JP2008019894A - Automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rationale structure supplying air in a device of an electric motor as clean air without constructing the electric motor in a firm sealed construction in a style that both of the electric motor and a pneumatic actuator are used as driving power of a transmission. <P>SOLUTION: Air is supplied into the electric motor from the pneumatic actuator. Since air of the pneumatic actuator is clean air made pass through a filter and pressure thereof is higher than atmospheric pressure, invasion of moisture and dust together with air from an outside into the electric motor is prevented. Invasion of a foreign matter into the electric motor can be prevented by providing labyrinth structure in an air pressure supply path. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transmission that is installed in a vehicle or other vehicle as a power transmission device. The present invention relates to a transmission that uses both an electric motor and a pneumatic actuator as power for driving a gear change mechanism of the transmission. In particular, the present invention relates to a structure for communicating air pressure in an electric motor casing to the atmosphere.

  In order to design an automatic transmission for a large vehicle, the inventors of the present application use an electric motor or a combination of an electric motor and a pneumatic actuator as a driving force in the shift direction and / or select direction of the transmission. And made a prototype. The electric motor is advantageous for displacing a mechanical element as a driven body inside the transmission at an approximately constant speed. The pneumatic actuator is advantageous when the driven body is displaced against the drag when a large drag is temporarily generated in the driven body. However, since the displacement speed of the pneumatic actuator changes greatly according to the drag force, it is difficult to control the pneumatic actuator to be displaced at a constant speed.

  In designing a large transmission, if only an electric motor is used as displacement driving power for a mechanical element, a large electric motor corresponding to a large drag force temporarily generated during a shift operation process must be used. However, by adopting a design that uses a pneumatic actuator in combination with the electric motor, it is possible to design the pneumatic actuator to act supplementarily at a timing when the output of the electric motor is insufficient. It can be rationally designed.

JP 2003-52145 (Tamakawa Seiki) JP2003-139242 (Hino) JP2003-148599 (Hitachi Unisia) JP2003-194213 (Hitachi Unisia) Utility Model Registration No. 2582310 (1998, Matsushita Electric)

  The inventors of the present invention designed, prototyped, and tested the automatic transmission used for a large vehicle by adopting a driving device that uses a pneumatic booster in addition to an electric motor. The position where the transmission is arranged includes the splashing of water and sludge from the road surface, and the use environment of the mechanical device is considerably inferior. For this reason, it is necessary to design the electric motor in the form of a mechanical sealing structure so that foreign matter such as water, oil and dust does not enter the electric motor. However, a permanent sealed structure is very expensive, although not impossible to design. In other words, the temperature environment from when the vehicle is parked to when it is in operation fluctuates in the range of sushi minus tens of degrees to plus tens of degrees, so the air pressure in the internal space of the sealed structure varies greatly in response to this temperature fluctuation. To do. And it is too expensive to design and manufacture a leak-tight sealed structure over the entire life of the vehicle against this air pressure variation.

  On the other hand, a structure in which a vent hole communicating with the surrounding external atmosphere is provided without using an internal atmosphere of the electric motor as a sealed structure. In this structure, moisture and foreign matter enter through the vent in response to changes in the apparatus temperature, so it is necessary to provide a filter in the vent. Moreover, the filter requires a considerably advanced device to eliminate fine dust, and has a drawback that the filter has to be changed frequently.

  The present invention is to improve this, and for an automatic transmission that uses both an electric motor and a pneumatic booster, the structure for communicating the internal atmosphere of the electric motor with the external atmosphere is improved, and the apparatus is simply and The purpose is to construct economically. It is an object of the present invention to lengthen the period of maintenance work such as replacement of parts of an automatic transmission. It is further desirable to provide an automatic transmission as a device that does not require periodic replacement of filter parts and seal parts. The present invention relates to an automatic transmission that uses both an electric motor and a pneumatic booster. Even if the electric motor is not designed to have a permanent sealing structure, foreign matter such as water, oil, and dust does not enter the interior of the automatic transmission. An object is to provide an automatic transmission. Another object of the present invention is to provide an apparatus in which foreign matter is not mixed into the electric motor over the lifetime of the vehicle and causes failure. It is an object of the present invention to provide an automatic transmission at a low cost as a whole and to provide a form that requires almost no maintenance and replacement of its parts.

  The present invention provides this specific solution. The first feature of the present invention is that the electric motor is formed in a sealed structure with respect to the external atmosphere, and the prior art in which a small respiratory passage is provided in the sealed structure. Although it follows, it is not making the internal atmosphere of the sealed structure communicate with the outside air directly, but communicating with the atmosphere in the pneumatic actuator. That is, the internal atmosphere of the pneumatic actuator is air supplied from a pneumatic tank mounted on the vehicle, and this is arranged at a position where the intake port can avoid splashing from the road surface, and one or more It is clean air from which moisture and foreign matter have been removed by passing through a filter, and the atmospheric pressure is set higher than atmospheric pressure. Compared with a structure in which this is directly communicated with the outside air, there is an advantage that moisture and dust from outside air do not easily enter the apparatus.

  A second feature of the present invention is that a labyrinth structure (maze) is provided in an air passage communicating with air in the pneumatic actuator. With this structure, even when a small foreign matter is mixed in the air supplied into the electric motor, it can be removed by the labyrinth structure when passing through the air passage.

  Furthermore, the third feature of the present invention is that the labyrinth structure is provided by utilizing the space around the axis of the electric motor. Even if a pair of electrical terminals is provided in the vicinity of the bearing in order to supply current to the electric motor, it is possible to form a space that reaches almost one turn around the output shaft of the electric motor. Providing the labyrinth structure in the form of a multi-chamber structure does not substantially increase the shape of the electric motor.

