MODULAR PROGRESSIVE HYDRAULIC DISTRIBUTOR FOR LUBRICATION SYSTEMS

Abstract: A progressive hydraulic distributor which comprises a control block (2) containing three pistons (5, 6, 7) disposed at the vertices of an ideal triangle and ducting (4) for the lubricant fluid, and is removably supported on a second block (3) comprising only ducts (32C, 44, 80, 44A, 43, 44C) with a purely distributing function. The connections between the ducts of the second block and the ducting of the first block are made by way of several ports, and in particular by passage ports comprising two distinct holes which are in mutual communication but can be separated from each other by O-rings, these connections being such as to enable the output fluid flow rate to be varied without disconnecting any pipe connected to a user.

Description: This invention relates to a progressive hydraulic distributor for lubrication systems of the type recited in the preamble of the main claim. A progressive hydraulic distributor of that known type is disclosed in EP-A-0 090 943. This distributor comprises a cylindrical control block located in a corresponding hole of a distribution block. The distribution block has one lubricant inlet and two lubricant outlets only, so it can be used to supply lubricant to two lines or users only. Besides that it does not provide means for adjusting the lubricant flow of the lubricant outlets. A no less serious drawback of also known progressive hydraulic distributors is that adjusting the output flows is inconvenient and relatively complicated. An object of the present invention is to provide a small-dimension and thus more compact and less bulky progressive hydraulic distributor which is of less complicated construction than known distributors and allows very simple adjustment of output flow without having to disconnect any pipes. This results in lower costs both for the manufacturer and the user, and to a more simple utilization. This and further objects which will be apparent to the expert of the art are attained by a progressive distributor whose inventive features are recited in the characterizing clause of the appended main claim. From GB-A-1 160 336 is known an arrangement for adjusting the lubricant flow between at least two outlet ports, in order to render, in a first condition or state of the arrangement, both outlet ports operative to supply a lubricant flow and, in a second condition or state, only one of them operative to supply an amount of lubricant which is a combination of the two flows. Two different embodiments are disclosed: one involving the use of two different kinds of inserts and various seal means, and the other two different kinds of gaskets. The two embodiments are both expensive and relatively complicated. The invention will be more apparent from the accompanying drawings which are provided by way of example and in which: Figure 1 is a side view of a distributor according to the invention in its utilization state, with a part shown in section; Figure 2 is a front view of the distributor of Figure 1; Figure 3 is a section on the line III-III of Figure 2; Figure 4 is an exploded view of the distributor of Figure 1 with the control block shown transparent; Figure 5 is a diagrammatic perspective view of the distributor of Figure 1. In the figures, the modular progressive hydraulic distributor for lubrication systems, indicated overall by 1, comprises two parallelepiped blocks 2 and 3, of which that indicated by 2 provides a control function while that indicated by 3 provides only a distribution function. They are removably connected together along an interface R. The control block 2 comprises internal ducting indicated overall by 4, and three floating collar-type pistons, namely a first 5, and second 6 and a third 7, which are disposed at the vertices of an ideal triangle. Said pistons comprise two depressed regions X, Y lying between three collars 10A, B, C, 11A, B, C and 12A, B, C. The pistons 5, 6, 7 move within cylindrical chambers 13, 14, 15 having end sections 13A, 13B; 14A, 14B; 15A, 15B of greater diameter than the remainder of the chamber. The pistons 5, 6, 7 move within said sections by the action of the pressurised lubricant fluid present alternately in said section. The control block 2 comprises the following ducting (see Figure 5): a main inlet duct 16 which receives the pressurised lubricant fluid from a suitable known source and conveys it to the various sections 13A, B, 14A, B and 15A, B depending on the piston positions, a duct 17 starting from an intermediate position in the chamber 15 and extending to the end section 13A of the chamber 13, a duct 18 starting from a different intermediate position in the chamber 15 and extending to the other end section 13B of said chamber, a duct 19 leading from the interface R to the chamber 15, a duct 70 leading from the interface R to a position in the chamber 13 slightly before the end section 13A, a duct 71 leading from the interface R to a position in the chamber 14 slightly before the end section 14A, a duct 72 leading from the interface R to a