KR20000022130A - Automotive accessory driving system particularly for air-conditioning units - Google Patents

Abstract

According to the invention, there is provided a transmission device 20 for increasing the rotational speed of the compressor unit 18 in the air conditioner of a motor vehicle while the motor is running at low speed. The transmission device comprises a planetary gear assembly connected between the drive shaft 24 of the motor and the compressor, and is provided with two friction clutches 28 and 54 which are electrically or pneumatically controlled. The transmission ratio can be changed by engaging and / or disengaging one or two clutches with respect to motor speed.

Description

Drives for automotive accessories such as air conditioning units

Conventionally, accessory devices such as air conditioning (A / C) compressor units, alternators, coolant circulation pumps, power steering hydraulic pumps, etc. are directly connected to the crankshaft of the engine via one or more belt drive transmissions (usually fan belts). Connected. As a result, these devices rarely operate in their optimum efficiency range. Thus, while driving at economic speeds for a long time on the road, subcooling is achieved by the A / C unit, while cooling at idling engine speed (e.g. under sizzling sun during traffic jams) Cooling is not enough when it is most needed.

In order to cure the inherent drawbacks of the conventional device, it has been proposed to incorporate a transmission device that automatically outputs a constant speed, which gradually increases the accessory drive speed at idle or low gear speeds. It is designed to gradually reduce the accessory drive speed at high gear speeds (see US Pat. No. 2,720,087 to Groene, which proposes a variable transmission device attached to the engine crankshaft).

However, the conventional device has some disadvantages. First, the device can only be applied as an OEM product. In other words, the device can only be produced in an automobile production line. Second, extra space must be provided within the engine compartment. Next, since the apparatus is complicated and sensitive, the manufacturing cost is high and requires special care and maintenance. Therefore, the practical use failed.

Especially with regard to the operating characteristics of the A / C compressor unit, for moderate practical purposes the need for a truly constant speed transmission need not be met, but only for a low speed engine operation. It has been found that it needs to be effectively negotiated by using single-stage, step-up transmission (see FIG. 5 of the accompanying drawings).

Most compressor products currently in the trade (in the form of wobbling discs) are not important as far as the direction of rotation of the drive shaft is concerned. That is, even if the direction is reversed, it does not damage or affect the operation of the compressor. This applies to alternators and any hydraulic pump products. However, the present invention is described and illustrated with reference to an automotive air conditioner, the advantages of which are most strongly highlighted.

The present invention relates generally to an automotive accessory drive device.

1 is a schematic perspective view of a typical automotive engine block equipped with several automotive accessories.

2 is a cross-sectional view of the transmission device for the A / C compressor unit according to the first preferred embodiment of the present invention.

3 is a cross-sectional view taken along the line III-III of FIG.

4 is a cross-sectional view taken along the line IV-IV of FIG.

5 is a diagram of the operation of a transmission device.

6 is a sectional view of a transmission device according to a second embodiment of the present invention.

7 is a cross-sectional view taken along the line VII-VII of FIG. 6;

8 to 10 are schematic diagrams illustrating a neutral stage, a direct connection stage and a speed driving stage of the apparatus shown in FIG. 6, respectively.

FIG. 11 is a cross-sectional view of another embodiment of the present invention taken along line II-II of FIG. 12;

12 is a cross-sectional view taken along the line XI-XI of FIG.

FIG. 13 is a schematic representation showing three modes of operation of the device shown in FIGS. 11 and 12.

It is an object of the present invention to provide an automotive accessory drive device which is free from the above mentioned problems and other disadvantages of the known devices.

It is a further object of the present invention to provide a transmission device which can be integrated with the vehicle accessory device and as a "parts market" item, i.e. independently produced, suitable, compact and easily mounted on an existing vehicle.

It is a further object of the present invention for the transmission device to constitute a gear unit of a single engine speed which is automatically controlled by an output which reverses direction.

Another object of the present invention is to use a planetary gear system in the transmission device, which uses a friction clutch and can be operated electrically or pneumatically.

According to a broad aspect of the present invention, there are provided connection means for connecting an accessory to an automobile engine, sensing means for sensing engine speed, transmission means that can be selectively engaged to increase the operating speed of the accessory, and said sensing means Enabling means for enabling the transmission means upon detecting a decrease in engine speed below this predetermined first value and increasing engine speed above the second predetermined value; A vehicle accessory drive device is provided that includes means for disabling the transmission means upon sensing the transmission means.

These and other aspects, objects, advantages and structural features of the present invention will be more clearly understood from the following preferred embodiments of the present invention, given by way of example only with reference to the accompanying drawings.

