JPS59167334A - Front wheel auxiliary driving device for car - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle drive system, and more particularly to an auxiliary drive system for driving normally unpowered front wheels of a vehicle.

Vehicles are typically driven by supplying power to the rear wheels. It is known that vehicle productivity can be improved by selectively applying an auxiliary drive to the normally unpowered front wheels. If it is particularly useful to power the front wheels,
When traction conditions are insufficient or variable, for example, operation may occur in snow, mud, sand, or ice. Although such adverse conditions may be short-lived, sufficient traction force is required to keep the production capacity of the vehicle at the required value and to prevent the vehicle from getting stuck.

If the vehicle is a civil engineering machine, such as a motor grader,
An advantage of powering the front wheels is to counteract the lateral forces that occur when the shovel is loaded during grader operation. The wheels are tilted and another front axle weight comes into play, but the front wheel drive makes the production dog in this case.

The installation of front wheel drive in equipment such as vehicles, such as earthmoving machines, especially motor graders, requires consideration of many physical characteristics. For example, motor graders have long wheelbases and typically have blades whose support is intermediate between the rear drive axle and the front axle.

The vehicle has a large steering angle and the front wheels need to be tilted in various cases.

Providing a hydraulic drive as the front wheel auxiliary drive solves many of the problems mentioned above. However, the use of hydraulic drives presents other problems. For example, conventional hydraulic systems inherently create dynamic braking, which is undesirable. Additionally, it is difficult to synchronize the speed of the hydraulic drive to the speed of the gear transmission normally used for rear wheel drive.

SUMMARY OF THE INVENTION An object of the present invention is to provide a front wheel auxiliary drive for a motor grader.

Another object of the present invention is to utilize a hydraulic drive system to selectively power the front wheels of an earthmoving machine to avoid dynamic braking.

Another object of the invention is to effectively synchronize the speed of the front auxiliary drive to the speed of the rear wheel drive. The purpose is to selectively supply power to the front wheels of civil engineering machinery.

In order to achieve the above object, the front auxiliary drive of a vehicle with a rear main drive according to the invention is provided with a hydraulic pump. The pump is connected to a hydraulic motor. The motor is connected to the output shaft. A one-way clutch is interposed between the motor and the output shaft to selectively connect the shaft to the motor when the motor rotates in the first direction. The output shaft is connected to a front wheel, and the front wheel is driven in a first direction by the motor. A controller is connected to the motor to prevent the motor from applying dynamic brakes to the vehicle when the wheels are driven in the opposite direction by the main drive.

Embodiments and drawings illustrating the present invention will be described. Like parts or parts are indicated by the same reference numerals in each figure.

A vehicle such as a civil engineering machine shown in FIG. 1 has a front wheel auxiliary drive device according to the present invention. The illustrated civil engineering machine is a motor grader 10. The motor grader is an example, and other types of multi-wheeled vehicles can be provided with the front wheel auxiliary drive system of the present invention.

Grader 10 has a main front frame member 12 with link members 20 connected to frame member 12. A hydraulic cylinder 18 is connected to the link member 20 to control the position of the forming plate 14. The molded plate 14 has a blade 16 connected thereto.
control the position of

The driver's cab 22 is located longitudinally behind the forming plate 14 and the blade 16. The chamber 22 is secured to the platform member 21, and the member 21 is secured to the frame member 12 by welding or the like. Plant home member 21 is supported by tires 26,28. Tires are attached to each wheel and move along the ground. The front tires 30,32 likewise support the frame member 12.

The engine housing 24 is located on the platform 21 directly behind the cab 22. The housing 24 accommodates a main grader engine (not shown) and various parts of the grader's power transmission device. These parts include a transmission 35, a pump 34, a liquid reservoir 102, and a hydraulic oil cooler 37. Pump 34 circulates hydraulic fluid used in a hydraulic transmission system used in combination with the front wheel auxiliary drive system of the present invention. Pump 34 is transmission 3
5 through a transfer case 39 to adapt the output of the pump to the output of the main drive engine.

As the grader moves forward, oil from pump 34 is supplied to conduit 36 and conduit 38 returns the oil to the pump port. If the rotation of the pump is reversed, ie, when the grader is in reverse, the pump outlet is reversed and the role of the conduits 36, 38 is also reversed. Conduit 36 supplies oil to a flow diverter 40 .

The flow dividing device 40 is located within the control device. The flow divider 40 evenly distributes the oil into parallel circuits or conduits 42,46. Conduits 42,46 supply oil to a hydraulic motor 50, shown in FIG. 2, to drive the front wheels individually when front wheel auxiliary drive is required.

Conduits 44,48 provide a parallel return circuit from motor 50. Conduits 44,48 communicate with conduit 38.

