JP2000204962A - Auxiliary driving gear for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an auxiliary driving gear for an engine to prevent the generation of wear and noise and to control the number of revolutions of an auxiliary machine through simple structure. SOLUTION: An endless belt 23 is run around a drive pulley 14 fixed on the crankshaft 11 of an engine and a driven pulley 22 supported on the rotary shaft 20 of an AC generator 19, being an auxiliary machine, and through a ball bearing 21, and a coupling means 31 is arranged between a rotor 25 fixed on the rotary shaft 20 and the driven pulley 22. Since the coupling means 31 comprises a plurality of permanent magnets 26 fixed on the outer peripheral surface of the rotor 25; and an annular hysteresis material 27 (or non-magnetic conductor 32) fixed on the inner peripheral surface of the driven pulley 22. Rotation of the driven pulley 22 is transmitted in an electromagnetic non-contact state to the rotor 25 and the rotary shaft 20 to drive the AC generator 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive rotary member provided on a crankshaft and a driven rotary member provided on an auxiliary machine rotary shaft connected by an endless power transmission member. The present invention relates to an accessory driving device for an engine that transmits power to an accessory rotating shaft via a power transmission member and a driven rotary member.

[0002]

2. Description of the Related Art An automobile engine is provided with various accessories such as an AC generator, a compressor for an air conditioner, and a pump for power steering, and the driving force of a crankshaft is supplied to the accessories by a pulley or an endless belt. Is transmitted through a power transmission member such as However, since the variation in the number of revolutions of an automobile engine in a practical range is extremely large, when the ratio of the diameter of the drive pulley provided on the crankshaft to the diameter of the driven pulley provided on the accessory rotating shaft is determined, the number of accessory The rotation speed greatly increases and decreases in proportion to the increase and decrease of the engine rotation speed. Therefore, in the case of an auxiliary machine such as an AC generator, a sufficient amount of power cannot be obtained because the rotation speed of the auxiliary machine rotating shaft is insufficient during idling of the engine. There is a problem that the rotational speed of the shaft becomes excessive and the drive loss of the auxiliary machine increases.

Japanese Patent Application Laid-Open No. H8-225027 discloses a device in which a transmission equipped with a planetary gear mechanism is interposed between a crankshaft of an engine and a rotating shaft of an accessory to control the rotation speed of the accessory. It is proposed by the gazette.

[0004]

However, the above-mentioned prior art is not only complicated in structure and large in size due to the use of a planetary gear mechanism, but also causes wear and noise of mechanical sliding parts. There was a problem that could not be avoided.

The present invention has been made in view of the above-mentioned circumstances, and provides an auxiliary device driving device for an engine capable of controlling the rotation speed of the auxiliary device with a simple structure without generating abrasion or noise. The purpose is to:

[0006]

According to the first aspect of the present invention, a driving rotary member provided on a crankshaft and a driven rotary member provided on an auxiliary machine rotary shaft are provided. An auxiliary drive device for an engine connected by an endless power transmission member and transmitting the rotation of the crankshaft to the auxiliary rotation shaft via a drive rotation member, an endless power transmission member and a driven rotation member. , Or between the accessory rotating shaft and the driven rotary member, a coupling means for electromagnetically transmitting the driving force in a non-contact manner is provided. .

According to the above construction, the coupling means for electromagnetically transmitting the driving force without contact between the crankshaft and the driving rotary member or between the auxiliary rotary shaft and the driven rotary member is provided. Therefore, while having a very simple and compact structure, it is possible to control the rotation speed of the accessory rotating shaft while avoiding the occurrence of wear and noise which cannot be avoided by mechanical coupling means.

According to the invention described in claim 2,
In addition to the configuration of claim 1, the coupling means includes a first member made of a magnetism generating material, and a second member made of a hysteresis material opposed to the first member via a gap. A featured engine accessory drive is proposed.

