US2204119A - Lubricator - Google Patents

Description

June 11, 1940. Q M E 2,204,119

LUBRICA'I'OR Filed May 9, 1938 2 Sheets-Sheet 1 3noentor Gnornegs LUBRICATOR Filed May 9, 1958 2 Sheets-Sheet 2 3nnentor @mmm @u/n Gttornegs Patented June 11, 1940 UNITED STATES LUBRICATOR Charles A. Campbell, Watertown, N. Y., assignor to The New York Air poration of New Jersey Brake Comps a cor;

Application May 9, 1938, Serial No. 206,8!51

6 Claims.

This invention relates to force feed lubricators and particularly to such lubricators for use with direct connectedsteam driven compressors having no rotary parts. A familiar example is the type of compressor (simple or compound) used as a part of the air brake system in steam locomotives. I

In a compressor of this type there is no externally accessible part from which motion can be derived conveniently, and furthermore the amount of oil to be fed per stroke is so small that any oil pump operated in time with the reciprocatlons of the compressor will afford an .intolerably variable rate of delivery. This is because the total displacement of the pump plunger would be so small as to-be seriously affected by leakage and by'slip through the pump valves. It has been found impossible to hold this slip within extremely close limits.

According to the present invention an oil feeding pump of proportionally large capacity is operated by an impulse motor which receives an air pressure impulse from a low stage working, space of the compressor once in a considerable number of strokes. Forty-eight has been selected as a convenient number because it permits satisfactory accuracy of feed and is divisible by 2, 3, 4, 6 and 8 which are common numbers of lubricated points for which individual pumps can be provided.

To time the impulses for one or more lubrieating pumps a rotary distributor valve 'is used, and is driven by; an impulse plunger subject to impulses in the same working space. The drive to the distributor is conveniently through a pawl and ratchet wheel (having 48 teeth in the preferred example illustrated). This arrangement permits a single impulse connection from the pump working space to the distributor valve actuating piston and to the distributor valve, the latter delivering selected impulses to the impulse motors of selected pumps.

Thus a plurality of pumps or groups of pumps may be operated successively at such intervals as to permit the. pumps to be given a delivery displacement per stroke large enough to ensure reasonably precise measurement of oil.

Any suitable number of pumps may be controlled by a single distributor and they may be operated according to the design of the distributor in any desired order, and singly or in groups.

The example chosen-for illustration has four pumps arranged in pairs. Thus the pairs .are operated in alternation so that alternating pairs are operated every 24 strokes of the compressor. ,ence each pump delivers oncein 48 strokes.

There are various mechanical details of importance which will be understood as the description proceeds. 2

In the accompanyin drawings:'

Fig. 1 is an elevation of a cross-compound compressor with" e lubricator applied.

Fig. 2 is an elevation of the lubricator with the body of the distributor sectioned to show the distributor motor, rotary valve and ratchet feed.

Fig. 3 is a plan view, partly sectional.

Fig.4 is a section on the line 4-4 of Fig. 3.

Fig. 5 is a view similar to a portion of Fig.2 but showing a slightly modified construction.

Referring first to Fig. 1, the high pressure steam cylinder is to the right of the casing 6 which encloses lagging and the low pressure steam cylinder is.to the left therein, while the steam distributing valve mechanism, whose form is immaterial to the present invention; is housed in the-casing l. The first or low stage com-. pressor cylinder is indicated at 8, and the second or high pressure compressor cylinder is indicated at 9. These are equipped with automatic valves whose form is not material to the present invention.

The steam supply line ll leading to the steam end of the compressor is controlled by a throttle valve i2 and pump governor l0, which last responds to pressure in the usual main reservoir (not shown) to start and stop the compressor. The-lubrlcator is bolted to the lower flange of the high pressure steam cylinder, and aportion of it enters the casing 6 so that it lies partly within the lagging on the steam cylinder and is heated by conduction from the-high pressure steam cylinder walls. The purpose of this is to keep the oil in a fluid condition irrespective of atmospheric temperature.

