RU2476738C1 - Coupling - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: coupling includes the first link connected to the first shaft, the second link connected to the second shaft, a spring and a hydraulic pump of volumetric displacement, the cavity of which is filled with working liquid. The first link is a middle screw of three-screw pump of volumetric displacement. The second link is housing of volumetric displacement hydraulic pump. Pressure cavity of the pump is interconnected with the suction cavity through a hydraulic valve.

EFFECT: providing stable transfer of the coupling torque moment at overloads on the second shaft and improving the coupling reliability.

4 dwg

Description

The invention relates to a clutch, in particular to a clutch for transmission of an agricultural machine, for example a transmission of a machine for harvesting sugar beet root crops (hereinafter referred to as a beet harvesting machine).

Couplings are known, for example, according to GOST 15620-93 "Safety cam couplings"; according to OST 23.2.461-77: working drawings of cam and friction clutches according to the RTM-A 23.2.038-90 album “Safety clutches of chain and belt transmissions of agricultural machines with a trigger moment of up to 1000 Nm”.

The disadvantages of cam and friction clutches are as follows.

When triggered by short-term overload, the cam clutch significantly reduces the transmitted torque, since the protrusions of the cams do not have time to enter the depressions between the cams of the mating part. Therefore, a short-term overload leads to a stop of rotation, for example, of a beet harvester cleaner, to clogging by root crops and soil, especially when the soil is wet, which are removed manually with hard work, losing every time up to half an hour of working time, or stop harvesting altogether.

The friction clutch during short-term and not very frequent operation causes the torque to transfer almost completely, but the friction surfaces heat up quickly when activated, the friction linings change their friction properties and strength when heated, which also leads to technological failure [1] p.262.

A known clutch for transmitting torque from the first shaft to the second shaft, containing the first link having the ability to connect it to the first shaft, the second link having the ability to connect it to the second shaft, and a spring set so that the magnitude of the torque transmitted from the first link to the second link depends on the amount of compression of the spring, for example SKB-3 coupling [1] p.264, Fig. VII.12 - prototype.

Its disadvantage is the same as above, the friction clutch linings of the ferrodo coupling with frequent or not very short-term overloads “burn out”, become thinner, therefore they transmit less torque.

The objective and technical result of the invention is a clutch transmitting the rated torque stably.

The essence of the invention is a coupling for transmitting torque from the first shaft to the second shaft, containing a first link having the ability to connect it to the first shaft, a second link having the ability to connect it to the second shaft, and a spring set so that the magnitude of the torque transmitted from the first link to the second link, it depends on the amount of compression of the spring, while according to the invention the coupling contains a volume displacement hydraulic pump, the first link being the middle screw of a three-screw volume displacement pump with the shank, the second link of the coupling is a volumetric displacement hydraulic pump housing, the cavities of which are filled with a working fluid, the suction and pressure cavities of the volumetric displacement hydraulic pump are interconnected by channels through the hydraulic valve so that its spring is located on the side of the suction channel of the volumetric displacement hydraulic pump.

Due to this, during overloads, the clutch stably transmits torque not less than the rated one.

A clutch is installed, including a volume displacement hydraulic pump (hereinafter pump), for example, as follows.

Figure 1 shows the coupling in the position of the axes of all the screws of the three-screw pump in the plane of the drawing.

Figure 2 shows the coupling in the position of the axes of all the screws of a three-screw pump perpendicular to the plane of the drawing.

