JPH04108382U - Cooling structure of braking drum of eddy current reduction gear - Google Patents

Abstract

(57) [Summary] [Purpose] To actively send air to the inner peripheral surface of the brake drum to increase the cooling effect and suppress abnormal temperature rises in the brake drum. [Structure] A base end portion of a brake drum 13 is coupled to the tips of spokes 12 that extend radially from a boss portion 9 supported by a rotating shaft 4. A windmill 51 with the cross section of the spokes 12 shaped like an airfoil
Configure. When the brake drum 13 rotates, air is sucked in from the base end of the brake drum 13 by the windmill 51 and sent to the gap between the inner peripheral surface 13b of the brake drum 13 and the outer peripheral surface of the magnet guide frame 18. The peripheral surface 13b is cooled and discharged to the tip side.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a special eddy current reduction gear that is mounted on large vehicles to assist friction brakes. Cooling of the brake drum of an eddy current reduction gear with improved cooling performance against heat generated during braking. It's about structure.

0002

[Conventional technology]

In the eddy current type reduction gear disclosed in Japanese Patent Application Laid-open No. 1-234043, there is no A magnet support ring is supported by the magnet guide frame to be slidable in the axial direction, and the magnet support ring is supported by the magnet guide frame. A large number of permanent magnets facing the circumferential surface are installed in a magnet support ring so that the polarity alternates in the circumferential direction. is combined with When a vehicle is continuously braked while driving at high speed, the inner circumferential surface of the brake drum is damaged. Due to high temperatures, the strength of the brake drum may decrease, causing thermal deformation of the brake drum, or There is a risk of cracking.

0003 In order to cool the brake drum, a conventional brake drum projects radially outward on its outer circumferential surface. The fins are arranged at equal intervals in the circumferential direction, and the longitudinal direction of the fins is aligned with the center axis of the brake drum. Since the fins are tilted to the line, as the brake drum rotates, air flows into the spaces between the fins. flows from one end of the brake drum to the other end. However, the brake drum generates a lot of heat. There is no active air flow on the inner circumferential surface, and the permanent magnet (actually the outer circumferential surface of the magnet guide frame) ) is narrow, resulting in poor cooling performance.

0004

[Problem that the invention attempts to solve]

In view of the above-mentioned problems, the purpose of this invention is to actively send air to the inner peripheral surface of the brake drum. This is an eddy current reduction gear that increases the cooling effect and suppresses abnormal temperature rises in the brake drum. The object of the present invention is to provide a cooling structure for a brake drum.

[0005]

[Means to solve the problem]

In order to achieve the above object, the configuration of the present invention is such that the boss part supported by the rotating shaft is released. A windmill is constructed by making the cross section of the spokes extending in a radial shape into an airfoil shape, and a control is installed at the tip of the spoke. The base end of the brake drum is connected, and as the brake drum rotates, the brake is applied from the base end of the brake drum. The airflow towards the front end of the brake drum passes through the gap between the inner peripheral surface of the dynamic drum and the magnet guide frame. It is something that causes

[0006]

[Effect]

In this invention, the windmill is constructed using spokes that connect the boss and the braking drum as blades. This windmill sucks air from the base end of the brake drum, and the inner circumference of the brake drum. It is sent to the gap between the surface and the permanent magnet, cools the inner peripheral surface of the brake drum, and cools the tip of the brake drum. Drain to the side.

[0007]

[Example of idea]

Figure 4 shows an eddy current reduction gear for a vehicle equipped with a brake drum cooling structure according to the present invention. FIG. It is supported by the bearing 3 on the end wall of the gear box 2 of the transmission and is connected to the end wall. The mounting flange 5 is spline-fitted to the output rotating shaft 4 protruding from the shaft and cannot be removed. It is fastened with a nut 6 as shown in FIG. Brake drum of parking brake on mounting flange 5 7 and a flange portion 9a integral with the boss portion 9 of the braking drum 13 of the reduction gear. They are overlapped and fastened with a plurality of bolts 10 and nuts 10a.

