DESCRIPTION

GEAR MOTOR WITH INTEGRATED BRAKE FOR DIRECT DRIVE OF AN ELECTRIC TRACTION VEHICLE WHEEL

Technical Field

5 This invention relates to an electroratio-motor with integrated brake for direct drive to the electric-traction vehicle wheel according to the preamble of the main claim.

The electric-traction vehicle with this type of electroratio-motor-brake is also part of this invention.

10 Background Art

In the present state of the art it is well known that in the transmission of motion to the driving wheels of vehicles, particularly industrial vehicles, e.g. tractors, forklift trucks, operating machines, independent electric engines are used, one for the driving-wheel with the aid of a transmission system

15 with a gear-reducing device and incorporated brake.

The current tendency leans towards the use of increasingly compact and faster engines in order to reduce the external encumbrances of the ratio- motor system as the final users require increasingly silent machines. Drawbacks of the Present State of the Art

20 The following are drawbacks of the aforementioned current state of the art:

1 ) need to apply a connection system between the motor shaft and the entry of the gear-reducing device that causes undesired encumbrance;

2) difficulty of alignment between motor and transmission that can generate unexpected noise and the instability of the system;

25 3) high costs as it must provide support means for all the rotating elements; 4) poor versatility of the braking system: it is often impossible to pass from one type of system to another as the mechanical structure of the system does not allow the application of solutions different from the initial one.

Aim of the Invention

The aim of the invention is to avoid the aforementioned drawbacks and make the system more efficient and with higher performance. In substance, the aim is to implement an integrated system made up of a gear-reducing device, a reliable and very compact motor and brake, that is also economical and that allows the complete adaptability of different types of brakes, it allows easy access to the operative systems and in particular both to the transmission as well as to the brake for maintenance. Solution to the Problem and Summary of the Invention The problem is solved with the characteristics of the main claim. The sub-claims provide preferred solutions. Advantages

With this invention the motor is directly integrated m into the transmission forming a single body with said transmission. Therefore, a strong compact solution is obtained with all the advantages of a monobloc, the casing of the motor being an integral part of the transmission as it also acts as cover for the gear casing, namely the transmission chamber. In this way, for example, by dismantling the case of the motor it opens the group in two, on one side the gear drive with complete access from the interior of the vehicle and on the other side the engine and brake are also completely and easily accessible because they can be completely detached from the vehicle by means of the simple unscrewing of a series of bolts. Moreover, In this way all the misaligning and engaging problems are avoided that may be found during the installation of an external motor. The motor casing incorporates one or more cavities that may be utilized as an oil reserve for the braking chamber and/or as a recirculation channel of this oil, in case all the reducer oil is to be used for cooling. The motor shaft assumes the triple function of:

a) input gear of the transmission, b) complete driving shaft, c) connection for the application of the braking system, it provides the maximum functional and structural advantage of the monobloc. In particular, more types of braking systems can be applied to the motor, in order to be provided at the opposite side to the gearing pinion for the transmission system with a gear-reducing device.

With this, the advantage of the possibility of adopting different types of braking to the monobloc is obtained, without for this reason having to vary the structure of the monobloc, and this therefore according to the needs of use.

With this solution a very economic and compact transmission is obtained that can reach almost absolute constructive precision limits: by obtaining the input gear directly on the motor shaft moreover it is possible to increase the reduction relations with the consequent possibility of increasing the rotation speed of the motor because of the perfect constructive form. The system can provide or not the use of engines in an oil bath, realizing in this way a system in which the oil of the gear-reducing device re-circulates through opportune channels passing through the motor and the brake, without however passing close to the rotor to carry out a form of generalized cooling of the system: in this way the use of security seals is avoided between motor, transmission and brake, m to the advantage of mechanical efficiency. At the free end of the motor shaft more types of brake can be applied, the most common among which are: a1 ) electromagnetic brake; a2) a positive brake or a negative and/or combined brake with oil-immersed discs;

a3) oil-immersed mechanical brake; a4) dry mechanical brake.

These and other advantages will appear from the following description of a preferred solution with the aid of the included drawings, whose details are not to be considered limitative but are only provided as an example. Description of Some Embodiments

The invention is now described with the aid of the enclosed drawings wherein:

- Figure 1 shows a design of the proposed solution that provides the use of an oil-immersed disc brake activated by means of a mechanical lever.

