DE10116807B4 - Method and device for producing transmission disks of a continuously variable transmission - Google Patents

Abstract

method for the production of gear discs (1) for a continuously variable Transmission in which at least one pair of transmission disks (1) with their transmission surfaces (2) arranged opposite which is in operation of the transmission with a power transmission element force fit are in contact, on a device with at least one workpiece spindle (3) and with a grinding wheel (4), which for grinding the transmission surface (2) at least one gear disc (1) via a grinding spindle (5) is driven, characterized in that when grinding the transmission surface (2) a repeated, regarding the Workpiece spindle (3) radial relative pendulum motion between the grinding wheel (4) and the gear disc (1) is executed so that the grinding area the grinding wheel between an inner radius (2.1) and an outer radius (2.2) the transmission surface (2) reciprocates, wherein the transmission disc (1) so by means of the workpiece spindle (3) rotates that the entire transmission surface (2) is ground, and the movements of the grinding wheel (4) and the gear disc (1) be tuned to each other so that by generating ...

Description

The The invention relates to a method and a device for the production of transmission discs of a continuously variable transmission, at which at least one pair of transmission disks arranged opposite to their transmission surfaces which is in operation of the transmission with a power transmission element force fit are in contact, on a device with at least one workpiece spindle and with a grinding wheel, which for grinding the transmission surface at least a gear disc over a grinding spindle is driven.

Such a method and such a device are based on the abstract JP 2000271827 A out.

such continuously variable transmissions, e.g. variable transmission, are also referred to as CVT (Continuously Variable Transmission) transmissions and have at least one pair of transmission disks each with one for example, substantially conical or crowned, i. curved Transmission surface. Under transmission surface here is the surface understood, which for power transmission serves. The transmission surface can be a curved in the radial direction of the transmission plate or straight shape. The gear wheels arranged in pairs are adjustable at a distance to each other, with a between them Power transmission element, such as. a delicate chain can be deflected. By a Adjustment of the distance between the gear disks is the stepless adjustability achieved. Here, the power transmission element moves force fit along the transmission surface the opposite one Gear wheels. The power transmission element So in the operation of the transmission along the transmission surface of the Transmission washers between an inner diameter and an outer diameter on the transmission surface and from inside to outside or vice versa.

It here is the problem that the transmission discs with a such force against the power transmission element pressed Need to become, that the power transmission element can not slip. Slippage must be effectively avoided. On the other hand, it is desirable to keep the contact pressure of the gear discs as low as possible unnecessary high surface pressure in the power transmission to avoid from the transmission sheaves on the power transmission element. Nevertheless, it may be between the transmission discs and the power transmission element not to slip.

at the production of such transmission discs for continuously variable transmission exists as well the problem that the transmission washes a high strength and in as possible must have a low tolerance machined transmission surface. The high strength of the gear disc is essential for a possible long life of the gearbox. Bumps and shape deviations of the Transmission surface Such transmission discs are to be avoided to a trouble-free and as possible noise To ensure operation of the transmission.

According to the JP 2000271827 A the transmission surface of the gear disc is ground with a narrow grinding wheel, whose circumferential surface has a conical contour. The rotating grinding wheel is driven by a grinding spindle, which is moved during the grinding process along a surface line of the transmission surface. The direction of movement of the grinding spindle thus also runs parallel to a surface line on the conical contour of the rotating grinding wheel. The delivery of the grinding wheel to the transmission surface is perpendicular to the direction of movement of the grinding spindle. In this way, the usual circular grinding pattern of cylindrical grinding is produced on the transmission surface.

With the known grinding method according to the JP 2000271827 A Thus, if the roughness is sufficiently low, the unevenness and shape deviations of the transmission surface can be kept low. This will be all the more the case if the surface is sanded very smoothly. But there is also a certain roughness required so that the power transmission element does not slip under heavy load on the transmission surfaces during operation of the transmission. Thus, when processing by grinding, there are contradictory objectives.

From the EP 0 997 670 A2 It has also been known to treat the transmission surfaces of such gear wheels by a shot peening process. In this case, jet bodies were provided with a particle diameter of 0.03 to 0.2 mm. The aim was to have transmission surfaces with an average center roughness of 0.1 to 0.5 μm and a Vickers hardness of not less than 850 at a load of 200 g. In this known method creates an irregular surface image with a sufficient roughness. However, it is to be feared that the unavoidable unevenness and deviations in shape of the resulting transmission surfaces will result in a trouble-free and as quiet as possible long-lasting operation of the device assembled gearbox no longer guarantee.

It is therefore the object of the present invention, a method or provide a device of the type mentioned, with which the power transmission properties improved between the transmission disks and a power transmission element be, life increases and nevertheless a slippage of the power transmission element sure is avoided.

