GB2037097A

GB2037097A - Electrical coupling

Info

Publication number: GB2037097A
Application number: GB7937500A
Authority: GB
Original assignee: Micafil AG
Current assignee: Micafil AG
Priority date: 1978-11-01
Filing date: 1979-10-30
Publication date: 1980-07-02
Also published as: DE2900343A1; GB2037097B; CH639780A5

Abstract

In a contact apparatus of a measuring equipment for testing an armature 4, pivoted contact levers are provided to make contact with respective segments of the collector 5, at their ends 2. Means 10, 12 are provided for moving all levers simultaneously to close their ends 2 radially onto the running surface of the collector. The armature is tested whilst stationary, thus avoiding wear on the contacts of the apparatus, and armatures complete with bearings 6 may be accommodated by the apparatus. <IMAGE>

Description

SPECIFICATION Apparatus for contacting collectors of armatures under test This invention relates to an apparatus for making contact to a collector or commutator of an armature of an electrical machine, for testing the armature.

In armature testing equipment it is usual for contact brushes to make contact with the collector or commutator of the rotating test sample. A disadvantageous effect is the considerably extended test time, whilst wear of the contact brushes cannot be avoided.

In order to overcome this disavantage, it has already been proposed to construct the contact apparatus to receive the armature to be tested by axial insertion of the collector so that it comes into contact, at its end, with contact faces disposed obliquely outwards, the armature then being tested in stationary position. The making of contact is effected through contact points or a contact line at the periphery of the end of the collector and the contact pressure is effected only by the insertion pressure of the armature.

Such a contact apparatus does not permit any testing of armatures wherein a rolling bearing and/or an energy disc are mounted on the armature spindle axially outwards of the collector, as a result of which making contact would be rendered impossible. For this reason, the bearing elements are only mounted on the armature after testing, as a result of which a source of error may occur which cannot be checked, because damage to the test sample may occur when the bearing is pressed on.

A further disadvantage consists in that the collector may have an unclean contact surface, for example a non-smooth surface caused by pressboard residues at its end to be received by the contact apparatus, which can result in inadequate contact-making and may lead to faulty measurements.

In accordance with this invention, there is provided apparatus for making contact to a collector or commutator of an armature of an electrical machine, for testing the armature, said apparatus comprising a plurality of electrical contact levers, one for each of the segments of the collector of the armature to be tested, the apparatus being arranged to receive the armature, and means for moving the levers, once the armature has been received by the apparatus so that one end of each lever moves radially into or out of contact with a respective said segment.

The armature is tested in stationary position, and it is possible to make contact to a test sample having a rolling bearing and/or an energy disc already mounted, as a result of which reliable measurement results are assured.

A further advantage consists in the sure making of contact at the running face of the collector with a stationary armature, without the least wear, erroneous measurements being avoided.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawing, the single figure of which is a longitudinal section through a contact apparatus.

The contact apparatus shown, of an armature testing apparatus, comprises movable and controlled contact levers 2, provided in a number corresponding to the number of segments of a collector or commutator 5 of the armature to be tested. The one end of each contact lever 2 is constructed in the form of a sensor and the other end in the form of a plug contact 3. The number of contact levers is preferably 6 to 36, but collectors or commutators with an odd number of segments can also be tested. The contact levers 2 are adapted for movement via upright points of rotation and can be actuated simultaneously. A test sample 4, 5, 6, consisting of an armature 4 with the collector 5 and a bearing 6, provided on the armature spindle, for example a rolling bearing and/or energy disc, is pushed axially into the contact apparatus against a shaft 8.

Before receiving the actual test sample, the contact levers 2 with their sensors are opened radially outwards according to the collector diameter, and the opening can be adjusted by turning an adjusting nut 7. A piston 10, preferably actuated pneumatically, holds the contact levers 2 open, and the force of springs 13, which, through thrust bolts 12, exert the contact pressure of the contact levers 2 against the running surface of the collector 5, is overcome by air pressure acting on the piston 1 0. After the test sample 4, 5, 6 has been introduced axially into the contact apparatus, the end of the armature spindle comes into contact with the shaft 8 and displaces this into the contact apparatus and releases the venting of the piston 10 through a switch 9, as a result of which the piston 10 is pushed back by a return spring 11 and the contact levers 2 are closed radially inwards simultaneously by the action of the springbiassed thrust bolts 1 2 already mentioned and make contact with adjustable contact pressure at the running surface of the collector 5, so that the measurement can begin through the plug contacts 3 leading to measuring apparatus. The simultaneous opening of all the contact levers 2 is effected by means of the pneumatic piston 10, the simultaneous closing of all the contact levers 2 is effected by the thrust bolts 1 2 after venting of the piston 1 0. The actuation of the piston 10 could also be effected hydraulically or mechanically.