- Figure 2 shows instead a section portion of the system in which, as a realization system of the oil-immersed disc brake, a cartridge has been installed that integrates a combined system made up of a positive brake with hydraulic activation and by a negative brake with mechanical drive (by springs) and hydraulic release (SAHR).

- Figure 3 indicates a solution in which the activation of the oil-immersed disc brake is entrusted to an electromagnetic actuator.

- Figure 4 shows instead a design similar to Figure 1 , in which however the use of a dry disc is provided and therefore the recirculation channel of the oil toward the gear-reducing device has been obstructed and the brake chamber has been opened outwards.

The three embodiments in Fig.1 , 2, 3 can also be applied to this design. Detailed Description of the Figures The driving-wheei is indicated with (1 ), while (2) indicates the wheel hub that receives the motion and is integrated into the gear reducer- transmission system by means of a satellite gear-reducing device (5) that forms the second stage of the gear-reducing device that receives the motion from the crown wheel (3) that gears directly on the pinion of the first

reduction stage (4), the pinion being directly obtained on the motor shaft. Naturally, the optimal solution is that the pinion is directly obtained by the driving shaft by means of mechanical work, but it is evident that less preferable solutions could provide a keyed and bushed pinion on the end of the motor, therefore interchangeable.

All the gears of the reducer-transmission are englobed in the gear-reducing device chamber (6) that communicates with the connecting channel (7) with the additional chamber/container integrated into the fusion (8) of the electromotor casing (13). The cylinder head at the opposite side to the reducer-transmission is closed by a closing flange of the motor (9) for easy access and inspection. In a similar way, the casing of the engine housing (14) acts as cover of the gear-reducing device (3-5), whose opening places in view both the reducer- transmission (3-5) on one side and the motor (13) on the other. The casing of the gear-reducing device (3-5) that also bears the connection transmission to the wheel (2) and that is screwed to the casing of the motor (14) is indicated with (CR).

Inside the closing flange of the motor (9) and between this and the head wall of the motor a brake chamber is formed (in Fig. 1 dish type 11 ) the brake being keyed to the motor shaft (4).

The lever for the mechanical working of the brake is indicated with (12) in Fig.1 and the brake chamber (10) communicates by means of said additional chamber /container (8) and duct (7) with the oil chamber of the reducer-transmission system (6). Moreover, in the Figure 2 the alternative solution of the brake is seen with a connection to the positive brake (15) and a connection to the negative brake (16), associated to the negative brake operating springs (17), the negative brake piston (18) and the positive brake piston (19).

In the solution in Figure 3 the coil of the electromagnetic actuator is seen (20), with the operating anchor of the electromagnetic system for the dry disc (21 ).

In the solution of Fig.4 the closing means of the recirculation channel (23- 24) can be seen, while the jaw clamping system of the disc of the keyed brake on the motor axis is indicated by (22).

With this solution it is possible to obtain any of the following combinations: a) oil-immersed transmission-gear reducing device, dry motor and dry brake; b) oil-immersed transmission-gear reducing device with dry motor and oil- immersed brake; c) oil-immersed transmission-gear reducing device with oil-immersed motor and dry brake; d) oil-immersed transmission-gear reducing device with oil-immersed motor and oil-immersed brake.

However, the details can obviously change.

In the drawings the numbers indicate the entities described below:

1 ) wheel

2) wheel hub 3) crown of the first reduction stage of the transmission

4) pinion of the first reduction stage, directly obtained on the motor shaft

5) second reduction stage of the transmission

6) reducer chamber

7) connecting channel 8) additional chamber/container integrated in the fusion

9) closing flange of the motor

10) disc brake chamber

11 ) brake clutch disc, connected to the motor shaft

12) lever for mechanical working of the brake

13) electromotor

14) cover of the gear-reducing device, that integrates the motor casing

15) connection to the positive brake 16) connection to the negative brake

17) negative brake operating springs

18) negative brake piston

19) positive brake piston

20) coil of the electromagnetic actuator 21 ) operating anchor of the electromagnetic system

22) flat disc

23) closing means of the recirculation channel

24) free outward opening

25) opening for oil recirculation, across the motor CR) reducer control casing and wheel axle support (2)