Abstract:
A brush assembly (2) with a plug housing (3) is inserted into an axial opening of a motor housing (1) so that interference suppression devices (5, 6) can be connected easily from a production point of view and the plug terminals and the brush apparatus can be protected against corrosive media. The plug housing is formed with pockets which hold the interference suppression devices and the plug terminals for easy assembly.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of invention 
     The invention relates to a commutator motor with a housing having a closed design and more particularly to a motor housing which includes interference suppression elements. 
     2. Description of the prior art 
     In a known arrangement, disclosed in European Pat. No. 0043460, a connecting plug is cast into a plug housing. The internal terminal ends of the plug protrude into the motor housing and are connected to the carbon brushes. Interference suppression means, if any, are likewise arranged and disposed within the interior of the motor housing. 
     However the above-described arrangement cannot be used if, for operating reasons or because of the size of the motor, the interference suppression means and the plug contacts must be relocated outside the housing. 
     SUMMARY OF THE INVENTION 
     In the present invention, a commutator motor housing is provided which contains connecting plug and interference means and which may be used for oversized motors. A motor housing of a closed design is provided in a manner simple to manufacture. The housing is particularly advantageous for use in automatic production machines and it can assure, especially if used for a pump motor, absolute protection of the interference suppression means, of the electric plug terminals and of the entire brush assembly against vapors or liquids. 
     The commutator motor housing designed in accordance with the invention permits, in spite of its small overall size, the relocation of the interference suppression means and the plug terminals outside the motor housing. The present arrangement further allows these parts to contact each other and the brushes in a moisture-protected manner. All components to be mounted and contacted in the brush assembly or in the integrally-formed-on plug housing can be supplied in space-saving axial handling direction and in a simple manner. 
     If, nevertheless, a corrosive medium should penetrate at extraordinary stress points, for instance, at the feedthroughs of the connecting lines to the motor housing, additional protection of the brush assembly is made possible by the provision of a covering sleeve formed adjacent to the brush assembly which extends along the inside wall of the motor housing in the circumferential direction. The sleeve protects the entire brush assembly against moisture from the outside. Optionally an end cap can be attached to the end face of the sleeve as protection against a liquid that might penetrate from the end bell side of the motor. By this measure, moisture is conducted away from the brush assembly and then, if required, discharged through an opening provided at the lowest point of the motor housing without damage to the brush assembly. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES 
     The invention, as well as further advantageous embodiments of the invention, will be explained in the following with the aid of the drawings wherein: 
     FIG. 1 shows an axial longitudinal section through a commutator motor housing for a hydraulic system constructed in accordance with the invention; 
     FIG. 2 shows an end view of a brush assembly with integrally formed plug housing; 
     FIG. 3 shows a sectional view of the motor housing of FIG. 2 taken along section line II--II; 
     FIG. 4 shows an end view from direction Z of FIG. 3; 
     FIG. 5 shows a further embodiment of the arrangement of the invention; 
     FIG. 6 shows a pre-assembled unit consisting of terminal plugs, interference suppression means and brush holders; 
     FIG. 7 shows an end view of a cover cap provided for closing the service openings of the commutator housing; 
     FIG. 8 shows the arrangement of FIG. 7 along line VIII--VIII. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows an axial longitudinal section of a commutator motor for driving a hydraulic system. In a manner not shown here in detail, but known from the European Patent mentioned above, a brush assembly with an integrally-formed plug housing 3 extending radially outwardly at an opening of the motor housing. 
     Plug housing 3 (shown in more detail in FIGS. 2 to 5) extends radially outwardly of the motor housing and includes three pockets 31, 32 and 33 which are formed at their left end with a service opening which can be closed by a cover cap 4 in such a manner that terminal plugs 7, 8 and a capacitor 6 can be inserted, for instance, into the pocket 31 an interference suppression choke 5 can be inserted axially into the pocket 32. The pockets have radial wiring openings for installing the supply lines 51, 61 from the inner terminal ends 72, 82 of the plugs 7, 8 to the interference suppression choke 5 or to the carbon brushes 11, 12. As can be seen particularly from FIG. 3, the wiring openings for the connecting lines 51, 61 are disposed at the right ends of the pockets 32, 33 and comprise slots at the service opening of pocket 31 so that the connecting lines 51, 61 can be inserted axially through the slotted wiring openings. 