These The object is achieved by a production method having the features according to claim 1 or by a device having the features according to claim 10 solved. Advantageous embodiments and further developments of the invention are Subject of the respective subclaims.

at the method of manufacturing transmission disks according to the invention is when grinding the cone-shaped or convex transmission surface in relation to the workpiece spindle a radial, relative oscillating motion between the grinding wheel and the gear disc executed, so that the grinding area of the grinding wheel on the transmission surface between an inner and an outer radius the surface emigrated. As a result, the grinding pattern of the transmission surface can be targeted changed become. Instead of the usual circular grinding, essentially circular grinding pattern is in the inventive method produces a cross-cut. With cross-cut here is a sanding picture meant, in which grinding marks somehow intersect. To this Way can specifically the surface roughness the transmission surface the transmission washers are adjusted, ensuring optimum conditions to prevent slippage from a power transmission element be created during operation of the transmission. The surface is in the required tight dimensional tolerances can be produced and has the necessary strength. As with the targeted adjustment of the surface roughness the transmission discs significantly improved the slip behavior slippage to a great extent is avoided, the contact pressure of the transmission discs can continue be reduced, resulting in a reduction in surface pressure and thus also the friction in the power transmission and thus one increase the efficiency of the transmission results. A continuously adjustable Transmission with inventively produced Transmission discs leads thus ultimately also to a reduction in fuel consumption an internal combustion engine compared to conventionally produced transmissions.

One The cross-cut produced in this way also has the advantage that the load-bearing components on the surface of the gear disks are higher, because it is a similar "cross-cut" as honored surfaces is.

At the Angular plunge grinding creates a Peripherieschliff, exactly in the geometric negative form must be trained so that any form error of dressing on the workpiece is shown. Due to the pendulum motion form errors of Dressing "warped", so they do not more on the workpiece be imaged. Furthermore offers cross-grinding in terms of power transmission at the power transmission point Advantages. The pendulum grinding also results in a lower thermal load of the workpiece when grinding, because the workpiece until re-engagement of the grinding wheel at the same grinding point completely cooled again Has.

To an advantageous embodiment of the invention, the speed the workpiece spindle matched the relative pendulum motion. This allows a uniform sanding image on the transmission surface be generated in all areas. Also in this way the surface roughness purposefully increased or reduced. After a related advantageous aspect the invention, the speed of the workpiece spindle in dependence changed from the radial grinding position of the grinding wheel on the transmission surface. hereby can be a uniform sanding picture be generated on all areas of the transmission surface, for example by increasing or decreasing workpiece spindle speed, in particular by achieving equal grinding conditions at all grinding locations, around the same surface roughness to produce on all peripheral areas of the transmission plate. It will This avoids that at different positions on the Transmission disc with the power transmission element different slip limits works.

To a further advantageous embodiment of the invention is the Speed of the pendulum movement as a function of the radial position the grinding wheel on the transmission surface of the gear disc changed. By one in the direction of the outer circumference Decreasing speed of the pendulum motion becomes one depending on the respective peripheral area uneven grinding pattern avoided. The relative pendulum motion can be either by a back and forth the grinding wheel or the gear disc are performed.

According to a further advantageous embodiment of the invention, two workpiece spindles are provided, which are arranged to each other such that a pendulum movement over the Transmissi Ons surfaces of two gear wheels can be performed so that two gear discs are ground in a single clamping with a grinding wheel. The two workpiece spindles are in this case adjusted so that the transmission surfaces of the two gear wheels are arranged adjacent, wherein the conical or spherical transmission surfaces are each in a plane. The machining of two gear disks in one clamping in accordance with the method according to the invention thus enables a reduction of the production times. The cycle times can be approximately halved. It goes without saying that the respective workpiece spindle speeds are adapted to the extended pendulum path.

To a related matter Aspect of the invention are the two workpiece spindles around a common Pivot point so pivotable that produces a spherical shell shape of the transmission surfaces can be. The position of the pivot point is determined by the radius of the spherical shape.

The inventive device for the production of gear discs with a transmission surface for a stepless adjustable transmission for performing the method after a the claims 1 to 9 is specified in claim 10. It includes a device with a grinding wheel used for grinding the workpiece via a grinding spindle is driven, with rotary drive and clamping the workpieces by means of Workpiece spindle, wherein it is provided that for receiving a respective transmission disk two workpiece spindles are provided, which in terms of their orientation and the distance in relation adjustable to a swivel angle α so that a pendulum motion between grinding wheel and transmission surfaces of both Gear disks are carried out in one clamping with a grinding wheel can.