Figure 2.3 shows details of the front wheel auxiliary drive according to the invention.

Motor 50 is a hydraulically operated motor and is mounted within housing 51. The motor 50 is provided with an output shaft 53. axis 53
A gear 54 coupled to drives a main gear 56 . Bearing 55
．． 55A supports the shaft 53. A coupling device such as a bolt 60 couples main gear 56 to rotating housing member 58 . The fixed housing member 62 is connected to the housing member 58.
outside in the radial direction. Second fixed housing member 64
is connected to the end of the housing member 62, and the piston chamber 65
form. Piston 66 is piston ring 67.67
A, and is movable within the piston chamber 65. Connecting member 6
An orifice 9 is formed in the housing member 64 to allow oil to flow into and out of the piston chamber 65. It has a bearing cap 68.

The main gear 56 is selectively coupled to the output shaft 80 via a one-way clutch 86 when the motor 50 rotates in a first direction and via a hydraulically actuated friction clutch 72 when the motor rotates in the opposite direction. Connect to the output shaft 8°. The one-way clutch 86 is, for example, model 140572 manufactured by BorgWarner. The clutch 72 is provided with a pressure plate 78, a separation plate 78A, and a thrust plate 73.

The clutch has a return spring 74. During operation, oil flows into the chamber 65 via the oil connecting member 69 and the piston 66
When the clutch 72 is pushed to the right in FIG. 3, the clutch 72 is engaged. When the clutch is released, the flow of oil into the connecting member 69 is cut off, the force of the return spring 74 moves the piston 66 to the left in FIG. 3, and the oil in the chamber 65 is discharged through the connecting member 69. Ru. The bearing 76 rotatably supports the main gear around the output shaft 80 . A planetary gear 84 rotates around a Zang gear 82 at the end of the output shaft 80, and the outer periphery of the planetary gear 84 meshes with a fixed ring gear 88.

A rotating member 90 connected to the planetary gear 84 is connected to a wheel 94 via the required connection device, such as a bolt 92. This gear drive is housed within a housing 96 and wheels 94.

Details of the operation of the above-mentioned front wheel auxiliary drive device will be described later.

The control device shown in FIG. 4 is suitable for controlling the front wheel auxiliary drive system according to the present invention. The control system uses a fluid, such as hydraulic oil, which the pump 34 draws from the sump 102 and supplies to the conduit 36 as the gray moves in the first direction. The liquid flows into a flow divider 40 where it is evenly divided into parallel conduits 42.
．． 46 flows through the circuit formed by. Conduits 42 , 46 carry fluid to both hydraulic motors 50 , one motor driving the wheel mount tire 30 and the other motor driving the wheel mount tire 32 . Parallel return conduits 44.48 connect the motor outlet to conduit 38 and connect the two conduits 104 to conduits 42.46 for liquid return to the pump 340, for reasons explained below. A check valve 108 is inserted into each conduit 104. Connect another conduit 130 to conduit 104 to create a check valve】0
8 bypass flow circuits are formed.

Conduit 110 is connected to conduit 130 to supply liquid to control valve 124 . The control valve 124 has an open circuit 126 and a closed circuit 1.
28. As will be discussed below, closed circuit 128 communicates with conduit 112 when the gray gear moves forward. Open circuit 126 communicates with conduit 112 when the vehicle is in reverse.

Conduit 115 connects to the outlet of charging pump 34A. Conduit 115 supplies pressurized fluid from pump 34A to valve 118, which will be discussed in more detail below. Valve 118 has an internal circuit 120.12
It has 2. Circuit 122 connects conduits 115 and 114 when the gray gear is moving in reverse. A circuit 120 connects conduit 114 to reservoir 102 as the gray gear advances.

The operation will be explained.

Initially, assume that vehicle 10 is in forward motion due to normal rear wheel drive operation. The front wheels 30,32 are driven to rotate by vehicle motion. The liquid flows from the pump 34 to the conduit 3
6, flow divider 40, conduit 42, 46, each hydraulic motor 50
However, during normal forward movement, for example when the vehicle is traveling at high speeds, the front wheels are not affected by the operation of the motor. As described above, the motor 50 connects to the output shaft 8 via the main gear 56.
Drive 0. A one-way clutch 86 selectively couples the main gear to the output shaft. When the rotational speed driven by the front wheel 30.320 forward motion of the vehicle is greater than the rotational speed of the motor 5o, the one-way clutch 86 connects the output shaft 80 and the main gear 5.
6. That is, operation of motor 50 does not interfere with normal rear wheel drive operation of the vehicle.