1. Apparatus for making contact to a col

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Apparatus for contacting collectors of armatures under test This invention relates to an apparatus for making contact to a collector or commutator of an armature of an electrical machine, for testing the armature. In armature testing equipment it is usual for contact brushes to make contact with the collector or commutator of the rotating test sample. A disadvantageous effect is the considerably extended test time, whilst wear of the contact brushes cannot be avoided. In order to overcome this disavantage, it has already been proposed to construct the contact apparatus to receive the armature to be tested by axial insertion of the collector so that it comes into contact, at its end, with contact faces disposed obliquely outwards, the armature then being tested in stationary position. The making of contact is effected through contact points or a contact line at the periphery of the end of the collector and the contact pressure is effected only by the insertion pressure of the armature. Such a contact apparatus does not permit any testing of armatures wherein a rolling bearing and/or an energy disc are mounted on the armature spindle axially outwards of the collector, as a result of which making contact would be rendered impossible. For this reason, the bearing elements are only mounted on the armature after testing, as a result of which a source of error may occur which cannot be checked, because damage to the test sample may occur when the bearing is pressed on. A further disadvantage consists in that the collector may have an unclean contact surface, for example a non-smooth surface caused by pressboard residues at its end to be received by the contact apparatus, which can result in inadequate contact-making and may lead to faulty measurements. In accordance with this invention, there is provided apparatus for making contact to a collector or commutator of an armature of an electrical machine, for testing the armature, said apparatus comprising a plurality of electrical contact levers, one for each of the segments of the collector of the armature to be tested, the apparatus being arranged to receive the armature, and means for moving the levers, once the armature has been received by the apparatus so that one end of each lever moves radially into or out of contact with a respective said segment. The armature is tested in stationary position, and it is possible to make contact to a test sample having a rolling bearing and/or an energy disc already mounted, as a result of which reliable measurement results are assured. A further advantage consists in the sure making of contact at the running face of the collector with a stationary armature, without the least wear, erroneous measurements being avoided. An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawing, the single figure of which is a longitudinal section through a contact apparatus. The contact apparatus shown, of an armature testing apparatus, comprises movable and controlled contact levers 2, provided in a number corresponding to the number of segments of a collector or commutator 5 of the armature to be tested. The one end of each contact lever 2 is constructed in the form of a sensor and the other end in the form of a plug contact 3. The number of contact levers is preferably 6 to 36, but collectors or commutators with an odd number of segments can also be tested. The contact levers 2 are adapted for movement via upright points of rotation and can be actuated simultaneously. A test sample 4, 5, 6, consisting of an armature 4 with the collector 5 and a bearing 6, provided on the armature spindle, for example a rolling bearing and/or energy disc, is pushed axially into the contact apparatus against a shaft 8. Before receiving the actual test sample, the contact levers 2 with their sensors are opened radially outwards according to the collector diameter, and the opening can be adjusted by turning an adjusting nut 7. A piston 10, preferably actuated pneumatically, holds the contact levers 2 open, and the force of springs 13, which, through thrust bolts 12, exert the contact pressure of the contact levers 2 against the running surface of the collector 5, is overcome by air pressure acting on the piston 1 0. After the test sample 4, 5, 6 has been introduced axially into the contact apparatus, the end of the armature spindle comes into contact with the shaft 8 and displaces this into the contact apparatus and releases the venting of the piston 10 through a switch 9, as a result of which the piston 10 is pushed back by a return spring 11 and the contact levers 2 are closed radially inwards simultaneously by the action of the springbiassed thrust bolts 1 2 already mentioned and make contact with adjustable contact pressure at the running surface of the collector 5, so that the measurement can begin through the plug contacts 3 leading to measuring apparatus. The simultaneous opening of all the contact levers 2 is effected by means of the pneumatic piston 10, the simultaneous closing of all the contact levers 2 is effected by the thrust bolts 1 2 after venting of the piston 1 0. The actuation of the piston 10 could also be effected hydraulically or mechanically. CLAIMS

1. Apparatus for making contact to a col lector or commutator of an armature of an electrical machine, for testing the armature, said apparatus comprising a plurality of electrical contact levers, one for each of the segments of the collector of the armature to be tested, the apparatus being arranged to receive the armature, and means for moving the levers once the armature has been received by the apparatus, so that one end of each lever moves radially into or out of contact with a respective said segment.

2. Apparatus as claimed in claim 1, wherein an axially displaceable piston, provided with a return spring, is provided for the simultaneous opening of all contact levers.

3. Apparatus as claimed in claim 1 or 2, comprising means for adjusting the diameter to which the contact levers open.

4. Apparatus as claimed in claim 2 or claim 3 appended to claim 2, further comprising a centrally disposed and axially displaceable shaft, being displaceable upon the apparatus receiving an armature to be tested, to cause actuation of the piston.

5. Apparatus as claimed in any preceding claim, comprising means for biassing the contact levers for the simultaneous closing of them all.

6. Apparatus for making contact to a collector or commutator of an armature of an electrical machine, for testing the armature, substantially as herein described with reference to the accompanying drawing.