By the pendulum movement between grinding wheel and transmission surfaces will be possible, the desired cross-section, a spiral outward running or another desired one Create a sanding picture. This allows transmission discs with the device with a desired and predefined surface roughness getting produced. The detailed arrangement of two Workpiece spindles allows so the simultaneous grinding of two gear wheels simultaneously as well as the execution of pendulum movement according to the invention when grinding. The production times can be reduced in this way become. Due to the adjustability of the workpiece spindles at a distance from each other can also different sizes Gear disks with a specifically influenced surface roughness getting produced. In addition, thereby the cone angle is adjustable.

The relative oscillatory motion may preferably be achieved either by a reciprocating grinding wheel or a correspondingly movable gear disc can be realized.

To Another aspect of the invention are the two workpiece spindles pivotable about a common pivot point; this allows the Production of crowned or curved lateral surfaces of the Transmission surfaces. The pivot point determined here by the desired or required radius of curvature. The pivoting movement then also serves to generate the relative pendulum motion.

To a further advantageous embodiment of the invention is the Device part of a CNC machining center. In this way can the gear disks are processed in one clamping. A conversion between different ones, preceding or following the grinding Processing steps is not required.

The inventive device may comprise a control device with which the relative Pendulum motion is specifically controlled. This allows the pendulum movement to be changed in a targeted way that a predefined surface roughness the transmission surface the transmission washers can be adjusted on the device. At the control device can e.g. the speed of the workpiece spindle and the speed of the pendulum motion be variable. On this way you can made with the device a variety of surface roughness become. The processing of the transmission surface can so in each case application-related, i.

in the With regard to their slip and friction properties during operation a gearbox, to be optimized.

The Invention will be described below with reference to the accompanying Drawing described in detail. In the drawing show:

1 a schematic plan view of a first embodiment for carrying out the grinding method according to the invention;

2 a schematic plan view of a grinding apparatus according to the invention with two workpiece spindles;

3 a schematic plan view of an alternative embodiment of the 1 ; and

4 a schematic plan view of an alternative executed grinding device to the off 2 ,

In the 1 is simplified a plan view of a grinding device for performing the grinding method according to the invention shown. As a workpiece 1 is a gear disc with a conical surface, namely the transmission surface 2 , on a workpiece spindle 3 clamped. The gear disc 1 has a conical transmission surface 2 on, ie it is curved in one direction only. It goes without saying, however, that the gear disc 1 may also have a curved shape in two directions. A grinding wheel 4 is on a grinding spindle 5 for grinding the conical transmission surface 2 the gear disc 1 intended. The grinding wheel 4 and the grinding spindle 5 are on a grinding spindle slide 6 so provided that the grinding wheel 4 while grinding the surface 2 can perform a pendulum motion. For this purpose, further is a control device 7 provided, via which the speed of the workpiece spindle 3 as well as the pendulum movement of the grinding wheel 4 is controllable. The grinding wheel 4 oscillates during grinding of the transmission surface 2 the gear disc 1 between an outer radius 2.2 and an inner radius 2.1 so back and forth that the sanding marks on the surface 2 cross. That way, on the surface 2 a cross-cut are generated. With the device can thus specifically the surface roughness of the transmission surface 2 the gear disc 1 to be influenced. With the control device 7 In particular, the speed of the workpiece spindle 3 and the speed of the pendulum motion adjustable. Other setting parameters are known, such as the delivery of the grinding wheel 4 towards the surface 2 in the XY plane.

The 2 schematically illustrates a second embodiment of the grinding apparatus according to the invention, in which, in contrast to the embodiment described above, two workpiece spindles 3 . 3 ' are provided. In this way, with the device is a grinding of two transmission disks 1 . 1' in one clamping with a single grinding wheel 4 possible. For this purpose, the two workpiece spindles 3 . 3 ' according to the conical shape of the transmission surface 2 . 2 ' the transmission washers 1 . 1' aligned with each other so that the generatrices of one half of the conical surface 2 . 2 ' lie in one plane. The grinding spindle 5 is on a grinding spindle slide 6 arranged, which is a pendulum motion of the inner radius 2.1 the surface 2 the one transmission disc 1 up to the inner radius 2.1 the other gear disc 1' allowed. As a result, the manufacturing times for the grinding of the transmission surface of transmission disks can be reduced.

3 schematically illustrates an alternative embodiment of the grinding device 1 Instead of a movable grinding spindle slide 6 here is the pendulum motion when grinding the transmission surface 2 by a pivotable, ie swinging back and forth workpiece spindle 10 executed. This creates a radius shape, ie convex shape of the transmission surface 2 which has a targeted surface roughness because of the crosscut produced. The position of the pivot point 8th determines the radius of curvature of the spherical surface and is preferably adjustable.

In 4 is analogous to 3 an alternative embodiment of the grinding machine 2 shown schematically with two workpiece spindles. The two workpiece spindles 10 . 10 ' are about a common pivot point 9 pivotally arranged so that the pendulum movement over the workpiece spindle, 10 . 10 ' is executable while the grinding wheel 4 is delivered in the Y direction. The pivot point 9 is adjustable, as well as the pivoting angle α for an adaptation of the device to different forms of transmission discs.

