US2354037A - Hydraulic jack and brake arrangement for vertical generators and the like - Google Patents

Description

J y 18, 1944. E. MAINWARING 2,354,031

CK AND BRAKE ANGEMENT FOR HYDRAULIC VERTICAL GENERATORS THE L- Original Filed Oct. 194

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Waltev- E. Mainwar'mg,

His Attorney.

Patented July 18, 1944 HYDRAULIC JACK-AND BRAKE- ARRANGE- M-ENT roe VERTICAL GENERATORS AND THE LIKE Walter E.- Mairiwa'r-lng, Schenectady. N. Y., as- "signor .t'o'Genera'l Electric Company, .a corporaion of New York Original application October 31.1942, Serial No.

Divided and this application September 15, 1943, Serial No. 502,538

2 Claims. (Cl. 171.252)

I This is a division of my application, Serial No. 464,128, filed on October 31, 1942, and relating to hydraulic jack and brake arrangements for vertical generators and the like. Upon shutdown of vertical electric generators, such as are used for example in hydro-electric power stations, it is often desirable to bring the generator quickly from full speed to standstill and also to relieve the pressure of the generator Weight on the thrust bearing While the generator is out of operation. This has been accomplished heretofore by the provision of brake means to slowdown the generator and jack supporting means for re-" lieving the pressure on thrust bearings during standstill.

The object of my invention is to provide an ii. proved construction of hydraulic jack and brake arrangements'ior vertical generators the like which is both rugged in construction and requires comparatively little space.

For consideration of what I believe to be novel my invention, attention is directed to the following description and the claims appended thereto in connection with the accompanying drawing.

In the drawing Fig. 1 illustrates a sectional view of a hydraulic jack arrangement embodying my invention; Figs. 2 and 3 show front views of the arrangement of Fig. 1 in two different operating positions; and Fig. 4 shows a vertical generator arrangement according to my invention.

A hydraulic jack and brake arrangement for vertical electric generators and the like as illustrated in Fig. 4 comprises a generator I having a rotor 2 and a stator 3. The rotor is rotatably held on a foundation or supporting structure 4. In order to slow down the rotor and bring it to a quick standstill a plurality of jack and brake arrangements 5, 6 are provided, each arrangement being held on the supporting structure 4 and having an element cooperatively associated with a ring or like brake member 1 securely fastened to and forming part of the rotor 2. During normal operation of the rotor the jack and brake arrangements 5, 6 form a clearance 8 with the adjacent brake surface of the ring 1. Upon shutdown the jack and brake arrangements 5, 6 are raised frictionally to engage the ring 1 and upon standstill to support the rotor 2.

Each arrangement 6 as shown in Figs. 1 to 3 comprises a hydraulic cylinder In with a bottom H fused to a base l2 by a weld I3. A conduit [4 projects through an opening in the base l2 and is secured to a channel I5 in the cylinder wall for conducting fluid under presire, suchas air or oil, to the cylinder. A plunger 01" piston 56 is slidably disposed within the cylindrical chamber formed by the cylinder Ill. The piston to has a central bore H and the lower end of the piston forms a central cylindrical extension or projection H3. The upper end of the bore l"! is sealed by means of a plug 19. A stud 2'5} screwed into an opening of the bottom I l projects centrally into the bore ii and atits upper endcarr'ies a nut 2| forming a seat for'the upper end of a helical spring 22 surrounding the stub fiii'arizd having a lower end bearing against a shoulder 23 formed at the lower end of the extension 58. The spring 22 is under compression biases the plunger IE into its lower endposition in which it engages the bottom H of the cylinder (Fig. 1). Packing means are provided to reduce'leakage of operating medium along'the clearance between the plunger and the wall of the cylinder. This packing means includes a sealing ring 24 having a cylindrical portion engaging the wall of the cylinder IF] and biased radially outward towards the wall by means of a spring 25 held in a retainer 26, which latter together with a disk portion of the ring 24 is secured to the lower face of the plunger l6 by a plurality of bolts 21. The upper end of the plunger [6 in the present example is secured to a platform or friction block plate 28 by a plurality of bolts 29. The platform 28 carries a shoe in the form of a flat friction block or disk 30 made of suitable brake material. The platform and shoe are cooperatively associated with an object such as a brake ring 1 to be raised or to be engaged by the block 30 to reduce rotary movement thereof.

