US1501265A - Speed-regulator system - Google Patents

Description

July 15 1924. 1,501,265

. v c. A. BODDIE SPEED REGULATOR SYSTEM Filed Jan. 26, 1921 WITNESSES: i lNVENTOR (/inwaflaadia Patented July 15, 1924.

UNITED 'srArEs PATENT OFFICE.

OLABENCE A. BODDIE, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

SPEED -REGULATOR SYSTEM.

Application filed January 26, 1921. Serial No. 440,043.

T 0 all whom it may concern:

Be it known that I, CLARENCE A. BODDIE, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Speed- Regulator Systems, of which the following is a specification.

My invention relates to regulator systems and has special relation to regulator systems for maintaining the speed of rotating members substantiall constant.

One object of my 1nvention is to provide a speed-regulator system that shall have a motor-operated rheostat so controlled by a differential gear mechanism as to govern the excitation of the motor being controlled to maintain its speed substantially constant and that shall be provided with means controlled by the motor-operated rheostat for reacting on the differential gear mechanism to revent hunting action.

11 many industries, such, for example, as the steel industries, many operations are performed which require motors to be operated at substantially constant speed, irrespective of the loads carried by them. Thus, in a rolling mill and, particularly, in a continuous mill for rolling ingots into billets, it'is essential that the various sets of rolls operate at substantially constant speed to prevent buckling or stretching of thesteel passing through the rolls.

In a speed-regulator system constructed in accordance with my invention, a small alternating-current generator is rotated in accordance with the speed of the main motor being controlled. A small synchronous motor is connected to a direct-current generator and serves to operateone end of a differential gear mechanism. The opposite end of the differential gear mechanism is operated by a constant-speed motor. The central portion of the differential gear mechanism operates a contact arm which, in turn, controls the operation of a motoroperated rheostat.

The motor-operated rheostat so controls the excitation of the main motor as to maintain its speed substantially constant. A cam member, which is operated by the motor-operated-,rheostat, is loosely connected to the contact arm in order to react on such arm and prevent hunting action.

. The single figure of the accompanying drawing is a diagrammatic illustration of a regulator system constructed in accordance with my invention.

Referring to the drawing, a main motor 1, comprisin an armature 2 and a fieldmagnet winding 3, is connected, in any suitable manner, to a set of rolls, one only of which, 4, is illustrated on the drawing. The armature 2 is connected to a supply circult, comprising conductors 5 and 6, through any suitable control apparatus, not shown on the drawing. The field-magnet winding 3 is connected, through the resistor 7 of a motor-operated rheostat 8, to an auxiliary supply circuit comprising conductors 9 and 10. i

A differential gear mechanism 11 is operated in accordance with the variations in speed of the main motor 1 and serves to control the operation of the motor-operated rheostat 8. The rheostat 8 so controls the excitation of the main motor as to maintain its speed substantially constant.

An alternating-current generator 12 is operated in accordance with the speed of the main motor 1, and, preferably, is directly connected to the armature shaft 13 of the main motor. The generator 12 comprises a field-magnet winding 14, which is connected to the supply conductors 9 and 10, and an armature 15 which is electrically con nected to the armature 16 of a synchronous motor 17. The synchronous motor 17 serves to operate one end of the differential gear mechanism 11 in accordance with the speed of the main motor 1. The field-magnet winding 18 of the synchronous motor 17 is connected to any suitable direct-current source.

An auxiliary constant-speed, direct-current motor 19 is connected to the opposite end of the differential gear mechanism 11. The auxiliary motor 19 comprises an armature 20 and a field-magnet winding 21 which is connected, through a speed-adjusting rheostat 22 and a temperature compensating rheost'at 23, to the supply conductors 9 and 10. The motor 19 is operated at a substantially constant speed in any well known manner. I

The differential gear mechanism 11 comprises a bevel pinion 24 'and a gear wheel 25' which are rigidly connected together and are rotatably mounted on a shaft 26. The gear wheel meshes with a gear wheel 27 which is mounted on the armature shaft of the synchronous motor 17. A similar pinion 28 and gear wheel 29 are mounted on the sha ft 26 and are adapted to be operated, by the constant-speed motor 19, through a gear wheel 30 which meshes with the gear wheel 29. The central portion of the differential gear mechanism comprises two pinions 31 which are rotatably mounted on a block 32 and mesh with the pinions 24 and 28. The block 32 is fixedly mounted on the shaft 26.

In the structure above described, one end,

of the differential gear mechanism 11 is operated at a constant speed by means of the direct-current motor 19. The opposite end of the differential gear mechanism is operated in accordance with the speed of the main motor 1. Consequently, the central portion of the differential gear mechanism is operated in accordance with the variations in speed of the motor 1.

