JP2796980B2 - Transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission that is provided between a drive shaft and a rotating body mounted on the drive shaft, and that switches a gear ratio according to the rotation speed of the drive shaft.

<Prior art> Generally, in an automobile or the like, an alternator,
It uses engine power to drive auxiliary equipment such as hydraulic pumps for power steering and compressors for coolers. That is, pulleys are respectively attached to both the crankshaft of the engine and the driven shaft of the accessory,
A belt is stretched between the two pulleys, and power is transmitted by the belt, and the rotation ratio between the crankshaft of the engine and the driven shaft of each accessory is made approximately 1: 1.

However, when the engine is idling, the speed is set to low speed (about 700 to 1000 rpm). At this speed, the function of the auxiliary equipment tends to be insufficient, so we want to improve the function of the auxiliary equipment even during idling operation. There is a request that.

Therefore, conventionally, when the engine is idling, the power of the engine is increased and transmitted to the auxiliary equipment,
When the engine is operating at high speed, a device for transmitting the power of the engine at a rotation ratio of approximately 1: 1 has been considered. As this device, for example, there is an engine accessory drive device with a planetary gear mechanism disclosed in Japanese Utility Model Laid-Open No. 58-173854.

This device operates the planetary gear mechanism during idling operation of the engine to increase the rotational power of the crankshaft, drives the pulley at a higher rotational speed than the crankshaft, and reduces the rotational speed of the crankshaft. When the number of rotations exceeds a certain value, the planetary gear mechanism is disabled and the rotation ratio between the pulley and the crankshaft is almost 1:
It is configured to be 1.

<Problems to be Solved by the Invention> The conventional example having such a configuration has the following disadvantages.

There is a limit to downsizing the planetary gear of the planetary gear mechanism, and the sun gear, the planetary gear, and the pulley as a rotating body of the planetary gear mechanism are radially overlapped with each other, so that the size in the radial direction is large. This is an obstacle to downsizing the device. There is also room for improvement in terms of noise and vibration due to gear meshing.

The present invention has been made in view of such circumstances,
In particular, it is an object of the present invention to provide a transmission capable of realizing compactness in the radial direction and improving noise and vibration characteristics.

<Means for Solving the Problems> In order to achieve such an object, the present invention is provided between a drive shaft and a rotating body mounted on the drive shaft, and adjusts a gear ratio according to a rotation speed of the drive shaft. The transmission to be switched has the following configuration.

The transmission of the present invention is a sun roller which is coupled to the rotating body so as to rotate together and has a tapered surface on one side in the axial direction, and a sun roller provided on the side of the tapered surface of the sun roller so as to be movable only in the axial direction. An annular member having a tapered surface facing the tapered surface, a plurality of conical planetary rollers interposed in a press-contact state between the respective tapered surfaces of the sun roller and the annular member, and rotatably holding the conical planetary roller. A planetary friction type speed increasing mechanism comprising a carrier coupled to rotate coaxially with the drive shaft; a one-way clutch provided between the drive shaft and the sun roller; and separating the annular member from the conical planetary roller. And the one-way clutch is in a free state when the annular member is not separated from the conical planetary roller, and is rotated by rotation of the drive shaft and the carrier to form the conical planetary roller. While the rotation speed of the sun roller and the rotating body is increased from the rotation speed of the drive shaft by rotating and revolving, the lock member is locked when the ring member is separated from the conical planetary roller by the separation means. The drive shaft and the sun roller are rotated synchronously.

<Operation> In the above configuration, when the annular member is separated from the conical planetary roller by the separating means, the one clutch between the drive shaft and the sun roller is locked, and the one clutch and the sun roller from the drive shaft are locked. As a result, power is transmitted to the rotating body, and the drive shaft and the rotating body are rotated at a ratio of approximately 1: 1.

On the other hand, when the annular member is not separated from the conical planetary roller by the separating means, the conical planetary roller revolved around the drive shaft by the carrier rotates by friction with the sun roller and each tapered surface of the annular member. So
The sun roller and the rotating body are rotated at a predetermined rate while being accelerated, and the clutch is free to rotate relative to the rotating body and the drive shaft.