During operation, fluid under pressure is supplied to the conduit [4 through the lower end of the cylinder II] to efiect upward movement of the piston I6. When the piston l6 has been raised to a desired position it may be held in such position by the provision of means mechanically locking Or holding the piston and platform in position. This means according to my invention is in the form of two cylindrical cams 32 and 33 having adjacent like cam surfaces 34 and 35 respectively and concentrically surrounding the cylinder Ill. The lower cam 32 is loosely held on the base l2 and rotatable about the cylinder Ill whereas the upper cam 33 is secured to the platform 28 by a weld 3B. The upper cam 33 has an axial slot 31. A guide pin 38 secured to the cylinder [0 projects through the slot 31 and prevents rotational movement of the plunger and the cam 33, which latter is secured to the plunger through the intermediary of the platform. The lower cam 32 has a radial projection or attachment 39 with a bore or opening 40 for receiving a rod or like tool to turn the lower cam abut the axis of the cylinder in order to bring the cam surface 34 of the lower cam into engagement with the cam surface 35 of the upper cam.

Fig. 2 shows the arrangement in raised position, the cam surfaces 34, 35 being axially spaced. After the plunger IS with the platform 28 has thus been raised the lower rotatable cam 32 may be turned or rotated until the cam surfaces 34, 35 engage each other again. The arrangement is shown in such position in Fig. 3. Thereupon the hydraulic fluid under pressure in the cylinder chamber may be relieved. The platform then is being held in elevated position by the cams 34, 35 which together constitute a means for supporting the platform 28 in any raised position. The cam surfaces 34, 35 have a small pitch. Therefore, with the platform or the shoe 30 supporting a heavy object, such as part of a large hydro-electric generator, the jack could not be lowered mechanically by merely turning the lower cam. In order to lower the jack it is necessary first to admit fluid under pressure to the cylinder chamber in order to raise slightly the upper cam from the lower cam. Thereupon the lower cam may be moved from the position in Fig. 3 into that of Fig. 2 so that upon release of the fluid pressure the piston l6 may move downward into engagement with the bottom II. This downward movement is partly efiected by the biasing action of the spring 22.

Thus, with my invention I have accomplished an improved construction of hydraulic jack arrangements used in combination with vertically disposed electric generators to bring the rotors thereof to a quick standstill upon shutdown and to hold the rotors in vertically raised position upon release of the fluid pressure from the jacks. Upon restarting of the rotor it is desirable first to apply fluid pressure to the thrust bearings before the jacks are lowered to permit rotation of the rotor. The jack arrangements reduce considerably the wear of the thrust bearings because they facilitate the formation of a lubricating film on the thrust bearings while the rotor is standing still.

Having described the method of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Hydraulic jack and brake arrangement for vertical generators and the like comprising in combination a generator support, a rotor having a brake ring rotatably held on the support, and a plurality of jack and brake arrangements each being held on the support and having a platform for engaging the ring, and adjustable cam means for holding the platform in raised position.

2. The combination with a vertical generator having a support, a rotor held on the support, a brake ring secured to one end of the rotor and facing the support, and means for slowing down the rotor upon shutdown and holding the rotor in raised position during standstill, said means comprising a plurality of hydraulic jack and brake arrangements, each arrangement including a hydraulic cylinder with a piston movably disposed in the cylinder, a platform with a friction plate secured to the piston and facing the ring and two cylindrical cams surrounding the cylinder for holding the platform in raised position.

WALTER E. MAINWARING.

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