Referring to FIG. 1, the main (crankshaft) drive pulley 10 of the engine 12 is connected to the air conditioning compressor unit 16 from the accessories of a vehicle such as the alternator 15 by means of a belt (s) 14. How it is connected is shown. The compressor 16 is composed of a compressor casing 18 and a pulley unit 20.

The pulley unit 20 is somewhat like the conventional one, especially in size and dimensions. However, the pulley unit includes a planetary gear transmission device, and this unique fact is emphasized. This is because this satisfies the stringent space saving requirements that typically govern automotive and automotive engine compartment designs.

More specifically, as shown in FIGS. 2 to 4, the pulley wheel 22 may be freely rotated about the drive shaft 24 by the ball bearing 26.

Also included is a friction disc type clutch that is effective for engaging pulley wheel 22 to friction surface 30a of planetary gear housing 30 (the supply of current and its associated configuration for actuating clutch 28 are described. The detailed description thereof as a conventional one is omitted for the sake of brevity.

The gear device housing 30 comprises an internal gear crown 32 (which constitutes the "annular part" of the planetary device as described below), on the one hand by means of the drive shaft 24 via the one-way roller clutch 34. It is rotatably supported and, on the other hand, is rotatably supported by a ball bearing 38 disposed between the flange 30a and the portion 36a of the compressor casing cover plate 36.

The planetary gear device comprises four (or other suitable numbers) of the "planetary" or "satellite" gears 40, 41, 42, 43 and the "sun" gear 44.

The planetary gears 40-43 are connected to each other via the toroidal cage member 46 by shaft pins 40a, 41a, 42a, 43a passing through the respective gears, and the roller bearings are free to rotate on each gear. 40b, 41b, 42b, and 43b are provided.

The cage member 46 may be rotated about the hub-shaped portion 36b of the casing cover plate 36 by a bearing 48.

The sun gear 44 is operatively connected to the drive shaft 24 by the key 50.

A second electromagnetic friction clutch 54 operatively connected to the cage member 46 is provided, which is engaged with the (fixed) compressor casing cover plate 36 and selectively locked to prevent rotation.

The operation of the transmission device 20 will now be described. As can be readily understood from the foregoing description, three modes of operation are possible.

A-no current flows through any of the clutches 28 and 54 ("neutral" position).

B-only clutch 28 is activated ("direct connection" position).

C-Both clutches 38 and 54 are activated ("speed drive" position).

The non-fastening direction in which the unidirectional roller clutch 34 freely rotates is opposite to the rotational direction of the pulley wheel 22 by the engine 12 (as driven by the belt 14).

In the neutral position A, the pulley wheel 22 only rotates, with the neutral position representing the position where the A / C device is disengaged or turned off.

When the first clutch 28 is actuated and the pulley wheel 22 engages the casing 30, the unidirectional clutch 34 is directly engaged with the compressor drive shaft 24. Thus, the drive shaft 24 is rotated at the same speed, that is, a transmission ratio of 1: 1.

Since the sun gear 44 is fixed to the drive shaft 24, the sun gear is also rotated at the same speed. The planetary gears 40-43 do not rotate about their axes, but can rotate freely with the cage 46 as they rotate around the sun gear 44.

Therefore, the transmission ratio is not changed by such a planetary gear device.

The B mode of operation is suitable for driving at high economic speeds on the road.

When running at low speeds, especially when idling, the C mode of operation is used. That is, the cage restraint friction clutch 54 is operated. For this purpose, any known type of converter means such as manifold vacuum reaction switch, tachometer switch, etc. can be used, which is activated when the revolution of the crankshaft falls below a preset value.

The planetary gears 40-43 are engaged so that once they are not orbitally moved, according to the number of teeth (= pitch) of the annular portion divided by the pitch of the sun gear) at a high ratio and the pulley wheel 22 [and the casing ( 30), the rotation of the annular portion 32 is transmitted to the sun gear 44 in the opposite direction.

Since the direction is changed, the unidirectional clutch 34 is disengaged (rotated freely), and thus does not interfere with the casing 30 (and pulley wheel 22) and continues to rotate in its normal direction.

Considering the dimensions of the standard A / C unit (mainly the diameter of the compressor housing and the diameter of the pulley wheels), the practical transmission ratio is about 2.0 to 2.5: 1.

Since the normal idle speed of most automobiles is 900-1000 rpm, the ratio between the crankshaft 10 (FIG. 1) and the pulley wheel 22 is about 1: 1, and the speed of the compressor is about 2000-2500 rpm, That is, the speed is quite close to the optimum operating conditions.

When the vehicle is accelerated to the preset rpm of the crankshaft, the transmission is switched back to its "direct connection" position B, and the direction of the axis 24 is also reversed.

