Field of the Invention

The present invention relates to a ball hydraulic clutch which is located between the engine and the gearbox and which is designed to operate with any type of gearbox.

Background of the Invention

Conventional mechanical clutches use friction discs to provide for the transmission and interruption of power from the engine to the gears. One disadvantage of mechanical clutches is that the friction discs wear out over time.

Hydraulic clutches are also available which use paddle wheels or turbines submerged in a fluid for power transmission. The disadvantages of hydraulic clutches include slippage between the clutch parts and delays in their coupling.

There is also an electromagnetic clutch which uses a magnetic fluid subjected to an electrical potential difference for coupling. One disadvantage of this type of clutch is the constant consumption of electricity required to maintain the electrical field.

Furthermore, all of the above-mentioned types of clutches are heavy and bulky, and some of them have an extremely complex design.

Summary of the Invention

The present invention eliminates the above-mentioned technical problems, as it relates to a clutch with multiple applications. The invention provides progressive engaging and disengaging of the gears in a gearbox, thus ensuring, when engaged, a perfect no-loss coupling between the engine and the transmission, fully achieving delivery of maximum torque of the engine without any slippage.

According to the present invention, the ball hydraulic clutch eliminates the above disadvantages because it comprises a metal disc engaged with an engine flywheel, a PTO shaft engaged with the metal disc and attached to the rotor of a vane-type hydraulic pump. It also includes a pressure chamber mounted on the PTO shaft. Inside the hydraulic pump is a ball drum attached to the pump rotor and engaged, by selective mechanical attachment means, with the pump stator, which is attached to the clutch shaft. A low-pressure chamber and a high- pressure chamber are connected to the clutch shaft. The high-pressure chamber is connected to a pressure controller and, through a solenoid valve, to the pressure chamber on the PTO shaft. The pressure controller is connected to an oil cooling radiator, which, in turn, is connected to the low-pressure chamber. The vane pump rotor is fitted with radial rectangular seats, inside which metal blades and radial passages reciprocate. The radial passages are connected to an axial passage and a radial passage, both communicating with the pressure chamber on the PTO shaft. The axial passage communicates with a circumferential passage and with the radial passages on the drum. A number of balls exert pressure on a circumferential passage with stator lugs. The stator includes a number of inlets which communicate with cross passages, radial passages and axial passages from the clutch shaft. All these passages connect to the low-pressure and high-pressure chambers. On the outside, the stator is fitted with a threaded section on which a threaded securing ring is mounted. The ring regulates the axial distance between the rotor blades and the stator blades, as well as the tightening of the bearings within the hydraulic pump.

According to the present invention, the ball hydraulic clutch has the following advantages:

It provides a gradual coupling of the engine with the transmission;

It enables the discharge of the heat produced during the closure of the pressure controller;

It has an increased service life and resistance to wear compared to other clutches;

It has a low net weight;

Its configuration provides for very high safety in operation;

It has a simple design;

The basic parameters do not change during operation;

- It transmits the maximum torque with respect to its small size; and

It has a substantial life expectancy. Brief Description of the Drawings

The following is a preferred embodiment of the present invention, in connection with Figures 1-3, wherein:

Figure 1 is an overall sectional view of the ball hydraulic clutch, according to the present invention;

Figure 2 is a sectional view taken through the axis of Figure 1 ; and

Figure 3 is a fragmentary sectional section view taken along the plane of section line I - I in Figure 2.

Detailed Description of the Invention

According to the present invention, the ball hydraulic clutch comprises a metal disc 1 mounted on a flywheel 2 and adapted for selective engagement with a PTO shaft 3. The PTO shaft drives an oil pump 4 sealed with a threaded safety ring 5, and it is through the PTO shaft that the driving torque is transmitted to a clutch shaft 6.

The metal disc 1 has the same configuration as the friction plate of a traditional clutch. It is attached to the flywheel 2 with attachment screws. The PTO shaft 3, fitted with a pressure chamber 7 and attached to a rotor 8 and a drum 9, is permanently engaged with the hub of the metal disc 1.

As shown in Figure 2, the PTO clutch 3, the rotor 8 and the drum 9 are all fitted with connecting fluid passages that provide for the passage of pressurized hydraulic fluid. The hydraulic fluid is in a closed circuit: it passes through pressure chamber 1, through a radial passage 10 and an axial passage 1 1 of the PTO shaft 3. From there, as suggested in Figure 3, the fluid passes through the radial passages 12 of the rotor 8, which communicate with rectangular radial seats 13. Inside each of these seats, there are axial blades 14 which are pushed by the hydraulic fluid into engagement with the inside surface of the stator 15.

