JPH05155568A - Drive sheave for elevator - Google Patents

Abstract

PURPOSE:To provide an elevator drive sheave in which increase in traction ability resulting from the wear of a drive sheave driving face is restrained. CONSTITUTION:A driving face 14 is formed by a first groove 12 of V-shaped cross section opened in the cylindrical face of a drive sheave 1 and by a second groove 15 open to the curved portion 11 of the first groove 12 and having a narrow near-bottom portion. The driving face 14 has its angle of contact with the upper side of a main rope 3 increased by the wear of the first groove 12 and has its angle of contact with the lower side of the main rope 3 decreased by the inclination of the side wall 16 of the second groove 15. Thereby the traction ability of the main rope 3 displaced downward by the wear of the driving face 14 is restrained from increasing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elevator drive sheave for frictionally driving a wound main rope.

[0002]

2. Description of the Related Art FIG. 3 and FIG.
It is a figure which shows the conventional drive sheave for elevators shown by 33562. In the figure, (1) is a drive sheave of a hoisting machine (not shown), which is open to the cylindrical surface and curved toward the bottom.
A first groove (12) having a V-shaped cross section and having a (11) formed therein, and a second groove (13) having a side wall formed in parallel with the curved portion (11) and opening.
Is provided with a drive surface (14). (2) is a drive sheave
Baffle wheel installed near (1), (3) drive sheave (1)
The main surface of the elevator wound around the drive surface (14) and the deflecting vehicle (2), (4) is a car suspended at one end of the main rope (3),
(5) is a counterweight suspended from the other end of the main rope (3).

The conventional elevator drive sheave is constructed as described above, and the counterweight (5) is arranged at a proper position in the horizontal direction with respect to the car (4) by the deflector (2). Also,
The main rope (3) is wound around the drive surface (14) in contact with the curved portion (11), that is, in contact with a portion of the angle A shown in FIG. 4 excluding the angle B, and as shown in FIG. It is wound around the drive sheave (1) at an angle θ. When the hoisting machine is energized, the drive sheave (1) rotates and the main rope (3) is driven by friction, and the car (4) and the counterweight (5) move up and down in opposite directions. To do. The transmission capacity of the driving force in this case is called the traction capacity and is represented by the following equation.

[0004]

[Equation 1] Where e: base of natural logarithm μ: coefficient of friction between main rope (3) and drive surface (14) K: shape coefficient of drive surface (14) θ: drive sheave (1) of main rope (3) Wrap angle (ra
d.) A: Contact angle of the main rope (3) to the upper side of the first groove (12) B: Contact angle of the opening of the second groove (15) with the main rope (3)

Further, the traction ability is designed by the following equation.

[0006]

[Equation 2] Where e: base of natural logarithm μ: coefficient of friction between main rope (3) and drive surface (14) K: shape coefficient of drive surface (14) θ: drive sheave (1) of main rope (3) Wrap angle (ra
d.) T ₁ : Tension on the car (4) side of the main rope (3) T ₂ : Tension on the counterweight (5) side of the main rope (3) L: Rated load of the elevator W: On the car (4) Own weight g: Elevator operating acceleration

In the drive surface 14 designed as described above, the first groove 12 is worn and the angle A in FIG. 4 increases as the elevator runs. Since the side walls of the second groove (13) are parallel to each other, the angle B is constant and the main rope (3)
The wedge action of the is increased and the traction ability is gradually increased.
Also, although the increase of the angle A can be considered up to 180 °,
Due to the vibration of the main rope (3) and the fact that the main rope (3) is wound while being inclined, it actually reaches about 170 °. Then, the angle B90 in FIG. 4 which is a typical shape of the driving surface (14)
When the initial value of the angle A is 140 °, the traction ability is increased by 14%.

[0008]

In the conventional elevator drive sheave as described above, an increase in traction capacity due to wear of the drive surface (14) is preferable for the function of the drive sheave (1), but on the other hand , An excessive braking force acts during abnormal braking operation that exceeds the traction ability. Because of this, the basket
(4) There was a problem that it may give an impact to passengers inside and cause an accident. In the above formula, as a general elevator, the coefficient of friction is 0.1, the shape factor of the drive surface (14) is 1.18, the angle of the main rope (3) is 150 °, and the balance with the car (4) side. Set the conditions of a tension ratio of the main rope (3) of the weight (5) of 1.31 and an operating acceleration of the elevator of 0.1G. In such a case, when the tension of the main rope (3) on the car (4) side is larger than the tension of the main rope (3) of the counterweight (5), the braking impact when the car (4) descends Is about 0.13 G, and the braking impact when the counterweight (5) descends is about 0.38 G.

The present invention has been made to solve the above problems, and an object thereof is to obtain an elevator drive sheave in which the traction capacity is not significantly increased due to wear of the drive surface of the drive sheave.

[0010]

In the elevator sheave for elevator according to the present invention, a first groove having a V-shaped cross section and having a curved portion formed on the cylindrical surface of the sheave is formed. A drive surface is provided which is formed in the curved portion of the first groove and includes a second groove which is narrowed toward the bottom and has a narrow width.

