JPH0221046A - Toothed belt and driving gear using same - Google Patents

Abstract

PURPOSE:To stop a belt from jumping by locating the center point of an arc which forms the power transmission region of the toothed part of the belt and the addendum of the belt between the pitch line and the land line of the belt and in a position distanced from the center line of the toothed part of the belt by half the size of the width of a tooth of the belt. CONSTITUTION:The center point 12 of the radius RB of curvature of the toothed part 3 of a belt within its power transmission region 9 is located in between its belt pitch line 5 and its belt land line 6 and in a position distanced from the center line of the toothed part 3 of the belt by half the size of the width W of a tooth of the belt, and the radius RB of curvature is approximately equal to the width W. In this case, therefore, the toothed part 3 of the belt itself is bigger than in the case of being located on the pitch line 5 of the toothed belt 1, regardless of the width W being invariable in two cases; Thus the device is capable of dealing with heavy load transmission; besides, the power transmission region 9 of the toothed part 3 is more inclined than usual, and its torque transmitting performance is improved together with gripping force of the toothed part 3 of the belt.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a toothed belt and a drive device using the same.
More specifically, the present invention relates to a toothed belt that prevents belt jumping and is capable of transmitting high loads, and a drive device using the same.

(Prior art) 1. Belts with belts are capable of reliable transmission without slippage, and have advantages such as no need for lubrication and low noise compared to drive devices using gears and chains, which are one of the other reliable transmission methods. Therefore, the demand for it has been increasing steadily in recent years. As a drive device consisting of a combination of a toothed belt and a pulley that is widely used in general, as specified in RAM II)-24 (1978), a belt tooth section with an inverted trapezoid cross section and a group of grooves similar to the southern part of the belt tooth section are provided. There is a transmission system that meshes with a pulley provided on the circumference.

In addition, the teeth of the toothed belt constituting this type of transmission system disclosed in U.S. Pat. No. 3,756,091 and U.S. Pat. The pulley is constructed with round teeth consisting of a pair of intersecting circular arcs each having the same radius of curvature. Correspondingly, the pulley also has a pulley groove formed from a pair of circular arcs on its circumferential surface. When the belt meshes with the pulley, the belt teeth contact or compressively engage the groove bottom of the pulley, and are designed to reduce wear on the belt groove surface.

Also, U.S. Patent No. 4,108,011 (Japanese Patent Publication No. 57
-51589) discloses a toothed belt having round teeth consisting of a pair of circular arcs having a center point on the belt pitch line, and a groove portion similar to the belt tooth portion on the circumferential surface of a pulley. A toothed belt drive device has been disclosed which is made up of a combination of pulleys provided in the above, in which the toothed belt is compressively engaged with the pulleys, and which has been improved mainly in terms of noise prevention.

Furthermore, U.S. Patent No. 4t452t594 (corresponding to Japanese Patent Publication No. 60-22216) discloses a toothed belt having an arcuate flank surface having a starting point on the belt land line and on the outside of the belt teeth. A technical idea is disclosed which is intended to minimize interference when meshing with a pulley and maximize the strength of the belt teeth.

In this way, today's toothed belt drive devices consist of a combination of a toothed belt having teeth with an inverted trapezoid cross section and a pulley having a pulley groove of the same shape as the belt teeth, or a part of a pair of circular arcs. The most common type of belt is a combination of a toothed belt with round teeth and a pulley with a pulley groove having a shape similar to the round teeth.

(Problems to be Solved by the Invention) Generally speaking, in conventional toothed belt drive devices, the largest amount of backlash occurs at the root of the belt teeth. Although they mesh smoothly, there is a drawback that when the belt starts driving, the remaining movement of the belt or pulley becomes large, and the surface of the belt teeth is easily rubbed by the pulley, causing wear. In order to deal with this situation, setting a high belt tension will reduce the amount of belt or pulley movement remaining, which is effective in preventing belt wear, but on the other hand, the belt will stretch more easily, leading to premature belt failure. There were drawbacks.

In addition, in today's belts in which the center point of the arc forming the side wall of the belt teeth is located on the pitch line of the belt, the slope of the side wall at the root of the belt tooth is too gentle with respect to the belt land line. Since the teeth 8 (and the pulley grooves are also smaller), torque transmission performance deteriorates, and there is a great concern that this may cause a jumping phenomenon in the belt.

