SKI CREAMER WITH A TRACKED DRIVE

Description

[0001] The invention relates to a snow groomer with a tracked undercarriage that can be driven by means of a drive system, wherein the drive system has two electric motors, each of which is assigned to a sprocket wheel on one side of the tracked undercarriage.

[0002] DE 296 07 651 U1 discloses a snow groomer in which the sprockets of a tracked snow groomer's chassis are driven by electric motors. A central combustion engine is provided to drive the electric motors for the sprockets, which is coupled to a generator, each of which is connected to the electric motor for the sprocket wheel. A winch and a rear tiller are powered by electric drives. Electrohydraulic drives are provided for linear adjustment mechanisms of front and rear implement carriers or for other attachments such as front tiller blowers or dozer blades.

[0003] EP 1 245 736 A2 discloses a hydrostatic rotary drive for a rear tiller of a snow groomer, which is driven by a diesel engine via a control pump.

[0004] Another snow groomer is known from US Pat. No. 5,363,937 A. The snow groomer has a tracked drive system with two tracks located on opposite longitudinal sides of the snow groomer, each driven by a drive wheel. Each drive wheel is driven by an electric motor. The snow groomer also has a rear tiller attached to the rear of the snow groomer. The rear tiller has two tiller shafts, each driven by an electric motor.

[0005] DE 20 2013 004 087 U1 discloses another snow groomer equipped with an emission-free drive system. Two sides of the snow groomer's tracked drive are each driven by a drive wheel and an electric motor. A rotating tiller shaft of a rear-mounted tiller is also driven by an electric motor. Furthermore, the snow groomer features additional hydraulic adjustment devices for adjusting a front-mounted clearing blade and for adjusting a rear implement carrier and the rear tiller, which are fed by a hydraulic pump. The hydraulic pump is driven by an electric motor to build up the required hydraulic pressure within the hydraulic system.

[0006] The object of the invention is to create a snow groomer of the type mentioned above which enables emission-free operation without major safety-related expenditure.

[0007] This object is achieved by the features of claim 1. Since - as with conventional snow groomers - a working hydraulic system with at least one hydrostatic rotary drive is provided, no safety measures need to be taken for corresponding working functions, which would be necessary with purely electric drives. In addition to rear tiller operation, the working functions include, in particular, winch operation of a cable winch on the snow groomer, which enables the snow groomer to maintain slopes even on steep terrain. The corresponding working functions are achieved by hydrostatic rotary drives, whereby, in particular, a rear tiller function can also be achieved by two hydrostatic rotary drives, provided the rear tiller has two drivable tiller shafts arranged side by side in the transverse direction of the vehicle. A fuel cell or a battery system can preferably be provided as the energy source.

[0008] In one embodiment of the invention, a rechargeable battery system is provided to supply energy to the at least one electric motor. The battery system comprises at least one accumulator, preferably one or more accumulator packs each comprising a plurality of accumulators. The accumulators can be lithium-ion accumulators.

[0009] In a further embodiment of the invention, the at least one electric motor for the working hydraulic system and / or the electric motors for the traction drive system are designed as synchronous motors and are supplied with a battery voltage of 400 V or 100 V during operation. The comparatively low voltage of 100 V makes it possible to dispense with the safety-related effort required with high-voltage electrical systems (400 V). This ensures a comparatively simple design of the snow groomer's driving and working functions while still maintaining emission-free operation. When using a battery voltage of approximately 400 V, appropriate high-voltage electrical and electronic systems are required.

[0010] In a further embodiment of the invention, a charger, in particular with a charging plug, is provided on the vehicle. The vehicle-side arrangement of the charger and the optional charging plug enables easy connection of the snow groomer to a stationary power grid. The voltage converter enables the connection of a 100 V synchronous motor to a 220 V power grid or a 380 V power grid or a similar high-voltage network, thus ensuring rapid charging. The charger is particularly advantageously mounted near the rear wall of a driver's cab. This allows particularly easy access to the charger for an operator. The optional charging plug with charging cable, also located on board the snow groomer, enables simple connection to a stationary socket in the building or at the charging station. For an operating voltage of 100 V, the charger is additionally equipped with a voltage converter.