According to the above-described structure, the coupling member is constructed by opposing the first member made of the magnetic material and the second member made of the hysteresis material, so that the transmission torque of the coupling member is reduced by the first member and the second member. The value is constant regardless of the relative rotation speed of the two members. When the engine rotates at a low speed, a sufficient transmission torque is secured. When the engine rotates at a high speed, the transmission torque does not increase more than necessary. Excessive rotation speed can be prevented.

According to the third aspect of the present invention,
In addition to the configuration of claim 1, the coupling means includes a first member made of a magnetic material and a second member made of a non-magnetic conductor opposed to the first member via a gap. An engine accessory drive device characterized by the following is proposed.

According to the above-described structure, the coupling member is configured by facing the first member made of the magnetic material and the second member made of the nonmagnetic conductor, so that the transmission torque of the coupling member is reduced by the first member and the coupling member. It becomes a value proportional to the square of the relative rotation speed of the second member, and it is possible to generate a transmission torque commensurate with the required torque of the accessory in a wide range of the engine rotation speed.

According to the invention described in claim 4,
In addition to the configuration of claim 2 or claim 3, an auxiliary drive device for an engine is proposed, wherein the first member and the second member are arranged on the same plane orthogonal to their rotation axes. .

According to the above configuration, since the first member and the second member are arranged on the same plane orthogonal to the rotation axis, the size of the coupling means in the direction along the rotation axis can be reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

1 to 3 show a first embodiment of the present invention. FIG. 1 is a diagram showing a driving device of an AC generator of an automobile engine, and FIG. 2 is a diagram showing a relative rotation speed of a hysteresis material and a permanent magnet. FIG. 3 is a diagram showing the relationship between the relative rotation speed of the non-magnetic conductor and the permanent magnet and the transmission torque.

As shown in FIG. 1, three drive pulleys 1 are provided at the shaft end of a crankshaft 11 of an automobile engine.
2, 13 and 14 are overlapped in the axial direction and fixed with bolts 15. The drive pulley 12 drives a camshaft (not shown) via an endless belt 16, and the drive pulley 13 drives a balancer shaft (not shown) via an endless belt 17. 1
The endless belts 2, 13 and the two endless belts 16, 17 are covered by a belt cover 18. Drive pulley exposed to the outside of the belt cover 18 14 comprises a 14 ₂ and the large diameter of the pulley groove 14 ₁ and a small-diameter pulley groove. A driven pulley 22 is connected to a rotating shaft 20 of an AC generator 19 via a ball bearing 21.
Are supported rotatably relative to each other, and the driven pulley 22
A larger diameter of the pulley groove of the pulley groove 22 ₁ and the driving pulley 14 1
The endless belt 23 is wound in 4 ₁ and. The small-diameter pulley groove 14 _{and second} drive pulley 14, the endless belt 24 is wound around the pulley groove of the driven pulley of the power steering pump (not shown).

The drive pulley 14 constitutes a drive rotary member of the present invention, the driven pulley 22 constitutes a driven rotary member of the present invention, and the endless belt 23 constitutes an endless power transmission member of the present invention. The AC generator 19 constitutes the accessory of the present invention, and the rotating shaft 20 of the AC generator 19 constitutes the accessory rotating shaft of the present invention.

The rotating shaft 20 of the AC generator 19 has a rotor 2
5, a plurality of permanent magnets 26 fixed to the outer peripheral surface of the rotor 25 at predetermined intervals, and a hysteresis material such as iron formed in a ring shape and fixed to the inner peripheral surface of the driven pulley 22. (Magnetic material) 27 and a small gap α (for example,
(Preferably 1 mm or less).
A labyrinth 29 is formed between the outer peripheral portion of the driven pulley 22 and the housing 28 of the AC generator 19 to prevent foreign matter such as iron powder from entering the space 30 containing the permanent magnets 26. I have.

The permanent magnets 26 constitute a first member of the present invention, the hysteresis member 27 constitutes a second member of the present invention, and the first member and the second member constitute coupling means 31 of the present invention. Is configured.

Next, the operation of the first embodiment of the present invention having the above configuration will be described.