In addition, in a belt in which the center point for forming the circular arc of the belt teeth is set on the belt land line, the slope of the side wall at the base of the belt tooth becomes too steep with respect to the belt land line.
As a result, the performance of torque transmission to the pulley is improved, but interference between the belt teeth increases. For this reason, a large backlash must be provided at the root of the belt teeth, and as mentioned above, this causes various problems as the belt moves to a large extent when the belt starts to rotate or when it reverses rotation. That is, the belt positioning accuracy decreases, the belt tension body becomes polygonal at an angle in the belt groove, and
Disadvantages include that the belt tensile member is susceptible to bending fatigue, and furthermore, that the side wall portion of the belt tooth portion is subject to increased wear due to pulsating loads.

The present invention aims to improve a number of problems related to such an organic relationship, and provides a toothed belt that can transmit high loads and prevent belt jumping, and a drive device using the same. The purpose is to

(Means for Solving the Problems) That is, the toothed belt characterized by the present invention has a tensile member embedded on the pitch line of the belt body and a tensile member disposed at a constant pitch on the land line of the belt body. , the belt tooth portion is formed by a belt tooth root portion, a power transmission region, and a belt tooth tip portion, and the power transmission region of the belt tooth portion and the belt tooth tip portion are located between a belt pitch line and a land line, It is formed as a part of an arc having a center point at a position about 1/2 of the belt tooth width W from the center cotton of the belt tooth portion, and having a radius of the curve approximately equal to the belt tooth width W.

Further, in the toothed belt driving device of the present invention, the toothed belt has a tensile member embedded on the pitch line of the belt body and belt teeth arranged at a constant pitch on the belt body, and the belt teeth are arranged on the belt body at a constant pitch. Consisting of a tooth root, a power transmission area, and a belt tooth root, the power transmission area of the tooth and the belt tooth tip are between the belt pitch line and the land line, and from the center cotton of the belt tooth, the belt tooth width is It is formed from a part of a circular arc having a center point at a position 1/2 width of W and having a curve radius RB approximately equal to the belt tooth width W, and the pulley that meshes with this is similar to the belt tooth portion. The belt has a pulley groove shaped like this, and when the belt and the pulley engage, the backlash between the belt tooth and the pulley groove wall is made almost uniform from the power transmission area of the belt tooth to the root of the belt tooth. It is characterized by

(Function) According to the toothed belt of the present invention and the drive device using the same, the center point of the circular arc forming the power transmission region of the belt tooth portion and the belt tooth tip portion is located between the pitch line and the land line of the belt. Since it is located approximately 1/2 of the belt tooth width W from the center cotton of the belt tooth, the belt tooth is located at a distance of approximately 1/2 of the belt tooth width W from the center cotton of the belt tooth, so even if the tooth width W is the same, the belt tooth is located on the pitch line of the belt. The belt itself is larger, which makes it able to adequately handle high-load transmission, and the inclination of the power transmission area of the belt teeth is larger than before, improving torque transmission performance. It also improves grip strength.

(Example) Next, specific examples of a toothed belt and a drive device using the same according to the present invention will be described with reference to the drawings.

FIG. 1 is a front view of the teeth of a toothed belt according to the present invention, FIG. 2 is a front view of the groove of a pulley used in the device of the present invention, and FIG. 3 is a front view of the toothed belt and pulley in the device of the present invention. FIG.

As shown in FIG. 1, the toothed belt (1) used in the present invention has a belt main body (2) made of a rubber-like elastic material such as rubber or synthetic resin, and the belt land of the belt main body (2). On the line (6), teeth (3) and belt grooves (4) are formed alternately at a constant pitch (P), and on the belt pitch line (5), a thin material such as glass fiber or aramid fiber is formed. A tensile rope with high elongation and strength is buried. Further, the inner circumferential surface of the belt constituted by the tooth portion (3) and the belt groove portion (4) is entirely covered with a cover canvas (not shown) if necessary.

In FIG. 1, the belt teeth (3) are symmetrical with respect to the center line (1) of the teeth (3), and the side walls of the belt teeth that form part of the inner peripheral surface of the belt are aligned with the belt land line. (6)
A belt root part (8) extending from the side wall, and a power transmission area (9) from a starting point S to an ending point F (described later) located in the middle part of the side wall.
It is composed of a region connected to the belt tooth tip (10).