In Fig. 1 the lubricator is generally indicated by the numeral l3 applied to the main body. The numeral N indicates the body housing the impulse distributor mechanism. 45

A tube l5 which leads from the upper working space of the low pressureair cylinder is the connection throughwhich air impulses are delivered, to the lubricator. 0n the upward stroke of the low pressure piston a pressure impulse rising to 5 about 40"pounds gauge-is delivered, and on the ensuing downward stroke the pressure drops to a value slightly below atmospheric pressure. The tubes l6 and l8- are oil delivery'connections. The tube It leads to the throttle valve i2 through a terminal check valve 11. This is to protect the lubricator against back flow and against the entrance of water. The tube 13 leads through a terminal check valve l3 to the steam inlet of the steam distributing valve in casing 1. The terminal check valve is is for the same purpose as the terminal check valve i1.

A tube 21 leads to and delivers through a port in the intermediate frame of the compressor leading to the interior of the high pressure cylinder 3. The tube 22 leads to the interior of the low pressure air cylinder 3. In these two connections no terminal check valves need be used for the reason that they lead downward and there is no danger of the entry of water into the connections from the compressor.

Reference should now be made to Figs. 2, 3 and 4. It will be observed that the main body i3 of the lubricator is hollow and is divided into two oil reservoir chambers by an internal partition 23 through which partition the mounting bolt 24 extends. This is the bolt that attaches the lubricator to the flange of the compressor cylinder.

Referring to Fig. 3, the arcuate vertical face 25 conforms to the contour of the high pressure steam cylinder, and the arcuate face 26 conforms similarly to the low pressure steam cylinder. There are two filling plugs 21, one for each oil chamber, and there are two air vent connections 28 each equipped with a felt dust excluding filter, there being one such vent for each of the two oil reservoirs. It is considered better to use two distinct reservoirs, but this construction is not absolutely essential as all of the pumps could draw from a single reservoir instead of having two reservoirs, one for each pair of pumps as hereinafter explained.

Removal of plug 30 in an offset portion of partition 23 (see Figs. 3 and 4) will connect the reservoirs. Access to plug 30 may be had by removing plug 40.

Formed in the upper wall of the housing 13 are four cylinder forming sleeves each comprising coaxial cylindrical bosses, an upwardly extending boss 29 and a downwardly extending boss 3i. The upper end of each upper boss is closed by corresponding cylinder head 32 with a removable screw plug 33.

Since the pump mechanisms now about to be described are identical, the description will proceed with reference to a single one. that is, the third one from the left in Fig. 3, which is shown in axial vertical section in Fig. 4.

A cup-shaped or thimble piston 34 works in the cylinder just described and is limited in its upward motion by stand-oil bosses or lugs 35. It. is urged upward by a coiled compression spring 38 which is housed within the skirt of the piston and reacts between the piston and a shoulder or spring seat formed on the body 31 of the oil pump unit.

The pump body 31 is threaded at 33 into the lower wall of body l3 and beneath the unit is a tapped connection 39, which in the case oi the pump shown in section in Fig. 3, is intended to receive the oil tube 18 already mentioned. The upper end of the body 31 serves as a guide for the upper end of a pump plunger 4| which works in a cylinder bushing 42 inserted through the lower end of the body 31 with which it makes a slipflt and with which it is connected by threads indicated at 43. The cylinder bushing 42 is axially bored to receive the plunger 4| and this is urged upward by a coil compression spring 44 which reacts between the upper end of the cyl- 'and that the retainer and spring seat for the upper and larger ball check serves as a housing and seat for the lower and smaller ball valve. A still smaller. threaded plug acts as a retainer and spring seat for the smaller ball check valve. Oil displaced by the plunger 4| flows past the valves to the connection 33 and thence by the tube i8 and terminal check 13 to the interior of the steam distributing valve.

The cylinder bushing 42 is formed with a plurality of radial ports 41 which communicate with the peripheral groove formed in the bushing and arranged to communicate with radial ports 43 in the pump body 31. A screen 43 protects the pump against the entrance of any solids which might be carried by the oil. When the piston 34 is forced down pneumatically, it forces down the pump plunger 41. In the first portion of its downward excursion it closes the inlet ports 41 and then displaces oil past the valves 45 and 46 to the point of use. When the pressure impulses above the piston fade out, the spring 36 restores the motor piston 34 and the spring 44 restores the pump plunger 41.

