JPH0532669Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to improvements in fluid couplings used in overhead traveling cranes, swing devices, trolley drive devices, and the like.

(b) Prior art As a fluid coupling using a viscous fluid, for example, as in JP-A No. 58-152941 "Fluid coupling", an input shaft connected to a drive power source and the input shaft are surrounded so as to be relatively rotatable. It consists of a rotary casing in a closed state filled with viscous fluid inside, and an output shaft connection part provided coaxially with the input shaft on the output side of the casing, and a plurality of drive plates are arranged on the outer peripheral surface of the input shaft. The disks are provided to be slidable in the axial direction at appropriate intervals, and donut-shaped driven disks are provided on the inner circumferential surface of the casing to alternately overlap the plurality of driving disks at slight intervals in the axial direction. Further, on the output side of the casing, there is a tapered surface 15 for generating a pressing force in the axial direction using a steel ball 8.
is provided, and the centrifugal force during rotation causes the steel ball 8 to move toward the outer periphery and apply a pressing force to the driven disk along the tapered surface 15, thereby reducing the distance between the disks and preventing a decrease in the transmitted torque. things are known (see Figure 5).

In addition, the inventor of the present application has previously filed a "fluid coupling" filed on June 9, 1985, in which a driven disk and a driving disk are provided so as to be slidable in the axial direction, and the adjacent A metal member having a shape memory effect that has been subjected to shape memory heat treatment in a coil spring shape so as to harden at a desired temperature between the driving discs, and a spacer that maintains a gap between the driven discs are disposed, and the fluid coupling is activated. When the fluid filled inside reaches the desired temperature, the metal member disposed between the driven disks hardens, the coil length of the coil spring is shortened, and its tensile force reduces the gap between adjacent driven disks. is reduced to the size of the spacer, which prevents the transmission torque from decreasing.

In such a fluid coupling, the transmission torque transmitted to the output shaft is Tb, the torque applied to the input shaft is Ta, and the rotational speed of the input shaft and output shaft is na, respectively.
nb, the gap between the driving disk and the driven disk is δ, and the viscosity coefficient of the fluid is μ, then Tb=C・μ(na−nb)/δ (first equation). (Here, C is a constant determined from design factors other than those mentioned above.) As can be seen from the first equation above, the torque Tb transmitted to the output shaft depends on the rotation speed na of the input shaft and the rotation speed nb of the output shaft. is proportional to the difference between From this, compared to a fluid coupling that uses centrifugal force, where the transmitted torque Tb is proportional to the square of the rotation speed na of the input shaft, there is less shock at startup, and torque is transmitted even when the output shaft of the drive power source is stopped. This allows the driven object to coast for a short time until it comes to a stop, and when a brake motor or the like is used as the drive power source, braking force can also be transmitted.

C. Problem to be solved by the invention Although the viscosity coefficient μ of a fluid generally decreases as its temperature rises, since the gap δ remains constant, the torque Tb transmitted to the output shaft decreases as the fluid temperature increases. Put it away. For example, if the transmission torque Tb at 25°C is 1, this reduction amount is 80°C.
This was a problem that could not be ignored, both in terms of energy efficiency and in driving sensations such as changes in coasting distance.

In addition, in the case of the "fluid coupling" of the previous application, which was developed to improve the above-mentioned problems, although it is possible to adjust the transmission torque when driving the fluid coupling, when stopping, it is possible to adjust the transmission torque at startup or when braking. It was impossible to keep the brake force adjusted.

Therefore, when the temperature of the fluid is low, the transmitted torque is large, and during startup or braking, the trolley, overhead crane, etc. may suddenly start or stop, which may cause the load to swing or collapse. Ta. Conversely, when the temperature of the fluid is high, the transmitted torque is small and there is less shock during startup and braking, but
Acceleration and deceleration are slow, reducing work efficiency, and when braking, the trolley, overhead crane, etc. has a longer travel distance, does not stop at the desired position, collides with the safety stopper, and loads may collide with other equipment. There was a risk of him colliding with the wall.

D. Means for solving the problem In view of the above-mentioned problems with the conventional fluid coupling, the fluid coupling of the present invention is capable of adjusting the transmission torque at startup and the braking force at braking when the fluid coupling is not driven. It consists of an eccentric cam plate that is pivoted at a position facing the pressing ball on the outside of the side surface of the casing, and an eccentric cam plate that comes into contact with the outer peripheral surface of the pressing ball and is pressed against the outer peripheral edge of the eccentric cam plate by the biasing force of a spring. A pressurizing shaft is provided in contact with the pressurizing shaft, and a pressurizing means is provided which presses the press ball in the direction of increasing the pressing force by rotating the eccentric cam plate.

Note that here, the direction of increasing pressing force indicates a direction in which the gap between each disk is reduced, that is, a direction having a vector perpendicular to each disk.

E. Effect When the fluid coupling is not driven, by applying an appropriate amount of pressure to the pressing ball in the direction of increasing the pressing force through the rotation of the eccentric cam, the gap between each driven disk can be changed. It is possible to adjust the transmission torque during startup and the braking force during braking.