First, the belt tooth root (8) is formed by a part of an arc of radius (RA) having a center point (11) in the belt groove (4), and the power transmission area (9) and the belt tooth tip ( 1
0) is between the belt land line (6) and the belt pitch line (5), and is located at the center of the tooth portion (3).
From (1), it is formed by a part of a circular arc with a radius of curvature (Ra) having a center point (12) at a position approximately 1/2 the tooth width (W) of the belt teeth, and the belt tooth tip. Part (10
) has a center point (13) inside the belt teeth (3).
The connection portion between the power transmission region (9) and the belt root portion (8) is formed by a portion of a circular arc with a radius of curvature (Rc) having The connection with section (10) is indicated by end point F. The leading edge (14) of the belt tooth tip (10) is formed with a surface parallel to the belt land line (6).

The end point F is located at a distance of about 1/2 of the height HB of the belt teeth from the land line (6) of the belt, and the start point S is located at a distance HB of the belt teeth from the belt land line (6). It is located about 1/4 of the way away.

In particular, the center point (12) of the radius of curvature (RB) in the power transmission region (9) of the belt teeth (3) is between the belt pitch line (5) and the belt land line (6),
Moreover, it is located above the belt tooth base (8).

To explain this component in more detail, the center point (12) (1
2) has a belt tooth width W, and the center point (12
) and the Bertrand line (6) is 10 of the PLD value (distance between the belt pitch line and the Bertrand line).
This corresponds to a range of ~90%.

At the same time, the radius of curvature R in the power transmission region (9)
The size of B is approximately equal to the distance W between the center points (12) (12).

Furthermore, the rising angle of the power transmission region (9), that is, the straight line connecting the start point (S) and the end point (F) of this region and the belt tooth portion (
The intersection angle (α) of 3) with the center line (1) is 10 to 18°
, more preferably 12 to 16 degrees.

On the other hand, the button 1 which engages with the toothed belt (1) 15)
As shown in Fig. 2, the pulley teeth (16)
The tooth tip (18
) and a tooth tip surface portion (19) formed by a convex curve,
In addition, the pulley groove (20) adjacent to the pulley teeth (16) is located between the pitch line (5) of the toothed belt and the belt land line (6) when the main pulley and the toothed belt (1) mesh with each other.
) and above the pulley tooth tip surface (19) (same as the Bertrand line).
) and a part of the arc of radius re (where R6>r) having a center point (23) in the pulley groove (20). a pulley groove bottom (2) having a convex curve connecting a pair of left and right groove corners (24) and a pulley groove corner (24) having a concave curve continuous with the groove wall (22);
5).

When the toothed belt (1) having round teeth having the above configuration is suspended on a pulley (15), and the teeth (3) of the belt are meshed with the pulley groove (20) as shown in Fig. 3. , the center point (2) forming the groove wall (22) of the pulley groove (20)
1) and the center point (12) for forming the power transmission region (9) and the belt tooth tip (10) of the belt tooth portion (3) almost coincide with each other, and the groove wall (22) and the power transmission region (9
) between each radius of curvature rb and RB, r, ≧RB
There is a relationship between Therefore, in the drive device according to the present invention,
Uniform backlash (B) exists between the pulley grooves (20) in which the belt teeth (3) engage. Here, rb is 0.005 to 1.010 times as large as RB.

That is, the belt tooth base (8) and the tooth tips of the pulley teeth (
18) and shift the center points (11) and (17) of the circular arcs forming
By setting the relational expression A≧r, the backlash f+1 of the belt root (8) can be reduced or RA
(By setting the relational expression of ra, the belt tooth base (+
3) and the pulley tooth tip (18).

Also, belt power transmission area (9), belt tooth tip (10)
and the center points (12) and (21) of the arcs forming the groove wall (22) of the pulley groove (20), and set the relational expression Rs>rb between the respective radii RB and r. By doing so, the backlash (1t) of the power transmission area (9) between the pulley groove and the belt teeth and the belt tooth tip (10) can be made uniform over the entire area.

Furthermore, the belt tooth tip (10) and the pulley groove (20)
) the center point (13) of the arc forming the groove corner (24);
(23) and the respective radii Rc and r.

By setting the relational expression R6>rc between them, the backlash amount of the belt tooth tip (10) can be desirably maximized with force.

Height I(B) of the belt tooth portion (3) of the toothed belt (1)
is equal to or larger than the depth DP of the groove (20) of the pulley (I5), and the belt teeth are placed on the bottom surface of the pulley groove (20).
5) is compressed and engaged. The height HB of the belt tooth portion (3) is set to be larger than the depth DP of the pulley groove portion (20) by about 10% at most, but preferably about 3%.