However, the motor 50 is the wheel 30. If the rotational speed of the main gear 56 tends to be higher than the rotational speed of the shaft 8o, the rotational speed of the main gear 56 becomes equal to the rotational speed of the shaft 8o. Under this condition, the one-way clutch operates to couple the output shaft 80 to the main gear 56, and the output shaft is driven by the motor 50. In FIG. 4, as pump 34 rotates in the direction of forward motion, liquid is supplied to conduit 36 and flow diverter 40. Each motor 50 is supplied via conduits 42,46. At the same time, liquid flow passes through conduit 104. The direction of liquid flow through conduit 104 is determined by check valve 1.
This is the opening direction of 08. However, conduits 130, 110 flow fluid from upstream to downstream of valve 108, and the fluid pressures on both sides of the valve balance and maintain the valve in the closed position. Valve 124 is actuated to align circuit 128 with conduit 112 and maintain pressure downstream of valve 108.

Valve 118 is actuated to communicate internal circuit 120 to conduit 114. Liquid thus flows from chamber 65 to reservoir 102 via connecting circuit 69, conduit 114, and circuit 120 shown in FIG. Therefore, the hydraulic pressure inside the chamber 65 decreases.

As described above, the output shaft 80 includes the sun gear 82.

When motor 50 is drivingly engaged to shaft 80 via clutch 86, rotation of gear 82 rotates planetary gear 84, member 90, wheel 98, and tire 30.32. That is, if the rotational speed of the front wheels tends to be lower than the rotational speed of the motor 50, the front wheels are directly driven by the operation of the motor 50 during forward movement of the vehicle.

A case where the vehicle is moving backward will be explained. Wheels 30.3 when going backwards
Two rotations drive the hydraulic motor in the opposite direction. The characteristic of the one-way clutch 86 is to directly connect the output shaft 80 to the main gear 56 when the wheels 30,32 rotate in the opposite direction. Thus, rotation of the wheels in the opposite direction causes the motor 50 to rotate in the opposite direction. If the motor 50 rotates in the opposite direction, the oil will be transferred to the conduit 4.
4.48 to conduit 104.42.46. Valve 1
24 is in the reverse mode operating position, aligning internal circuit 126 with conduit 112. Therefore, the liquid flows through conduit 130.11
0 to the liquid reservoir 102. Since the pressure on the downstream side of the valve 108 becomes zero, the pressure on the upstream side opens the valve.

Check valve 108 opens, creating a low pressure flow path between conduits 44, 48, and 104. That is, the low pressure bypass path equalizes the pressure between the inlet and outlet of the motor 50, and the motor becomes unloaded. The motor and wheels rotate freely and do not affect the steady vehicle drive system.

If it is desired to operate the front wheel drive even when the vehicle is moving backwards, the displacement of pump 34 is increased to increase the delivery flow rate. The pump 34 has a pump output inverted.
An increased flow rate is applied to conduit 38 creating a pressure downstream of check valve 108 to close the check valve. Liquid flow from charge pump 34A flows via conduit 115 to valve 118. Valve 118 is actuated and internal circuit 122 corresponds to conduit 115.114, supplying liquid to chamber 65 via coupling member 69. The rotation speed of the motor 5° is 30.320 degrees faster than the rotation speed of the tire.
The main gear 56 is not in driving engagement with the output shaft 80 via the one-way clutch 86. As previously mentioned, clutch 86 requires check valve 108 to couple shaft 8o to motor 50 when rotating in the opposite direction. However, if the motor speed exceeds the shaft speed, the clutch 86 will cut off the connection between the motor and the shaft.

As mentioned above, liquid is supplied to the piston chamber 65.

Piston 66 moves to the right in FIG. 3 to engage clutch 72. Main gear 56 drives output shaft 80 via clutch 72 when motor 50 rotates in the opposite direction.

By using a combination of one-way clutch and friction clutch,
The front wheel drive motor can drive the front wheels 30, 32 both forward and backward, and both clutches provide insulation between the motor and the front wheel drive gear when front wheel auxiliary drive is not required. As mentioned above, there is no dynamic braking action from the front wheel auxiliary drive hydraulic circuit.

Although not shown, the output of the pump 35 is changed to engage the front wheel drive system automatically or manually under the driver's control via a device that senses the difference in rotational speed, the speed difference between the front and rear wheels, etc. It can also be combined.

The present invention can be modified in various ways, and the embodiments and drawings are illustrative and do not limit the invention.