The differential gear mechanism 11 controls a contact arm 33 for selectively operat. ing two switches 34 and 75. The contact arm 33 is frictionally mounted on a short shaft 74 and carries a main contact member 35. Between contact 35 and shaft 74, the arm 33 is provided with a flexible connection, such as the spring 33', the purpose of which will be hereinafter explained.

The contact member 35 is adapted to engage either a contact member 36 or a contact member 37, according to the operation of the differential gear mechanism 11. The contact arm 33 is biased to a central position, shown on this drawing. by means vmechanism. A- weight is connected to the shaft 41 in any suitable manner to. take up any lost motion in the connection between the'difi'erential gear mechanism and the contact arm 33.

The switch 34 comprises a contact arm 46 which is operated by an energizing coil 47.

The contact arm 46 carries two contact members 48 and 49 which engage stationary contact members 50 and 51, respectively, according to the operative position of the switch. Normally, the contact member 49 is held in engagement with the stationary contact member 51 by means of a spring 52. The coil 47 of the switch is connected across the supply conductors 9 and 10 upon engagemeit getween the maincontact members 35 an 3 a of the differential gear mechanism '11.

The switch 7 5 comprises a contact arm 53 which is controlled by an energizing coil 54. The contact arm 53 carries two contact members 55 and 56, which are adapted to engage stationary contact members and 58,.respectively, according to the operative position of the switch. A spring 59 is provided for so biasing the contact arm as to maintain the contact members 56' and 5 in engagement. The coil 54 is connected across the supply conductors 9 and 10, up-

on engagement between the contact members 35 and 36.

The motor-operated rheostat. 8 comprises a motor 60 which is controlled by the switches 34 and for rotating a rheostat arm 61 and a cam 62. The motor 60 comprises an armature 63 which is connected to the contact arms 46 and 53 of the switches 34 and 75. The field-magnet winding 64 of the motor 60 is connected to any suitable direct-current source.

The rheostat arm 61 and the cam member 62 are fixedly mounted upon a shaft 65. The shaft 65 is connected to the. arn1ature shaft of the motor 60 by any suitable gearing 66.

The cam 62 is yieldably connected to the contact arm 33 in order to react on such arm to prevent hunting action. In the drawing, two dash-pots 67 and 68 are shown to provide the yieldable connection between the cam member 62 and the contact arm 33. When the contact arm 33 is moved to effect engagement between the contact members 35 and 37. the cam 62 is so operated as to tend to effect disengagement of such contact members. Likewise, when the contac arm 33 is operated to effect engagement between the contact mcmbers 35 and 36. the cam member 62 is so operated as to tend to effect separation of the contact members 35 and 36. The above-described effect of the cam 62 on the arm 33' is rendered possible by reason of the flexible connection 33', which permits the separation of the engaged contacts, irrespective of the inertia. tendency of the differential gear mechanism.

Under normal conditions, the motors 17 and 19 operate at the same speed and produce no movement of the central portion It the speed of the motor 1 is raised above normal value, the frequency produced by the generator 12 is raised and, consequentl the speed of the synchronous motor 17 is increased. When the speed of the synchronous motor 17 is increased, the contact arm. 33 is operated by the above-described gear mechanism to effect engagement between the contact members 35 and 37. Upon engagement between the contact members 35 and 37, the switch 34 is operated toeffect rotation of the motor 60 in a clock- Wise direction. The circuit through the armature of'the motor 60 extends from the supply conductor 9, through the contact members 50 and 48, contact arm 46, arma ture 63, contact arm 53 and the contact members 56 and 58, to the supply conductor 10.

The motor 60 rotates the contact arm (31 in such manner as to decrease the resistance value of the rheostat 7 which is included in circuit with the field-magnet winding 3 of the main motor. Consequently, the excitation of the main motor is increased to decrease its speed. The motor 60 also op crates the cam member 62 to effect separation of the contact members and 37 just prior to the operation of the main motor 1 at normal speed. The yieldable clutch 42 is provided between the shafts 41 and .74 in order to prevent breaking of the contact arm or any or" the associated parts in case the differential gear mechanism continues the operation of the pinion 44 and the gear wheel 43 after the engagement of the contact member 35 with either of the contact members 36 and 37.

If the motor 1 is operated below normal speed, a lower frequency is produced by the generator 12 to decrease the speed of the synchronous motor 17. The diiferential geanmechanisrn is then operated to effect engagement between the contact members 35 and 36.