     The connecting lines 51, 61 run from inner terminal ends 72, 82 disposed on the left side of pocket 31 through the slotted wiring openings made in wall 38 separating pocket 31 from pockets 32 and 33 as shown in FIGS. 1 and 4. Terminals 7 and 8 extend from pocket 31 through an end wall 37, said end wall being disposed opposite to the service opening. 
     Advantageously it is provided that the terminal plugs 7, 8, the interference suppression means 5, 6 and the brush holders with the carbon brushes 11, 12 can be preassembled as shown in FIG. 6 and then installed with the mutual connecting lines 51, 61 and the capacitor 6 shunted across the terminal plugs 7, 8 into the brush bridge 2 or the plug housing 6 axially through the service openings. The right-hand external terminal ends 71, 81 of the terminal plugs 7, 8 are then pushed through wall parts 34 of the plug housing 3, opposite the service opening. As can be seen particularly from FIGS. 3 and 5, the external terminal ends 71, 81 of the terminal plugs 7, 8 extend into a plug terminal part 36, onto which an external supply line with a plug can be secured. 
     For a sealing termination of the plug housing 3 after the unassembled elements shown in FIG. 6 have been installed, a one-piece closing cover 4 consisting of a cover part 41 and a strap part 42 (shown in FIG. 3) can be installed. Alternatively the interior of the equipped pockets 31, 32 or 33 can be filled with a casting compound 35 as shown in FIG. 5. 
     FIGS. 7, 8 show details of cover cap 4 which is provided for closing off the service openings, and the slots forming some of the wire openings. The cover cap 4 consists of a lid 41 which closes the end face the service openings, and a cam part 42 which closes off the wire opening slots. 
     In the upper part of the lid part 41 of the cover cap 4, a handle projecting toward the outside is formed which advantageously is used at the same time for accommodating the capacitor 6. In order to seal the assembly well with the cover cap 4, ultrasonic welding of the cover cap 4 is provided, according to one embodiment of the invention, at least in the wall region adjacent to the end face of the cover opening of the pocket 31. 
     As can be seen from FIG. 7, the cover part 41 has thin, axially protruding lips 43, 44 in the vicinity of the connecting lines 51, 61 as these lines are brought through from the pocket 31 into the pockets 32 and 33, respectively. The lips 43, 44 protrude prior to the ultrasonic welding sufficiently so that the connecting wires 51, 61 are pressed against the walls of the pocket 31 or the pockets 32 and 33, but the cover cap 4 cannot yet make contact with its circular rim against the end face of the plug housing 3 in the vicinity of the service opening. During the ultrasonic welding operation, the lips 43, 44 and the opposite wall parts of the housing 3 are softened by the temperature rise and the axial pressure by which the cover cap 4 is pressed against the end face of the plug housing 3, forces these members to flow around the connecting wires 51, 61 forming a seal, while the cover cap 4 reaches its final contact position at the end face of the housing 3. 
     For forming a seal between the motor housing 1 and the connecting wires 51, 61 brought through the strap part 42 of the cover cap 4 and the motor housing 1, a squeezable seal 13 is interposed according to one embodiment as can be seen from FIG. 1. If moisture should penetrate into the interior of the housing 1, in spite of this, additional protection of the brush apparatus is achieved by a cover sleeve 9 which is integrally formed with the brush assembly 3, and extends radially inwardly through the motor housing 1. The brush assembly can additionally be protected by an end cap 91 which can be disposed at the end face of the motor for protection against moisture on the end bell side. Moisture which may have penetrated can flow off through an opening 14 at the underside of the motor housing 1. 
     In a production-wise particularly simple manner, an interference suppression ground line 10 (see FIG. 4) which may be necessary for interference suppression, is connected at one end to the connecting line 61 and at another end to the housing 1. Line 10 forms a seal by the provision that it is contacted as a flexible line by clamping between the wall of the motor housing 1 alone in the region of the housing opening on the one hand, and the brush assembly 3 on the other hand, which can be inserted into the opening with a close fit.