JPH05126191A - Rotary damper - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To provide a stable damping characteristic of large torque as a rotary damper for vehicles without increasing the size and weight of the device. [Structure] A casing that rotatably supports the input shaft 1 is oil-tightly sealed, and a ring gear 8 centered on the input shaft 1 is formed on the inner circumference of the casing, and a freely rotatable sun gear is provided on the input shaft 1. 17 is provided, and a driven gear 10 that engages with the sun gear 17 with a part of the ring gear 8 serving as a pump case so as to define a plurality of oil chambers 18 in the circumferential direction therebetween, and the ring gear 8 and the sun gear 1 in the oil chamber 18.
The planet gears 20 that mesh with the gears 7 are housed, while the planet carrier 16 that is in sliding contact with one end face of each gear is integrally formed on the input shaft 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a rotary damper that damps oscillating motion.

[0002]

2. Description of the Related Art As a conventional rotary damper, an oil chamber is defined between a vane rotating inside a rotary cylinder and a partition wall, and an orifice is passed through the working oil flowing in and out of the oil chamber as the vane rotates. It is known that resistance is applied to generate a predetermined damping force.

[0003]

By the way, in such a rotary damper, there are many technical problems in securing the oil tightness between the rotary cylinder and the vane, and the hydraulic oil leaks. The generated damping force tends to become unstable.

Further, in order to generate a high damping torque at a low speed rotation, either a pump capacity (displacement) of the oil chamber should be increased, or a gearbox that amplifies the generated damping torque and transmits it to the input shaft. Since it is necessary to provide the device, and the size and weight of the device are increased in any case, there is a problem that it is difficult to put the device into practical use for vehicle mounting (for example, application to a swing arm of a rear wheel of a motorcycle).

[0005]

In order to solve such a problem, the present invention seals the inside of a casing that rotatably supports an input shaft in an oil-tight manner and centers the input shaft on the inner circumference of the casing. A ring gear is formed on the input shaft, and a freely rotatable sun gear is provided on the input shaft. A part of the ring gear is engaged with the sun gear as a pump case so as to define a plurality of oil chambers at equal intervals in the circumferential direction. The driven gear and the planet gear that meshes with the ring gear and the sun gear in the oil chamber are housed, while the planet carrier that is in sliding contact with one end face of each gear is integrally formed on the input shaft.

[0006]

[Operation] Each oil chamber is partitioned by the planet gears in the front and rear of its revolution direction, and when the planet gears revolve around the ring gear as the input shaft rotates, one of the oil chambers is compressed by the movement of the planet gears. Was
The other will expand. At the same time, the planet gear speeds up the rotation of the input shaft and transmits it to the sun gear, so that the hydraulic oil is supplied from the expansion side chamber to the compression side chamber between the adjacent oil chambers by the pump action of the driven gear.

For this reason, the compression side of the oil chamber is further pressurized by the amount of movement of the planet gears and the amount of hydraulic oil supplied from the driven gear, and the pressure is increased by the action of a very large capacity pump. .. This high pressure acts on the effective diameter of the planet gear, directly acting as a load resistance of the input shaft via the carrier, and the load that multiplies the pump capacity by the drive ratio from the driven gear is transmitted to the planet carrier side via the sun gear. It

Since the casing has an oil-tight structure, the pressure oil in each oil chamber eventually leaks to the low pressure side of the oil chamber through a side clearance (a minute gap) such as the planet gear and the sun gear. This leakage flow rate is proportional to the rotation speed of the input shaft, and throttling resistance of the side clearance occurs depending on the flow rate. Therefore, a high level load torque proportional to the rotation speed acts as a damping force on the input shaft. become.

[0009]

1 and 2, reference numeral 1 denotes an input shaft which is connected to a lever (not shown) which swings in response to an input vibration, and which has a shaft hole of a body 2, a side plate 3 and a check valve seat 4. It is rotatably supported in the shaft hole via bearings 5 and 6.

Reference numeral 7 denotes a side flange which forms a casing by sandwiching a ring gear 8 with the body 2, and a bolt 11
It is fastened to the body 2 by.