In its upward motion the pump plunger tends to draw a vacuum in the oil pump cylinder so that when the inlet port 41 is cleared. oil prompt- 1y enters from the reservoir. The shim indicated at 50 is used to adjust the delivery capacity of the oil pump. This shim limits the downward motion of the piston 34 and consequently the. displacing stroke of the oil pump. By inserting shims of different thicknesses or by eliminating the shim altogether, the displacing stroke of the oil pump may be changed to suit the requirements of the particular part being lubricated. To make the interchange it is necessary to remove the cap 32 above the piston 34, withdraw the piston, place the proper shim, and restore the parts.

The operative characteristics of the .oil pumping unit Just described, are of substantial practical importance. In the first place the displacing stroke and the suction stroke are both rather rapid so that any leakage or slip will be minimized. Second, the motor piston acts in simple thrust on the oil piston. Consequently, there are no lateral stresses to cause wear or leakage.

Examination of Fig. 3 will indicate that the pumps are arranged in pairs, two pumps of a pair drawing from a corresponding one of the two chambers of the oil reservoir in housing l3. The two pumps of each pair are operated in unison, for the working spaces above the two pistons 34 of a pair are connected by a cross-port i and the pressure surge connection 52 consequently delivers to both pump motors. The other pair is similarly arranged. (See posts 52a, Ila on Fig. 3.)

The four pumps illustrated in Fig. 3 are shown in alignment, but one of the important features of the invention is that since each pump has its own motor, the location of the pump may be modified to accord with the space available.

This idea of individual pumps pneumatically op- 76 motor is afforded by pressure transmitting passages and obviously these can be provided in a variety of ways so that the specific arrangement here shown, while preferred, nevertheless should be considered merely as illustrative of one convenient arrangement.

Formed on the front face of the body I8 is a circular boss 58 which serves as a seat for a rotary distributor valve 54. The rotary valve 54 is centered by pin 55 which has a flange or head. Between head 58 and valve 54 and centered on pin 55 is the ratchet toothed drive disc 51 having in the example illustrated forty-eight teeth 58. Rivets 58 hold the parts 54, 55, 51 together. A spring in cup-shaped plunger 52 acts to hold valve'54 against seat 53.

Formed in seat 58 are two ports, the righthand one of which, 53, leads to port 52 for the right-hand group of pumps shown in Fig. 3 and the left-hand one of which, 84, leads to port 520 for the left-hand group. Ports 58 and 54 are 180 apart with respect to the rotation to the valve and each is connected once in each rotation of valve 54 to chamber 55 in which valve 54 is mounted, by means of a radial slot port 55. .(See Fig. 4.) I

The ports 63 and 84 are shown (see Fig. 2) as slots radial with respect to the rotary valve, and conveniently are formed by pressing slotted bushings into round holes formed in the seat 53. This is simply a convenient way to form the slot ports which register accurately with the radial slot port 88.

In the upper portion of housing I 4 is cylinder '81 for the double-acting impulse piston 58.

Piston 88 is relieved or reduced in diameter at its mid-length as shown at 58 so that it has two end head portions which are peripherally grooved at 1| and 12 respectively. Cross ports 13 and 14 with axial ports 15, 15 connect grooves 1| and 12 with respective working spaces at the opposite ends of the piston.

A transverse guide passage receives ratchet plunger "and spring 18 and is located at midlength of the piston so that the latter is symmetrical. Plunger 11 has a fish-tail toothed end 19 to coact with ratchet teeth 58. Hence'piston and ratchet may be assembled in reversed positions without effect on function. In this way faulty assembly is precluded.

The end of ratchet plunger 11 works .in slot 8| connecting cylinder 61 with valve chamber 55. Plug 82 (Figs. 1 and 3) and plug 83 (Figs. 2 and 3) permit removal of the ratchet plunger. To do so, the plugs are removed, the plunger is pushed back, so that its end may turn in groove '84 as piston 68 is rotated in the cylinder through |88. This permits removal of the plunger through the tapped hole in which plug 83 is normally mounted, without dismounting the rotary valve 54 and drive disc 51. If these parts be removed from the housing the ratchet plunger 11 may be inserted from the valve chamber 85 where the intersection of the groove 84 produces an enlargement of the slot 8|.

