GB2365944A

GB2365944A - Drive mechanism

Info

Publication number: GB2365944A
Application number: GB0019945A
Authority: GB
Inventors: Mark Nelson
Original assignee: Llanelli Radiators Ltd
Current assignee: Marelli Automotive Systems UK Ltd
Priority date: 2000-08-14
Filing date: 2000-08-14
Publication date: 2002-02-27
Anticipated expiration: 2020-08-14
Also published as: GB0019945D0; GB2365944B

Abstract

A drive mechanism particularly for controlling air distribution apparatus in vehicle HVAC apparatus has a driving device and at least one driven device The driving device 2 and driven device 8 each have respective match-up zones configured for mutual match-up during the movement regime. Match-up of first zones of the respective devices results in a first routine of relative movement of the devices and match-up of the second zones of the respective devices results in a second routine of relative movement of the devices.

Description

<Desc/Clms Page number 1> A Drive Mechanism Particularly For Controlling Air Distribution Apparatus In Vehicle Air Conditioning Systems The present invention relates to a drive mechanism and in particular to a drive system particularly suited for use in control of air distribution apparatus in vehicular applications. Air distribution apparatus in vehicle climate control systems utilise doors, flaps and rotary closures controlled to open and close passages to the flow of conditioned air to the required cabin vent outlet (or combination of outlets) in accordance with user demand and/or preset requirements. Some such systems employ rotary drive motors to control the opening and closing of distribution passages. Systems requiring several motors have the disadvantage of increased cost and also increase in space envelope and weight. An improved drive arrangement has now been devised. According to a first aspect, the invention provides a drive mechanism comprising a driving device and a driven device, the devices having a movement regime in which movement of the driven device is determined by the driving device, the driving device and driven device each having respective first and second match-up zones configured for mutual match-up during the movement regime, wherein match-up of

first zones of the respective devices results in a first routine of relative movement of the devices and match-up of second zones of the respective devices results in a second routine of relative movement of the devices.

In one of the first and second movement routines, the driven device is preferably held against movement to be substantially at a standstill.

In one of the first and second movement routines, the driven device is moving. The driving device is preferably moving during both the first and second driving routines. Through the first and second driving routines the driving device is preferably moving in a substantially uniform fashion, desirably such that: in one of the first and second movement routines, the driven device is held substantially at a standstill; and in the other of the first and second movement routines, the driven device moving.

Beneficially, both the driving device and the driven device have a motion during the regime which is primarily rotational motion. In an alternative embodiment, one of the devices has a motion during the regime which is primarily linear, the other of the devices having a motion during the regime which is primarily rotational.

Desirably, one pair of mutual match-up zones comprise drive zones configured to provide driving engagement between the devices. The drive zones preferably comprise gear tooth zones, arranged for meshing engagement.

The other pair of mutual match-up zones preferably comprise by-pass zones configured to cooperate to render the devices in a non-drivingly engaged condition. The by-pass zones preferably comprise slide-by zones of the respective devices, preferably configured to inhibit rotation of the driven device during match up of the zones but permit rotation of the driving device.

The match-up zones on the respective devices which cooperate to render the devices in a non drivingly engaged condition preferably comprise respective complementary arcuate concave and convex match-up edges. The curvature of the convex match-up edge is beneficially substantially the same as the curvature of the concave match-up edge. Where one pair of mutual match-up zones comprise drive zones configured to provide driving engagement between the devices and one pair of mutual match-up zones comprise bypass zones configured to cooperate to render the devices in a non-drivingly engaged condition, the driving device is preferably rotatable about an axis to drive the driven device, the drive zone and the by-pass zone of the driving device preferably being staggered in the axial direction of rotation.

The driving device preferably comprises a drive component

having a drive zone comprising a gear tooth arc, and intermediate spaced ends of the arc, a by-pass zone comprising a formation spaced from the circumference defined by the gear tooth arc. Preferably the mechanism includes a plurality of driven devices, the driven devices having respective movement routines in which movement of the driven devices is determined by the driving device, the driving device and respective driven devices each having respective first and second match-up zones configured for mutual match-up during the movement regime, wherein match-up of first zones of the respective devices results in a first routine of relative movement of the devices and match-up of second zones of the respective devices results in a second routine of relative movement of the devices. The movement routines of the driven devices are preferably different. The drive mechanism is preferably utilised for controlling operation of an air distribution arrangement in a vehicle air conditioning system. According to a second aspect, the invention provides a drive mechanism comprising a driving device and a plurality of driven devices, the driven devices having respective movement routines in which movement of the driven devices is determined by the driving device, the driving device and respective driven devices each having respective first and second match-up zones configured for mutual match-up during the movement regime, wherein match-up of first zones of the respective devices results in a first routine of relative

movement of the devices and match-up of second zones of the respective devices resul in a second routine of relative movement of the devices, wherein the routines of movement of the driven devices include an intermittent in nature movement part.