Thereupon, the switch 75 is operated to effect rotation of the motor 60 in a counter-clockwise direction. The circuit through the motor 60 extends from the supply conductor 9, through the contact members and 57, contact arm' 53, armature 63, contact arm 46 and the contact members 49 and 51, to the supply conductor '10. The counter-clockwise rotation of the motor operates the rheostat arm 6] to increase the resistance value of the rheostat 7 which is included in circuit with the field-magnet winding 3 of the main motor. The excitation ofthe main motor is decreased and the speed of such motor is, consequently, increased.

The cam member 62 is so operated by the motor 60 as to effect separation of the contact members 35 and 36 just prior to the operation of the main motor 1 at normal speed. The cam member 62 and the loose connection between it and the contact arm 33 so changes the setting of the regulator as to allow for the inertia of the various moving parts to prevent overtravel thereof.

Modifications 1n the system and in the arrangement and location of parts may be made within the spirit and scope of my in vention, and such modifications are intended to be covered by the appended claims.

I claim as my invention 1. In a regulator system, the combination with a main motor and a difierential gear mechanism operated in accordance with the variations in the speed of said motor, of a contact arm, a yieldable clutch for connecting said arm to the gear mechanism, means for preventing any lost motion between the contact arm and the gear mechanism, means controlled by the contact arm for governing the excitation of the main motor, and means for reacting 'upon the contact arm proportional to the correction eflected upon the main motor.

2. In a regulator system, the combination with a main motor and a differential gear mechanism operated in accordance with the variations in the speed of the'main motor, of a contact arm operated by said mechanism, means comprising a motor-operated rheostat controlled by said contract arm for governing the excitation of the main motor, and means comprising a cam member operated with said motor-operated rheostat and yieldably connected to the contact arm for preventing hunting action in said system.

3. In a regulator system, the combination with a main motor and a differential gear mechanism. operated in accordance with variations in the speed of the main motor, of a motor-operated rheostate, means comprising a contact arm operated by said mechanism for controlling said rheostat, and means comprising a cam member connected to said rheostat and yieldably connected to said contact arm for preventing hunting action in said system.

4. In a regulator system, the combination with a main motor, a differential gear mechanism operated by said motor, a contact arm, and a yieldable connection between the contact arm and said gear mechanism,

of means comprising a motor-operated rheostat controlled by said contact arm for governing the excitation of said main motor, and means for reacting upon said con tact arm proportional to the operation of said rheostat.

5. In a regulator system, the combination with a main motor and a differential gear mechanism operated in accordance with the speed of the main motor, of means comprising a motor-operated rheostat controlled by said gear mechanism for governing the excitation of the main motor to maintain its speed substantiallyconstant, and means controlled by the operation of said motoroperated rheostat to prevent hunting action in said system.

6. In a regulator system, the combination with a main motor and adiflt'erential gear mechanism operated in accordance with variations in the speed of the main motor, of a motor-operated rheostat for controlling the excitation of the main motor, regulator means operated by said gear mechanism for controlling said rheostat, and means connected to said rheostat for reacting on the regulator means to prevent. hunting action in said system.

7. In a regulator system, the combination with a main propelling motor, a generator operated in accordance with the speed of the main motor, and a differential gear mechanism controlled by said generator, of means for controlling the main-motor excitation in accordance with the operation of said difl'erential gear mechanism, and means adapted to prevent hunting action in said system. i

8. Ina regulator system, thecombinationwith a main motor and a differential gear mechanism operated in accordance with Variations in the speed of-the motor, of regulator operated by said gear mechanism, a motor-operated rheostat controlled by said regulator for governing the excitation of the main motor, and means for reacting on said regulator to prevent hunting action in said. system.

9. In a regulator system, the combination with a main motor and a motor-operated rheostat for controlling the motor excitation to maintain its speed substantially constant, of regulator means for operating said rheostat in accordance with the motor speed, and means comprising a cam member moved by said motor-operated rheostat for reacting on said regulator means to prevent hunting action in said system.

10. In a regulator system, the combination with a main motor, an alternating-current generator operated in accordance with the speed of the main motor, a .synchronous mo tor operated by said generator, a constantspeed motor, and a differential gear mechanism jointly controlled by said synchronous motor and the constant speed motor, of a contact arm controlled by said differential gear mechanism, switch mechanism controlled by said contact arm, an auxiliary motor controlled by said switch mechanism, a rheostat controlled by said auxiliary motor for governing the excitation of the mam motor, and means comprising a cam member operated by said auxiliary motor for reacting on the contact arm to prevent hunting action in said system.

In testimony whereof, I have hereunto subscribed my name. this 20th day of January 1921. I

CLARENCE A BODDIE.

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