When the crankshaft 11 of the engine rotates, the drive pulley 1 provided on the crankshaft 11
4 is connected to the driven pulley 22 via an endless belt 23
Rotates. At this time, the driven pulley 22 is
Since the rotating shaft 20 is supported by the rotating shaft 20 via the ball bearing 21, relative rotation occurs between the rotating shaft 20 and the rotor 25 fixed to the rotating shaft 20 in a stopped state. As a result, the ring-shaped hysteresis member 27 fixed to the driven pulley 22
And the permanent magnets 26 fixed to the rotor 25 rotate relative to each other to cause an eddy current to flow through the hysteresis member 27 and magnetic friction is generated between the hysteresis member 27 and the permanent magnets 26. 26 are dragged, and the rotation of the driven pulley 22 is transmitted to the rotor 25 and the rotating shaft 20 in a non-contact manner.

The principle of power transmission in the coupling means 31 composed of the hysteresis material 27 and the permanent magnets 26 described above is a known principle used in an electromagnetic brake, an integrated wattmeter and the like.

The solid line in FIG. 2 indicates that when the hysteresis material 27 is used as the second member, the hysteresis material 27
And how the transmission torque T changes with respect to the relative rotation speed N of the permanent magnets 26. The transmission torque T is maintained at a constant value even if the relative rotation speed N changes. Dashed line in Figure 2 shows the torque required to drive the AC generator 19, the solid line and the relative rotational speed N _{ma x} corresponding to dashed intersections, alternator also the engine rotational speed is increased 19 shows the upper limit value at which the rotation speed does not increase any more. That is, even if the engine rotation speed increases and the relative rotation speed N exceeds _Nmax , the coupling means 31 slips because the transmission torque T is less than the required torque, and the rotation speed of the alternator 19 is further increased. Does not increase.

Thus, even if the speed increase ratio between the driving pulley 14 and the driven pulley 22 is set so that the amount of power generated by the AC generator 19 can be sufficiently secured even when the engine is running at a low speed, the engine speed increases. Therefore, the upper limit of the rotation speed of the alternator 19 is automatically limited in accordance with the condition (1), so that it is possible to reduce auxiliary equipment drive loss during high-speed rotation of the engine, thereby contributing to energy saving. As described above, the coupling composed of the hysteresis member 27 and the permanent magnets 26 is provided in the power transmission path from the crankshaft 11 to the AC generator 19 without using a large coupling means having a complicated structure such as a planetary gear mechanism. The rotation speed of the alternator 19 can be controlled with a simple structure in which only the means 31 is interposed. In particular, by adopting the non-contact coupling means 31, it is possible to avoid wear and noise without taking lubrication into consideration and to ensure durability.

FIG. 3 shows a case where a non-magnetic conductor 32 such as aluminum is used as the second member in place of the hysteresis material 27, and the transmission is performed with respect to the relative rotational speed N of the non-magnetic conductor 32 and the permanent magnets 26. This shows how the torque T changes. With non-magnetic conductor 32 as a second member, for the transmitted torque T is increased in proportion to the square of the relative rotational speed N, in practice the magnetic flux in the thin portion 25 ₁ of the rotor 25 is saturated, there relative At the rotation speed N, the transmission torque T reaches a plateau.

When the non-magnetic conductor 32 is used as the second member, the alternator 19
It is possible to increase the transmission torque T according to an increase in the required torque, and by which to saturate the magnetic flux in the thin-walled portion 25 ₁ of the rotor 25 restricts the upper limit of the transmission torque T, the rotation speed of the alternator 19 Can be prevented from becoming excessive.

[0027] Since the ball bearing 21 supporting the driven pulley 22 in the space facing the thin portion 25 ₁ of the rotor 25 is accommodated, hysteresis material 27 (or non-magnetic conductor 32) and the permanent magnet 26 ... and rotating shaft Together with the arrangement in the radial direction on the same plane orthogonal to 20, the axial dimension of the coupling mechanism 31 can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIGS.