5 is an explanatory diagram in view of the foregoing description, which clearly shows that the operating range of the compressor is always maintained above 2000 rpm, the selected minimum speed, rather than dropping to 900 rpm, the actual idle speed.

It will be appreciated that the transmission unit 20 is a unit of extremely simple and compact structure. That is, even if the transmission unit is installed, whether it is an original (OEM) or "aftermarket" product (a conventional switching A / C unit installed on an existing vehicle), the layout and space required for the engine compartment by the installation is required. This is not disturbed.

In addition, smaller proportions of the compressor can be used, thus reducing fuel consumption. But in terms of efficiency and occupant comfort, the same results are obtained.

Reference is now made to the embodiment shown in FIGS. 6 to 10. The same reference numerals are used for similar parts and parts. As can be readily seen, the A / C transmission device 120 of FIG. 6 differs from the transmission device of FIG. 2 in that the pulley wheel 122 is integrated with the casing 130. Additional planetary cages 146 '(mirror with cage 146) are provided rotatably on bearing 148' for planet gears 140-143. The cage 146 'is constrained to the casing 130 by a second electromagnetic friction clutch 154'.

No unidirectional clutch is included as is apparent from the following description (see FIGS. 8-10).

In the A mode of operation, the clutches 154 and 154 'are interrupted in current, and the casing 130 is rotated by an engine belt (not shown) together with the annular gear 132.

As a result of the compressor shaft 124 being slightly loaded (by friction and back-pressure by the compressor), the planetary gears 140-143 orbitally move around the sun gear 144. That is, no rotational movement is transmitted to the sun gear.

A "neutral" mode of operation is also obtained. A 1: 1 ratio of B modes of operation, which are "direct connections" that run at economic speeds, is obtained by simply energizing the clutch 154 '. The cage 146 'is tightened by the casing 130 and is reliably driven with the casing. The free orbital rotation of the planetary gears 140-143 is changed to a unified movement so that the planetary gears do not rotate, but remain fixed relative to both the annulus 132 and the sun gear 144 and thus from the planetary gears. It relays rotation to the sun gear.

Thus, the sun gear 144, which is directly connected to the shaft 124, drives the compressor at the same speed as the pulley wheel 122.

Switching to the step-up transmission mode of operation for increasing speed is achieved by disengaging the clutch 154 'and engaging the second clutch 154. This causes the planetary gears 140-143 to rotate over their respective axes 140a-143a and the rotation of the annular portion 132 increased by an applicable ratio factor (2.0 to 2.5) as described in connection with the previous embodiment. It again transmits to the sun gear 144 in the opposite direction. That is, the operating characteristics shown in FIG. 5 can also be applied to this embodiment.

In order not to cause an impact by a sudden reversal, the transition from the "high gear" position to the "low gear" position (and vice versa) may, for example, release and actuate the clutches 154, 154 'or 28, 54. The time between can be alleviated or absorbed by causing the moving parts to be sufficiently delayed to stop.

Returning to the third embodiment of the present invention, the device 220 shown in FIGS. 11 and 12 is similar to the device of FIG. 6 of the parent source, but is controlled pneumatically rather than electrically.

It is essentially engaged with the compressor shaft 224, the pulley wheel 222 integrally formed with the casing 230, and four planetary gears 240-243 that can be freely rotated about each of the shaft pins 240a-243a. An annular portion 232 is included. The pin shafts are supported by the (unified) cage member 246. The sun gear 244 is mounted to the compressor shaft 224 (key 250) and meshes with all four planetary gears 240-243.

The transmission casing 230 may rotate about the front roller bearing 226 and the rear needle bearing 238. Needle bearing 238 is mounted around a stationary cylinder or flange 260 attached to the housing wall 236 of the compressor.

A pair of pneumatic (or hydraulic, see below) plungers, ie rear plunger 262 (with gaskets 262a, 262b) and front plunger 264 (with gaskets 264a, 264b) move It is accommodated in the cylinder 260 possibly. The plungers 262, 264 are both annular and one plunger is located inside the other plunger as shown, but can move independently, first under pressure supplied through conduit 266 and second Can move by pressure through the extension passage 268a and conduit 268 to the gap 268b left between the upstream side of the plunger 262 and the downstream side of the plunger 264.

Movement of the front plunger 264 is transmitted to the friction disk clutch 254 'by a series of four pins 270 abutting the plunger 262 in the middle of the thrust needle bearing 272 and compressing coil spring 274 It encounters against the deflection of. The disks of the clutch 254 are in turn connected to the cage 246 and the flange 260 attached to the housing wall 236.

The friction clutch 254 is actuated by a circular lip 264a of the front plunger 264 against the compression coil spring 276 to restrain and secure the cage 246.

