B is a perspective view of a cam follower.

FIG. 10 is an explanatory view of a linear reciprocating state of the transmission shown in FIG. 9;

FIG. 11 is an explanatory diagram of a rotational reciprocating state of the transmission shown in FIG. 9;

[Explanation of symbols]

 Reference Signs List 10 Transmission device 11 Cam follower 14 Contact surface for rotary reciprocating motion (second engaging portion) 15 Contact surface for linear reciprocating motion (first engaging portion) 16 Cam body 17 First eccentric cam 18 Second eccentric cam 19 Third cam (Cam mechanism) 20 Slot 23 Face gear (gear) 24 Gear shaft 25 Locking part 29 Motor (drive source)

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-242139 (JP, A) JP-A-63-77404 (JP, A) JP-A-62-196463 (JP, A) JP-A-4- 8380 (JP, A)

Claims (1)

(57) [Claims] 1. A gear shaft of a gear rotated by a drive source is inserted into an elongated hole provided at a central portion of a cam body, and the cam body is rotatable with respect to the gear shaft and along the elongated hole. The cam body is movably attached to the gear shaft, and the cam body is formed by first and second cylindrical eccentric cams connected along the gear shaft and having different center axes from each other. A cam follower having a second engaging portion is attached to the cam body by engaging the first engaging portion with the first eccentric cam and engaging the second engaging portion with the second eccentric cam. When the cam body is moved to one side along the elongated hole to position the gear shaft at one end of the elongated hole, the center axis of the first eccentric cam and the gear shaft are coaxial, and the cam body is elongated. When the gear shaft is moved to the other end along the axis to position the gear shaft at the other end of the elongated hole, the second eccentric force When the first eccentric cam and the gear shaft are coaxial with each other and the cam body is rotated around the gear shaft, the cam follower rotates and reciprocates. A transmission device in which the cam follower linearly reciprocates when the cam body is rotated about the gear shaft with the second eccentric cam and the gear shaft being coaxial with each other; An engagement portion is provided on one side surface of the gear, and the engagement portion engages with the engagement portion, and the cam body is moved along the elongated hole by rotation of the gear, and then the cam body is centered on the gear shaft. A transmission mechanism provided with a cam mechanism that rotates in the same direction as the gear and changes the moving direction of the cam body in the elongated hole by forward / reverse rotation of the drive source.