In the above-described first embodiment, the permanent magnets 26 are used as the first members.
5 are fixed by the high magnetic permeability material 33 fixed to the outer peripheral surface of
A member is formed, and the second member is formed by the nonmagnetic conductor 32 fixed to the inner peripheral surface of the driven pulley 22. By inducing the magnetic flux generated by the electromagnet 34 provided in the housing 28 of the AC generator 19 to the high magnetic permeability materials 33, the high magnetic permeability materials 33 generate a magnetic force to generate the permanent magnet 26 of the first embodiment. Performs the same function as. At this time, the control means 3
5 controls the amount of current to the electromagnet 34 to control
The magnitude of the transmission torque T can be arbitrarily controlled by changing the magnetic force of 3.

That is, as shown in FIG.
.. Constitute the first member, the transmission torque T increases in proportion to the square of the relative rotation speed N.
By controlling the transmission torque T to be a constant value by reducing the amount of energization to the electromagnet 34 when the rotation speed reaches the predetermined rotation speed N ₀ , the upper limit of the rotation speed of the rotor 25 is suppressed to _Nmax , 19 can be prevented from rotating excessively.

Next, a third embodiment of the present invention will be described with reference to FIG.

In the first and second embodiments described above, the coupling means 31 is provided on the auxiliary machine side, but in the third embodiment, the coupling means 31 is provided on the crankshaft 11 side. That is, in the third embodiment, the crankshaft 11
The driving pulley 14 is relatively rotatably supported via a ball bearing 21, a rotor 25 is fixed to the crankshaft 11, and a permanent magnet 26 as a first member is attached to the outer peripheral surface of the rotor 25, A hysteresis member 27 (or a non-magnetic conductor 32) as a second member is attached to the inner peripheral surface of the second member.

In this embodiment, the rotation of the crankshaft 11 is controlled by the rotation of the rotor 25, the permanent magnets 26,.
(Alternatively, the nonmagnetic conductor 32), the driving pulley 14, the endless belt 23, and the driven pulley (not shown) are transmitted to an AC generator (not shown), and the coupling means 31 is provided in the first and second embodiments. The same function as described above can be exerted to obtain the same function and effect.

Next, a fourth embodiment of the present invention will be described with reference to FIG.

The fourth embodiment is an improvement of the third embodiment,
It is characterized in that the permanent magnets 26 are supported by the rotor 25 that rotates relative to the drive pulley 14. In the third embodiment, all the permanent magnets 26 are fixed to the rotor 25. In the fourth embodiment, three of the nine permanent magnets 26 are pivotally supported by the rotor 25 with pins 36. ing. One end of a swing arm 38... Pivotally supported at an intermediate portion to the rotor 25 via a support shaft 37 is connected to the permanent magnet 26 via a pin 39, and a centrifugal weight 40 is attached to the other end. You. The centrifugal weights 40 are urged radially inward by springs 41 and are held at positions where they contact the stoppers 42.

Accordingly, when the rotation speed of the rotor 25 integral with the crankshaft 11 increases and the centrifugal force acting on the centrifugal weights 40 exceeds the set load of the springs 41, the centrifugal weights 40 move outward in the radial direction. As a result, the swing arms 38 swing around the support shaft 37, and the three permanent magnets 26 swing around the pins 36 and move inward in the radial direction (see the chain line). As a result, the driving pulley 1
The gap α between the non-magnetic conductor 32 provided in 4 and the three permanent magnets 26 increases, and the transmission torque T from the rotor 25 to the drive pulley 14 decreases. Thus, the characteristic of the transmission torque T indicated by the solid line in FIG. 5 can be obtained mechanically without using the electric control means 35.

Although the embodiments of the present invention have been described in detail, various design changes can be made in the present invention without departing from the gist thereof.

For example, in the embodiment, the coupling means 31
The permanent magnets 26 or the high magnetic permeability materials 33 are arranged radially inside, and the hysteresis material 27 or the nonmagnetic conductor 32 is arranged radially outside. And they can also be arranged axially back and forth rather than radially in and out. However, since the hysteresis material 27 and the non-magnetic conductor 32 generate heat during operation, heat radiation can be promoted by arranging them outside in the radial direction.