[0008] The brake drum 13 is supported by a number of spokes 12 extending radially from the boss portion 9. It will be done. Therefore, the tips of the spokes 12 are connected to the base end of the brake drum 13 by welding. will be combined. A large number of fins 13a are provided on the outer peripheral wall of the brake drum 13 at equal intervals in the circumferential direction. available.

[0009] Inside the brake drum 13 made of an electrical conductor, there is a cylindrical drum with a box-shaped inner cavity. A magnet guide frame 18 is provided. The magnet guide frame 18 is externally fitted and fixed to the projecting wall 2a of the gear box 2. It is fixed by bolts 32 and 33 to a frame plate 31 having reinforced ribs 31a.

0010 The magnet guide frame 18 may be constructed by connecting annular end wall plates to both ends of the outer cylinder and the inner cylinder. However, the illustrated magnet guide frame 18 is made of a material such as ordinary iron and has a U-shaped cross section on the left half. Cross section of the cylindrical frame portion 18a and the right half made of a non-magnetic material such as aluminum A cylindrical frame portion 18b forming an inverted L shape is connected with a large number of bolts 14. be done.

[0011] The outer cylindrical portion, that is, the frame portion 1 of the magnet guide frame 18 facing the inner circumferential surface of the brake drum 13 A large number of openings are provided at equal intervals in the circumferential direction on the peripheral wall of 8b, and a ferromagnetic plate (port) is provided in each opening. piece) 21 is fitted and fixed. Actually, the frame portion 18b is made of aluminum. When casting, the ferromagnetic plate 21 is inserted into the casting. At equal intervals in the circumferential direction on the frame plate 31 A plurality of actuators (not shown) are supported. Actuator is in cylinder A magnet is attached to the end of the rod 17 that protrudes from the fitted piston into the inner space of the magnet guide frame 18. A stone support ring 19 is attached. The magnet support ring 19 is arranged axially in the inner cavity of the magnet guide frame 18. movably supported. On the outer peripheral wall of the magnet support ring 19, facing each ferromagnetic plate 21 Permanent magnets 20 are coupled with alternating polarities in the circumferential direction.

0012 During braking, the magnet support ring 19 is moved to the rod 1 by an actuator as shown in the figure. 7 into the interior of the brake drum 13. The rotating brake drum 13 is permanently The magnetic field passes through the ferromagnetic plate 21 from the magnet 20 to the inner peripheral wall of the brake drum 13. eddy current is generated in the brake drum 13, and the brake drum 13 receives braking torque. . The brake drum 13 generates heat due to eddy currents, and is heated directly or by air using the fins 13a. cooled down.

[0013] In order to effectively cool the inner circumferential surface of the brake drum 13, which generates the most heat, the present invention has the following features: Regarding the spokes 12 that connect the braking drum 13 and the boss portion 9, the spokes 12 are disconnected. The windmill 51 has an airfoil-shaped surface and sends air from the base end of the brake drum 13 to the inner peripheral surface. It is something that can be achieved. As shown in FIG. 1, a conical wall is provided at the base end of the brake drum 13. 43, and a large number of spokes 1 are arranged between the wall portion 43 and the boss portion 9 at equal intervals in the circumferential direction. 2 are integrally combined.

[0014] As shown in FIG. 2, the cross section of each plate-shaped spoke 12 is relative to the central axis of the boss portion 9. By tilting or twisting the brake drum 13 in the rotational direction y, The air is directed radially outward from the base end of the brake drum 13 through between the spokes 12 to perform braking. It is guided to the inner peripheral surface 13b of the drum 13. As shown in FIG. 3, each spoke 12 has a boss portion. 9 to the brake drum 13, it is curved in the opposite direction to the rotational direction y. preferable.

[0015] As shown in FIG. A cylindrical body 41 is fitted to the fins 13a to create a ventilation passage 42 with a closed cross section between the fins 13a. compartmentalize. The cylindrical body 41 has a longer axial dimension than the brake drum 13 and a brake drum. It is made to protrude further toward the tip side (to the left) than the ram 13. A flat plate is placed on the outer peripheral surface of the magnet guide frame 18. flange 18c is formed, and the outer peripheral edge of the flange 18c is brought close to the inner peripheral surface of the cylindrical body 41. , a ventilation passage 45 is formed between the flange 18c and the end wall of the brake drum 13, and It communicates with the ventilation path 42.