  That is, the present invention is characterized in that a labyrinth structure (maze) is provided between a housing of the electric motor and a housing of the pneumatic actuator in an automatic transmission device including an electric motor and a pneumatic actuator as driving power. Further, the present invention is characterized in that an air passage is provided for communicating the internal air pressure of the electric motor and the internal air pressure of the housing of the pneumatic actuator. The labyrinth structure is preferably formed as a multi-chamber structure in which the circulating airflow circulates in a space around the rotation axis inside the casing of the electric motor for not less than a half turn and less than one turn.

(1) Due to the first feature, foreign matter is not directly mixed into the electric motor from the atmosphere,
(2) According to the second feature, even if a difference between the air pressure inside the electric motor and the atmospheric pressure is generated and fluctuates, it is difficult for foreign matter to pass through the air passage in any direction,
(3) Since the third feature does not require a separate space for providing the labyrinth structure, the apparatus can be designed to be small as a whole.

(Example)
FIG. 1 is a partially broken structural view of an apparatus according to an embodiment of the present invention. This device is a drive device that is provided in the shift direction of the transmission to generate drive power for the shift operation. The output rod 1 visible at the right end of the figure is mechanically connected to the drive end of the shift gear position of the shift unit of the transmission. By shifting to a range indicated by an arrow in a direction parallel to the paper surface according to the speed change operation, a drive output for changing an effective gear combination is generated. This driving power is generated by the piston displacement power of the pneumatic actuator 3 in addition to the rotational power of the electric motor 2. That is, when current is supplied to the electric motor 2, its output shaft rotates, and air pressure is supplied to the intake port 11, the first air chamber 12 a or the second air chamber 12 b of the electric motor 2 is rotated. Air pressure is introduced into one of them, and the piston 13 is displaced rightward or leftward in the figure by assisting the driving force of the electric motor 2. At this time, the air pressure of the air chamber on the side where the air pressure is not introduced is discharged from the exhaust port 14 to the outside. Since the basic structure of the transmission of this embodiment is a well-known structure, further detailed description is omitted.

  FIG. 2 is a partially broken structural view of the apparatus according to the present invention. Referring to FIG. 2, the first feature of the present invention is that an air passage 4 that connects the internal atmosphere of the electric motor 2 to the internal atmosphere of the pneumatic actuator 3 is provided. That is, in the structure of the conventional example, as shown in FIG. 6 (reference example of the conventional example), the internal atmosphere of the electric motor 2 is provided with a conduit 10 and connected to another structure filter or the like not shown. The air supplied to the pneumatic actuator 3 is air supplied from a pneumatic tank (not shown), which has already been purified via a filter and the like, and is set to a pressure higher than the atmospheric pressure. Accordingly, the air supplied from the air passage 4 is correspondingly clean air, so that an air filter having a different structure is not required again, and the internal air pressure of the electric motor 2 is higher than the atmospheric pressure. Foreign matter does not enter from the outside air together with air.

  The second feature of the present invention resides in that a labyrinth structure (maze) is provided in the air passage 4 connected to the internal atmosphere of the pneumatic actuator 3 as shown in FIGS. The third feature of the present invention is that the labyrinth structure is provided in the space around the axis of the electric motor 2 so as to make one round of the axis. FIG. 3 shows an AA cross section (in the direction of the arrow) indicated by a thick line segment in FIG. FIG. 5 shows a BB cross section (in the direction of the arrow) indicated by a thick line segment in FIG. FIG. 4 shows the labyrinth plate 8 and the strength rib 9 so that they can be understood.

  The white arrows in FIGS. 3, 4 and 5 indicate the flow of air. That is, as shown in FIG. 3, the internal air of the pneumatic actuator 3 supplied from the air passage 4 passes around the space of the labyrinth structure as shown in FIGS. To reach the inside of the electric motor 2. With this structure, even if a small amount of foreign matter is mixed in the internal air of the pneumatic actuator 3, it is removed while passing through this labyrinth structure, and the foreign matter reaches the inside of the electric motor 2. Is almost gone.

  INDUSTRIAL APPLICABILITY The present invention is widely used in a transmission that uses, as power in the shift direction and select direction, rotational power generated by an electric motor or rotational power generated by an electric motor and linear power generated by a pneumatic cylinder. Can do.

The partially broken structure figure of this invention Example apparatus. The partially broken structure figure of this invention Example apparatus. The partially broken structure figure (AA sectional drawing) of this invention Example apparatus. The figure which shows the cross-sectional structure perpendicular | vertical to the electric motor of this invention Example apparatus. FIG. 3 is a cross-sectional view (BB cross-sectional view) of the main part structure of the embodiment device of the present invention. The figure which shows the example of the vent hole of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Output rod 2 Electric motor 3 Pneumatic actuator 4 Air passage 7 Filter 8 Labyrinth plate 9 Strength rib 10 Pipe line 11 Intake port 12a First air chamber 12b Second air chamber 13 Piston 14 Exhaust port

Claims (3)

In an automatic transmission device including an electric motor and a pneumatic actuator as drive power for the shift unit,
An automatic transmission comprising a labyrinth structure (maze) between a housing of the electric motor and the pneumatic actuator housing. In an automatic transmission device including an electric motor and a pneumatic actuator as drive power for the shift unit,
An automatic transmission comprising an air passage that communicates the air pressure inside the housing of the electric motor and the air pressure inside the housing of the pneumatic actuator.   2. The automatic transmission according to claim 1, wherein the labyrinth structure is formed as a multi-chamber structure in which a circulating airflow circulates in a space around a rotation shaft inside the casing of the electric motor for a half or more and less than one turn.

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