The axial passage 1 1 also communicates with a radial passage 16 (Figure 2), through which the pressurized hydraulic fluid is supplied to the drum 9, where it enters a circumferential passage 17 and then moves to radial passages 18. In each of these passages are freely reciprocatable axial pistons 19 and associated pressure balls 20, which are forced into engagement with the surface of a circumferential passage 21, formed on axial lugs 22 of the stator 15.

The stator 15 is attached to the clutch shaft 6. As shown in Figure 3, on its inside, the stator 15 has an elliptical shape which is engaged by the axial blades 14. This shape enables admission and discharge of the pressurized hydraulic fluid through inlets 23 and respectively outlets 24.

As shown in Figure 2, the hydraulic fluid that is forced through the outlet 24 reaches a cross passage 25 and from there a radial passage 26, which communicates with axial passages 27 in the clutch shaft 6 and with a high-pressure chamber 28 mounted on the clutch shaft 6. Moreover, the stator 15 is fitted with seats 29 shaped to receive balls 30. These balls 30 are loosely held within thin rings 30a (Figure 2) which are coupled to the ball drum 9. This allows both the rotor 8 and the stator 15 to rotate independently. In addition, the PTO shaft 3 is supported by a bearing (not shown) which can be located inside the flywheel 2, the engine shaft or on the radial bearings 31 connected to the pressure chamber 7.

As shown in Figure 2, the clutch shaft 6 is supported by a bearing (not shown) which can be located on the clutch shafts and the radial bearings 32 of the high-pressure chamber 28 or the low-pressure chamber 33.

As suggested in Figure 1, the three pressure chambers 7, 28 and 33 are fitted with hydraulic fluid retainer rings that isolate the fluid inside the chambers from the outside, thus sealing the chambers. The high-pressure chamber 28 is fitted with an element 34 with two hydraulic fluid passage circuits connected to high-pressure pipes 35 and 36. A solenoid valve 37 which connects with pressure chamber 7 is installed on pipe 35 and a pressure controller 38 is installed on pipe 36. The pressure controller is connected through a low-pressure pipe 39 to a hydraulic fluid cooling radiator 40. From there, the hydraulic fluid is sent through a low- pressure pipe 41 towards the low-pressure chamber 33 on the clutch shaft 6. The two pressure chambers 28 and 33 are attached by attachment screws (not shown), but they have separate circuits.

The fluid in the low-pressure chamber 33 follows the same route through the stator 15 (Figure 3), but is separated from the pressurized hydraulic fluid route, reaching the pump inlet 23.

When flywheel 2 starts to spin, it transmits torque to the PTO shaft 3 which rotates the rotor 8 and the ball drum 9 (Figure 2). As suggested in Figures 2 and 3, due to the centrifugal force, the axial blades 14 are forced out of the rectangular radial seats 13, engaging the fluid from the inlets 23 and sending it pressurized through the outlets 24 and the stator passages 15 to the high-pressure chamber 28. From here, the hydraulic fluid reaches the solenoid passage valve 37 and implicitly, the pressure controller 38, which gradually closes the circuit based on the required pressure setting and the torque received from the PTO shaft 3.

The solenoid passage valve 37 allows the passage of the pressurized fluid to the pressure chamber 7, and then through the fluid passages of the PTO shaft 3, the fluid reaches the rotor 8 of the pump, thereby providing the required radially outward pressure under the axial blades

14, as well as the necessary pressure to the radial pistons 19 which push the pressure balls 20 rolling on the circumferential passage 21 into their activating and locking positions.

When the fluid pressure increases in the elliptical space between the rotor 8 and the stator

15, the fluid is prevented from advancing. Thereby, it opposes the axial blades 14 of the rotor 8 which gradually engage the stator 15 in a rotary motion. When the revolution of the rotor 8 is equal to the revolution of the stator 15, the solenoid passage valve 37, upon command from a computer (not shown), closes the hydraulic fluid circuit to the ball drum 9, leaving the radial pistons 19 and the pressure balls 29 pressurized and thus, blocked inside the circumferential passage 21 of the stator 15. Thereby, a rigid coupling is created between the rotor 8 and the stator 15.

Upon command from the computer, the solenoid valve 37 opens and releases the pressurized hydraulic fluid from the drum 9, thereby disengaging the rotor 8 from the stator 15.

Numerous structural and functional modifications and adaptions may be achieved, as those of ordinary skill in the art will readily appreciate, without departing from the spirit and scope of the invention.