DE102009001685A1 - External disk for shifting element i.e. multiple disk clutch, has synchronized gear tooth system that intervenes in internal teeth of external disk carrier, where system is designed as involute toothing system with specific contact angle - Google Patents

Abstract

The disk (9) has a synchronized gear tooth system that intervenes in internal teeth of an external disk carrier of a shifting element, where the synchronized gear tooth system is designed as involute toothing system (10) with a specific contact angle. Distance between a centroid of the external disk and support points of the external disk is small, where the support points are shifted toward a stable equilibrium. A contact angle of a tooth profile of the tooth system is changed.

Description

The Invention relates to an outer fin for a switching element, in particular a multi-plate clutch according to the preamble of claim 1 and the use of the outer fin.

slats are used as friction elements in frictionally switchable switching elements, d. H. Multi-plate clutches or disc brakes used. The switching element includes a package of inner and outer plates, which have an internal or external driving toothing, which in each case in an inner or an outer disk carrier of the switching element engages. In general, it is about wet-running lamellae, which - not to each other sticking - are designed as so-called sine slats. The driving teeth of inner and outer disks are usually trapezoidal. At fast-running Multi-plate clutches, d. H. at differential speeds of over 50 m / s in the non-switched state, the problem occurs that the outer disks tend to wobble. This is due to the fact that the outer plates in a labile equilibrium, as their points of support in the outer plate carrier below the lamella center of gravity are located. It has therefore already been proposed, the transport profile the outer lamella form dovetail, so that the outer disks are "suspended" in the outer disk carrier. there the suspension points of the outer disks are above the lamella center of gravity, so that a stable balance gives and the outer plate no longer the risk of tumbling subject. The dovetail profile can, however, in some constructions not be implemented or only with great effort.

It is also known, the driving profile of the outer disk form as involute toothing, the standard toothing a Pressure angle of 20 °. A disadvantage of the known involute gears for outer disks is also a tumble at higher relative speeds between the slats. Even with involute gear teeth is the outer plate below its center of gravity in the toothing and thus forms a fragile balance.

It Object of the present invention, an outer fin of the type mentioned in such a way that their tendency to tumble reduced or switched off at higher relative speeds becomes.

The The object of the invention is achieved by the features of the independent Claims 1 and 5 solved. Advantageous embodiments emerge from the dependent claims.

According to the invention provided that the outer plate an involute toothing having a pressure angle α, which is smaller than 15 ° and preferably greater than 5 °. Particularly preferably, the pressure angle α is in the range from 6 ° to 8 °, especially at 7 °. In order to the advantage is achieved that the support points of the outer plate in the internal teeth approach closer to their center of gravity, d. H. the distance between the center of gravity of the outer plate and their support points in the internal teeth is smaller. As a result, the unstable equilibrium and unstable balance the tendency to tumble at higher relative speeds is reduced. It is also advantageous that the inventive Involute toothing cost-effective, d. H. by pitching can be produced. Only the area below 7 ° can be made by simply bumping. The involute toothing as driving teeth facing the simpler Mitnahmeverzahnungen the advantage that higher circumferential forces can be transmitted more uniformly. This allows relatively small and compact switching elements realize, as they especially in high-speed marine transmissions Find use.

The Invention will become apparent from the drawings described below explained, with the description and / or the Drawing further features and / or benefits may result.

It demonstrate

1 a wobble-prone outer lamella according to the prior art,

2 a prior art dovetail spline of the prior art,

3 an involute outer lamella according to the prior art,

4 a further outer plate with involute toothing according to the prior art and

5 an inventive outer disk with involute toothing.

1 shows an outer lamella 1 with a trapezoidal driving toothing 2 According to the state of the art. Such outer plates are used together with inner plates as friction elements for switching elements in transmissions. The slats are usually made of steel and can have a thin friction lining. The outer lamella 1 engages with their driving teeth 2 in a corresponding toothing of an outer disk carrier, not shown, of the switching element. When installed horizontally switching element is the outer plate 1 due to their gravity in the internal toothing, not shown, that is on support or support points, which are connected by a horizontal line a. The center of gravity of the outer plate 1 is denoted by S. It can be seen that the center of gravity S is located clearly above the line a, ie there is a labile equilibrium. The outer lamella 1 tends to wobble at higher differential speeds.

