JPS6235551B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a friction plate type speed reducer that controls a friction clutch so as to obtain a steplessly decelerated rotation output from a constant speed rotation input source.

Conventionally, a friction plate clutch using a hydraulic friction plate, or a friction plate clutch that applies slip to the friction plate to reduce the rotation from a constant rotation input shaft and transmit the power, is stacked as a method of engaging the friction plate of a power transmission device. Pressure is applied to the pressure plate in contact with the end friction plate, which pressurizes the friction plate.
As a method of applying this pressure, a hydraulic cylinder is constructed in the device, and the cylinder or piston member of the hydraulic cylinder is brought into direct, indirect, or pressure contact with the pressing plate, and when the friction plate engages with the hydraulic cylinder, There are types in which the hydraulic cylinders rotate together, and types in which the hydraulic cylinders are fixed. In the former case, a hydraulic cylinder is configured on the shaft that transmits power and the hydraulic cylinder is supported on the shaft, but the configuration becomes complicated, the moment of inertia of the rotating shaft increases, and the rotating shaft is also long. In addition, pressure oil must be led to the hydraulic cylinder via a rotating joint that supplies pressure oil from some part, and with a normal rotating joint, the normal pressure is 15
Since it is as low as about Kg/cm ² , the hydraulic cylinder is made large, which further increases the moment of inertia of the rotating shaft.

On the other hand, in the latter case where the pressing force of the friction plate is obtained by a hydraulic cylinder, the hydraulic cylinder is fixed, so the working pressure can be 70 kg/cm ² , which is usually determined from the rating of the hydraulic valve, or it can be changed if necessary. The above hydraulic pressure can be used. When the hydraulic cylinder is fixed and the friction plate is pressed, the friction plate engages and rotates, and also slides on some part, usually the surface of the pressing plate of the friction plate and the end of the piston of the hydraulic cylinder. Therefore, since this part slides under a large thrust, the PV value will also be large. Therefore, a rolling bearing is inserted into this part, but if a rolling bearing is used to transmit a large amount of power, it will generate a lot of noise and a large amount of heat. Also, if no measures are taken, the pressing force must be reduced and the number of friction plates must be increased. In a friction plate type reducer that performs control to reduce speed, it is difficult to control the output rotation speed, and the output rotation speed also becomes unstable.

The present invention is a friction plate type speed reducer that engages friction plates to create a slip between the friction plates to provide an output shaft with a steplessly reduced rotational speed, in which a hydraulic cylinder is fixed and a high output compact device is obtained. The object of the present invention is to provide a friction plate pressing section that can be used as a friction plate.

The present invention connects an input shaft and an output shaft with a friction plate, and fixes a fixed hydraulic cylinder that presses the friction plate fixed to the input shaft and the output shaft in the axial direction to a housing that houses the device on the outer periphery of the output shaft. In a device in which the piston of a hydraulic cylinder is configured to press a pressing plate that presses a friction plate, and the rotation speed of the output shaft is changed by adjusting the hydraulic pressure applied to the hydraulic cylinder and giving slip to the friction plate, the rotation speed of the output shaft is changed. An orifice is provided in the cylinder chamber to guide the pressure oil in the cylinder chamber to a lubricating groove provided on the sliding contact surface between the pressing plate and the piston, thereby increasing the load capacity between the pressing plate and the piston. It is something.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a friction plate type speed reducer of the present invention, and FIG. 2 is a partially enlarged view of FIG. 1.

The input shaft 1 is supported by two rolling bearings 2 on a bearing flange 3.
is attached to the housing 4. A seal cover 5 is attached to the bearing flange 3 and includes a shaft seal portion for preventing oil from leaking from the input shaft 1. An oil stopper plate 6 is fixed to the lower part of the bearing flange 3 so that its upper end reaches the middle of the rolling elements at the bottom of the rolling bearing 2, and the space between it and the outer ring of the rolling bearing 2 acts as an oil stopper when the bearing 2 is stopped. ing. An internal gear 7 is attached to the input shaft 1 by bolts 8 so as to transmit rotation of the input shaft 1.