[0011] In a further embodiment of the invention, the battery system is housed in a chassis frame beneath the driver's cab in a replaceable manner. The arrangement of the battery system according to this embodiment ensures, on the one hand, a low center of gravity for the snow groomer. On the other hand, it allows easy access to the battery system for replacement with another battery system. Advantageously, the driver's cab is arranged so that it can be tilted between an operating position and a service position. Access to the battery system is guaranteed when the driver's cab is tilted.

[0012] In a further embodiment of the invention, the battery system comprises a plurality of battery packs, each of which is quickly interchangeably connected to one another and to the at least one electric motor by means of an electrical plug connection. This configuration allows corresponding battery packs, also referred to as battery packs, to be very quickly disconnected from the snow groomer's electrical system and removed from the vehicle. Similarly, new battery packs can be quickly inserted into the vehicle and manually connected to the vehicle's electrical system by connecting the electrical plug connection. This enables a quick-change process for the battery system.

[0013] In a further embodiment of the invention, the battery packs are assigned an electrical circuit that electrically couples the battery packs to each other and to other electrical or electronic components of the vehicle's electrical system, in particular to the electric motors. The electrical circuit electrically connects the battery packs, in particular in series or parallel, to use the battery packs as a unified battery system for operating the electric motors.

[0014] Further advantages and features of the invention emerge from the claims. A preferred embodiment of the invention is described below and illustrated with reference to the drawings. Fig. 1 shows an embodiment of a snow groomer according to the invention in a partially cut-away, schematic side view, Fig. 2 a block diagram of the driving and working functions of the snow groomer according to Fig. 1 and Fig. 3 a block diagram of another embodiment of a snow groomer according to the invention similar to the Fig. 1 and 2 .

[0015] A snowcat 1 after the Fig. 1 and 2 has a chassis frame 2, on whose opposite longitudinal sides two drive sides of a tracked drive 3 are arranged. Each drive side of the tracked drive 3 has a rotating chain, a front tensioning wheel, several running wheels arranged in a row one behind the other in the longitudinal direction of the vehicle, and a drive wheel 4 at the rear, also referred to as a sprocket wheel. The chain is deflected in the area of ​​the front tensioning wheel and the rear sprocket wheel 4 and runs with an upper run above the running wheels and a lower run below the running wheels.

[0016] At the rear of the chassis frame 2, a hydraulically adjustable rear implement carrier, not further identified, is provided. The rear implement carrier carries a rear tiller 7. The rear tiller 7 is equipped with at least one rotatable tiller shaft and a finisher assembly that smooths the snow surface crushed and thrown up by the tiller shaft.

[0017] A dozer blade 6 is hinged to a front end of the chassis frame 2. The dozer blade 6 is adjustable using hydraulic adjustment devices. A driver's cab 5 is located on the chassis frame 2 in a front half, in which a driver sits to control the snow groomer 1 with regard to its driving and working functions. The driver's cab 5 is designed for service work from the Fig. 1 shown operating position into a service position can be tilted forward about a tilting axis extending in the transverse direction of the vehicle, which pivots the driver's cab 5 on the chassis frame 2 in a tiltable manner.

[0018] The snow groomer 1 has a working hydraulic system that controls a hydrostatic milling motor 14 for the milling shaft of the rear tiller 7 as well as various hydraulic working and operating functions of the snow groomer 1. In addition to the milling motor 14, designed as a hydrostatic rotary drive, a hydrostatic brake pump 18, a hydrostatic working pump 17, and a hydrostatic fan pump 16 are provided, which supply hydraulic working and operating functions of the snow groomer 1. A hydrostatic milling pump 15 is assigned to the hydrostatic milling motor 14, which accordingly generates the hydraulic pressure for the hydrostatic milling motor 14. The aforementioned hydrostatic pumps 15 to 18 are driven coaxially by a drive shaft of an electric motor 8. The working pump 17 serves to build up hydrostatic pressure for linear actuators for adjusting the clearing blade and / or linear actuators for adjusting the rear implement carrier.The fan pump 16 serves to generate a hydrostatic pressure for the operation of a hydrostatic rotary drive for a fan wheel or the like for ventilation and cooling of electrical functional units of the snow groomer 1, which are described in more detail below.

[0019] The brake pump 18, the working pump 17, the fan pump 16, the tiller pump 15 and the hydrostatic tiller motor 14 are parts of the working hydraulic system of the snow groomer 1.