The ends of cylinder 81 are closed by two identical heads 85 which are screwed into place,

each having stand-oil. lugs 85 to limit thereciprocation of piston 88.

Connection II from the upper low pressure compressor working space leads to the right end of cylinder 51 by passage 81. On the discharge stroke pressure rises so that piston 58 moves to the left turning valve 54 counter-clockwise. The motion is'so limited by lugs 88 that the valve is turned one tooth only,

Just before the limit of motion is reached groove 1| opens past shoulder 88 to chamber 85 so that compressor pressure is admitted to this chamber. veloped in the chamber to act against the left end of piston 88, but by this time the piston will have moved full stroke. If port 88 then registers with either port 53 or 84 the corresponding group of oil pumps will be actuated.

On the suction stroke in the compressor working space there is back flow through passage 81 and connection l5, so that piston 58 shifts back to the right. Just before it reaches its righthand limit of motion groove 12 opens to vent port 88 which leads to atmosphere through filter plug 8|. This causes pressure in chamber 85 to drop to atmospheric, allowing pistons 84 to move up if they have been depressed and conditioning the whole device for the next cycle of the compressor. I

A ratchet plunger 82 identical with plunger 11, urged by spring 88 and removable upon removal of plug 84 prevents retrograde motion of valve 54 by its engagement wth teeth 58.

The'impulse motor just described has important functional advantages.

valve 54 has been nearly completed. This reduces the friction of the rotary valve and ensures that the rotary valve opens and closes ports 58 and 54 before pressure is established in chamber 55, be-

cause the pressure is not admitted to the chamber until groove'1l overtravels shoulder 88, and this occurs near the end of the piston stroke when the advance of the rotary valve has been substantially completed. Hence double actuation of acting plunger were adopted. Such.a springis I considered objectionable because it is subject to possible failure.

Port 88 then admits the pressure de-.

The chamber 55 is at, atmospheric pressure until a step rotation of However, a satisfactory lubricator can be constructed by using a single acting piston with a spring return'of the piston, and further, it is not strictly essential that the piston have any valve function, i. e. it is not necessary that the piston shall time the impulse. with suflicient precision by the rotary valve.'

A construction of this type is shown in'Fig. 5. In this figure parts corresponding to similar parts in Fig. 2 are identified by the reference numerals used in Fig, 2 each with the distinguishing letter a. No detaileddescription of such parts is considered necessary.

The differences are as follows. There are no It can be timed peripheral grooves corresponding to the grooves cylinder heads 85a are not identical. butthe one to the left is formed to receive a piston return spring llb so that the piston is forced to the left during the delivery or discharge stroke in the upper working space of cylinder I and returns to the right under the urge of the spring upon the ensuing suction stroke.

strictcd port 01b, to make sure that the oil pumps will not be caused to make two successive delivery strokes, as it might happen if pressure could rise rapidly in the chamber 68a.

This double actuation is absolutely prevented in the structure of Fig. 2 because the piston in Fig. 2 must shift the rotary valve to its new position before any pressure surge is admitted to the rotary valve chamber. Thus the construction just described with reference to Fig. 5 is operative and commercially useful. but the refined embodiment shown in Fig. 2 is preferred because it avoids the use of the return spring and because the timing function in the piston prevents double actuation. as explained.

In the arrangement shown in the drawings the two groups of two pumps each are operated alternately at uniform intervals. Stated differently. for 23 strokes the impulses merely feed the rotary valve. 0n the 24th stroke they feed the rotary valve and deliver an actuating impulse to one group of oil pumps. Then for 23 strokes the rotary valve advances and flnally on the next (48th) stroke the valve completes a rotation and delivers an impulse to the other group of oil pumps.

It is possible to prime any pump manually without affecting any other pump by removing -the cap screw it and actuating the piston I4 by means of a small push rod.

The invention offers, as explained. the utmost flexibility in the location of the oil pump units and in thelocation of the distributor with its actuating motor. The only actuating connection from the compressor is the air connection II.