position in the chamber 15 in proximity to the section 15B, a duct 26 leading from the interface R to a position in the chamber 13 in proximity to the section 13B, and a duct 30 leading from the interface R to a position in the chamber 14 in proximity to the section 14B. Three ducts 16A, 22, 23 extend from the main inlet duct 16, the first 16A leading to an intermediate position in the chamber 13, the second 22 leading to an intermediate position in the chamber 15 and the third 23 leading to an intermediate position in the chamber 14. Close to the position in which the duct 16A opens into the chamber 13 there is a duct 24 which terminates in the end 14A of the chamber 14. A duct 25 which opens into the section 14B is connected to the chamber 13 in a position between the ducts 16A and 26. A duct 28 starts from a position close to the opening of the duct 23 in the chamber 14 and terminates in the end section 15A of the chamber 15 housing the piston 7 which, in this example, has a larger cross-section than the first two, which are of equal cross-section. A duct 29 starts at the end 15B of the chamber 15 and extends to a position in the chamber 14 between the ducts 23 and 30. The mouths of the ducts 30, 26, 72, 16, 71, 70, 19 mate at the interface R respectively with the mouths 60, 32, 33, 41, 42, 32A, 33A of ducts provided in the distribution block 3. At the interface R of the distribution block 3 there are two ports 33B, 32B. The former is connected to a duct 32C leading to the outlet port 45A and the latter leads to the outlet port 45B through the duct 44, said ports and ducts being provided in the block 3. The mouth 60 also leads to the outlet port 45B through the duct 44C. The mouths 32, 33 lead to the outlet ports 45F and 45C respectively, and the mouths 41, 42, 32A, 33A lead respectively to the pressurised lubricant fluid inlet port 46 by way of the duct 43, to the outlet port 45A by way of the ducts 44A and 80, and to the outlet port 45E and outlet port 45D. Each pair of mouths 32B, 33B; 32, 33; 32A, 33A is surrounded by a circular groove or cavity 38 to house an O-ring 39. Furthermore, each mouth 33B, 33 and 33A is surrounded by a smaller-diameter circular groove to house an O-ring 40A, B, C. The mouths of each pair are interconnected by radial grooves 34, 37. The interconnection is interrupted if the O-ring 40A, B, C is used. The O-rings are clamped between the two blocks 2 and 3 when these are connected together. Other O-rings, not shown, are inserted around the other mouths to provide the necessary seal. The inlet port 46 is connected in a manner not shown to a conventional lubricant fluid pump, also not shown. All the outlet ports 45A, B, C... and the inlet port 46 are threaded to allow pipes to be connected for conveying the lubricant fluid. A further reason for the threading is to make it possible to close said ports by known threaded plugs (not shown) if a certain outlet is not to be used. The distribution block 3 is fixed to the control block 2 by screws 47, the distributor 1 being fixed to a machine by screws 48 both cooperating with threaded ports 49, 50 provided in said blocks. For the description of operation it will be assumed that the distributor is in the position shown in Figure 5 in which the three pistons 5, 6, 7 are all to the right, the ring 40A is not used and the port 45B is plugged. It will also be assumed that the end sections 13B, 14B, 15B are full of lubricant. In this situation if lubricant is fed under pressure to the duct 16 through the inlet port, the pressurised fluid enters the duct 16 and then the duct 22 through the depressed portion X of the piston 7, to enter the duct 17 and reach the section 13A of the chamber 13, thus driving the piston 5 to the left. This movement displaces the lubricant from the other end 13B of the chamber 13 into the duct 18, from whence it passes to the depressed region Y of the piston 7 and then through the duct 19 to the mouth 33A and from here to the outlet port 45D. The next fluid to pass through the duct 16 no longer enters the duct 17 because the fluid pressure therein equals the pressure of the fluid passing through the duct 16. It therefore passes into the duct 16A and flows through the depressed region Y of the piston 5 to enter the duct 24, to reach the end 14A of the chamber 14 and displace the second piston 6 towards the left. This movement transfers the lubricant from the chamber 14B to the duct 25 from which it passes through the depression X in the piston 5 and into the duct 26, to reach the mouth 32 and then the outlet port 45F provided on the opposite side of the distributor to the radial outlet port 45D. Because of the pressure of the fluid already present in the ducts 17 and 24, the next fluid to enter the duct 16 is channelled into the duct 23 and passes through the depression Y in the second piston 6 to enter the duct 28 and reach the end 15A of the chamber 15, thus displacing the third piston 7 towards the left. This movement displaces the lubricant from the end 15B of the chamber 15 into the duct 29, from whence it passes through the