Example The fluid coupling of the present invention will be explained based on the drawings.

The drawing shows an embodiment of the present invention, which includes a casing consisting of a cylindrical body part 1, side plates 2 and 3 disposed on both sides of the body part, an output shaft connecting part 4, an input shaft 5, and its input shaft. 5, five driven disks 7 attached to the inner peripheral surface of the casing, and four steel balls 8 as pressing balls.

On both sides of the body 1, there are 8 at equal intervals in the radial direction.
Bolt holes 9 are drilled at the locations, and splines 10 are carved all around the inner cylindrical surface.

On the input shaft 5 side, a side plate 2 having a disk shape and a stepped hole 11 through which the input shaft 5 is inserted are formed in the central part, and an oil seal 1 is formed in the stepped portion of the stepped hole 11.
2 are fitted. Further, bolt holes 13 are bored in the outer peripheral portion of the side plate 2 at positions corresponding to the bolt holes 9 of the body 1.

The side plate 3 has a disk shape, and an output shaft connecting portion 4 protrudes from the center thereof, and furthermore, bolt holes 14 are bored in the outer periphery at positions corresponding to the bolt holes 9 of the body portion 1. .

Inside the outer periphery of the side plate 3, steel ball storage sections 16 surrounded by ribs on three sides are provided at four locations in the radial direction, with the open side facing the outer periphery. A tapered surface 15 having an inclination angle of 45 degrees with respect to the side plate 3 is provided to generate a pressing force on the steel ball 8 in the axial direction by utilizing centrifugal force. This steel ball 8 moves toward the outer circumference due to centrifugal force, applies a pressing force to the driven disk 7 along the tapered surface 15, shortens the overall distance between the driven disks 7, and increases the transmission efficiency by torque. It is configured as follows.

Further, a box-shaped cam storage section 17 is provided outside the steel ball storage section 16 of the side plate 3, and the inside of the casing and the inside of the cam storage section 17 are communicated through a through hole 18. An eccentric cam plate 19 is housed in a position facing the steel ball 8 in the cam housing 17. The eccentric cam plate 19 is pivotally attached to the cam housing 17 by a cam shaft 20, and can be adjusted from the outside of the cam housing 17. It can be rotated with a knob 21. A pressure shaft 22 having flanges at both ends is provided passing through the through hole 18, and the eccentric cam plate 1
Between the axial center of the collar of the pressure shaft 22 on the 9 side and the side plate 3,
A coil spring 23 is fitted so that one end of the pressure shaft 22 always comes into contact with the outer peripheral edge of the eccentric cam plate 19, and in this state, the collar at the other end of the pressure shaft 22 comes into contact with the steel ball 8. ing.

Furthermore, oil plug holes are bored at two locations on the outer periphery of the side plate 3, and an oil plug 24 is screwed into the oil plug holes. Further, the output shaft connecting portion 4 is provided with a mounting hole 25 and a keyway 26 into which a connecting shaft (not shown) of a driven object is inserted, and a shaft corresponding to the connecting shaft of the driven object is connected to the mounting hole 25. A set screw hole 27 is formed to maintain the directional position, and a set screw is screwed into this hole. A stop plate 28 is fitted into the bottom of the mounting hole 25 to prevent silicone oil sealed in the casing from leaking out. The body portion 1, side plates 2, and side plates 3 are integrally joined by eight tightening bolts and tightening nuts at bolt holes 9, 13, and 14, as shown in FIG.

The driven disk 7 is donut-shaped and has a spline 29 carved on its outer periphery, which engages with a spline 10 formed on the body 1 of the casing, making it possible to move in the axial direction. There is.

The input shaft 5 has a cylindrical shape with a mounting hole 30 for attaching an output shaft (not shown) of a driving power source having a spline carved therein.The input shaft 5 has a cylindrical shape with a mounting hole 30 for mounting an output shaft (not shown) of a driving power source having a spline carved therein. Matching spline 3
1 is engraved. Further, a spline 32 is carved on the outer surface of the input shaft 5, and a stop plate 33 is coupled to the end surface. Near both ends of the spline 32, there is a retaining ring groove 3 with a constant width around the entire circumference.
5 are respectively engraved, and as will be described later, after the drive disk 6 is fitted, a retaining ring is fitted to prevent the drive disk from coming off.

The drive disk 6 is connected to the spline 32 of the input shaft 5.
A spline 35 is carved to fit into the spline 35, and oil passage holes 36 for flowing silicone oil are bored at a plurality of locations on the same circumference on the outside of the spline 35.

To assemble the above components, first, the side plate 2 is placed on a table with its inner surface facing up, and the body 1 is placed thereon with the bolt holes 9 and 13 concentrically aligned. Furthermore, the input shaft 5 fitted with the retaining ring on the retaining plate 33 side is installed in the center, and the steel ball storage portion 16
One steel ball 8 is placed in each. Thereafter, the splines 29 of the driven disk 7 and the splines 35 of the drive disk 6 are fitted to the splines 10 of the body 1 and the splines 32 of the input shaft 5, respectively, and are fitted alternately.