The output shaft 9 is supported by being fitted into inner rings of a rolling bearing 10 housed in a bearing flange 11 fixed to the housing 4 and a rolling bearing 12 fitted into the input shaft 1. A seal cover 13 for sealing the output shaft 9 is attached to the bearing flange 11. A disc 14 is fitted into the bearing flange 11 in contact with the rolling bearing 10 so as to fix the rolling bearing 10 in the axial direction and to retain oil when stopped.
It is locked by a retaining ring 15 for the hole. Similarly, the rolling bearing 12 is also fixed by a disc 16 or a retaining ring 17, and an oil reservoir is also provided.

A gear 18 is fixed to the right side of the output shaft 9 by a set screw 19, and an electromagnetic rotation detector 20 whose sensing piece is the outer periphery of the gear 18 is mounted on the seal cover 13.
is screwed in and detects the rotation speed using an electrical signal. Further, the cover 21 is fixed to the seal cover 13 to prevent foreign matter from entering the rotation detection chamber 22 from the outside.

The outer ring of the rolling bearing 23 is fitted into the end of the bearing flange 11, and the inner ring thereof is fitted into the end of the internal gear 7.
An input shaft 1 is supported via an internal gear 7. An oil sump plate 24 is attached to the bearing flange 11 so that its upper end reaches the lower ball of the rolling bearing 23.

As shown in FIG. 2, a sleeve 25 is press-fitted into the bearing flange 11, a piston 26 is fitted into this sleeve 25, and is oil-tightened by sealing rings 27 and 28 fitted into the sleeve 25 so that it can move smoothly in the axial direction. It's getting old. Pin 29 is piston 2
6 from rotating, one end is driven into the bearing flange 11, and the other end is slid into a bush 31 press-fitted into the piston 26. piston 26
A plurality of coil springs 32 are incorporated in the outer periphery of the spring 32, one end of the spring 32 is fitted into the bearing flange 11 and abuts against a disk 34 fixed by a retaining ring 33 for the hole, and the other end is attached to the piston 26. The piston 26 is pressed against the bearing flange 11 when there is no pressure oil in the cylinder chamber 35 or when the pressure is low. Further, an orifice 36 is screwed into the piston 26 to control the amount of oil flowing out from the cylinder chamber 35 to the left.

A plurality of friction plates 37 having powder alloy sintered on both sides and having numerous oil grooves are engaged with the internal gear 7 by the gears on the outer periphery. A mating plate 38, which is a steel plate, is inserted. A gear is cut on the inner periphery of the mating plate 38, and meshes with an external gear cut on the output shaft 9. At the right end of the friction plate portion, which is a combination of the plurality of friction plates 37 and the mating plate 38, a pressing plate 39 formed by cutting an external gear is engaged with the internal gear 7. Furthermore, the sliding plate 41 is attached to the bolt 4 on the pressing plate 39.
It is installed with 2. A piano wire snap ring 43 is fitted into the internal gear 7 to prevent the friction plate from falling off during assembly and disassembly.

Joint flanges 44 and 45 are attached to the housing 4 and serve as an oil connection port with the outside.The joint flange 44 is attached to the upper part and is connected to a hydraulic pipe for controlling the pressing force of the friction plate. That is, the pressure oil passes through the short pipe 46, the oil passage 47 of the bearing flange 11, the oil passage 48 of the sleeve 25, and enters the cylinder chamber 35.
It leads to. The joint flange 45 has the same shape as the joint flange 44 but has a different size, and is attached to the side of the housing 4 at right angles to the plane of the drawing, and a pressure oil pipe for cooling the friction plate is connected here, and the pressure oil is connected to a short pipe (not shown). The cooling oil passage 50 around the output shaft 9 is communicated through a port 49 that passes through the pipe, the bearing flange, and the inside and outside of the sleeve 25 in the radial direction.

The outer side of the output shaft 9 of the cooling oil passage 50 is the output shaft 9
It is sealed by a rotary seal 51 provided for this purpose.

The external gear into which the mating plate 38 at the end of the output shaft 9 is fitted has an oil groove 52 in the axial direction as a primary missing tooth.
An oil passage 53 is provided from the end of the input shaft 1 to communicate between the rolling bearings 2, and an orifice 54 is provided in the oil passage 53.
is screwed in. An oil passage 55 passing through the bearing flange 3 from the space between the seal cover 5 and the rolling bearing 2 is provided.