Symbols in figures 1 and 2:

1 - the middle screw of a three-screw pump-coupling, the first link having the ability to connect, for example, the slots of its shank, with the first transmission shaft of the agricultural machine (hereinafter link),

2 - the housing of the pump-coupling of the second link, having the ability to connect it, for example, with splines, with the second transmission shaft of the agricultural machine (hereinafter link),

3 - with a through hole for the link shank 1 cover of the pump housing (hereinafter cover),

4 - blind cover of the pump housing with a splined shank of link 2 (hereinafter referred to as the shank),

5 - channel communicating the pressure cavity of the pump with the suction cavity of the same pump (hereinafter referred to as the channel),

6 - located in the channel 5 hydraulic valve:

a) direct action for couplings designed for a small nominal torque, for example, valve type U495 [2] p.172, Fig.4.46, lines 9 ... 6 from the bottom;

b) indirect action for couplings designed for a large nominal torque, for example, valve type 510.32.10 [2] p.178, 1st paragraph from above, p.177, Fig. 4. 54 (hereinafter valve),

7 - valve 6 spring, the amount of compression of which is regulated by a screw and guaranteed by a seal (hereinafter referred to as spring),

8 - shell with cooling fins (hereinafter referred to as shell),

9 - an annular container around link 2, filled with a working fluid (hereinafter capacity),

10 - a gap in the wall of the pump, communicating capacity 9 with the suction channel of the pump (hereinafter window),

11 - compensator for the thermal expansion of the working fluid - with plugged ends and an air-filled tube of heat-resistant rubber, several turns of which are placed in a container 9 (hereinafter referred to as the compensator),

12 - a whistle having a nozzle and a plate, for example, according to [3] p. 33, Fig. 14, p. 34, the left column, with parameters of sound radiation in the frequency range perceived by the human ear, for example, with a frequency of 4 to 20 kHz [4] p. 94, lines 3 ... 1 from below, (hereinafter the whistle).

The coupling contains the first 1 and second 2 links. The link shank 1, brought out through the cover 3, and the shank 4, the coupling is connected to the first and second drive shaft, for example, a beet harvester from the ground of root crops. In the pump housing of the coupling there is a group of channels 5 and in them valves 6 with springs 7. Link 2 also includes a shell 8, a container 9 filled with a non-combustible and explosion-proof working fluid based on fluorinated hydrocarbons (hereinafter referred to as the fluid), windows 10, a compensator 11 and a whistle 12 installed in channel 5 in front of valve 6.

Work. Let the shank of link 1 is connected to the first shaft (the transmission shaft of the beet harvesting machine), and the shank 4 is connected to the second shaft (the drive shaft of the beetroot cleaner of root crops). While the torque is transmitted by the coupling no more than the rated one, the parts of the pumping unit rotate around the axis of the link 1 almost mutually motionless, since in this case there is not enough fluid pressure in the pump pressure cavity to open valve 6. But due to the small and gradual leakage of liquid from the pressure the pump cavity into the suction cavity through the gaps of the pumping unit, the relative rotation of the parts of the pumping unit (and, therefore, links 1 and 2 of the coupling) is still possible, but so slow that the transmission of torque does not break. As soon as the resistance on the second shaft exceeds the nominal torque of the clutch, the fluid pressure will increase so much that the valves will open 6. By this, the fluid from the pressure chamber of the pump will be directed into the suction cavity through the whistle 12 and valves 6 while maintaining the fluid pressure determined by the compression value of the spring 7 Therefore, the coupling transmits to the cleaner shaft a torque not less than the nominal, although with a slightly lower speed. At the same time, the operation of valve 6 is accompanied by a characteristic sound (the same as when the safety valve of the standard tractor distributor was activated). At the same time, a whistle sound signal indicates an overload. In this case, the fluid heats up, expands, and partially enters the cavity 9 through the windows 10, compresses the air in the compensator 11. As soon as the resistance on the second shaft becomes less than the nominal, then the valves 6 are closed and the coupling is returned to its original position. Heat from the heated liquid is removed through the shell 8 and the compensator under the action of compressed air in it, the liquid through the windows 10 is returned to the suction cavity.