[0011]

The drive surface of the elevator drive sheave constructed as described above has an increase in the angle A shown in FIG. 4 due to the wear of the first groove, while the side surface of the second groove is inclined as shown in FIG. The angle B decreases.

[0012]

1 and 2 are views showing an embodiment of the present invention, in which the same symbols as those in FIGS. 3 and 4 indicate the corresponding parts, and (15) indicates the first groove (12). Angle B shown in FIG.
A second groove having a side wall (16) that is formed to have a narrow width near the bottom and has an inclined side wall (16), and the first groove (12) and the second groove (1).
The drive surface consisting of 5), and (31) is the main rope in contact with the worn drive surface (14). The angle B of the opening of the second groove (15) shown in FIG. 1 in the initial stage is as shown in FIG. 1 of the second groove (15) at the main rope (31) position at the limit of use due to wear of the drive surface (14). It becomes larger than the opening angle B ₁ shown in.

In the elevator drive sheave constructed as described above, the main rope (3) gradually descends according to the wear depth H in FIG. 1 as the drive surface (14) wears. As a result, the angle A in FIG. 1 increases and reaches about 170 ° as described above. However, the angle B ₁ gradually decreases because the side wall 16 is inclined. Therefore, the increase in the wedge action of the lowered main rope (31) is small, and the increase in the traction ability is suppressed. Therefore, an excessive braking force does not act during an abnormal braking operation that exceeds the traction ability, and it is possible to prevent an accident from occurring due to the impact of passengers in the car (4).

The typical shape of the driving surface 14 will be described below. That is, in FIG. 2, the drive surface (14)
The degree of change in each value of the angle A when the wear occurs is shown. And, the condition is that the diameter of the main rope (3) is 12 mm, the first groove (1
The angle A140 ° of the upper end of the curved portion (11) of 2) (the angle D at which the opening of the first groove (12) is a vertical line is 20 °), the second groove (1
5) Assuming that the opening angle B is 90 °, in this case the driving surface
Angle A as wear of (14) progresses about 0.5 mm
Is increased by 10 °, the angle B is narrowed by about 5 ° in order to keep the shape factor K constant. In other words,
As the drive surface (14) wears 0.5 mm, the width of the opening of the second groove (15) becomes about the angle E of the side wall (16) shown in FIG.
At 1.8 °, it narrows by about 0.4 mm. In this way, the shape factor K can be kept substantially constant even if the drive surface 14 is worn. It should be noted that at the limit of use due to wear of the drive surface (14), an opening angle D _{1 of} the first groove (12) with respect to the vertical is formed as shown in FIG.

Although detailed description is omitted, when the extremely deep second groove (15) is provided, the side wall (16) is inclined only near the opening of the second groove (15), and the angle A1 is about 1. Even if the side walls that are deeper than the 170 ° position are formed with side walls parallel to each other, the same operation as in the first embodiment can be obtained. Also, drive surface (1
4) Various shapes are conceivable, but the following basic requirements can be set. That is, the shape required for the traction ability is the initial state when the shape factor of the drive surface (14) is the smallest. And the initial groove shape is the curved part (11)
Wear increases the contact angle to about 170 °,
After that, it becomes a constant value regardless of wear. Therefore, when the width of the second groove (15) retracted from the curved portion (11) is about 170
Make the depth range of ° deep and make parallel grooves. With this, it is possible to obtain the same operation as that of the first embodiment.

[0016]

As described above, according to the present invention, the first groove having the V-shaped cross section and opening to the cylindrical surface of the drive sheave and the curved portion formed at the bottom, and the curved portion of the first groove are provided. The driving surface is formed by a second groove that is opened and has a width closer to the bottom than the opening. As a result, the contact angle of the drive surface with the upper side of the main rope increases due to the wear of the first groove, and the contact angle with the lower side of the main rope decreases due to the inclination of the side wall of the second groove. Therefore, the increase in the traction ability of the main rope displaced to the lower side of the drive surface due to the wear of the drive surface is suppressed. Therefore, the generation of excessive braking force that acts during abnormal braking that exceeds the traction capacity is suppressed,
The impact of the braking force on the passengers in the car is reduced, which has the effect of preventing an accident from occurring.

[Brief description of drawings]

FIG. 1 is an enlarged view of an essential lateral second groove surface of a drive sheave according to an embodiment of the present invention.

FIG. 2 is a curve diagram showing the degree of change of each value such as the shape coefficient corresponding to FIG.

FIG. 3 is a conceptual configuration diagram of a traction drive by an elevator device.

FIG. 4 is a view corresponding to FIG. 1 showing a conventional elevator drive sheave.

[Explanation of symbols]

 1 Drive Sheave 3 Main Rope 11 Bending Part 12 First Groove 14 Drive Surface 15 Second Groove

Claims (1)

[Claims] 1. A first groove having a V-shaped cross section and having an opening in a cylindrical surface of a drive sheave and having a curved portion formed near the bottom portion, and an opening portion formed in the curved portion so that the opening portion is formed near the bottom portion. A drive sheave for an elevator, which comprises a second groove formed to be narrower than the portion and has a drive surface that frictionally drives the main ropes of the wound elevator.