Machine element or mechanism – Mechanical movements – Rotary to or from reciprocating or oscillating
Patent
1991-01-23
1992-07-28
Bonck, Rodney H.
Machine element or mechanism
Mechanical movements
Rotary to or from reciprocating or oscillating
74 32, 74 42, 74409, 74440, 152503, F16H 2118, F16H 5518
Patent
active
051332213
DESCRIPTION:
BRIEF SUMMARY
INTRODUCTION
The invention relates to a pendulum gear which is especially used for driving windshield wipers of motor vehicles.
BACKGROUND OF THE INVENTION
Such gears, which are usually located in a gear housing and, together with an electric motor onto which the gear housing is mounted, form a drive unit, the driven shaft of which drive unit extending the gear housing can be moved in pendulum motion, are used for driving windshield wipers in big numbers of pieces in the automobile industry. Such a pendulum gear is known, for instance from the DE-PS 32 37 269. In this known pendulum gear as a first gear member a tooth segment is fixed in a way that is protected against twisting onto a driven shaft which can simultaneously also be called wiper shaft because a wiper arm is directly mounted onto it. This tooth segment meshes with a second gear member which as a tooth segment is integrally formed with a push rod which at its one end is rotatably connected with a crank pin and at its other end is rotatably connected with a crank rocker which is rotatably mounted onto the driven shaft and ensures that the two tooth segments engage into each other. Thereby the axis of the link between the push rod and the crank rocker is identical with the axis of the tooth segment on the push rod.
Since motor vehicles making little noise are demanded more and more by the passengers inside as well as other road-users outside the cars, in the known pendulum gear the noises are considered to be disturbing, which especially occur in the reversing points of the gear, that is then, when the driven shaft reverses its direction of rotation.
BRIEF DESCRIPTION OF THE INVENTION
Therefore the object of the invention is to develop a pendulum gear in such a way that the noises are reduced when the shaft driven in pendulum motion reverses its direction of rotation.
This object is achieved according to the invention by the fact that in the pendulum gear the tooth play between the teeth of the two gear members decreases at least towards one reversing position. Thus first of all the invention is based on the knowledge that the noises in the known pendulum gear go back to the fact that, when reversing the direction of rotation, the teeth of the two gear members meshing with each other change the tooth flanks, on which they lie, and thereby due to the tooth play make a beating noise. However, a certain tooth play is desired for not wearing out the teeth of the gear members nor reducing the effectivity of the motor too much. According to the invention the tooth play between the teeth of the gear members decreases towards the reversing positions of said gear members. Thus wear is only slightly increased and the effectivity of the motor is not reduced because in the reversing positions of the gear members only a minimum torque is required. Simultaneously it is achieved that the teeth of the gear members engaging into each other near the reversing positions lie on both tooth flanks of a tooth gap so that no reversing noise can occur any longer.
The noise is already reduced to a certain extent by the fact that the tooth play between the teeth of the two gear members only decreases towards one reversing position. Of course, the tooth play, whenever it is possible, is to be decreased towards both reversing positions.
Advantageous developments of a pendulum gear according to the invention can be gathered from the subclaims.
So in a first preferred embodiment the tooth play between the teeth of the two gear members is decreased by the fact that towards one reversing position the teeth engage into the tooth gaps between the teeth more deeply. This can advantageously be achieved by displacing the center of a reference circle, which the teeth of a gear member have, with respect to the axis of rotation of the gear member in such a way that the distance between the reference circle and the axis of rotation increases towards the teeth, by way of which in a reversing position the gear member engages into the teeth of the other gear member. In such an embodi
REFERENCES:
patent: 2771782 (1956-11-01), Darby
patent: 3689955 (1972-09-01), Winkelmann
patent: 3754298 (1973-08-01), Menil
patent: 3796104 (1974-03-01), Templeton
patent: 3899933 (1975-08-01), Wright et al.
patent: 4011764 (1977-03-01), Buck et al.
patent: 4137782 (1979-02-01), Lange
patent: 4747321 (1988-05-01), Hannel
patent: 4912998 (1990-04-01), Sugano et al.
Bruhn Rainer
Klinar Robert
Bonck Rodney H.
Lewis J. Gordon
Seitter Robert P.
SWF Auto-Electric GmbH
Wittels Daniel
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