The pressure oil flowing into the oil groove 52 passes through a number of grooves provided on the surface of the friction plate 37 and returns to the bottom of the housing 4 through the radial hole 56 of the internal gear 7. Rolling bearing 1 from cooling oil passage 50
An oil passage 70 for supplying oil to the bearing flange 11 is provided in the bearing flange 11.

The orifices 36 already described are provided at two equally spaced locations on the circumference of the piston 26, and are inserted into an annular oil groove 58 formed by a small hole 57 in the axial direction following the hole in which the orifice 36 is fitted. I understand. The oil groove 58 may be provided in the sliding plate 41.

An air breather 59 is installed at the top of the housing 4.
is installed to allow ventilation between the inside and outside, preventing internal pressure from increasing due to thermal expansion.

The circuit diagram on the right side of FIG. 1 shows the hydraulic equipment and electrical equipment attached to this machine. Hydraulic pump 60, 61
is driven by an electric motor 62, and oil sucked in from a flange connection port 63 of the housing 4 passes through a filter 64 and is discharged from the hydraulic pumps 60, 61. Pressure oil discharged from the hydraulic pump 60 passes through the oil cooler 65 and flows into the aforementioned cooling oil passage 50 as cooling oil. Valve 66 is a safety valve.
The oil discharged from the hydraulic pump 61 flows through the flow control valve 6.
After passing through 7, it flows into the cylinder chamber 35. Valve 6
Reference numeral 8 maintains the pump discharge pressure constant, and valve 69 is an electromagnetic proportional pressure control valve that controls the pressure in proportion to an electric signal. The amplifier 71 sends an electric signal to the valve 69, and in order to maintain the target output side rotation speed, it compares and determines an externally set electric signal 72 and an electric signal 73 from the electromagnetic rotation detector 20, and then controls the valve 69. It is an operational amplifier that outputs an electrical signal 74.

When the input shaft 1 is driven and rotated by the prime mover, the friction plate 37 engaged with the internal gear 7 rotates at the same speed. The pressure oil led to the cylinder chamber 35 is transferred to the valve 6
9 is controlled and raised, the piston 26 pushes the rotating sliding plate 41, and the friction plate 37 clamps the mating plate 38 via the pressing plate 39, so that the rotational force due to the frictional force is transmitted to the mating plate 38. The mating plate 38 is connected to the output shaft 9, so that rotational force is transmitted to the output shaft 9 and drives the rotary machine connected to the output shaft 9.

The transmission torque T of the friction plate part is the effective radius of the friction surface R, the number of friction surfaces n, the pressing force W, the effective efficiency of the friction surface η, and the friction coefficient μ, then T=μ×R×W×n×η ……( 1). When the driven machine is a fluid machine, the driving torque T is the rotation speed N and the dimensionless coefficient C. Therefore, if the friction plate pressing force W is controlled, the friction plate 37 and the mating plate 38 will slip, making it possible to control the rotational speed of the driven machine. That is, by controlling the hydraulic pressure that presses the piston 26, an arbitrary deceleration can be obtained. When the hydraulic pressure of the hydraulic pump 61 is reduced to a certain value or less by controlling the valve 69, the coil spring 3
The force of 2 causes the piston 26 to move to the right in FIGS. 1 and 2, and since the pressing force of the sliding plate 41 is removed, the friction plate 37 and the mating plate 38 almost completely slide, and the rotation of the output shaft 9 is minimized. Become.

The hydraulic pressure that presses the piston 26 against the sliding plate 41 passes through the orifice 36 and enters the oil groove 5 through the small hole 57.
8 enters the piston 26 and the sliding plate 41 from the oil groove 58.
The pressure oil flows in the radial direction through the sliding surface, and the pressure drops. Pressure oil is discharged against the pressure force between the sliding plate 41 and the end surface of the piston 26, and fluid lubrication can be achieved between them. Since the amount of lubricating oil required is extremely small, piston 2
6 and the sliding plate 41 are preferably in mirror contact so that the amount of oil passing therethrough is small.

As shown in FIG. 2, the outer diameter of the piston 26 at the portion in contact with the sliding plate 41 is R ₁
The inner diameter of the piston 26 and the sliding plate 41 are R ₄ , the outer diameter of the oil groove 58 is R ₂ , and the inner diameter of the oil groove 58 is R ₃ .
The total reaction force due to the pressure distribution of the supply pressure oil between the cylinder chambers 35 and 35 is selected so that the total reaction force is approximately equal to the thrust force of the cylinder chamber 35.