As a result, when the belt starts driving, RA≧r,
When the relationship RA(rI) is set, the belt does not move significantly, and when the relationship RA(rI) is set, the pulley tooth tips rotate without interfering with the belt teeth.

The power transmission region (9) of the belt tooth portion efficiently contacts the wall portion (22) of the pulley groove over a wide area without being subjected to local distortion, and furthermore, the curved surface of this power transmission region (9) The relatively large angle of inclination enables high load transmission. Further, since the gripping force in the southern part of the belt is increased, the belt jumping phenomenon is prevented from occurring, and furthermore, the belt tooth tip (10) meshes with the pulley that interferes with the groove wall (22) of the pulley groove.

(Effects) As described above, in the toothed belt of the present invention and the drive device using the same, the power transmission region of the belt tooth portion and the belt tooth tip portion are located between the belt pitch line and the belt land line, and the belt tooth portion is located between the belt pitch line and the belt land line. Belt tooth width medium W from center cotton 1
Since the center point is approximately 1/2 away from the belt and the radius of the curve is approximately equal to W, the belt dentition itself is larger than the conventional belt dentition and has a high height. Load transmission can be adequately coped with, and since the inclination angle of the power transmission region of the belt teeth is set to be relatively large, torque transmission and gripping force of the belt teeth are improved.

Furthermore, since the backlash between the southern part of the belt and the pulley groove wall is uniform in the power transmission area of the belt teeth and the tip of the belt teeth, the power transmission area of the belt teeth is close to the pulley groove wall and the entire surface when the belt is driven. As a result, the above-mentioned performance of torque transmission to the pulley by 4° and the gripping force of the belt teeth are improved, which has the effect of suppressing the belt jumping phenomenon A (which tends to occur when the belt runs).

[Brief explanation of the drawing]

FIG. 1 is a front view of the pulley groove of the pulley used in the device of the present invention, FIG. 2 is a front view of the toothed portion of the toothed belt of the present invention, and FIG. 3 is the toothed belt of the device of the present invention. FIG. 3 is a front view showing the meshing state of the teeth and the pulley. (1)...Toothed belt (3)...Belt tooth section (5)...Belt pitch line (6)...Belt land line (8)...Belt tooth base (9)... (10)... Belt tooth tips (12), (15)...
Pulley (20)/(21)...center point
(22)・(1)・・・Center line of belt teeth (B)・・・Backlash patent applicant Mitsuboshi Belting Co., Ltd.・Power transmission area・Center point・Pulley groove・Groove wall (2 )... Belt body procedure amendment (voluntary) 1. Display of the case 1986 Patent Application No. 335908 2 Name of the invention Toothed belt and drive device using the same 3 Person making the amendment Relationship to the case Patent applicant address 4-1-21 Hamazoe-dori, Nagata-ku, Kobe Spontaneous amendment No. 5, “Claims” column and “Detailed description of the invention” column 6 of the specification subject to amendment, contents of the amendment (1) The statement of the claims of the specification as shown in the attached sheet. Correct to. (2) Correct rRAMJ on page 4, line 6 of the specification to rRMAJ. (3) "Curve radius" on page 8, line 14 of the specification is corrected to "curvature radius." (4) "Curve radius" in lines 4 and 5 on page 9 of the specification is corrected to "radius of curvature." (5) Correct "approximately 1/2 of height H," in line 9 of page 12 of the specification to "approximately 2/3 of height H, at most." (6) "Approximately 1/4" on page 12, line 11 of the specification is corrected to "approximately 1/4 at most." (7) rO,005J on page 15, line 1 of the specification is rl,
Corrected to 005J. (8) In the first line of page 17 of the specification, "will interfere" is amended to "without interference." Attachment 2, Claim 1, a tensile body embedded on the pitch line of the belt body,
The belt body has belt teeth arranged at a partial pitch on the land line of the belt body, and the belt teeth are divided into a belt tooth base, a power transmission area, and a belt tooth tip, and the belt teeth transmit the power of the belt teeth. The transmission region and the belt tooth tip are located between the belt pitch line and the land line, and have a center point at a position approximately 1/2 of the belt tooth width W from the center line of the belt tooth, and the belt tooth width W is A toothed belt characterized by being formed from a part of a circular arc having a radius of curvature approximately equal to . 2. The power transmission area of the belt teeth has a starting point at a distance of approximately 1/4 of the belt tooth height Ha from the belt land line, and is located at a distance of approximately 1/4 of the belt tooth height Ha from the belt land line. The toothed belt according to claim 1, which is located in an area whose end point is approximately /8 away from the toothed belt. 3. The intersection angle (α) between the straight line connecting the start and end points of the power transmission area of the belt teeth and the center line of the belt teeth is 10 to 1.
The toothed belt according to claim 1, which has an angle of 8°. 4. The distance from the center point of the circular arc surface forming the power transmission area of the belt teeth and the tip of the belt teeth to the belt land line is 10 to 90 of the PLD value, which is the distance between the belt pitch line and the belt land line. The toothed belt according to claim 1, which corresponds to the range of %. 5. The toothed belt has a tensile member embedded on the pitch line of the belt body and a belt tooth portion disposed at a partial pitch on the land line of the belt body, and the belt tooth portion is a belt tooth root portion, It is divided into a power transmission area and a belt tooth tip, and the power transmission area of the tooth and the belt tooth tip are located between the belt pitch line and the land line, and 1/1 of the belt tooth width W from the center line of the belt tooth. The center point is located about 2 degrees away,
The pulley that is formed from a part of a circular arc having a radius of curvature RB that is approximately equal to the belt tooth width W and that fits therein has a pulley groove portion that has a shape similar to the belt tooth portion, and the belt and pulley are connected to each other. A drive device for a toothed belt, characterized in that the backlash between the belt teeth and the pulley groove is substantially uniform from the power transmission area of the belt teeth to the tip of the belt teeth during meshing. 6. The pulley that fits into the toothed belt has a pulley groove wall located at approximately the same position as the center point of the curvature half @RB that forms the power transmission area of the belt tooth portion and the circular arc of the belt tooth tip portion;
The toothed belt drive device according to claim 5, which is formed from a circular arc having a radius of curvature rb larger than RB.