The invention will now be described in specific embodiments, by way of example only, and with reference to the accompanying drawings in which: Figures la to lc show a drive mechanism in accordance with the invention in differing configurations during operation; Figures 2a and 2b show an alternative drive mechanism in different configurations during operation; Figure 3 shows an alternative embodiment of drive mechanism in accordance with the invention; Figure 4 shows a still further alternative configuration of drive mechanism; and Figure 5 is a perspective view of a further embodiment of drive mechanism in accordance with the invention. Referring to the drawings, and initially to Figures la to lc, there is shown a driver gear 2 having a shaft 3 to which rotary motion is imparted by means of an electric actuator motor (not shown). Driver gear 2 comprises a peripheral driving edge having a number of readily spaced gear teeth 4 and a bypass edge 5 projecting outwardly.

Bypass edge 5 is provided on segment 6 upstanding from the face of the toothed gear portion 7. Tooth gear portion 7 and segment 6 are moulded, cast or machined integrally as a single item. There are consequently no gear teeth in the zone obscured by the body of segment 6. Edge 5 comprises a circular arc of specific radius r. Driven gear 8 comprises a gear tooth circumferential edge (driving edge) 9 and a concave arcuate peripheral surface 10 intermediate the ends of the run of peripheral gear teeth 4. Driven gear 8 is, once again, provided as a cast, moulded or machined component having segment 11 (carrying concave arcuate surface 10) standing proud of the gear disc portion 12. The conrigurar--ion of the gears 2, 8 in the mechanism shown in Figures la to lc is specifically designed to produce a predefined regime (routine) of intermittent driving of gear 8 for a predetermined regime (routine) of driving movement of driving gear 2. This is possible because of the arrangement of the segments 6, 11 having surfaces 5, 10. In Figure 1a, driver 2 has meshing teeth 4 with driven gear 8 resulting in simultaneous rotation of both gears 2, 8. In this condition there is match-up of gear teeth 4 for both gears 2, 8. The gears continue to rotate to the situation shown in Figure lb where there is total disengagement of gear teeth 4 between the gears and, instead match-up of arcuate surfaces 5, 10 for the respective gears. Due to the precision manufacture of surfaces 5, 10 on segments 6, 9, in the situation shown. in Figure b driver gear 2 continues to rotate with surface 5 of segment 6 sliding past surface 10 of segment 11.

Consequently gear 8 does not rotate and is, indeed, held against rotation out of specific match-up of the arcuate surfaces 5, 10. When surface 5 has moved completely past surface 10, re-engagement of gear teeth 4 for the respective gears results in continued rotation of the gears in unison. This arrangement is particularly suited to moving items between a start position and a finish position in a precise manner. The movement is reversible such that the gear teeth can be reversed from the position in Figure lc to the position in Figure 1a by rotation of the driver gear 2 in the alternate sense. The reversible rotation of driver gear 2 is controlled by the driving actuator motor (not shown) which is reversible in rotational driving direction. The precise movement regime between the driver gear 2 and driven gear 8 depends upon the shape, configuration and arrangement of the gear teeth peripheral portion 4 relative to the arcuate surface 5, 10 of the relevant segments 6, 11. The arrangement in Figure 2a corresponds to the arrangement shown in Figures la to 1c. This can be compared and contrasted with the arrangement in Figure 2b in which the convex arcuate surface 105 of segment 106 on the driver gear 102 has a significantly greater arc than the arc of surface 5 in the arrangement shown in Figure 2a. Corresponding concave arcuate surface 110 is provided on the segment 111 of driven gear 108. The movement regime of the mechanism shown in Figure 2b will be varied considerably from the regime in Figure 2a in that a far greater proportion of the rotation of driver gear 102 will

be accompanied by slide by of surface 105 and surface 110. The design of the gears is therefore specifically tailored to the resultant desired movement regime required of the mechanisms, and the individual routines required by driven gears 8, 108. It will be seen that a single rotary drive input (into the shaft of gear 2, 102) results in continuous drive output from shaft 3, 103 and also an intermittent drive output to shaft 14, 114 of the driven gear 8, 108. Additionally, as is shown in Figure 3, two driven gears 208, 218 can be driven by a single driver gear 202 providing the rotational orientations of the relative gears and orientation of match-up slide by edges 210, 220 and 205 are carefully matched.

The arrangement in Figure 4 shows, in addition to driver gear 302, driving a rotary driven gear 308, a rack gear 316 is also driven in a routine in which linear motion of rack 316 is halted as surface 305 of segment 306 slides by arcuate concave recess 310 of rack 316.

In the arrangement shown in Figure 5, the driver gear 402 is arranged to drive two driven gears 408, 418 in a predetermined regime of relative movement. Driven gears 418 and 408 are offset and match-up with different respective drive teeth portions and by-past portions of gear 402 in order to follow their specific routines of rotation. By-pass segment 406 has slide by surface 405 which matches up with slide by surface 410 of by-pass segment 411. Gear tooth periphery 404 of gear 408 matches up with gear tooth periphery 404 of driving gear 402.