The pumps are not subject to damage by side thrust, they cannot be overloaded. All the components of the mechanism are simple in form and a large proportion of them are susceptible of manufacture on automatic machines. The use of a pneumatically actuated distributor to secure spaced pneumatic impulses for operating the oil pump makes it possible to increase the stroke displacement of the pumps to a point at which valve slip and leakage become negligible as disturbing factors.

In the construction shown in Figs. 1 to 4 the rotary valve determines when an oil pump motor is to receive an impulse but the piston I, by its groove ll actually times the delivery of the impulse to the pump motor. This is a desirable but not strictly indispensable feature, for the timing can be performed by the rotary distributing valve as indicated in Fig. 5.

While the lubricator particularly meets the requirements of the railway air brake service and meets conditions peculiar to that believed to have utility in other susceptible of modification to meet peculiar to particular installations. used to lubricate any device having spaceinwhichtherearerecurrentpressure impulses.

What is claimed is:

l. A lubricator for devices having a working space in which a pulsing fluid pressure is developed as an incident to operation, said lubricator comprising in combination a lubricant delivering force pump; a pressure-operated motor of the expansible chamber type capable of responding to said pulsing fluid pressure and connected to actuate said pump; a distributing valve comprising a rotary disc valve mounted in a chamber. said valve having a recurrent series of successive positions in at least one of which positions it establishes a connection between said chamber and said motor and in the others of which it interrupts such connection; a second motor of the expansible chamber type having a working space connected with the working space of said device. said second motor being capable of reciprocating in response to said pulsing fluid pressure; an intermittent drive connection between said second motor and said rotary disc valve whereby the motor rotates the valve step by step through said series of positions; and means establishing a connection between the working space in which the pulsing fluid pressure is developed and the chamber of said distributing valve, said connection being arranged to delay the development of a pressure pulse in said chamber whereby the second motor will respond to a given pressure pulse before the same becomes substantially effective in said valve chamber.

2. The combination defined in claim 1 in which the connection for delaying the development of pressure in the distributing valve chamber comprises valve means operated by said second motor mearm.

3. The combination deflned in claim 1 in which the connection from the working space to the second motor is relatively large and that to the chamber of the distributing valve is relatively restricted.

4. A iubricator for devices having a working space in which a pulsing fluid pressure is developed as an incident to operation, said lubricator comprising in combination a lubricant delivering force pump; a pressure operated motor of the expansible chamber type capable of responding to said pulsing fluid pressure and connected to actuate said pump: a distributing valve comprising a valve member shiftabie in a chamber through a recurrent series of positions in at least one of which it offers a connection between its chamber and said motor and in the others of which it interrupts such connection; a reciprocating piston subject to and reciprocable by said pulsing pressure; an intermittent drive connection through which said piston shifts said distributing valve step by step through its series of positions: and valve means associated with said reciprocating piston and controlling a vent from said valve chamber and also controlling a connection between said valve chamber and said working space, said valve means being so timed relatively to the reciprocation of the piston that in the normal position oi the piston the valve opens said vent and interrupts said connection and as the piston completes its excursion in response to a rising pressure surge, the valve closes the vent and establishes said connection.

5. The combination defined in claim 4 in which the reciprocating piston is double acting and sublect on one end to pressure in said distributing valve chamber.

6. A lubricator for devices having a working space in which pulsing fluid pressure is developed as an incident to operation, said lubricator' comprising in combination, means forming an oil reservoir; a force pump mounted in said reservoir, said pump being connected to receive charges of oil from said reservoir and to discharge it to the having a series of positions in at least one of which its port establishes a connection between said valve chamber and said motor and in the others of which the valve interrupts such connection; a movable abutment subject to pressure in said working space and capable of reciprocating through a limited range in response to the pulsing fluid pressures therein; valve means associated with said abutment and arranged to open and close a communication between said working space and said rotary valve chamber as the abutment reciprocates; and a ratchet mechanism interposed between said abutment and said rotary valve and adapted to serve as a drive connection through which said abutment shifts said rotary valve step by step through a recurrent series of positions CHARLES A. CAMPBELL.

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