[Brief explanation of the drawing]

FIG. 1 is a partially removed perspective view of a vehicle having a front wheel auxiliary drive device according to the present invention; FIG. 2 is a partially enlarged perspective view showing the front end of the vehicle of FIG. 1 showing the device of the present invention; Third
The figure is a sectional view of the front wheel shown in Fig. 1.2, and Fig. 4 is a hydraulic pressure circuit diagram of a control device suitable for the drive device of the present invention. 10: Motor grader 12: Front frame 16: Blade 21 Nibrat home member 34: Pump
40: Flow divider 50: Hydraulic motor 51: Housing 53.80: Output shaft 54.56.82.84.88: Gear 58.6
2.64: Housing member 65: Piston chamber 66: Piston 72: Friction clutch 108: Check valve 118.124: Control valve 120.122.126.128: Internal circuit Patent applicant Dresser Industries, Inc. name) C10)

Claims (1)

[Scope of Claims] 1. A front wheel auxiliary drive device for a vehicle having a rear wheel main drive device, which comprises a liquid pump, a conduit device connected to an inlet and an outlet of the pump for sucking and discharging liquid, and a pump outlet. a hydraulic motor having a population outlet connected to the population via a conduit device;
an output shaft that is connected to and operated by the motor; a one-way clutch that is inserted between the motor and the output shaft to selectively connect the shaft to the motor when the motor rotates in the first direction; a connecting device connected to the motor to drive the front wheels in a first direction; and a normally closed check valve device in fluid communication with the motor; A front wheel auxiliary drive device for a vehicle, characterized in that the device forms a flow path from the motor outlet to the outlet to prevent the motor from operating as a pump; 2. A motor interposed between the motor and the output shaft; a positive latch that selectively connects the shaft to the motor when rotating in the opposite direction; a device that actuates the positive latch; and a check valve device that closes the check valve device when the positive latch is activated so that the motor continues in the reverse direction. 3. The device according to claim 2, wherein the positive latch is hydraulically actuated, 4. , the device according to claim 1 or 3, wherein the vehicle is a motor grader; 5. a front wheel auxiliary drive device for a vehicle having a rear wheel main drive device, comprising: a liquid pump; A hydraulic motor having a conduit device connected to the outlet for sucking and discharging liquid, and an artificial outlet connected to the pump outlet inlet via the conduit device, and an output shaft equipped with a gear, and drivingly engaged with the gear of the motor. a human-powered gear; an output shaft including a sun gear and connected to the human-powered gear;
A one-way clutch is inserted between the human gear and the output shaft to selectively connect the output shaft to the motor via the input gear when the motor rotates in the first direction, and a one-way clutch is inserted between the human gear and the output shaft. a set of planetary gears inserted between the sun gear and the internal gear and drivingly engaged with the sun gear; and a set of planetary gears driven by the set of planetary gears and connected to the front wheel to move the front wheel in a first direction. A front wheel auxiliary drive device for a vehicle, characterized in that it comprises a drive device and a control device connected to the motor to prevent the motor from acting as a pump when the front wheels are driven in the opposite direction by the main drive device. The control device includes a normally closed check valve device in fluid communication with the motor port, and a check valve device connected to the valve device that opens the valve device between the motor port and the outlet when the front wheels are driven in the opposite direction by the main drive device. 7. The apparatus according to claim 5, comprising: a control circuit for forming a flow path of the motor; 7. an apparatus inserted between the motor and the output shaft; It is equipped with a positive latch that connects, a device that operates the positive latch, and a device that closes the check valve, thereby ensuring continuous operation of the motor in the reverse direction and driving the front wheels in the reverse direction via the latch. 8. The device according to claim 7, wherein the positive latch is operated by hydraulic pressure; 9. The device according to claim 7, wherein the vehicle is a motor grader. 10. A front wheel auxiliary drive device for a vehicle having a rear wheel main drive device, comprising: a liquid pump;
A conduit device connected to an outlet of the pump to suck and discharge liquid, a hydraulic motor having an outlet connected to the outlet of the pump via the conduit device, and an output shaft connected to the motor to be operated. a one-way clutch interposed between the motor and the output shaft to selectively connect the shaft to the motor when the motor rotates in the first direction; and a one-way clutch to selectively connect the shaft to the motor when the motor rotates in the first direction; A front wheel of a vehicle, comprising a device connected to the front wheel and a control device connected to the motor to prevent the motor from dynamically braking the vehicle when the front wheel is driven in the opposite direction by the main drive. The control device includes a normally closed check valve device in fluid communication with the motor control device, and a normally closed check valve device connected to the valve device to open the valve device when the front wheels are driven in the opposite direction by the main drive device. 12. The device according to claim 10, further comprising a liquid control circuit that forms a flow path between the motor port and the outlet and prevents the motor from operating as a pump. A positive latch is inserted between the motor and the shaft to selectively connect the shaft to the motor when the motor rotates in the opposite direction, a device for actuating the positive latch, and a device for closing a check valve are provided. 12. The device according to claim 11, wherein continuous operation in the opposite direction of the positive latch drives the front wheels in the opposite direction through the positive latch. 13. The positive latch is hydraulically actuated. The device described.