Now, assuming that the supply oil pressure to the cylinder chamber 35 is P and the area of the cylinder chamber 35 is A, the thrust force of the piston 26 is W ₁
is W ₁ =P×A, and the reaction force W ₂ between the sliding plate 41 and the piston 26 is
teeth However, since W ₁ is slightly larger than W _{2 and} W 1 ≈W ₂ , the surface pressure on the sliding surface can be extremely low, and the life of the sliding bearing is long.

These pressure oils are selected to be about 70 kg/cm ² as an example.

The pressure oil discharged from the hydraulic pump 60 has a set pressure of 1 to 2 kg/cm ² for lubrication and cooling.
It is cooled through the oil cooler 65, reaches the joint flange 45, passes through a short pipe, and passes through the port 49 of the sleeve to the cooling oil passage 50 on the outer periphery of the output shaft 9.
reach. This pressure oil flows to the left in FIG. 1, passes through the oil groove 52, lubricates the rolling bearing 12, and has its flow rate adjusted by the orifice 54.
3, the two rolling bearings 2 are lubricated by a crossfeed, and the oil flows down the housing 4 through the oil passage 55, while overflowing from the oil stop plate 6 and flowing down.

The cooling pressure oil that has reached the oil groove 52 flows through the orifice 54.
The pressure drop caused by the orifice 54 is small, and the fluid passes between the friction plate 37 and the mating plate 38 and is discharged through the hole 56 of the internal gear 7. At that time, the oil that has lost some pressure is the internal gear 7.
The oil flows to the right in FIG. 1 through the tooth grooves, lubricates the rolling bearing 23 from the space in front of the disc 34, and flows down through the oil escape hole 75 of the bearing flange 11. On the other hand, the cooling oil that passes through the oil passage 70 from the cooling oil passage 50 and lubricates the rolling bearing 10 flows down through the oil escape hole 76 of the bearing flange 11.

When the friction plate 37 and the mating plate 38 are in a sliding state and the output shaft 9 is rotating at a reduced speed, the friction plate 3 generates heat.
7. It is designed to be taken away by pressure oil passing through the mating plate 38.

As described above, in the friction plate type reducer of the present invention, an oil groove is provided between the piston and the sliding plate that applies a pressing force to the friction plate and the mating plate, and the pressure oil of the piston that presses the sliding plate is supplied to this oil groove. Therefore, it is possible to provide a sliding bearing with a large load capacity and a long life between the piston and the sliding plate while reducing the surface pressure on the sliding surface. An orifice is installed in the oil passage between the piston and the sliding plate, and the sliding surface is precisely finished to reduce leakage.
Since it receives the thrust of the piston, the piston thrust and the reaction force of the sliding part are almost equal, so this state is maintained even if the pressure is changed, and it can be used over a wide range in pressure control to cause the friction plate and the mating plate to slide. supply oil pressure can be changed accordingly. As for the cooling of the friction plate, since it passes through the outer periphery of the rotating shaft, it is easy to guide the oil passage for lubrication of each bearing, and there is no need for a rotating joint or a long hole oil passage passing through the shaft center.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is a partially enlarged view of FIG. 1. 1...Input shaft, 4...Housing, 7...Internal gear, 9...Output shaft, 11...Bearing flange, 2
5... Sleeve, 26... Piston, 27, 28
... Sealing ring, 29 ... Pin, 31 ... Butsuyu,
32...Coil spring, 33...Retaining ring for hole, 34...
...Disc plate, 35...Cylinder chamber, 36...Orifice, 37...Friction plate, 38...Mating plate, 39...
Pressing plate, 41...Sliding plate, 44, 45...Joint flange, 46...Short pipe, 47, 48...Oil passage.

Claims (1)

[Claims] 1. In a friction plate type reducer that reduces rotation of the output end by applying slip between friction plates, the piston and friction are driven by adjusting the oil pressure of a hydraulic cylinder that is fixed to a housing that houses the device and is configured around a rotating shaft. A sliding plate that rotates with the pressing plate of the plate is brought into sliding contact, and an orifice is inserted from the hydraulic cylinder chamber through the piston into either the sliding plate or the piston in the sliding contact area, or into the oil groove provided in the sliding plate and the piston. A friction plate type reducer that guides the operating pressure oil of the piston through the piston.