In order to seal the inside of the casing, the input shaft 1
An oil seal 12 and a dust seal 13 are provided between the ring gear 8 and the body 2, and O-rings 14 and 15 are provided between the ring gear 8 and the body 2 and the side flange 7, respectively.

In the ring gear 8, a driven gear 10 that engages with the sun gear 17 with a part of the inner periphery of the gear 8 serving as a pump case so as to define a plurality of oil chambers 18 at equal intervals in the circumferential direction between the ring gear 8 and a sun gear 17 which will be described later. Is rotatably accommodated through the pin 11.

A sun gear 17 is rotatably supported on the input shaft 1 via a bearing 9, and a planet gear 20 that meshes with the ring gear 8 and the sun gear 17 in an oil chamber 18 is provided.

The planet gear 20 is rotatably supported by a carrier 16 which is spline-fitted with the input shaft 1 via a pin 19, and the ring gear 8 on the fixed side is rotated as the input shaft 1 rotates.
The sun gear 17 is revolved while rotating on top to rotate the sun gear 17 at an increased speed.

Each gear 10, 17, 20 is sandwiched between the carrier 16 and the side plate 3 inside the ring gear 8 and is tightened to the input shaft 1 by the nut 35 via the check valve seat 4 and the bearing 6 with a certain side clearance. ..

The side flange 7 is provided with an oil reservoir chamber 21 for compensating for fluctuations in the amount of oil inside the casing. Oil sump 21
Through the orifice 23 on the plate 22 for partitioning this into the inner chamber 24 of the input shaft 1 and through the passage 25 of the side flange 7 through holes 26a, 26 of the check valve seat 4.
It is connected to b.

The inner chamber 24 of the input shaft 1 is opened at the spline fitting portion of the carrier 16 through a through hole 27, and the sun gear 1
The side leak from 7 is absorbed to prevent the high pressure from acting on the oil seal 12. Reference numeral 29 denotes a foam material as an elastic member that expands and contracts the volume in the oil reservoir chamber 21 according to the fluctuation of the oil amount.

The side plate 3 has ports 30a and 30b opening at both ends in each oil chamber 18, and the planet gear 2
Port 3 whose front-back relationship is the same with respect to the revolution direction of 0
The check valves 32a and 32b are formed with annular grooves 31a and 31b that connect the 0a and 30a, 30b and 30b to each other, and allow suction of hydraulic oil from the through holes 26a and 26b of the check valve seat 4 into the annular grooves 31a and 31b. Is provided. The inside of the casing is filled with hydraulic oil having a specified pressure.

Next, the operation based on such a configuration will be described.

Each oil chamber 18 has a planet gear 20.
When the planet gear 20 revolves on the ring gear 8 while rotating around the input shaft 1 in the direction of the arrow as the input shaft 1 rotates, the planet gear 2
By moving 0, one side 18A in the oil chamber 18 is compressed,
On the other hand, 18B becomes enlarged. At the same time, since the planet gear 20 rotates the sun gear 17 at an increased speed, the hydraulic oil is supplied from the expansion side chamber 18B to the compression side chamber 18A between the adjacent oil chambers 18 by the pump action of the driven gear 10.

Therefore, the compression side 18A of the oil chamber 18 is further pressurized by the amount of movement of the planet gear 20 as well as the amount of hydraulic oil supplied from the driven gear 10, and receives an extremely large capacity pumping action. To increase the pressure. This high pressure acts on the effective diameter of the planet gear 20, acts as a load resistance of the input shaft 1 directly through the carrier 16, and a load for multiplying the pump capacity of the driven gear 10 by the speed increasing ratio is transmitted through the planetary gear 17 through the planetary gear 17. It is transmitted to the carrier 16 side.

Since the pressure oil in each oil chamber 18 is blocked by the check valve 32a, it leaks to the low pressure side 18B of the oil chamber 18 through the side clearances of the gears 20, 17, 10 and the like. Although a part of the side leak from the side gear 17 flows into the inner chamber 24 of the input shaft 1, the insufficient amount of hydraulic oil from the oil reservoir chamber 21 passes through the check valve 32b to the oil chamber 1
8 is sucked into the low pressure side 18A.