After fitting the last driven disk 7, a retaining ring is attached to the input shaft 5, the side plates 2 are aligned, and the whole is joined together with a tightening nut. After that, a predetermined amount of silicone oil is injected from the oil plug hole 23, and the oil plug 24 is screwed in.

In the fluid coupling thus assembled, the shaft of the motor, which is the drive power source, is attached to the input shaft attachment hole, and, for example, a crane's traveling wheel shaft is attached to the output shaft connection portion.

When the fluid coupling is not driven, the steel balls 8 are stored in the steel ball storage portion 16, so by operating each adjustment knob 21 and rotating the four eccentric cam plates 19, the pressure shaft 22 is adjusted. The steel ball 8 can be pressurized via. This makes it possible to adjust the gap between each driven disk 7, making it possible to change the transmitted torque during startup and the braking force during braking.

When the fluid coupling is driven, the steel balls gradually press the driven disks using centrifugal force according to the number of rotations of the side plates, thereby reducing the gap between the driven disks.

When the rotational speed of the fluid coupling is reduced and braking is started, the steel balls return to the steel ball storage area and the gap between the driven discs gradually widens, but
Since the eccentric cam plate pressurizes the steel balls in the steel ball housing via the pressurizing shaft, the gap between the driven disks will not widen beyond a certain level, preventing the fluid coupling from stopping suddenly. are doing.

In this embodiment, nothing is interposed between the driven disks, but to prevent the gap between the disks from becoming too narrow and the driven disks from coming into contact with the driving disks, normal coil springs or spacers may be interposed.
As in the "fluid coupling" filed on the same day, a compression coil spring and a spacer made of a shape memory alloy may be inserted between the driven disks to control the gap between the driven disks even after the fluid temperature rises.

In addition, as shown in Figure 3, if steel balls and eccentric cam plates are installed on both the input and output sides so that pressure is applied from both sides, the pressure applied to the lateral driven discs can be reduced by half. The pressure applied to the eccentric cam plate, pressurizing shaft, etc. is also halved, extending the life of each component and making it possible to pressurize the driven disk more reliably.

Furthermore, as shown in FIG. 4, instead of using the eccentric cam plate, the steel ball may be pressurized by screwing bolts 37 into the side plates. However, in this case, use nut 3 to prevent loosening.
8 is recommended.

G. Effect When the fluid coupling is not driven, if the pressing ball is appropriately pressurized by the pressurizing means, the pressing ball is pressed in a direction that reduces the gap between each disk, so the gap between the disks is reduced, and in addition, the pressing ball By making the pressing force variable using the eccentric cam plate, the gap between each disk can be changed as appropriate, and the transmitted torque at startup and the braking force at rest can be appropriately adjusted. Therefore, by appropriately pressurizing the pressure ball in accordance with the rotation speed of the input shaft, torque at startup and braking force at braking can be reliably transmitted, so that the bogies and overhead cranes are prevented from swinging or loading during startup. It does not cause collapse, does not extend the running distance during braking, and makes it possible to reliably stop trolleys, overhead cranes, etc. in the specified position.
It has excellent practical effects.

[Brief explanation of the drawing]

The drawings show an embodiment of the fluid coupling according to the present invention. Fig. 1 is a sectional view taken along line A-A in Fig. 2, Fig. 2 is a left side view of the embodiment, and Fig. 3 is a view of a modified embodiment. FIG. 4 is an explanatory diagram of a modified example of the pressurizing means, and FIG. 5 is an explanatory diagram of a conventional example. 2, 3... Side plate, 5... Input shaft, 6... Drive disk, 7... Driven disk, 8... Steel ball, 16... Steel ball storage section, 17...
...Cam storage section, 19... Eccentric cam plate, 20... Camshaft, 21... Adjustment knob, 22... Pressure shaft, 2
3...Coil spring.

Claims (1)

[Scope of utility model registration request] An input shaft connected to a driving power source, a sealed rotary casing that surrounds the input shaft so as to be relatively rotatable and is filled with a viscous fluid, and a rotary casing provided coaxially with the input shaft on the output side of the casing. A plurality of drive disks are provided on the outer peripheral surface of the input shaft so as to be slidable in the axial direction at appropriate intervals, and the plurality of drive disks are provided on the inner peripheral surface of the casing. Donut-shaped driven disks are provided so as to be able to slide in the axial direction and are alternately overlapped with each other with a slight spacing between them, and the driving disks and the driven disks are moved by pressing balls that move in the radial direction due to centrifugal force during rotation. In this fluid coupling, an eccentric cam plate is pivoted at a position opposite to the pressing ball on the outside of the side surface of the casing, and an outer periphery of the pressing ball is provided. a pressing shaft that contacts the outer peripheral edge of the eccentric cam plate by the biasing force of a spring, and presses the pressing ball in the direction of increasing the pressing force by rotation of the eccentric cam plate. A fluid coupling characterized by being provided with a pressure means.