Such a planetary friction type speed increasing mechanism can reduce the size of each component as compared with a conventional planetary gear mechanism, and has a configuration in which a conical planetary roller, a sun roller, and an annular member are overlapped in the axial direction. Downsizing in the direction is easy,
This is convenient for reducing the size of the entire apparatus. In addition, since the power transmission from the drive shaft to the rotating body is performed by friction at the time of speed increase, noise and vibration can be suppressed to be smaller than in a conventional gear meshing system.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In this embodiment, an example in which such a transmission is provided between a crankshaft of an engine and a pulley attached thereto will be described. In the figure, reference numeral 1 denotes a crankshaft (drive shaft) having a shaft end protruding from an engine block 2 to the outside, 3 denotes a pulley (rotary body) mounted on the crankshaft 1 via a transmission device described in detail below, and 4 denotes a pulley. A driven shaft 5 of an accessory (not shown) is a pulley directly fixed to the driven shaft 4, and a belt 6 is stretched between the pulleys 3 and 5.

The transmission is mainly composed of a planetary friction type speed increasing mechanism 10, one clutch 20 and an electromagnetic clutch 30 as separation means.

The planetary friction type speed increasing device 10 includes a sun roller 12 which is coupled to the inner diameter side of the pulley 3 so as to rotate together and has a tapered surface 11 on one side in the axial direction, An annular member 14 movably provided with a tapered surface 13 facing the tapered surface 11 of the sun roller 12, and a plurality of cones interposed in a press-contact state between the respective tapered surfaces of the annular member 14 and the sun roller 12. It comprises a planetary roller 15 and a carrier 16 fixed to the crankshaft 1 and holding each of the conical planetary rollers 15 rotatably. Note that the annular member 14 is formed of a magnetic material.

On the other hand, the clutch 20 is provided between the outer peripheral surface of the sleeve 8 fixed to the crankshaft 1 and the inner peripheral surface of the cylindrical portion 17 of the sun roller 12, and has a structure using a so-called sprag. On the other hand, the operation of the clutch 20 is such that when the crankshaft 1 is rotating at a higher speed than the cylindrical portion 17 of the sun roller 12, the clutch 20 locks, and the cylindrical portion 17 of the sun roller 12 rotates at a higher speed than the crankshaft 1. Free when you are.

The electromagnetic clutch 30 is provided on the back side of the annular member 14, and includes an electromagnet 31 attached to the engine block 2 via the cylindrical stay 9, and a side that separates the annular member 14 from the electromagnet 31, that is, a conical planetary roller. It is comprised of a leaf spring 32 which presses and urges to the 15 side. The electromagnetic clutch 30 has an annular member that resists the extension force of the leaf spring 32 by energizing the electromagnet 31.
14 is attracted to the electromagnet 31 side and is separated from the conical planetary roller 15.

Then, between the outer peripheral surface of the axial end of the sleeve 8 integral with the crankshaft 1 and the inner peripheral surface of the axial end of the cylindrical portion 17 of the sun roller 12, and the outer diameter portion of the tapered surface 11 of the sun roller 12 and the cylindrical stay 9. Seals 40 and 41 are mounted between the inner peripheral portion and a seal 42 between the inner peripheral surface of the annular member 14 and the outer peripheral surface of the sleeve 8. With these three seals, the planetary friction type speed increasing mechanism 10 and the one-way clutch 20
Is sealed from the outside to prevent leakage of lubricant from the inside space and intrusion of dust from the outside.

 Next, the operation will be described.

Here, during the period from the start of the rotation of the crankshaft 1 to the idling operation (about 700 to 1000 rpm), the electromagnet 31
The following describes an example in which the power supply to the electromagnet 31 is stopped and the power supply to the electromagnet 31 is performed when the number of rotations during the idling operation is exceeded.

