Patent GB-547245-A (GB)
Title: Improvements in electric motors
IPC: F16H15/38
Filed: 1940-02-05
Abstract: 547,245. Motors; friction gearing. ALLSPEED ELECTRIC MOTORS, Ltd. Feb. 5, 1940, Nos. 2229 and 2230. Convention dates, May 24, 1939 and Nov. 16, 1939. [Class 35] [Also in Group XXIV] In a motor of the type having oppositely-rotating armature and field members variably geared together, the carrier for a part of the gearing is made capable of rotation in either direction with an infinitely variable speed. In the form shown in Fig. 1, the friction gears 33 are trunnioned in frames 35 in a rotatable carrier 25 and engage annular channels in members 32, 31 respectively keyed to the armature shaft 6 and attached to the field framing 1. The armature shaft is journalled in a pedestal bearing 27a at one end and at the other end it runs on an extension of a second shaft 28 journalled in a pedestal. The field frame is journalled on the armature shaft at 27 and in the pedestal at 29. Toothed or friction gears 43, carried by a fixed member 24 couple the armature and field and the inclination of the friction discs 33, and therefore the speed and direction of rotation of the carrier 25 in which they are mounted, is controlled with either-way infinite gradation, by a lever-operated pinion 38 engaging a rack 39 on a sleeve 37 to which spring members 37a are attached, these being connected at their other ends to the trunnion frames 35 of the discs 33. Power may be taken from a pulley 30 or from the rotating carrier 25. Fig. 4 shows a form in which the friction rollers 33 are mounted in a fixed carrier and the gears 43 between the armature and field rotate together with the shaft 44 which carries them and the driving pulley. In this form, in which driving power may be taken from the armature, field or pulley, the discs 33 serve only to determine the relative velocities of the armature and field. To engage the discs 33 with their annular friction channels with a pressure proportional to the required driving torque the device of Fig. 5 may be used, viz. angularly toothed members 49, 50 respectively fixed to the armature shaft and the member 31<SP>1</SP> which runs loosely on the armature shaft. Engagement of the inclined teeth is controlled by a compression spring 51 and locking device 52. The friction discs 33 may, as shown in Fig. 7, each consist of two discs coupled together by cranked pins 46 and a similarly cranked spindle 45 mounted in slotted bearings so that the two discs may be made to overlap each other. A weight or spring and arm 48 causes them to overlap and bear against their tracks with a pressure which increases as the transmitted torque increases. In another form, two-part friction discs, as just described, are mounted on a carrier so that one set of the half-members of the discs engages a friction track on an overhung flange of the field frame and the other half-members engage a collar on the armature shaft. The Specification as open to inspection under Sect. 91 comprises also a form in which a rotating armature and field carry annular friction tracks engaged by either-way inclinable friction discs mounted in a carrier which is not rotatable, as in the above-described forms, but which is rigid with the machine frame. This subjectmatter does not appear in the Specification as accepted.