2 shows a known outer fin 3 with a driving toothing 4 , which is designed as a dovetail profile. The center of gravity of the outer plate 3 is denoted by S. Due to the dovetail profile 4 hangs the outer plate 3 in the internal toothing of the outer disk carrier, not shown, in contact points, which are connected by a line a. The line a is above the center of gravity S, ie there is a stable equilibrium here, the risk of tumbling therefore does not exist.

3 shows a schematic representation of an outer fin 5 with an indicated involute toothing 6 According to the state of the art. The involute toothing 6 has an engagement angle α = 30 °, which is not shown in the drawing, but from the literature, for example G. Niemann and H. Winter, Maschinenelemente, Volume II, 1985, page 37 or off DIN 867,868 is known. The involute toothing 6 with an engagement angle of α = 30 ° is on the corresponding internal toothing in the amount of a line a, which to the center M and the center of gravity of the outer disk 5 has a distance A. Since the center of gravity M is above the contact line a, there is an unstable equilibrium, ie the risk of tumbling.

4 shows another known outer fin 7 with an involute toothing 8th , which has an engagement angle of α = 15 °. This leads to a riot line a with a distance A to the center M and the center line m through the center M. The comparison between 3 and 4 shows that the distance A in 4 smaller at a smaller pressure angle. There is still a fragile balance and thus the risk of tumbling.

5 shows an outer fin according to the invention 9 with an involute toothing 10 , which has an engagement angle of α = 7 °. By changing the pressure angle α, the tooth profile changes: a large α means a flat profile with a tendency to sharp teeth and a thick tooth root, while a small α means a steep flank, a thick tooth head and a thin tooth root. This leads to the outer fin according to the invention 9 with a small α to a contact line a relatively close to the center of gravity M a. The distance of the riot line a to the center of gravity M is marked with C. The height difference of the line a in 5 and the line a in 4 is represented by B. It can be seen that the distance C to the center of gravity at a pressure angle of α = 7 ° relatively low and the tendency to tumble of the outer disk 9 is therefore substantially reduced. The support of the outer plate 9 is more relocated towards stable equilibrium. The involute toothing with an engagement angle of α = 7 ° can be inexpensively manufactured by Wälzstoßen.

The outer plate according to the invention 9 can be used advantageously in multi-plate clutches in transmissions, in particular marine and marine gearboxes, in which a differential speed between the inner and outer plates in the non-switched state reaches or exceeds the value of 50 m / s.

1

outer plate

2

Outside engaging gears

3

outer plate

4

dovetail teeth

5

outer plate

6

involute (α = 30 °)

7

outer plate

8th

involute (α = 15 °)

9

outer plate

10

involute (α = 7 °)

a

perpendicular line

m

center line

M

Focus (Main emphasis)

S

main emphasis

A

distance

B

distance difference

C

distance

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited non-patent literature

• - G. Niemann and H. Winter, Maschinenelemente, Vol. II, 1985, page 37 [0016]
• - DIN 867,868 [0016]

Claims (5)

Outer plate ( 9 ) for a switching element, in particular a multi-plate clutch, comprising an outer driving toothing, which engages in an internal toothing of an outer disk carrier of the switching element, characterized in that the external driving toothing as involute toothing ( 10 ) is formed with an engagement angle α <15 °. Outer fin according to claim 1, characterized the pressure angle a is> 5 °. Outer fin according to claim 1 or 2, characterized characterized in that the pressure angle α 6 ° to 8 °, in particular 7 °. Outer plate according to claim 1, 2 or 3, characterized in that the internal toothing as involute toothing with the same pressure angle α as the external toothing ( 10 ) of the outer plate ( 9 ) is trained. Use of outer plate ( 9 ) according to one of claims 1 to 4 for multi-plate clutches with relative speeds between the slats of more than 50 m / s.