[0020] A drive system for the snow groomer 1 has two electric motors 11, which are designed as wheel hub motors, each coaxial with a respective sprocket wheel 4, and are mechanically connected to the respective sprocket wheel 4 by means of a planetary gear 13 in order to drive the sprocket wheel. The two electric motors 11 are synchronous motors, each fed by a frequency converter 12 with direct current from a battery system 9 formed by a plurality of rechargeable accumulators. The battery system 9 is housed in the chassis frame 2 below the driver's cab 5 and is detachably fastened there to allow the battery system 9 to be replaced. The battery system 9 is positioned below the driver's cab 5 relative to the chassis frame 2 in such a way that the battery system 9 is accessible from above when the driver's cab 5 is in the tilted service position for removal. This allows the battery system 9 to be easily replaced with a new battery system.

[0021] The working hydraulic system is driven by an electric motor 8, which rotates the various pump units and thereby generates the desired hydrostatic pressure. The various pump units are arranged coaxially with a drive shaft of the electric motor 8 to enable simple drive transmission. The electric motor 8 is also designed as a synchronous motor and is powered by the battery system 9. A frequency converter 19 is also used in the electric motor 8 to convert the direct current from the battery system 9 into the alternating current required for the synchronous motor of the electric motor 8.

[0022] Both the electric motor 8 and the two electric motors 11 are operated with an operating voltage of 100 V.

[0023] An electronic control unit S is assigned to the electric motors 8 and 11 and the battery system 9. This control unit controls the electric motors 8, 11 and includes a battery management system that ensures uniform utilization of the plurality of accumulators within the battery system 9. A brake chopper 20 assigned to the battery system 9 can absorb electrical energy that can no longer be absorbed by the battery system 9, particularly during downhill travel of the snowcat 1 and a corresponding energy recovery.

[0024] To enable charging of the battery system 9, a charger 10 is permanently connected to the battery system 9 and is fixed to the vehicle on a rear wall of the driver's cab 5. The charger 10 is equipped with a voltage converter to enable charging of the battery system 9, which has a battery voltage of 100 V, from a building-side 380 V power grid.

[0025] The snow groomer 1 therefore has a purely electric drive system, with the two electric motors 11 acting directly on the sprockets 4 on both sides of the tracked drive unit 3. Furthermore, the snow groomer 1 has hydrostatic drives for the rear tiller 7 on the one hand and various working and operating functions of the snow groomer 1 on the other, which are driven by a common electric motor 8.

[0026] A snowcat according to Fig. 3 corresponds in structure and function to the snowcat, except for the differences listed below, as previously described with the help of the Fig. 1 and 2 The block diagram according to Fig. 3 Accordingly, functionally equivalent parts and components are provided with the same reference numerals with the addition of the letter a. To avoid repetition, with regard to structurally and functionally equivalent components as well as with regard to the basic structure and function of the snow groomer, reference is made to the Fig. 1 and 2 described embodiment.

[0027] The design of a snowcat according to Fig. 3 has some key differences, which are described below.

[0028] The power supply for the snowcat's various electric motors is provided in the high-voltage range with an operating voltage of 380 V / 400 V.

[0029] The battery system 9a is formed by several battery packs B 1 to B 3. The battery packs B 1 to B 3 are electrically connected to one another by an electrical circuit SB. The electrical circuit SB is housed in a closed housing. Both a charger 21 and a charging plug 22 are connected to the electrical circuit SB, wherein the charging plug 22 is connected to the charger via a flexible charging cable. The charging plug 22 can be plugged into a socket of a stationary power supply network if required. The battery system 9a is analogous to the embodiment according to Fig. 2 an electronic control unit S, which includes a battery management system. In the illustrated embodiment, battery packs B 1 and B 2 are equipped with four batteries, and battery pack B 3 is equipped with eight batteries.

[0030] Due to the operation of the electric motors 8a, 11, 26 in the high-voltage range of 380 V / 400 V, the corresponding vehicle electrical system includes a high-voltage distributor 24. The electric motor 8a, which operates the working hydraulic system, is connected to the high-voltage distributor 24 via a frequency converter 19a. The working hydraulic system includes a hydrostatic brake pump 18, a hydrostatic working pump 17, and a hydrostatic fan pump 16, whose functions are described previously based on the Fig. 1 and 2 functions already described.