First, when the energization of the electromagnet 31 is stopped, the annular member 14 is pressed against the conical planetary roller 15 by the tension of the leaf spring 32. Since the annular member 14 is held so as not to rotate, the carrier that rotates integrally with the crankshaft 1
16 conical planetary rollers around the crankshaft by 16
Are revolved while rotating, and the sun roller 12 and the pulley 3 are rotated at a predetermined rate and increased by the frictional force generated by the rotation of the conical guide roller 15.
At the same time, the pulley 3
As the rotation speed of the sun roller 12 starts to increase, the clutch 20 is released, and power is transmitted from the crankshaft 1 to the carrier 16, the conical planetary roller 15, the sun roller 12, and the pulley 3. As a result, the pulley 3 is rotated at a predetermined rate higher than the rotation speed of the crankshaft 1.

By the way, when the rotation speed of the crankshaft 1 exceeds the rotation speed during idling operation, the electromagnet 31 is energized. Therefore, the annular member 14 is attracted to the electromagnet 31 against the extension force of the leaf spring 32, and the annular member 14 is pulled. Is separated from the conical planetary roller 15. As a result, while there is a difference in the rotational speed between the carrier 16 co-rotating with the crankshaft 1 and the sun roller 12 co-rotating with the pulley 3, the conical planetary roller 15 between them acts as a rolling bearing, When the rotation speed of the pulley 3 and the sun roller 12 is temporarily lower than the rotation speed of the crankshaft 1, the clutch 20 is locked and the carrier 16 and the sun roller 12 are locked. 12 is integrated, that is, they are rotated synchronously.
, And the pulley 3 is rotated with the crankshaft 1 at a ratio of approximately 1: 1.

It is needless to say that the transmission of the present invention can be applied to various parts in addition to being provided between the crankshaft 1 and the pulley 3 of the engine. For example, if the transmission according to the present invention is provided between the driven shaft 4 and the pulley 5 of the accessory, it can be used in a rotation range suitable for each accessory. Further, in the above embodiment, an electromagnetic clutch is used as the separating means.
30 is adopted, but anything else is acceptable.

<Effects of the Invention> As described above, according to the present invention, power transmission from the drive shaft to the rotating body is performed by friction of the conical planetary roller at the time of speed increase, so that noise and vibration are generated. Can be controlled smaller than the conventional gear meshing, the size of the conical planetary roller is smaller than that of the planetary gear, and the conical planetary roller, the sun roller and the annular member are stacked in the axial direction. Therefore, it is possible to realize a significant downsizing especially in the radial direction.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing a mode of use of a transmission according to one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Crankshaft (drive shaft), 3 ... Pulley (rotary body), 10 ... Planetary friction type speed increasing mechanism, 11 ... Taper surface of sun roller, 12 ... Sun roller, 13 ... Tapered surface, 14 ... annular member, 15 ... conical planetary roller, 16 ... carrier, 20 ... one-way clutch, 30 ... electromagnetic clutch (separation means).

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F16H 13 / 08,55 / 36 F02B 67 / 04,67 / 06

Claims (1)

(57) [Claims] 1. A transmission device provided between a drive shaft and a rotating body mounted thereon for switching a gear ratio in accordance with a rotation speed of the drive shaft, wherein the transmission is coupled to the rotating body so as to rotate together with the rotating body. A sun roller having a tapered surface on its side, an annular member having a tapered surface facing the tapered surface of the sun roller provided movably only in the axial direction on a side of the tapered surface of the sun roller, and a sun roller and an annular member. A planetary friction type speed increasing system comprising a plurality of conical planetary rollers interposed in a press-contact state between respective tapered surfaces, and a carrier which rotatably holds the conical planetary rollers and is coupled to co-rotate with a drive shaft. A clutch provided between the drive shaft and the sun roller; and separating means for separating the annular member from the conical planetary roller. When it is not separated from the drive shaft, it is in a free state and the conical planetary roller rotates and revolves by the rotation of the drive shaft and the carrier, thereby increasing the rotation speed of the sun roller and the rotating body more than the rotation speed of the drive shaft. A transmission which is in a locked state when the annular member is separated from the conical planetary roller by the separating means, and synchronously rotates the drive shaft and the sun roller.