With an average yield of sugar beets on a plantation of 200 ... 300 c / ha, individual small plots have yields of up to 1000 c / ha and more. Therefore, the supply of root crops to the cleaner periodically and briefly increases. Moreover, in places with locally higher soil moisture than mainly on a sugar beet plantation, the gauge of the copying wheels is deeper. Therefore, digging in such places go deeper and feed the cleaner much more land of high humidity. As a result, the load on the drive of the cleaner periodically and briefly also increases. Therefore, the clutch engages periodically, but the torque transmitted by it does not decrease, as is the case with the cam clutch, and the friction linings do not wear out intensively, as with the friction clutch. Therefore, the rotation of the cleaner is not stopped, the heap of root crops and the earth are not unloaded on it, but they are advanced to the exit, although somewhat more slowly, but they also somewhat improve the efficiency of cleaning root crops from the ground, they do not stop the machine, they do not lose working time. If, nevertheless, the cleaner is overfilled with root crops and earth so that the advancement of the heap is unnecessarily slowed down, then the beet-harvesting machine is stopped, but the transmission of the drive of the working bodies is not turned off. The clutch continues to transmit torque to the cleaner and let it slowly, but the root crops advance to the exit, and the earth is sifted to the surface of the soil under the cleaner. Therefore, the loss of working time is significantly less than with manual unloading by hard labor. Similarly, the coupling works on other agricultural machines.

It is known that practically all tractors engaged in agricultural work shift gears with carriages, gear couplings and synchronizers when the unit is stopped [5] p.200, lines 22 ... 15 from the bottom.

Let the clutch according to the invention be installed between the clutch of the tractor and the speed gearbox (hereinafter CAT), not having the ability to change gears without interrupting the power flow. In this case, the acceleration of a stopped machine-tractor unit to a working speed at any gearbox engaged is performed in less time and at a lower permissible rotational speed of the tractor diesel shaft than without the clutch of the invention. This improves the most important dynamic characteristic of the tractor [5] p.206, 2nd paragraph from above. Therefore, in energy-intensive work, such as plowing, it becomes possible to load the tractor engine more fully than without the clutch described above, that is, commensurate with loading it in a tractor having a gearbox without breaking the power flow. The acceleration of a stopped machine-tractor unit to a working speed is performed automatically without the tractor operator manipulating gear changes on the go from first gear to working.

It is possible to use the clutch according to the invention in other machines, for example, in a jaw crusher as a shockproof clutch, in a ball mill as a starting clutch, etc.

So, the coupling, characterized by the above signs, even when activated, stably transmits the rated torque. This achieves an increase in productivity with reliable anticipation of technical and technological failures of various machines.

Information sources

1. B.C. Polyakov et al. Coupling manual. Ed. B.C. Polyakova. 2nd ed., Rev. and add. - L.: Engineering, Leningrad Branch, 1979. - 344 p.

2. Vasilchenko V.A. Hydraulic Equipment for Mobile Machines: A Guide. - M.: Mechanical Engineering, 1983, 301 p.

3. Goncharenko S.U. Weird sounds of workarounds. - K .: Technika, 1987 .-- 192 p.

4. Enukhovich A.S. A quick reference to physics. Ed. 2nd, rev. and add. M., "Higher School", 1976. - 288 p.

5. Tractors: theory: A textbook for university students with a degree in Automobiles and Tractors. / V.V. Guskov and others. Under the general. ed. V.V. Guskova. - M.: Mechanical Engineering, 1988 .-- 376 p.

Claims (1)

A clutch for transmitting torque from the first shaft to the second shaft, comprising a first link having the ability to connect it to the first shaft, a second link having the ability to connect it to the second shaft, and a spring set so that the magnitude of the torque transmitted from the first link to the second link, it depends on the amount of compression of the spring, characterized in that the coupling contains a volume displacement hydraulic pump, the first link being the middle screw of a three-screw volume displacement pump with a shank, the second link ohm is the body of the volume displacement hydraulic pump, the cavities of which are filled with a working fluid, the suction and pressure cavities of the volume displacement hydraulic pump are connected to each other by channels through the hydraulic valve so that its spring is located on the side of the suction channel of the volume displacement hydraulic pump.

Images