[0031] Another significant difference in the snowcat according to Fig. 3 is that an electric motor 26 for driving at least one tiller shaft of the rear tiller 7a is mounted directly on the rear tiller 7a, so that the power supply to this electric motor 26 is also provided via a frequency converter 25 using the battery system operated in the high-voltage range described above. The electric motor 26 for the rear tiller 7a is connected to the high-voltage distributor 24 via its frequency converter 25 via an electrical line. Since the rear tiller 7a is detachably arranged on a rear implement carrier of the snow groomer, a high-voltage plug connection 23 is provided in the area of ​​the implement carrier to connect the electric motor 26 for the rear tiller 7a to the vehicle's electrical system. The high-voltage connector 23 has two complementary and pluggable connector parts, of which one connector part is connected to the electric motor 26 via a flexible cable and the other connector part is connected to the vehicle-side electrical system.The latter connector is permanently mounted in the area of ​​the implement carrier. When the rear tiller 7a is removed from the snow groomer, the high-voltage connector 23 can be easily disconnected and the rear tiller 7a can be detached from the implement carrier.

[0032] The electric drive units 11 to 13 for the two sprockets 4 of the track drive do not differ from the design according to the Fig. 1 and 2 , so there is no need to go into this in more detail here.

Claims

1. A snow groomer (1) having a track (3) drivable by means of a drive system, wherein das drive system has two electric motors (11) associated with a sprocket wheel (4) of each side of the track (3), characterized in that a work hydraulics system is provided which has at least one hydrostatic rotary drive associated with a work function of the snow groomer, wherein the work hydraulics system has a tiller motor (14) designed as a hydrostatic rotary drive for a tilling shaft of a rear-mounted tiller (7) and a hydrostatic brake pump (18), a hydrostatic work pump (17) and a hydrostatic fan pump (16); wherein a hydrostatic tiller pump (15) applying a hydraulic pressure for the tiller motor (14) is associated with the tiller motor (14); wherein the work pump (17) serves to build up a hydrostatic pressure for linear actuators to adjust the clearing blade and / or for linear actuators to adjust the rear attachment carrier; and wherein the fan pump (16) serves to generate a hydrostatic pressure for operating a hydrostatic rotary drive for a fan wheel to ventilate and cool electric function units of the snow groomer (1), and in that the work hydraulics system is driven by at least one electric motor (8, 8a) supplied from an energy source mounted on the vehicle side, and in that the hydrostatic tiller pump (15), the hydrostatic fan pump (16), the hydrostatic work pump (17) and the hydrostatic brake pump (18) are driven coaxially by a drive shaft of the electric motor (8).

2. The snow groomer according to claim 1, characterized in that a rechargeable battery system (9, 9a) is provided for supplying energy to the at least one electric motor (8, 8a, 11).

3. The snow groomer according to claim 2, characterized in that the electric motor (8, 8a) for the work hydraulics system is designed as a synchronous motor and is supplied - in operation - with a battery voltage of 400 V or 100 V.

4. The snow groomer according to claim 1 or 2, characterized in that the electric motors (11) of the drive system are designed as synchronous motors and are supplied - in operation - with a battery voltage of 400 V or 100 V.

5. The snow groomer according to any of the preceding claims, characterized in that a charger (10, 21), in particular with a charging plug (22), is provided on the vehicle side.

6. The snow groomer according to claim 5, characterized in that the charger (10) is provided with a voltage converter.

7. The snow groomer according to claim 5 or 6, characterized in that the charger (10, 21) and the charging plug (22) are attached in the region of a rear wall of a cab (5).

8. The snow groomer according to claim 2 or 3, characterized in that the battery system (9, 9a) is replaceably accommodated in a chassis frame (2) underneath the cab (5).

9. The snow groomer according to claim 2 or 3, characterized in that the battery system (9a) has several battery packs (B1 to B3) each connected by means of an electric plug connection (23) to one another and to the at least one electric motor (26) in rapidly changeable manner.

10. The snow groomer according to claim 9, characterized in that an electric circuit (SB) which couples the battery packs (B1 to B3) electrically to one another and to further electric or electronic component parts of the vehicle electrics and in particular of the electric motors (8a, 11, 26) is associated with the battery packs (B1 to B3).