[0016] By configuring the present invention as described above, the brake drum 13 rotates in the direction of the arrow y. When rolling, air is sucked in from the base end side of the brake drum 13 by the windmill 51, and the wall portion 43 and the inner peripheral surface 13b of the brake drum 13 and the ferromagnetic plate 21. and efficiently cools the inner peripheral surface 13b of the brake drum 13. system The air that has cooled the inner circumferential surface 13b of the dynamic drum 13 passes through the ventilation passage 45 and then into the ventilation passage 42. It flows to the left end and connects the outer peripheral surface of the brake drum 13, the fin 13, and the inner peripheral surface of the cylindrical body 41. It flows out to the right end of the ventilation path 42 while being cooled.

[0017] According to the present invention, even if the ventilation passage 42 is not provided on the outer peripheral wall of the brake drum 13, cooling can be achieved. Although the performance is fully demonstrated, the magnet guide frame 18 disposed on the tip side of the brake drum 13 If the front end of the brake drum 13 cannot be fully opened outward due to the The air that has cooled the inner peripheral surface 13b of the drum 13 is transferred to a closed section on the outer peripheral side of the brake drum 13. By guiding the air to the ventilation passage 42, the cooling performance is further improved.

[0018]

[Effect of the idea]

As mentioned above, the present invention has a spork that extends radially from the boss supported by the rotating shaft. A windmill is constructed by making the cross section of the spokes airfoil-shaped, and the base end of the brake drum is attached to the tip of the spoke. As the brake drum rotates, it connects with the inner peripheral surface of the brake drum from the base end of the brake drum. This creates an airflow toward the front end of the brake drum through the gap with the magnet guide frame. Therefore, the inner circumferential surface of the brake drum, which generates the most amount of heat, is affected by the air sent from the wind turbine. It is efficiently cooled, suppressing a decrease in strength and thermal deformation of the brake drum.

[0019] Since the spokes of the conventional brake drum are constructed with blades, the brake drum There is no dimensional change and the cost burden is reduced.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing a cooling structure for a brake drum according to the present invention.

FIG. 2 is a plan cross-sectional view taken along line 2A-2A in FIG. 1, showing spokes supporting the brake drum expanded in the circumferential direction.

FIG. 3 is a front view of the cooling structure of the brake drum.

FIG. 4 is a side cross-sectional view of an overcurrent reduction gear equipped with a brake drum cooling structure according to the present invention.

[Explanation of symbols]

9: Boss part 12: Spoke 13: Braking drum 13
a: Fin 13b: Inner peripheral surface 18: Magnet guide frame 18
c: Flange 41: Cylindrical body 42, 45: Ventilation passage 5
1: Windmill

──────────────────────────────────────────────── ─── Continuation of front page (72) Creator Masayuki Sano 3-25-1 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside Isuzu Motors Kawasaki Plant

Claims (2)

[Scope of utility model registration request] [Claim 1] A windmill is constructed by making the cross section of spokes extending radially from a boss part supported by a rotating shaft into an airfoil shape, and a base end part of a brake drum is connected to the tip part of the spoke, and as the brake drum rotates. A cooling structure for a brake drum of an eddy current reduction device, characterized in that an airflow is generated from the base end of the brake drum toward the front end of the brake drum through a gap between the inner peripheral surface of the brake drum and the magnet guide frame. . 2. A cylindrical body is fitted onto the outer periphery of a large number of fins arranged at equal intervals in the circumferential direction on the outer periphery of the brake drum to form an axial ventilation passage, and the end of the cylindrical body is attached to the magnet guide frame. 2. Cooling of a brake drum of an eddy current speed reduction device according to claim 1, further comprising a flange that approaches a flange, and a ventilation passage that communicates the air gap with the ventilation passage between the flange and a tip wall of the brake drum. structure.