1, 1'

gear wheel (Workpiece)

2, 2 '

Transmission surface

2.1

inner radius the transmission surface

2.2

outer radius the transmission surface

3, 3 '

Workpiece spindle

4

grinding wheel

5

grinding spindle

6

Grinding spindle slide

7

control device

8th

pivot point

9

common pivot point

10 10 '

swiveling Workpiece spindle

α

swivel angle

Claims (14)

Method for producing gear disks ( 1 ) for a continuously variable transmission in which at least a pair of the transmission discs ( 1 ) with their transmission surfaces ( 2 ) is arranged opposite, which force during operation of the transmission with a power transmission element are conclusively in contact, on a device with at least one workpiece spindle ( 3 ) and with a grinding wheel ( 4 ), which are used for grinding the transmission surface ( 2 ) at least one transmission disc ( 1 ) via a grinding spindle ( 5 ), characterized in that during grinding of the transmission surface ( 2 ) a repeated, with respect to the workpiece spindle ( 3 ) radial relative oscillating motion between the grinding wheel ( 4 ) and the transmission disc ( 1 ) is performed so that the grinding area of the grinding wheel between an inner radius ( 2.1 ) and an outer radius ( 2.2 ) of the transmission surface ( 2 ), whereby the transmission disc ( 1 ) so by means of the workpiece spindle ( 3 ) rotates that the entire transmission surface ( 2 ), and wherein the movements of the grinding wheel ( 4 ) and the transmission disc ( 1 ) are adjusted to one another in such a way that, by generating a cross-cut grinding image, the surface roughness of the transmission surface ( 2 ) is set to a desired level. A method according to claim 1, characterized in that the rotational speed of the workpiece spindle ( 3 ) is tuned to the relative pendulum motion. A method according to claim 2, characterized in that the rotational speed of the workpiece spindle ( 3 ) as a function of the radial grinding position of the grinding wheel ( 4 ) on the transmission surface such ( 2 ), that on all areas of the transmission surface ( 2 . 2 ' ) a uniform sanding image is generated. A method according to claim 1, characterized in that the speed of the oscillating movement in dependence on the radial position of the grinding wheel ( 4 ) on the transmission surface ( 2 ) of the transmission disc ( 1 ) is changed in such a way that on all areas of the transmission surface ( 2 . 2 ' ) a uniform sanding image is generated. Method according to one of the preceding claims, characterized in that the gear disc ( 1 ) performs a pendulum motion. Method according to one of claims 1 to 4, characterized in that the grinding wheel ( 4 ) performs a pendulum motion. Method according to one of the preceding claims, characterized in that two workpiece spindles ( 3 . 3 ' ) and that when grinding the transmission surfaces ( 2 . 2 ' ) of two gear disks ( 1 . 1' ) a relative oscillating movement is carried out for grinding two gear disks ( 1 . 1' ) in one clamping. Method according to claim 7, characterized in that the workpiece spindles ( 3 . 3 ' ) about a common pivot point for producing a crowned shell shape of the transmission surfaces ( 2 . 2 ' ). A method according to claim 7, characterized in that for the production of a conical shell shape of the transmission surfaces ( 2 . 2 ' ) the grinding wheel performs a pendulum motion. Device for producing transmission disks ( 1 ) with a transmission surface ( 2 ) for a continuously variable transmission for carrying out the method according to one of claims 1 to 9, with a grinding wheel ( 4 ), which are used to grind the workpiece via a grinding spindle ( 5 ) is driven, with rotary drive and clamping the workpieces by means of workpiece spindle, characterized in that for receiving a respective transmission disc ( 1 ) two workpiece spindles ( 3 . 3 ' ) are provided, which are adjustable in their orientation and at a distance in relation to a pivot angle (α), so that a pendulum movement between grinding wheel ( 4 ) and transmission surfaces ( 2 . 2 ' ) of both transmission disks ( 1 . 1' ) in one clamping with a grinding wheel ( 4 ) can be performed. Apparatus according to claim 10, characterized in that a grinding spindle slide ( 6 ) and the grinding wheel ( 4 ) is arranged reciprocable. Apparatus according to claim 10, characterized in that the transmission discs ( 1 . 1' ) are arranged reciprocable. Apparatus according to claim 10, characterized in that the workpiece spindles ( 3 . 3 ' ) around a common pivot point ( 9 ) are pivotable for producing a spherical shell shape of the transmission surfaces ( 2 2 ' ) of both transmission disks ( 1 . 1' ). Device according to one of claims 11 to 13, characterized that it is part of a CNC machining center.