Claims (1)

[Claims] 1. A tensile member embedded on the pitch line of the belt body;
The belt has teeth disposed at a constant pitch on the land line of the belt body, and the belt teeth are divided into a belt tooth base, a power transmission area, and a belt tooth tip, and the belt teeth transmit power. The area and the belt tooth tip are located between the belt pitch line and the land line, and have a center point at a position approximately 1/2 of the belt tooth width W from the center line of the belt tooth, and the belt tooth width is A toothed belt characterized by being formed from a part of a circular arc having a curve radius approximately equal to W. 2. The power transmission area of the belt tooth section starts from a place approximately 1/4 of the belt tooth height H_B from the belt land line, and also from the belt land line to the belt tooth height H_B.
The toothed belt according to claim 1, wherein the toothed belt is located in an area whose end point is approximately 1/2 away from _B. 3. The intersection angle (α) between the straight line connecting the start and end points of the power transmission area of the belt teeth and the center line of the belt teeth is 10 to 1.
The toothed belt according to claim 1, characterized in that the angle is 8°. 4. The distance from the center point of the circular arc surface forming the power transmission area of the belt teeth and the tip of the belt teeth to the belt land line is 10 to 90 of the PLD value, which is the distance between the belt pitch line and the belt land line. The toothed belt according to claim 1, characterized in that the toothed belt corresponds to a range of %. 5. The toothed belt has a tensile member embedded on the pitch line of the belt body and a belt tooth portion arranged at a constant pitch on the land line of the belt body, and the belt tooth portion is the belt tooth root portion, the power source It is divided into a transmission area and a belt tooth tip, and the power transmission area of the tooth and the belt tooth tip are between the belt pitch line and the land line, and 1/2 of the belt tooth width W from the center line of the belt tooth. The center point is located at a certain distance,
The pulley is formed from a part of a circular arc having a curve radius R_B approximately equal to the belt tooth width W, and the pulley that fits therein has a pulley groove portion having a shape similar to the belt tooth portion;
A drive device for a toothed belt, characterized in that when the belt and the pulley engage, backlash between the belt teeth and the pulley groove is made substantially uniform from the power transmission area of the belt teeth to the tip of the belt teeth. 6. The pulley that fits into the toothed belt has a pulley groove wall located at approximately the same position as the center point of the radius of curvature R_B that forms the power transmission area of the belt teeth and the circular arc of the tip of the belt teeth, and The toothed belt drive device according to claim 5, which is formed from a circular arc having a radius of curvature r_b larger than R_B.