At this time, both ends of each oil chamber 18 are connected to the ports 30a and 30b of the side plate 3 and the annular grooves 31a and 3b.
Since the front and rear relations with respect to the moving direction of the planet gear 20 are communicated via 1b, the compression side chambers and the low pressure side chambers are always kept at the same pressure, and the leak amount of the hydraulic oil between the oil chambers 18 is unbalanced. There is no change.

The flow rate of side leak is proportional to the rotation speed of the input shaft, and throttling resistance of the side clearance is generated according to the flow rate. Therefore, a load torque proportional to the rotation speed acts on the input shaft 1 as a damping force. Will be done. A damping force having the same characteristics is generated even when the input shaft 1 is rotated in the reverse direction.

By the way, in this case, the planet gear 2
A moving capacity of 0 is directly loaded on the input shaft 1, and a load for multiplying the pump capacity of the driven gear 10 by a speed increasing ratio further acts on the input shaft 1. Therefore, an extremely large driving torque is required for the rotation of the input shaft 1. Therefore, it is possible to secure the cushioning characteristic of a large torque sufficient to suppress the rear wheel vibration of the motorcycle, for example, without increasing the size and weight of the device.

Further, the planet gear 20 is the sun gear 17
Since the ring gear 8 and the driven gear 10 rotate while meshing with the sun gear 17, there is no need for a seal at the meshing points of these gears, friction is extremely small, and the leak control of hydraulic oil is controlled by the gears 20, 17 ,.
It can be easily performed only by managing the side clearance such as 10.

The oil amount chamber 21 compensates for fluctuations in the amount of oil due to changes in the temperature inside the oil chamber 18. In addition, the orifice 23 of the plate 22 causes the leak flow rate to increase in the oil reservoir chamber 21.
It is possible to secure stable damping characteristics by limiting the flow into the.

Incidentally, it is conceivable to use the sun gear 17 as the input shaft 1 without providing the planet carrier 16, but in that case, in order to secure the same torque load, the driven gear 10 is used.
It is necessary to increase the pump capacity of. In other words, in this example, the torque can be significantly increased compared to the case where the sun gear 17 is used as the input shaft. Therefore, if the torque load is the same, the working pressure can be reduced by that amount. In addition to being advantageous, the side clearances of the gears 20, 17, 10 and the like can be set to be large, which is advantageous in managing dimensional accuracy.

[0029]

In summary, according to the present invention, the inside of the casing that rotatably supports the input shaft is oil-tightly sealed, and the ring gear having the input shaft as the center is formed on the inner circumference of the casing. A freely rotatable sun gear is installed on the top, and a driven gear that engages the sun gear with part of the ring gear as the pump case so as to define multiple oil chambers in the circumferential direction between them, and a planet that engages the ring gear and the sun gear in the oil chamber. While the gears are housed, a planet carrier that slidably contacts one end surface of each gear is integrally formed on the input shaft, so it can be used as a vehicle-mounted rotary damper without increasing the size and weight of the device and with a large torque. It is possible to obtain stable damping characteristics.

[Brief description of drawings]

FIG. 1 is a sectional view of a rotary damper.

FIG. 2 is a sectional view taken along line AA of FIG.

[Explanation of reference symbols] 1 input shaft 2 body 7 side flange 8 ring gear 10 driven gear 12 oil seal 14 O-ring 16 planet carrier 17 sun gear 18 oil chamber 20 planet gear 21 oil sump chamber 32a, 32b check valve

Claims (1)

[Claims] 1. A casing that rotatably supports an input shaft is oil-tightly sealed, a ring gear centered on the input shaft is formed on the inner circumference of the casing, and a freely rotatable sun gear is provided on the input shaft. , A driven gear that engages the sun gear with a part of the ring gear as a pump case so as to define a plurality of oil chambers in the circumferential direction between these, and a planet gear that engages the ring gear and the sun gear in the oil chamber are housed. A rotary damper characterized in that a planet carrier which is in sliding contact with one end face of a gear is integrally formed on an input shaft.