Driven gear 418 has a slide by surface 420 on segment 419 which matches up with slide by surface 405 on driving gear 402. Gear teeth portion 404 on driven gear 418 matches up with gear teeth peripheral portion 404 of driving gear 402. Arrangements such as that shown in Figure 5 are particularly useful in automotive air conditioning systems in which there is a requirement to drive a number of rotational components between defined positions in a particular manner or order. For example, it is known to have rotationally moveable air distribution/deflection apparatus, such as concentric drums which have side wall apertures arranged to overlap and/or close off one another in order to ensure distribution to the required output vents in the vehicle. An arrangement such as that shown in Figure 5 enables such components to be driven in the required predetermined manner using a single rotary input shaft into gear 402 and consequently utilise only one electric actuator. This results in a reduction in system cost, weight and overall size. Furthermore, complex linkage mechanisms can also be dispensed with.

Claims

Claims: 1. A drive mechanism comprising a driving device and a driven device, the devices having a movement regime in which movement of the driven device is determined by the driving device, the driving device and driven device each having respective first and second match- up zones configured for mutual match-up during the movement regime, wherein match-up of first zones of the respective devices results in a first routine of relative movement of the devices and match-up of second zones of the respective devices results in a second routine of relative movement of the devices.
2. A drive mechanism according to claim 1, wherein in one of the first and second movement routines, the driven device is substantially at a standstill.
3. A drive mechanism according to claim 1 or claim 2, wherein in one of the first and second movement routines, the driven device is moving.
4. A drive mechanism according to any preceding claim, wherein through the first and second driving routines the driving device is moving.
5. A drive mechanism according to claim 4, wherein through the first and second driving routines the driving device is moving at a substantially constant rate.

<Desc/Clms Page number 11>
6. A drive mechanism according to any preceding claim, wherein through the first and second driving routines the driving device is moving in a substantially uniform fashion; and, in one of the first and second movement routines, the driven device being substantially at a standstill; in the other of the first and second movement routines, the driven device moving.
7. A drive mechanism according to any preceding claim, wherein both of the driving device and the driven device have a motion during the regime which is primarily rotational motion.
8. A drive mechanism according to any of claims 1 to 6, wherein one of the devices has a motion during the regime which is primarily linear, the other of the devices having a motion during the regime which is primarily rotational.
9. A drive mechanism according to any preceding claim, wherein one pair of mutual match-up zones comprise drive zones configured to provide driving engagement between the devices.
10. A drive arrangement according to claim 9, wherein the drive zones comprise gear tooth zones, arranged for meshing engagement.

<Desc/Clms Page number 12>
11. A drive arrangement according to any preceding claim, wherein one pair of mutual match-up zones, comprise by-pass zones configured to cooperate to render the devices in a non-drivingly engaged condition.
12. A drive arrangement according to claim 11, wherein the by-pass zones comprise slide-by zones of the respective devices.
13. A drive arrangement according to claim 11 or claim 12, wherein the by pass zones are configured to inhibit rotation of the driven device during match up of the zones but permit rotation of the driving device.
14. A drive arrangement according to any preceding claim, wherein match-up zones on the respective devices cooperate to render the devices in a nor. drivingly engaged condition, the respective match-up zones having respective complementary arcuate concave and convex match-up edges.
15. A drive arrangement according to claim 14, wherein the curvature of the convex match-up edges is substantially the same as the curvature of the concave match-up surface.
16. A drive arrangement according to any preceding claim, wherein one pair of mutual match-up zones comprise drive zones configured to provide driving engagement between the devices and one pair of mutual match-up

<Desc/Clms Page number 13>

zones comprise by-pass zones configured to cooperate to render the devices in a non-drivingly engaged condition, the driving device being rotatable about an axis to drive the driven device, the drive zone and the by-pass zone of the driving device being staggered in the axial direction of rotation.
17. A drive mechanism according to claim 16, wherein the driving device comprises a drive component having a drive zone comprising a gear tooth arc, and intermediate spaced ends of the arc, a by-pass zone comprising a formation spaced from the circumference defined by the gear tooth arc.
18. A drive arrangement according to any preceding claim including a plurality of driven devices, the driven devices having respective movement routines in which movement of the driven devices is determined by the driving device, the driving device and respective driven devices each having respective first and second match-up zones configured for mutual match-up during the movement regime, wherein match-up of first zones of the respective devices results in a first routine of relative movement of the devices and match-up of second zones of the respective devices results in a second routine of relative movement of the devices.
19. A drive mechanism according to claim 16, wherein the movement routines of the driven devices are different.

<Desc/Clms Page number 14>
20. A drive mechanism for controlling operation of an air distribution arrangement in a vehicle air conditioning system.
21. A drive mechanism comprising a driving device and a plurality of driven devices, the driven devices having respective movement routines in which movement of the driven devices is determined by the driving device, the driving device and respective driven devices each having respective first and second match-up zones configured for mutual match-up during the movement regime, wherein match-up of first zones of the respective devices results in a first routine of relative movement of the devices and match-up of second zones of the respective devices results in a second routine of relative movement of the devices, wherein the routines of movement of the driven devices include an intermittent in nature movement part.