The permanent magnets 26 in the first, third and fourth embodiments are replaced by the high permeability material 33 in the second embodiment.
.. And the electromagnet 34.

In the embodiment, an AC generator 19 is used as an auxiliary machine.
However, the present invention can be applied to driving of any other accessory.

[0041]

As described above, according to the first aspect of the present invention, the driving force is electromagnetically applied between the crankshaft and the driving rotary member or between the accessory rotary shaft and the driven rotary member. Since the coupling means that transmits non-contact is interposed, it has a very simple and compact structure,
It is possible to control the rotation speed of the accessory rotating shaft while avoiding the occurrence of wear and noise that cannot be avoided by mechanical coupling means.

According to the second aspect of the present invention,
Since the first member made of the magnetic material and the second member made of the hysteresis material are opposed to each other to constitute the coupling means, the transmission torque of the coupling means is independent of the relative rotation speed of the first member and the second member. This value is constant, ensuring sufficient transmission torque when the engine is running at low speed, and preventing the transmission torque from increasing excessively when the engine is running at high speed by preventing the transmission torque from increasing more than necessary. can do.

According to the third aspect of the present invention,
A first member made of a magnetic material and a second member made of a nonmagnetic conductor
Because the coupling means is configured with the members facing each other,
The transmission torque of the coupling means becomes a value proportional to the square of the relative rotation speed of the first member and the second member, and it is possible to generate a transmission torque commensurate with the necessary torque of the accessory in a wide range of the engine rotation speed.

According to the invention described in claim 4,
Since the first member and the second member are arranged on the same plane orthogonal to the rotation axis, the size of the coupling means in the direction along the rotation axis can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a drive device for an AC generator of an automobile engine.

FIG. 2 is a diagram showing a relationship between a relative rotation speed of a hysteresis material and a permanent magnet and a transmission torque.

FIG. 3 is a diagram showing a relationship between a relative rotation speed of a nonmagnetic conductor and a permanent magnet and a transmission torque.

FIG. 4 is a view showing the structure of a coupling means according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between a relative rotation speed and a transmission torque in a second embodiment.

FIG. 6 is a view showing the structure of a coupling means according to a third embodiment of the present invention.

FIG. 7 is a view showing the structure of a coupling means according to a fourth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 11 crankshaft 14 drive pulley (drive rotary member) 20 rotary shaft (auxiliary rotary shaft) 22 driven pulley (driven rotary member) 23 endless belt (endless power transmission member) 26 permanent magnet (first member) 27 hysteresis material (first 2 members) 31 Coupling means 32 Non-magnetic conductor (second member) 33 High permeability material (first member) α gap

Claims (4)

[Claims] An endless power transmission member (23) connects a drive rotation member (14) provided on a crankshaft (11) and a driven rotation member (22) provided on an auxiliary machine rotation shaft (20). An auxiliary driving device for an engine, which transmits rotation of a shaft (11) to an auxiliary rotating shaft (20) via a driving rotating member (14), an endless power transmission member (23) and a driven rotating member (22). Between the shaft (11) and the driving rotary member (14), or between the accessory rotary shaft (20) and the driven rotary member (2).
And (2) interposing a coupling means (31) for electromagnetically transmitting a driving force in a non-contact manner. 2. The coupling means (31) comprises a first member (26, 33) made of a magnetic material and a hysteresis material opposed to the first member (26, 33) via a gap (α). The accessory drive device for an engine according to claim 1, characterized in that the accessory drive device comprises a second member (27). 3. The coupling means (31) includes a first member (26, 33) made of a magnetic material and a non-magnetic member opposed to the first member (26, 33) via a gap (α). 2. The accessory driving device for an engine according to claim 1, comprising a second member made of a conductor. 3. 4. The first member (26, 33) and a second member (26, 33).
The engine accessory driving device according to claim 2 or 3, wherein the members (27, 32) are arranged on the same plane orthogonal to their rotation axes.