depressed region X of the second piston and then through the duct 30 to the mouth 60 and finally to the outlet port 45B, from which however it cannot leave because this is plugged. The fluid therefore passes through the duct 44, the mouth 32B, the radial groove 34, the circular groove 35, the radial groove 37 and the mouth 33B to reach the outside through the port 45A. If however an O-ring 40A is placed in the radial groove 35 between said mouths 32B and 33B, the two mouths are separated, and as the mouth 32B is blocked the only mouth remaining for the fluid is the outlet port 45B, which must therefore be unplugged and connected to a user. In the first case, ie with the O-ring 40A absent, the flow rate from the outlet port 45A is double (per operating cycle) than that which would be obtained with the ring inserted. As clearly shown in Figure 4, an analogous flow change can be obtained for the other mouths 32, 33; 32A, 33A. The aforesaid relates to a first stage in the operating cycle of the distributor 1. In the second stage, the fluid entering the duct 16 from the block 3 displaces the pistons in the opposite direction to the aforesaid, the method in which the operation is effected being however analogous to that described. In this second stage of the cycle, the relevant outlets on the distribution block 3 are the outlet ports 45E and 45C and again the outlet port 45A (it being assumed that the O-ring 40A is not used). Thus if during the first part of the operation the displacement of the third piston forced fluid from the port 45A, during the complete cycle the amount of fluid passing through said port will be greater than that leaving the other radial outlet ports. In this manner the outlet port 45A can be used to connect the distributor 1 to a further distributor. The other outlet ports can also be connected to further distributors.

Claims: A progressive hydraulic distributor for lubrication systems, comprising a one piece control block (2) which contains three pistons (5,6,7) located at the vertices of a triangle, floating in relative chambers (13,14,15), and having three collars (10A,B,C'; 11A,B,C; 12A,B,C) separated by depressed regions (X,Y), said chambers defining with the ends of the pistons (5,6,7) variable volume spaces (13A,B; 14A,B; 15A,B) alternatively acting as pumping and driving spaces, the control block (2) further containing ducting (4) comprising a lubricant inlet (16) and lubricant outlets (30,26,72,71,70,19), the control block (2) being removably connectable-through an interface (R)-to a distributing block (3) comprising ducts (32C, 44,80,44A,43,44C), an inlet port (46), and outlet ports (45A,B,C,D,E,F), said ducts having mouths (33B,32B,60, 32,33,41,42,32A,33A) at said interface to establish hydraulic communication with the lubricant inlet (16) and outlets (30,26,72,71,70,19) of the control block (2) also opening at said interface (R). characterized in that a) the interface (R) between the two blocks (2,3) is a planar one and in which at least two mouths (32B,33B;32,33;32A,33A) are interconnected by grooves (34,37) interceptable by removable sealing means (40A,B,C), locatable in corresponding seats (35) forming part of the interconnection grooves (34,37) to adjust the lubricant flow from the control block (2); b) the lubricant inlet (16) comprises a branched inlet duct (22,16A,23), each branch of which supplies lubricant from the inlet port (46) to an intermediate point of one of the chambers (13,14,15); c) each variable volume space (13A,B;14A,B; 15A,B) of each chamber (13,14,15) is connected with a different intermediate point of another chamber (13,14,15), said different intermediate point being disaligned from the intermediate point; d) couple of outlets (30,26,72,71,70,19) are connected to each chamber (13,14,15) at further intermediate spaced points of said each chamber, said further intermediate spaced points being also disaligned from said different intermediate point and said intermediate point: e) the distributing block (3) comprises six outlet ports (45A,B,C,D,E,F), two (45A;45B) of which are each connected with two ducts (32C, 44A; 44,44C). A distributor according to claim 1, characterised in that only one (44A; 44C) of the two ducts (32C, 44A; 44, 44C) connected with each doubly connected outlet port (45A; 45B) is in direct fluid communication with the corresponding outlet (30, 71) of the distributing block (2). A distributor according to claim 1 or 2, characterised in that the seat (35) of the grooves (34,35,37) is of a circular shape and surrounds one (33B, 33, 33A) of the interconnected mouths (32B,33B; 32,33;32A,33A) , the circular groove accepting a seal means (40A,B,C) in the form of an O-ring (40A,B,C). A distributor according to claim 3, characterised in that a further circular groove (38) of larger diameter is provided in the interface, which surrounds both interconnected mouths (32B,33B;32,33;32A,33A) as well as the groove (35), and accepts an O-ring (39).

Inventors: DIVISI, GUALTIERO
Applicants: DROPSA S.P.A.
Application year: 1988
Main classification: F16N25
IPC codes: F16N25