The alternating actuation of the clutches 254, 254 'is accomplished by sending a press / relieve command through the conduits 268, 266, as indicated by the arrows in FIG. 1 and more clearly with reference to the schematics shown in FIGS. 13A-13C. It will be readily apparent that the operation of the transmission device 220 is the same as the electro-magnetic clutch variant 120 shown in FIGS. 6 and 7.

However, the pneumatic case offers two important and unique advantages. That is, it saves the electrical energy required to activate and maintain the tightening action of the magnetic clutch, and the vehicle does not need to be equipped with a compressed air source (for example, an air brake such as that installed in most trucks and buses), The air conditioning compressor can also suitably perform the function of supplying a pressurized fluid (here a cooling gas) to each plunger in the required manner (FIG. 3). Optionally, the device can be hydraulically operated by existing equipment or auxiliary equipment installed in each vehicle. In another aspect, the device is comparable to, and similar to, the device of the foregoing embodiments.

Although the present invention has been described with particular reference to an A / C device, it will be readily understood that the present invention can also be applied to other automotive accessories such as, for example, alternators, which do not change the operating performance by a change in the main drive shaft direction. Those skilled in the art will readily appreciate that numerous variations, modifications and variations of the present invention are possible without departing from the scope of the appended claims.

Thus, for example, a transmission other than a planetary form embedded in a unitary casing and comprising one or more (eg two or three) stages and interchangeable with or mounted to an A / C (or other accessory device) housing Can be used.

Claims (16)

Connecting means for connecting the accessory to the vehicle engine, Sensing means for detecting a speed of the vehicle engine; Transmission means selectively engageable to speed up the operation of the accessory; Enable means for enabling the transmission means when the detection means detects a decrease in engine speed below a predetermined first value; Means for disabling the transmission means if the detection means detects an increase in engine speed above a predetermined second value Car accessory drive device comprising a. 2. The accessory of claim 1, wherein the accessory includes a drive shaft connected to a pulley driven by the automobile engine, and the transmission means comprises: a first rotating member that can be selectively fastened to the pulley; And a second member, wherein the first rotating member and the second member are connected to each other via a transmission ratio changing means. 3. The gear wheel (s) according to claim 2, wherein gears are formed around the first rotating member and the second member, and the transmission ratio changing means is meshable with gears of the first rotating member and the second member. Car accessory drive device comprising a. 4. The vehicle accessory drive device according to claim 3, wherein the first rotating member, the second member and the gear wheel (s) respectively form an annular portion, a sun gear and a planetary gear (s) of the planetary gear transmission device. . 5. An apparatus according to claim 4, wherein said planetary gear (s) are mounted to a freely rotatable cage member, said transmission enabling means comprising means for restraining rotation of said cage. 6. An apparatus according to claim 5, wherein the restraining means comprises an electrically controlled first friction clutch. 7. A drive accessory according to claim 6, wherein the first friction clutch is fixedly mounted to a housing wall of the accessory. 8. The apparatus of claim 7, wherein the first rotating member is capable of rotating about the drive shaft of the accessory via a unidirectional clutch. 8. The apparatus of claim 7, wherein the first rotating member and the pulley form a unit that can freely rotate about the accessory drive shaft and are electrically controlled to connect the first rotating member to the planetary gear cage member. 2. A vehicle accessory drive device characterized in that a friction clutch is provided. 10. An automobile according to claim 7 or 9, wherein said transmission enable means and disable means comprise means for disengaging said second friction clutch and engaging said electrically controlled first friction clutch. Accessory Drive. 11. The vehicle accessory drive apparatus of claim 10, further comprising means for delaying the engagement of the first friction clutch (and vice versa) after the second friction clutch is disengaged. 6. The device of claim 1, wherein the means for restraining rotation of the planetary gear (s) cage member comprises a first friction disk clutch that can be selectively actuated by a first pneumatic means. 7. Car accessory drive device, characterized in that. 13. The apparatus of claim 12, wherein the first pneumatic means comprises: a first plunger movable in a pressure command to tighten the disks of the first friction clutch; a series of first disks connected to the cage; And a series of second disks connected to the fixed wall of the housing of the accessory. 13. The vehicle accessory drive apparatus of claim 12, further comprising a second friction disc clutch that is selectively operable to connect the pulley to the cage by the second pneumatic means. 13. The vehicle accessory drive of claim 12, wherein the second pneumatic means includes a second plunger that is moveable upon a pressing command to tighten the disk of the second friction clutch so that the pulley is connected to the cage. Device. 16. The apparatus of claim 15, wherein the first and second plungers are annular and one plunger is located inside the other plunger.